commit compiled shaders

.gitignore

@@ -2,4 +2,3 @@
 **/*.rs.bk
 .ninja_deps
 .ninja_log
-**/shader/gen

piet-gpu-hal/examples/shader/gen/collatz.hlsl

@@ -0,0 +1,62 @@
+static const uint3 gl_WorkGroupSize = uint3(1u, 1u, 1u);
+
+RWByteAddressBuffer _57 : register(u0);
+
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+float mod(float x, float y)
+{
+    return x - y * floor(x / y);
+}
+
+float2 mod(float2 x, float2 y)
+{
+    return x - y * floor(x / y);
+}
+
+float3 mod(float3 x, float3 y)
+{
+    return x - y * floor(x / y);
+}
+
+float4 mod(float4 x, float4 y)
+{
+    return x - y * floor(x / y);
+}
+
+uint collatz_iterations(inout uint n)
+{
+    uint i = 0u;
+    while (n != 1u)
+    {
+        if (mod(float(n), 2.0f) == 0.0f)
+        {
+            n /= 2u;
+        }
+        else
+        {
+            n = (3u * n) + 1u;
+        }
+        i++;
+    }
+    return i;
+}
+
+void comp_main()
+{
+    uint index = gl_GlobalInvocationID.x;
+    uint param = _57.Load(index * 4 + 0);
+    uint _65 = collatz_iterations(param);
+    _57.Store(index * 4 + 0, _65);
+}
+
+[numthreads(1, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu-hal/examples/shader/gen/collatz.msl

@@ -0,0 +1,48 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+// Implementation of the GLSL mod() function, which is slightly different than Metal fmod()
+template<typename Tx, typename Ty>
+inline Tx mod(Tx x, Ty y)
+{
+    return x - y * floor(x / y);
+}
+
+struct PrimeIndices
+{
+    uint indices[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(1u);
+
+static inline __attribute__((always_inline))
+uint collatz_iterations(thread uint& n)
+{
+    uint i = 0u;
+    while (n != 1u)
+    {
+        if (mod(float(n), 2.0) == 0.0)
+        {
+            n /= 2u;
+        }
+        else
+        {
+            n = (3u * n) + 1u;
+        }
+        i++;
+    }
+    return i;
+}
+
+kernel void main0(device PrimeIndices& _57 [[buffer(0)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    uint index = gl_GlobalInvocationID.x;
+    uint param = _57.indices[index];
+    uint _65 = collatz_iterations(param);
+    _57.indices[index] = _65;
+}
+

piet-gpu/shader/gen/backdrop.hlsl

@@ -0,0 +1,244 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+RWByteAddressBuffer _67 : register(u0, space0);
+ByteAddressBuffer _166 : register(t1, space0);
+
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+static uint gl_LocalInvocationIndex;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+    uint gl_LocalInvocationIndex : SV_GroupIndex;
+};
+
+groupshared uint sh_row_width[256];
+groupshared Alloc sh_row_alloc[256];
+groupshared uint sh_row_count[256];
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+uint read_mem(Alloc alloc, uint offset)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = _67.Load(offset * 4 + 8);
+    return v;
+}
+
+Path Path_read(Alloc a, PathRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5);
+    Path s;
+    s.bbox = uint4(raw0 & 65535u, raw0 >> uint(16), raw1 & 65535u, raw1 >> uint(16));
+    TileRef _134 = { raw2 };
+    s.tiles = _134;
+    return s;
+}
+
+Alloc new_alloc(uint offset, uint size, bool mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _67.Store(offset * 4 + 8, val);
+}
+
+void comp_main()
+{
+    uint th_ix = gl_LocalInvocationIndex;
+    uint element_ix = gl_GlobalInvocationID.x;
+    uint row_count = 0u;
+    bool mem_ok = _67.Load(4) == 0u;
+    if (gl_LocalInvocationID.y == 0u)
+    {
+        if (element_ix < _166.Load(0))
+        {
+            PathRef _180 = { _166.Load(16) + (element_ix * 12u) };
+            PathRef path_ref = _180;
+            Alloc _185;
+            _185.offset = _166.Load(16);
+            Alloc param;
+            param.offset = _185.offset;
+            PathRef param_1 = path_ref;
+            Path path = Path_read(param, param_1);
+            sh_row_width[th_ix] = path.bbox.z - path.bbox.x;
+            row_count = path.bbox.w - path.bbox.y;
+            bool _210 = row_count == 1u;
+            bool _216;
+            if (_210)
+            {
+                _216 = path.bbox.y > 0u;
+            }
+            else
+            {
+                _216 = _210;
+            }
+            if (_216)
+            {
+                row_count = 0u;
+            }
+            uint param_2 = path.tiles.offset;
+            uint param_3 = ((path.bbox.z - path.bbox.x) * (path.bbox.w - path.bbox.y)) * 8u;
+            bool param_4 = mem_ok;
+            Alloc path_alloc = new_alloc(param_2, param_3, param_4);
+            sh_row_alloc[th_ix] = path_alloc;
+        }
+        sh_row_count[th_ix] = row_count;
+    }
+    for (uint i = 0u; i < 8u; i++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        bool _262 = gl_LocalInvocationID.y == 0u;
+        bool _269;
+        if (_262)
+        {
+            _269 = th_ix >= (1u << i);
+        }
+        else
+        {
+            _269 = _262;
+        }
+        if (_269)
+        {
+            row_count += sh_row_count[th_ix - (1u << i)];
+        }
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.y == 0u)
+        {
+            sh_row_count[th_ix] = row_count;
+        }
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint total_rows = sh_row_count[255];
+    uint _348;
+    for (uint row = th_ix; row < total_rows; row += 256u)
+    {
+        uint el_ix = 0u;
+        for (uint i_1 = 0u; i_1 < 8u; i_1++)
+        {
+            uint probe = el_ix + (128u >> i_1);
+            if (row >= sh_row_count[probe - 1u])
+            {
+                el_ix = probe;
+            }
+        }
+        uint width = sh_row_width[el_ix];
+        if ((width > 0u) && mem_ok)
+        {
+            Alloc tiles_alloc = sh_row_alloc[el_ix];
+            if (el_ix > 0u)
+            {
+                _348 = sh_row_count[el_ix - 1u];
+            }
+            else
+            {
+                _348 = 0u;
+            }
+            uint seq_ix = row - _348;
+            uint tile_el_ix = ((tiles_alloc.offset >> uint(2)) + 1u) + ((seq_ix * 2u) * width);
+            Alloc param_5 = tiles_alloc;
+            uint param_6 = tile_el_ix;
+            uint sum = read_mem(param_5, param_6);
+            for (uint x = 1u; x < width; x++)
+            {
+                tile_el_ix += 2u;
+                Alloc param_7 = tiles_alloc;
+                uint param_8 = tile_el_ix;
+                sum += read_mem(param_7, param_8);
+                Alloc param_9 = tiles_alloc;
+                uint param_10 = tile_el_ix;
+                uint param_11 = sum;
+                write_mem(param_9, param_10, param_11);
+            }
+        }
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    gl_LocalInvocationIndex = stage_input.gl_LocalInvocationIndex;
+    comp_main();
+}

piet-gpu/shader/gen/backdrop.msl

@@ -0,0 +1,247 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+uint read_mem(thread const Alloc& alloc, thread const uint& offset, device Memory& v_67)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = v_67.memory[offset];
+    return v;
+}
+
+static inline __attribute__((always_inline))
+Path Path_read(thread const Alloc& a, thread const PathRef& ref, device Memory& v_67)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1, v_67);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3, v_67);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5, v_67);
+    Path s;
+    s.bbox = uint4(raw0 & 65535u, raw0 >> uint(16), raw1 & 65535u, raw1 >> uint(16));
+    s.tiles = TileRef{ raw2 };
+    return s;
+}
+
+static inline __attribute__((always_inline))
+Alloc new_alloc(thread const uint& offset, thread const uint& size, thread const bool& mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_67)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_67.memory[offset] = val;
+}
+
+kernel void main0(device Memory& v_67 [[buffer(0)]], const device ConfigBuf& _166 [[buffer(1)]], uint gl_LocalInvocationIndex [[thread_index_in_threadgroup]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]])
+{
+    threadgroup uint sh_row_width[256];
+    threadgroup Alloc sh_row_alloc[256];
+    threadgroup uint sh_row_count[256];
+    uint th_ix = gl_LocalInvocationIndex;
+    uint element_ix = gl_GlobalInvocationID.x;
+    uint row_count = 0u;
+    bool mem_ok = v_67.mem_error == 0u;
+    if (gl_LocalInvocationID.y == 0u)
+    {
+        if (element_ix < _166.conf.n_elements)
+        {
+            PathRef path_ref = PathRef{ _166.conf.tile_alloc.offset + (element_ix * 12u) };
+            Alloc param;
+            param.offset = _166.conf.tile_alloc.offset;
+            PathRef param_1 = path_ref;
+            Path path = Path_read(param, param_1, v_67);
+            sh_row_width[th_ix] = path.bbox.z - path.bbox.x;
+            row_count = path.bbox.w - path.bbox.y;
+            bool _210 = row_count == 1u;
+            bool _216;
+            if (_210)
+            {
+                _216 = path.bbox.y > 0u;
+            }
+            else
+            {
+                _216 = _210;
+            }
+            if (_216)
+            {
+                row_count = 0u;
+            }
+            uint param_2 = path.tiles.offset;
+            uint param_3 = ((path.bbox.z - path.bbox.x) * (path.bbox.w - path.bbox.y)) * 8u;
+            bool param_4 = mem_ok;
+            Alloc path_alloc = new_alloc(param_2, param_3, param_4);
+            sh_row_alloc[th_ix] = path_alloc;
+        }
+        sh_row_count[th_ix] = row_count;
+    }
+    for (uint i = 0u; i < 8u; i++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        bool _262 = gl_LocalInvocationID.y == 0u;
+        bool _269;
+        if (_262)
+        {
+            _269 = th_ix >= (1u << i);
+        }
+        else
+        {
+            _269 = _262;
+        }
+        if (_269)
+        {
+            row_count += sh_row_count[th_ix - (1u << i)];
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.y == 0u)
+        {
+            sh_row_count[th_ix] = row_count;
+        }
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint total_rows = sh_row_count[255];
+    uint _348;
+    for (uint row = th_ix; row < total_rows; row += 256u)
+    {
+        uint el_ix = 0u;
+        for (uint i_1 = 0u; i_1 < 8u; i_1++)
+        {
+            uint probe = el_ix + (128u >> i_1);
+            if (row >= sh_row_count[probe - 1u])
+            {
+                el_ix = probe;
+            }
+        }
+        uint width = sh_row_width[el_ix];
+        if ((width > 0u) && mem_ok)
+        {
+            Alloc tiles_alloc = sh_row_alloc[el_ix];
+            if (el_ix > 0u)
+            {
+                _348 = sh_row_count[el_ix - 1u];
+            }
+            else
+            {
+                _348 = 0u;
+            }
+            uint seq_ix = row - _348;
+            uint tile_el_ix = ((tiles_alloc.offset >> uint(2)) + 1u) + ((seq_ix * 2u) * width);
+            Alloc param_5 = tiles_alloc;
+            uint param_6 = tile_el_ix;
+            uint sum = read_mem(param_5, param_6, v_67);
+            for (uint x = 1u; x < width; x++)
+            {
+                tile_el_ix += 2u;
+                Alloc param_7 = tiles_alloc;
+                uint param_8 = tile_el_ix;
+                sum += read_mem(param_7, param_8, v_67);
+                Alloc param_9 = tiles_alloc;
+                uint param_10 = tile_el_ix;
+                uint param_11 = sum;
+                write_mem(param_9, param_10, param_11, v_67);
+            }
+        }
+    }
+}
+

piet-gpu/shader/gen/backdrop_lg.hlsl

@@ -0,0 +1,244 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 4u, 1u);
+
+RWByteAddressBuffer _67 : register(u0, space0);
+ByteAddressBuffer _166 : register(t1, space0);
+
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+static uint gl_LocalInvocationIndex;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+    uint gl_LocalInvocationIndex : SV_GroupIndex;
+};
+
+groupshared uint sh_row_width[256];
+groupshared Alloc sh_row_alloc[256];
+groupshared uint sh_row_count[256];
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+uint read_mem(Alloc alloc, uint offset)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = _67.Load(offset * 4 + 8);
+    return v;
+}
+
+Path Path_read(Alloc a, PathRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5);
+    Path s;
+    s.bbox = uint4(raw0 & 65535u, raw0 >> uint(16), raw1 & 65535u, raw1 >> uint(16));
+    TileRef _134 = { raw2 };
+    s.tiles = _134;
+    return s;
+}
+
+Alloc new_alloc(uint offset, uint size, bool mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _67.Store(offset * 4 + 8, val);
+}
+
+void comp_main()
+{
+    uint th_ix = gl_LocalInvocationIndex;
+    uint element_ix = gl_GlobalInvocationID.x;
+    uint row_count = 0u;
+    bool mem_ok = _67.Load(4) == 0u;
+    if (gl_LocalInvocationID.y == 0u)
+    {
+        if (element_ix < _166.Load(0))
+        {
+            PathRef _180 = { _166.Load(16) + (element_ix * 12u) };
+            PathRef path_ref = _180;
+            Alloc _185;
+            _185.offset = _166.Load(16);
+            Alloc param;
+            param.offset = _185.offset;
+            PathRef param_1 = path_ref;
+            Path path = Path_read(param, param_1);
+            sh_row_width[th_ix] = path.bbox.z - path.bbox.x;
+            row_count = path.bbox.w - path.bbox.y;
+            bool _210 = row_count == 1u;
+            bool _216;
+            if (_210)
+            {
+                _216 = path.bbox.y > 0u;
+            }
+            else
+            {
+                _216 = _210;
+            }
+            if (_216)
+            {
+                row_count = 0u;
+            }
+            uint param_2 = path.tiles.offset;
+            uint param_3 = ((path.bbox.z - path.bbox.x) * (path.bbox.w - path.bbox.y)) * 8u;
+            bool param_4 = mem_ok;
+            Alloc path_alloc = new_alloc(param_2, param_3, param_4);
+            sh_row_alloc[th_ix] = path_alloc;
+        }
+        sh_row_count[th_ix] = row_count;
+    }
+    for (uint i = 0u; i < 8u; i++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        bool _262 = gl_LocalInvocationID.y == 0u;
+        bool _269;
+        if (_262)
+        {
+            _269 = th_ix >= (1u << i);
+        }
+        else
+        {
+            _269 = _262;
+        }
+        if (_269)
+        {
+            row_count += sh_row_count[th_ix - (1u << i)];
+        }
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.y == 0u)
+        {
+            sh_row_count[th_ix] = row_count;
+        }
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint total_rows = sh_row_count[255];
+    uint _348;
+    for (uint row = th_ix; row < total_rows; row += 1024u)
+    {
+        uint el_ix = 0u;
+        for (uint i_1 = 0u; i_1 < 8u; i_1++)
+        {
+            uint probe = el_ix + (128u >> i_1);
+            if (row >= sh_row_count[probe - 1u])
+            {
+                el_ix = probe;
+            }
+        }
+        uint width = sh_row_width[el_ix];
+        if ((width > 0u) && mem_ok)
+        {
+            Alloc tiles_alloc = sh_row_alloc[el_ix];
+            if (el_ix > 0u)
+            {
+                _348 = sh_row_count[el_ix - 1u];
+            }
+            else
+            {
+                _348 = 0u;
+            }
+            uint seq_ix = row - _348;
+            uint tile_el_ix = ((tiles_alloc.offset >> uint(2)) + 1u) + ((seq_ix * 2u) * width);
+            Alloc param_5 = tiles_alloc;
+            uint param_6 = tile_el_ix;
+            uint sum = read_mem(param_5, param_6);
+            for (uint x = 1u; x < width; x++)
+            {
+                tile_el_ix += 2u;
+                Alloc param_7 = tiles_alloc;
+                uint param_8 = tile_el_ix;
+                sum += read_mem(param_7, param_8);
+                Alloc param_9 = tiles_alloc;
+                uint param_10 = tile_el_ix;
+                uint param_11 = sum;
+                write_mem(param_9, param_10, param_11);
+            }
+        }
+    }
+}
+
+[numthreads(256, 4, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    gl_LocalInvocationIndex = stage_input.gl_LocalInvocationIndex;
+    comp_main();
+}

piet-gpu/shader/gen/backdrop_lg.msl

@@ -0,0 +1,247 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 4u, 1u);
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+uint read_mem(thread const Alloc& alloc, thread const uint& offset, device Memory& v_67)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = v_67.memory[offset];
+    return v;
+}
+
+static inline __attribute__((always_inline))
+Path Path_read(thread const Alloc& a, thread const PathRef& ref, device Memory& v_67)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1, v_67);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3, v_67);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5, v_67);
+    Path s;
+    s.bbox = uint4(raw0 & 65535u, raw0 >> uint(16), raw1 & 65535u, raw1 >> uint(16));
+    s.tiles = TileRef{ raw2 };
+    return s;
+}
+
+static inline __attribute__((always_inline))
+Alloc new_alloc(thread const uint& offset, thread const uint& size, thread const bool& mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_67)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_67.memory[offset] = val;
+}
+
+kernel void main0(device Memory& v_67 [[buffer(0)]], const device ConfigBuf& _166 [[buffer(1)]], uint gl_LocalInvocationIndex [[thread_index_in_threadgroup]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]])
+{
+    threadgroup uint sh_row_width[256];
+    threadgroup Alloc sh_row_alloc[256];
+    threadgroup uint sh_row_count[256];
+    uint th_ix = gl_LocalInvocationIndex;
+    uint element_ix = gl_GlobalInvocationID.x;
+    uint row_count = 0u;
+    bool mem_ok = v_67.mem_error == 0u;
+    if (gl_LocalInvocationID.y == 0u)
+    {
+        if (element_ix < _166.conf.n_elements)
+        {
+            PathRef path_ref = PathRef{ _166.conf.tile_alloc.offset + (element_ix * 12u) };
+            Alloc param;
+            param.offset = _166.conf.tile_alloc.offset;
+            PathRef param_1 = path_ref;
+            Path path = Path_read(param, param_1, v_67);
+            sh_row_width[th_ix] = path.bbox.z - path.bbox.x;
+            row_count = path.bbox.w - path.bbox.y;
+            bool _210 = row_count == 1u;
+            bool _216;
+            if (_210)
+            {
+                _216 = path.bbox.y > 0u;
+            }
+            else
+            {
+                _216 = _210;
+            }
+            if (_216)
+            {
+                row_count = 0u;
+            }
+            uint param_2 = path.tiles.offset;
+            uint param_3 = ((path.bbox.z - path.bbox.x) * (path.bbox.w - path.bbox.y)) * 8u;
+            bool param_4 = mem_ok;
+            Alloc path_alloc = new_alloc(param_2, param_3, param_4);
+            sh_row_alloc[th_ix] = path_alloc;
+        }
+        sh_row_count[th_ix] = row_count;
+    }
+    for (uint i = 0u; i < 8u; i++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        bool _262 = gl_LocalInvocationID.y == 0u;
+        bool _269;
+        if (_262)
+        {
+            _269 = th_ix >= (1u << i);
+        }
+        else
+        {
+            _269 = _262;
+        }
+        if (_269)
+        {
+            row_count += sh_row_count[th_ix - (1u << i)];
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.y == 0u)
+        {
+            sh_row_count[th_ix] = row_count;
+        }
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint total_rows = sh_row_count[255];
+    uint _348;
+    for (uint row = th_ix; row < total_rows; row += 1024u)
+    {
+        uint el_ix = 0u;
+        for (uint i_1 = 0u; i_1 < 8u; i_1++)
+        {
+            uint probe = el_ix + (128u >> i_1);
+            if (row >= sh_row_count[probe - 1u])
+            {
+                el_ix = probe;
+            }
+        }
+        uint width = sh_row_width[el_ix];
+        if ((width > 0u) && mem_ok)
+        {
+            Alloc tiles_alloc = sh_row_alloc[el_ix];
+            if (el_ix > 0u)
+            {
+                _348 = sh_row_count[el_ix - 1u];
+            }
+            else
+            {
+                _348 = 0u;
+            }
+            uint seq_ix = row - _348;
+            uint tile_el_ix = ((tiles_alloc.offset >> uint(2)) + 1u) + ((seq_ix * 2u) * width);
+            Alloc param_5 = tiles_alloc;
+            uint param_6 = tile_el_ix;
+            uint sum = read_mem(param_5, param_6, v_67);
+            for (uint x = 1u; x < width; x++)
+            {
+                tile_el_ix += 2u;
+                Alloc param_7 = tiles_alloc;
+                uint param_8 = tile_el_ix;
+                sum += read_mem(param_7, param_8, v_67);
+                Alloc param_9 = tiles_alloc;
+                uint param_10 = tile_el_ix;
+                uint param_11 = sum;
+                write_mem(param_9, param_10, param_11, v_67);
+            }
+        }
+    }
+}
+

piet-gpu/shader/gen/bbox_clear.hlsl

@@ -0,0 +1,66 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(512u, 1u, 1u);
+
+ByteAddressBuffer _21 : register(t1, space0);
+RWByteAddressBuffer _45 : register(u0, space0);
+
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x;
+    if (ix < _21.Load(76))
+    {
+        uint out_ix = (_21.Load(40) >> uint(2)) + (6u * ix);
+        _45.Store(out_ix * 4 + 8, 65535u);
+        _45.Store((out_ix + 1u) * 4 + 8, 65535u);
+        _45.Store((out_ix + 2u) * 4 + 8, 0u);
+        _45.Store((out_ix + 3u) * 4 + 8, 0u);
+    }
+}
+
+[numthreads(512, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/bbox_clear.msl

@@ -0,0 +1,68 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(512u, 1u, 1u);
+
+kernel void main0(device Memory& _45 [[buffer(0)]], const device ConfigBuf& _21 [[buffer(1)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    uint ix = gl_GlobalInvocationID.x;
+    if (ix < _21.conf.n_path)
+    {
+        uint out_ix = (_21.conf.path_bbox_alloc.offset >> uint(2)) + (6u * ix);
+        _45.memory[out_ix] = 65535u;
+        _45.memory[out_ix + 1u] = 65535u;
+        _45.memory[out_ix + 2u] = 0u;
+        _45.memory[out_ix + 3u] = 0u;
+    }
+}
+

piet-gpu/shader/gen/binning.hlsl

@@ -0,0 +1,342 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct MallocResult
+{
+    Alloc alloc;
+    bool failed;
+};
+
+struct BinInstanceRef
+{
+    uint offset;
+};
+
+struct BinInstance
+{
+    uint element_ix;
+};
+
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+RWByteAddressBuffer _81 : register(u0, space0);
+ByteAddressBuffer _156 : register(t1, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+};
+
+groupshared uint bitmaps[8][256];
+groupshared bool sh_alloc_failed;
+groupshared uint count[8][256];
+groupshared Alloc sh_chunk_alloc[256];
+
+DrawMonoid load_draw_monoid(uint element_ix)
+{
+    uint base = (_156.Load(44) >> uint(2)) + (4u * element_ix);
+    uint path_ix = _81.Load(base * 4 + 8);
+    uint clip_ix = _81.Load((base + 1u) * 4 + 8);
+    uint scene_offset = _81.Load((base + 2u) * 4 + 8);
+    uint info_offset = _81.Load((base + 3u) * 4 + 8);
+    DrawMonoid _190 = { path_ix, clip_ix, scene_offset, info_offset };
+    return _190;
+}
+
+float4 load_clip_bbox(uint clip_ix)
+{
+    uint base = (_156.Load(60) >> uint(2)) + (4u * clip_ix);
+    float x0 = asfloat(_81.Load(base * 4 + 8));
+    float y0 = asfloat(_81.Load((base + 1u) * 4 + 8));
+    float x1 = asfloat(_81.Load((base + 2u) * 4 + 8));
+    float y1 = asfloat(_81.Load((base + 3u) * 4 + 8));
+    float4 bbox = float4(x0, y0, x1, y1);
+    return bbox;
+}
+
+float4 load_path_bbox(uint path_ix)
+{
+    uint base = (_156.Load(40) >> uint(2)) + (6u * path_ix);
+    float bbox_l = float(_81.Load(base * 4 + 8)) - 32768.0f;
+    float bbox_t = float(_81.Load((base + 1u) * 4 + 8)) - 32768.0f;
+    float bbox_r = float(_81.Load((base + 2u) * 4 + 8)) - 32768.0f;
+    float bbox_b = float(_81.Load((base + 3u) * 4 + 8)) - 32768.0f;
+    float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+    return bbox;
+}
+
+float4 bbox_intersect(float4 a, float4 b)
+{
+    return float4(max(a.xy, b.xy), min(a.zw, b.zw));
+}
+
+void store_draw_bbox(uint draw_ix, float4 bbox)
+{
+    uint base = (_156.Load(64) >> uint(2)) + (4u * draw_ix);
+    _81.Store(base * 4 + 8, asuint(bbox.x));
+    _81.Store((base + 1u) * 4 + 8, asuint(bbox.y));
+    _81.Store((base + 2u) * 4 + 8, asuint(bbox.z));
+    _81.Store((base + 3u) * 4 + 8, asuint(bbox.w));
+}
+
+Alloc new_alloc(uint offset, uint size, bool mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+MallocResult malloc(uint size)
+{
+    uint _87;
+    _81.InterlockedAdd(0, size, _87);
+    uint offset = _87;
+    uint _94;
+    _81.GetDimensions(_94);
+    _94 = (_94 - 8) / 4;
+    MallocResult r;
+    r.failed = (offset + size) > uint(int(_94) * 4);
+    uint param = offset;
+    uint param_1 = size;
+    bool param_2 = !r.failed;
+    r.alloc = new_alloc(param, param_1, param_2);
+    if (r.failed)
+    {
+        uint _116;
+        _81.InterlockedMax(4, 1u, _116);
+        return r;
+    }
+    return r;
+}
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _81.Store(offset * 4 + 8, val);
+}
+
+void BinInstance_write(Alloc a, BinInstanceRef ref, BinInstance s)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = s.element_ix;
+    write_mem(param, param_1, param_2);
+}
+
+void comp_main()
+{
+    uint my_partition = gl_WorkGroupID.x;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        bitmaps[i][gl_LocalInvocationID.x] = 0u;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        sh_alloc_failed = false;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint element_ix = (my_partition * 256u) + gl_LocalInvocationID.x;
+    int x0 = 0;
+    int y0 = 0;
+    int x1 = 0;
+    int y1 = 0;
+    if (element_ix < _156.Load(0))
+    {
+        uint param = element_ix;
+        DrawMonoid draw_monoid = load_draw_monoid(param);
+        uint path_ix = draw_monoid.path_ix;
+        float4 clip_bbox = float4(-1000000000.0f, -1000000000.0f, 1000000000.0f, 1000000000.0f);
+        uint clip_ix = draw_monoid.clip_ix;
+        if (clip_ix > 0u)
+        {
+            uint param_1 = clip_ix - 1u;
+            clip_bbox = load_clip_bbox(param_1);
+        }
+        uint param_2 = path_ix;
+        float4 path_bbox = load_path_bbox(param_2);
+        float4 param_3 = path_bbox;
+        float4 param_4 = clip_bbox;
+        float4 bbox = bbox_intersect(param_3, param_4);
+        float4 _417 = bbox;
+        float4 _419 = bbox;
+        float2 _421 = max(_417.xy, _419.zw);
+        bbox.z = _421.x;
+        bbox.w = _421.y;
+        uint param_5 = element_ix;
+        float4 param_6 = bbox;
+        store_draw_bbox(param_5, param_6);
+        x0 = int(floor(bbox.x * 0.00390625f));
+        y0 = int(floor(bbox.y * 0.00390625f));
+        x1 = int(ceil(bbox.z * 0.00390625f));
+        y1 = int(ceil(bbox.w * 0.00390625f));
+    }
+    uint width_in_bins = ((_156.Load(8) + 16u) - 1u) / 16u;
+    uint height_in_bins = ((_156.Load(12) + 16u) - 1u) / 16u;
+    x0 = clamp(x0, 0, int(width_in_bins));
+    x1 = clamp(x1, x0, int(width_in_bins));
+    y0 = clamp(y0, 0, int(height_in_bins));
+    y1 = clamp(y1, y0, int(height_in_bins));
+    if (x0 == x1)
+    {
+        y1 = y0;
+    }
+    int x = x0;
+    int y = y0;
+    uint my_slice = gl_LocalInvocationID.x / 32u;
+    uint my_mask = 1u << (gl_LocalInvocationID.x & 31u);
+    while (y < y1)
+    {
+        uint _523;
+        InterlockedOr(bitmaps[my_slice][(uint(y) * width_in_bins) + uint(x)], my_mask, _523);
+        x++;
+        if (x == x1)
+        {
+            x = x0;
+            y++;
+        }
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint element_count = 0u;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        element_count += uint(int(countbits(bitmaps[i_1][gl_LocalInvocationID.x])));
+        count[i_1][gl_LocalInvocationID.x] = element_count;
+    }
+    uint param_7 = 0u;
+    uint param_8 = 0u;
+    bool param_9 = true;
+    Alloc chunk_alloc = new_alloc(param_7, param_8, param_9);
+    if (element_count != 0u)
+    {
+        uint param_10 = element_count * 4u;
+        MallocResult _573 = malloc(param_10);
+        MallocResult chunk = _573;
+        chunk_alloc = chunk.alloc;
+        sh_chunk_alloc[gl_LocalInvocationID.x] = chunk_alloc;
+        if (chunk.failed)
+        {
+            sh_alloc_failed = true;
+        }
+    }
+    uint out_ix = (_156.Load(20) >> uint(2)) + (((my_partition * 256u) + gl_LocalInvocationID.x) * 2u);
+    Alloc _603;
+    _603.offset = _156.Load(20);
+    Alloc param_11;
+    param_11.offset = _603.offset;
+    uint param_12 = out_ix;
+    uint param_13 = element_count;
+    write_mem(param_11, param_12, param_13);
+    Alloc _615;
+    _615.offset = _156.Load(20);
+    Alloc param_14;
+    param_14.offset = _615.offset;
+    uint param_15 = out_ix + 1u;
+    uint param_16 = chunk_alloc.offset;
+    write_mem(param_14, param_15, param_16);
+    GroupMemoryBarrierWithGroupSync();
+    bool _630;
+    if (!sh_alloc_failed)
+    {
+        _630 = _81.Load(4) != 0u;
+    }
+    else
+    {
+        _630 = sh_alloc_failed;
+    }
+    if (_630)
+    {
+        return;
+    }
+    x = x0;
+    y = y0;
+    while (y < y1)
+    {
+        uint bin_ix = (uint(y) * width_in_bins) + uint(x);
+        uint out_mask = bitmaps[my_slice][bin_ix];
+        if ((out_mask & my_mask) != 0u)
+        {
+            uint idx = uint(int(countbits(out_mask & (my_mask - 1u))));
+            if (my_slice > 0u)
+            {
+                idx += count[my_slice - 1u][bin_ix];
+            }
+            Alloc out_alloc = sh_chunk_alloc[bin_ix];
+            uint out_offset = out_alloc.offset + (idx * 4u);
+            BinInstanceRef _692 = { out_offset };
+            BinInstance _694 = { element_ix };
+            Alloc param_17 = out_alloc;
+            BinInstanceRef param_18 = _692;
+            BinInstance param_19 = _694;
+            BinInstance_write(param_17, param_18, param_19);
+        }
+        x++;
+        if (x == x1)
+        {
+            x = x0;
+            y++;
+        }
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/binning.msl

@@ -0,0 +1,347 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_atomic>
+
+using namespace metal;
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct MallocResult
+{
+    Alloc alloc;
+    bool failed;
+};
+
+struct BinInstanceRef
+{
+    uint offset;
+};
+
+struct BinInstance
+{
+    uint element_ix;
+};
+
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+DrawMonoid load_draw_monoid(thread const uint& element_ix, device Memory& v_81, constant uint& v_81BufferSize, const device ConfigBuf& v_156)
+{
+    uint base = (v_156.conf.drawmonoid_alloc.offset >> uint(2)) + (4u * element_ix);
+    uint path_ix = v_81.memory[base];
+    uint clip_ix = v_81.memory[base + 1u];
+    uint scene_offset = v_81.memory[base + 2u];
+    uint info_offset = v_81.memory[base + 3u];
+    return DrawMonoid{ path_ix, clip_ix, scene_offset, info_offset };
+}
+
+static inline __attribute__((always_inline))
+float4 load_clip_bbox(thread const uint& clip_ix, device Memory& v_81, constant uint& v_81BufferSize, const device ConfigBuf& v_156)
+{
+    uint base = (v_156.conf.clip_bbox_alloc.offset >> uint(2)) + (4u * clip_ix);
+    float x0 = as_type<float>(v_81.memory[base]);
+    float y0 = as_type<float>(v_81.memory[base + 1u]);
+    float x1 = as_type<float>(v_81.memory[base + 2u]);
+    float y1 = as_type<float>(v_81.memory[base + 3u]);
+    float4 bbox = float4(x0, y0, x1, y1);
+    return bbox;
+}
+
+static inline __attribute__((always_inline))
+float4 load_path_bbox(thread const uint& path_ix, device Memory& v_81, constant uint& v_81BufferSize, const device ConfigBuf& v_156)
+{
+    uint base = (v_156.conf.path_bbox_alloc.offset >> uint(2)) + (6u * path_ix);
+    float bbox_l = float(v_81.memory[base]) - 32768.0;
+    float bbox_t = float(v_81.memory[base + 1u]) - 32768.0;
+    float bbox_r = float(v_81.memory[base + 2u]) - 32768.0;
+    float bbox_b = float(v_81.memory[base + 3u]) - 32768.0;
+    float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+    return bbox;
+}
+
+static inline __attribute__((always_inline))
+float4 bbox_intersect(thread const float4& a, thread const float4& b)
+{
+    return float4(fast::max(a.xy, b.xy), fast::min(a.zw, b.zw));
+}
+
+static inline __attribute__((always_inline))
+void store_draw_bbox(thread const uint& draw_ix, thread const float4& bbox, device Memory& v_81, constant uint& v_81BufferSize, const device ConfigBuf& v_156)
+{
+    uint base = (v_156.conf.draw_bbox_alloc.offset >> uint(2)) + (4u * draw_ix);
+    v_81.memory[base] = as_type<uint>(bbox.x);
+    v_81.memory[base + 1u] = as_type<uint>(bbox.y);
+    v_81.memory[base + 2u] = as_type<uint>(bbox.z);
+    v_81.memory[base + 3u] = as_type<uint>(bbox.w);
+}
+
+static inline __attribute__((always_inline))
+Alloc new_alloc(thread const uint& offset, thread const uint& size, thread const bool& mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+static inline __attribute__((always_inline))
+MallocResult malloc(thread const uint& size, device Memory& v_81, constant uint& v_81BufferSize)
+{
+    uint _87 = atomic_fetch_add_explicit((device atomic_uint*)&v_81.mem_offset, size, memory_order_relaxed);
+    uint offset = _87;
+    MallocResult r;
+    r.failed = (offset + size) > uint(int((v_81BufferSize - 8) / 4) * 4);
+    uint param = offset;
+    uint param_1 = size;
+    bool param_2 = !r.failed;
+    r.alloc = new_alloc(param, param_1, param_2);
+    if (r.failed)
+    {
+        uint _116 = atomic_fetch_max_explicit((device atomic_uint*)&v_81.mem_error, 1u, memory_order_relaxed);
+        return r;
+    }
+    return r;
+}
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_81, constant uint& v_81BufferSize)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_81.memory[offset] = val;
+}
+
+static inline __attribute__((always_inline))
+void BinInstance_write(thread const Alloc& a, thread const BinInstanceRef& ref, thread const BinInstance& s, device Memory& v_81, constant uint& v_81BufferSize)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = s.element_ix;
+    write_mem(param, param_1, param_2, v_81, v_81BufferSize);
+}
+
+kernel void main0(constant uint* spvBufferSizeConstants [[buffer(25)]], device Memory& v_81 [[buffer(0)]], const device ConfigBuf& v_156 [[buffer(1)]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]])
+{
+    threadgroup uint bitmaps[8][256];
+    threadgroup short sh_alloc_failed;
+    threadgroup uint count[8][256];
+    threadgroup Alloc sh_chunk_alloc[256];
+    constant uint& v_81BufferSize = spvBufferSizeConstants[0];
+    uint my_partition = gl_WorkGroupID.x;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        bitmaps[i][gl_LocalInvocationID.x] = 0u;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        sh_alloc_failed = short(false);
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint element_ix = (my_partition * 256u) + gl_LocalInvocationID.x;
+    int x0 = 0;
+    int y0 = 0;
+    int x1 = 0;
+    int y1 = 0;
+    if (element_ix < v_156.conf.n_elements)
+    {
+        uint param = element_ix;
+        DrawMonoid draw_monoid = load_draw_monoid(param, v_81, v_81BufferSize, v_156);
+        uint path_ix = draw_monoid.path_ix;
+        float4 clip_bbox = float4(-1000000000.0, -1000000000.0, 1000000000.0, 1000000000.0);
+        uint clip_ix = draw_monoid.clip_ix;
+        if (clip_ix > 0u)
+        {
+            uint param_1 = clip_ix - 1u;
+            clip_bbox = load_clip_bbox(param_1, v_81, v_81BufferSize, v_156);
+        }
+        uint param_2 = path_ix;
+        float4 path_bbox = load_path_bbox(param_2, v_81, v_81BufferSize, v_156);
+        float4 param_3 = path_bbox;
+        float4 param_4 = clip_bbox;
+        float4 bbox = bbox_intersect(param_3, param_4);
+        float4 _417 = bbox;
+        float4 _419 = bbox;
+        float2 _421 = fast::max(_417.xy, _419.zw);
+        bbox.z = _421.x;
+        bbox.w = _421.y;
+        uint param_5 = element_ix;
+        float4 param_6 = bbox;
+        store_draw_bbox(param_5, param_6, v_81, v_81BufferSize, v_156);
+        x0 = int(floor(bbox.x * 0.00390625));
+        y0 = int(floor(bbox.y * 0.00390625));
+        x1 = int(ceil(bbox.z * 0.00390625));
+        y1 = int(ceil(bbox.w * 0.00390625));
+    }
+    uint width_in_bins = ((v_156.conf.width_in_tiles + 16u) - 1u) / 16u;
+    uint height_in_bins = ((v_156.conf.height_in_tiles + 16u) - 1u) / 16u;
+    x0 = clamp(x0, 0, int(width_in_bins));
+    x1 = clamp(x1, x0, int(width_in_bins));
+    y0 = clamp(y0, 0, int(height_in_bins));
+    y1 = clamp(y1, y0, int(height_in_bins));
+    if (x0 == x1)
+    {
+        y1 = y0;
+    }
+    int x = x0;
+    int y = y0;
+    uint my_slice = gl_LocalInvocationID.x / 32u;
+    uint my_mask = 1u << (gl_LocalInvocationID.x & 31u);
+    while (y < y1)
+    {
+        uint _523 = atomic_fetch_or_explicit((threadgroup atomic_uint*)&bitmaps[my_slice][(uint(y) * width_in_bins) + uint(x)], my_mask, memory_order_relaxed);
+        x++;
+        if (x == x1)
+        {
+            x = x0;
+            y++;
+        }
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint element_count = 0u;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        element_count += uint(int(popcount(bitmaps[i_1][gl_LocalInvocationID.x])));
+        count[i_1][gl_LocalInvocationID.x] = element_count;
+    }
+    uint param_7 = 0u;
+    uint param_8 = 0u;
+    bool param_9 = true;
+    Alloc chunk_alloc = new_alloc(param_7, param_8, param_9);
+    if (element_count != 0u)
+    {
+        uint param_10 = element_count * 4u;
+        MallocResult _573 = malloc(param_10, v_81, v_81BufferSize);
+        MallocResult chunk = _573;
+        chunk_alloc = chunk.alloc;
+        sh_chunk_alloc[gl_LocalInvocationID.x] = chunk_alloc;
+        if (chunk.failed)
+        {
+            sh_alloc_failed = short(true);
+        }
+    }
+    uint out_ix = (v_156.conf.bin_alloc.offset >> uint(2)) + (((my_partition * 256u) + gl_LocalInvocationID.x) * 2u);
+    Alloc param_11;
+    param_11.offset = v_156.conf.bin_alloc.offset;
+    uint param_12 = out_ix;
+    uint param_13 = element_count;
+    write_mem(param_11, param_12, param_13, v_81, v_81BufferSize);
+    Alloc param_14;
+    param_14.offset = v_156.conf.bin_alloc.offset;
+    uint param_15 = out_ix + 1u;
+    uint param_16 = chunk_alloc.offset;
+    write_mem(param_14, param_15, param_16, v_81, v_81BufferSize);
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    bool _630;
+    if (!bool(sh_alloc_failed))
+    {
+        _630 = v_81.mem_error != 0u;
+    }
+    else
+    {
+        _630 = bool(sh_alloc_failed);
+    }
+    if (_630)
+    {
+        return;
+    }
+    x = x0;
+    y = y0;
+    while (y < y1)
+    {
+        uint bin_ix = (uint(y) * width_in_bins) + uint(x);
+        uint out_mask = bitmaps[my_slice][bin_ix];
+        if ((out_mask & my_mask) != 0u)
+        {
+            uint idx = uint(int(popcount(out_mask & (my_mask - 1u))));
+            if (my_slice > 0u)
+            {
+                idx += count[my_slice - 1u][bin_ix];
+            }
+            Alloc out_alloc = sh_chunk_alloc[bin_ix];
+            uint out_offset = out_alloc.offset + (idx * 4u);
+            Alloc param_17 = out_alloc;
+            BinInstanceRef param_18 = BinInstanceRef{ out_offset };
+            BinInstance param_19 = BinInstance{ element_ix };
+            BinInstance_write(param_17, param_18, param_19, v_81, v_81BufferSize);
+        }
+        x++;
+        if (x == x1)
+        {
+            x = x0;
+            y++;
+        }
+    }
+}
+

piet-gpu/shader/gen/clip_leaf.hlsl

@@ -0,0 +1,371 @@
+struct Bic
+{
+    uint a;
+    uint b;
+};
+
+struct ClipEl
+{
+    uint parent_ix;
+    float4 bbox;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const Bic _393 = { 0u, 0u };
+
+ByteAddressBuffer _80 : register(t1, space0);
+RWByteAddressBuffer _96 : register(u0, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared Bic sh_bic[510];
+groupshared uint sh_stack[256];
+groupshared float4 sh_stack_bbox[256];
+groupshared uint sh_link[256];
+groupshared float4 sh_bbox[256];
+
+Bic load_bic(uint ix)
+{
+    uint base = (_80.Load(52) >> uint(2)) + (2u * ix);
+    Bic _286 = { _96.Load(base * 4 + 8), _96.Load((base + 1u) * 4 + 8) };
+    return _286;
+}
+
+Bic bic_combine(Bic x, Bic y)
+{
+    uint m = min(x.b, y.a);
+    Bic _72 = { (x.a + y.a) - m, (x.b + y.b) - m };
+    return _72;
+}
+
+ClipEl load_clip_el(uint ix)
+{
+    uint base = (_80.Load(56) >> uint(2)) + (5u * ix);
+    uint parent_ix = _96.Load(base * 4 + 8);
+    float x0 = asfloat(_96.Load((base + 1u) * 4 + 8));
+    float y0 = asfloat(_96.Load((base + 2u) * 4 + 8));
+    float x1 = asfloat(_96.Load((base + 3u) * 4 + 8));
+    float y1 = asfloat(_96.Load((base + 4u) * 4 + 8));
+    float4 bbox = float4(x0, y0, x1, y1);
+    ClipEl _335 = { parent_ix, bbox };
+    return _335;
+}
+
+float4 bbox_intersect(float4 a, float4 b)
+{
+    return float4(max(a.xy, b.xy), min(a.zw, b.zw));
+}
+
+uint load_path_ix(uint ix)
+{
+    if (ix < _80.Load(80))
+    {
+        return _96.Load(((_80.Load(48) >> uint(2)) + ix) * 4 + 8);
+    }
+    else
+    {
+        return 2147483648u;
+    }
+}
+
+float4 load_path_bbox(uint path_ix)
+{
+    uint base = (_80.Load(40) >> uint(2)) + (6u * path_ix);
+    float bbox_l = float(_96.Load(base * 4 + 8)) - 32768.0f;
+    float bbox_t = float(_96.Load((base + 1u) * 4 + 8)) - 32768.0f;
+    float bbox_r = float(_96.Load((base + 2u) * 4 + 8)) - 32768.0f;
+    float bbox_b = float(_96.Load((base + 3u) * 4 + 8)) - 32768.0f;
+    float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+    return bbox;
+}
+
+uint search_link(inout Bic bic)
+{
+    uint ix = gl_LocalInvocationID.x;
+    uint j = 0u;
+    while (j < 8u)
+    {
+        uint base = 512u - (2u << (8u - j));
+        if (((ix >> j) & 1u) != 0u)
+        {
+            Bic param = sh_bic[(base + (ix >> j)) - 1u];
+            Bic param_1 = bic;
+            Bic test = bic_combine(param, param_1);
+            if (test.b > 0u)
+            {
+                break;
+            }
+            bic = test;
+            ix -= (1u << j);
+        }
+        j++;
+    }
+    if (ix > 0u)
+    {
+        while (j > 0u)
+        {
+            j--;
+            uint base_1 = 512u - (2u << (8u - j));
+            Bic param_2 = sh_bic[(base_1 + (ix >> j)) - 1u];
+            Bic param_3 = bic;
+            Bic test_1 = bic_combine(param_2, param_3);
+            if (test_1.b == 0u)
+            {
+                bic = test_1;
+                ix -= (1u << j);
+            }
+        }
+    }
+    if (ix > 0u)
+    {
+        return ix - 1u;
+    }
+    else
+    {
+        return 4294967295u - bic.a;
+    }
+}
+
+void store_clip_bbox(uint ix, float4 bbox)
+{
+    uint base = (_80.Load(60) >> uint(2)) + (4u * ix);
+    _96.Store(base * 4 + 8, asuint(bbox.x));
+    _96.Store((base + 1u) * 4 + 8, asuint(bbox.y));
+    _96.Store((base + 2u) * 4 + 8, asuint(bbox.z));
+    _96.Store((base + 3u) * 4 + 8, asuint(bbox.w));
+}
+
+void comp_main()
+{
+    uint th = gl_LocalInvocationID.x;
+    Bic bic = _393;
+    if (th < gl_WorkGroupID.x)
+    {
+        uint param = th;
+        bic = load_bic(param);
+    }
+    sh_bic[th] = bic;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if ((th + (1u << i)) < 256u)
+        {
+            Bic other = sh_bic[th + (1u << i)];
+            Bic param_1 = bic;
+            Bic param_2 = other;
+            bic = bic_combine(param_1, param_2);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_bic[th] = bic;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint stack_size = sh_bic[0].b;
+    uint sp = 255u - th;
+    uint ix = 0u;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        uint probe = ix + (128u >> i_1);
+        if (sp < sh_bic[probe].b)
+        {
+            ix = probe;
+        }
+    }
+    uint b = sh_bic[ix].b;
+    float4 bbox = float4(-1000000000.0f, -1000000000.0f, 1000000000.0f, 1000000000.0f);
+    if (sp < b)
+    {
+        uint param_3 = (((ix * 256u) + b) - sp) - 1u;
+        ClipEl el = load_clip_el(param_3);
+        sh_stack[th] = el.parent_ix;
+        bbox = el.bbox;
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        sh_stack_bbox[th] = bbox;
+        GroupMemoryBarrierWithGroupSync();
+        if (th >= (1u << i_2))
+        {
+            float4 param_4 = sh_stack_bbox[th - (1u << i_2)];
+            float4 param_5 = bbox;
+            bbox = bbox_intersect(param_4, param_5);
+        }
+        GroupMemoryBarrierWithGroupSync();
+    }
+    sh_stack_bbox[th] = bbox;
+    uint param_6 = gl_GlobalInvocationID.x;
+    uint inp = load_path_ix(param_6);
+    bool is_push = int(inp) >= 0;
+    Bic _559 = { 1u - uint(is_push), uint(is_push) };
+    bic = _559;
+    sh_bic[th] = bic;
+    if (is_push)
+    {
+        uint param_7 = inp;
+        bbox = load_path_bbox(param_7);
+    }
+    else
+    {
+        bbox = float4(-1000000000.0f, -1000000000.0f, 1000000000.0f, 1000000000.0f);
+    }
+    uint inbase = 0u;
+    for (uint i_3 = 0u; i_3 < 7u; i_3++)
+    {
+        uint outbase = 512u - (1u << (8u - i_3));
+        GroupMemoryBarrierWithGroupSync();
+        if (th < (1u << (7u - i_3)))
+        {
+            Bic param_8 = sh_bic[inbase + (th * 2u)];
+            Bic param_9 = sh_bic[(inbase + (th * 2u)) + 1u];
+            sh_bic[outbase + th] = bic_combine(param_8, param_9);
+        }
+        inbase = outbase;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    bic = _393;
+    Bic param_10 = bic;
+    uint _618 = search_link(param_10);
+    bic = param_10;
+    uint link = _618;
+    sh_link[th] = link;
+    GroupMemoryBarrierWithGroupSync();
+    uint grandparent;
+    if (int(link) >= 0)
+    {
+        grandparent = sh_link[link];
+    }
+    else
+    {
+        grandparent = link - 1u;
+    }
+    uint parent;
+    if (int(link) >= 0)
+    {
+        parent = (gl_WorkGroupID.x * 256u) + link;
+    }
+    else
+    {
+        if (int(link + stack_size) >= 0)
+        {
+            parent = sh_stack[256u + link];
+        }
+        else
+        {
+            parent = 4294967295u;
+        }
+    }
+    for (uint i_4 = 0u; i_4 < 8u; i_4++)
+    {
+        if (i_4 != 0u)
+        {
+            sh_link[th] = link;
+        }
+        sh_bbox[th] = bbox;
+        GroupMemoryBarrierWithGroupSync();
+        if (int(link) >= 0)
+        {
+            float4 param_11 = sh_bbox[link];
+            float4 param_12 = bbox;
+            bbox = bbox_intersect(param_11, param_12);
+            link = sh_link[link];
+        }
+        GroupMemoryBarrierWithGroupSync();
+    }
+    if (int(link + stack_size) >= 0)
+    {
+        float4 param_13 = sh_stack_bbox[256u + link];
+        float4 param_14 = bbox;
+        bbox = bbox_intersect(param_13, param_14);
+    }
+    sh_bbox[th] = bbox;
+    GroupMemoryBarrierWithGroupSync();
+    uint path_ix = inp;
+    bool _717 = !is_push;
+    bool _725;
+    if (_717)
+    {
+        _725 = gl_GlobalInvocationID.x < _80.Load(80);
+    }
+    else
+    {
+        _725 = _717;
+    }
+    if (_725)
+    {
+        uint param_15 = parent;
+        path_ix = load_path_ix(param_15);
+        uint drawmonoid_out_base = (_80.Load(44) >> uint(2)) + (4u * (~inp));
+        _96.Store(drawmonoid_out_base * 4 + 8, path_ix);
+        if (int(grandparent) >= 0)
+        {
+            bbox = sh_bbox[grandparent];
+        }
+        else
+        {
+            if (int(grandparent + stack_size) >= 0)
+            {
+                bbox = sh_stack_bbox[256u + grandparent];
+            }
+            else
+            {
+                bbox = float4(-1000000000.0f, -1000000000.0f, 1000000000.0f, 1000000000.0f);
+            }
+        }
+    }
+    uint param_16 = gl_GlobalInvocationID.x;
+    float4 param_17 = bbox;
+    store_clip_bbox(param_16, param_17);
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/clip_leaf.msl

@@ -0,0 +1,370 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct Bic
+{
+    uint a;
+    uint b;
+};
+
+struct ClipEl
+{
+    uint parent_ix;
+    float4 bbox;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+Bic load_bic(thread const uint& ix, const device ConfigBuf& v_80, device Memory& v_96)
+{
+    uint base = (v_80.conf.clip_bic_alloc.offset >> uint(2)) + (2u * ix);
+    return Bic{ v_96.memory[base], v_96.memory[base + 1u] };
+}
+
+static inline __attribute__((always_inline))
+Bic bic_combine(thread const Bic& x, thread const Bic& y)
+{
+    uint m = min(x.b, y.a);
+    return Bic{ (x.a + y.a) - m, (x.b + y.b) - m };
+}
+
+static inline __attribute__((always_inline))
+ClipEl load_clip_el(thread const uint& ix, const device ConfigBuf& v_80, device Memory& v_96)
+{
+    uint base = (v_80.conf.clip_stack_alloc.offset >> uint(2)) + (5u * ix);
+    uint parent_ix = v_96.memory[base];
+    float x0 = as_type<float>(v_96.memory[base + 1u]);
+    float y0 = as_type<float>(v_96.memory[base + 2u]);
+    float x1 = as_type<float>(v_96.memory[base + 3u]);
+    float y1 = as_type<float>(v_96.memory[base + 4u]);
+    float4 bbox = float4(x0, y0, x1, y1);
+    return ClipEl{ parent_ix, bbox };
+}
+
+static inline __attribute__((always_inline))
+float4 bbox_intersect(thread const float4& a, thread const float4& b)
+{
+    return float4(fast::max(a.xy, b.xy), fast::min(a.zw, b.zw));
+}
+
+static inline __attribute__((always_inline))
+uint load_path_ix(thread const uint& ix, const device ConfigBuf& v_80, device Memory& v_96)
+{
+    if (ix < v_80.conf.n_clip)
+    {
+        return v_96.memory[(v_80.conf.clip_alloc.offset >> uint(2)) + ix];
+    }
+    else
+    {
+        return 2147483648u;
+    }
+}
+
+static inline __attribute__((always_inline))
+float4 load_path_bbox(thread const uint& path_ix, const device ConfigBuf& v_80, device Memory& v_96)
+{
+    uint base = (v_80.conf.path_bbox_alloc.offset >> uint(2)) + (6u * path_ix);
+    float bbox_l = float(v_96.memory[base]) - 32768.0;
+    float bbox_t = float(v_96.memory[base + 1u]) - 32768.0;
+    float bbox_r = float(v_96.memory[base + 2u]) - 32768.0;
+    float bbox_b = float(v_96.memory[base + 3u]) - 32768.0;
+    float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+    return bbox;
+}
+
+static inline __attribute__((always_inline))
+uint search_link(thread Bic& bic, thread uint3& gl_LocalInvocationID, threadgroup Bic (&sh_bic)[510])
+{
+    uint ix = gl_LocalInvocationID.x;
+    uint j = 0u;
+    while (j < 8u)
+    {
+        uint base = 512u - (2u << (8u - j));
+        if (((ix >> j) & 1u) != 0u)
+        {
+            Bic param = sh_bic[(base + (ix >> j)) - 1u];
+            Bic param_1 = bic;
+            Bic test = bic_combine(param, param_1);
+            if (test.b > 0u)
+            {
+                break;
+            }
+            bic = test;
+            ix -= (1u << j);
+        }
+        j++;
+    }
+    if (ix > 0u)
+    {
+        while (j > 0u)
+        {
+            j--;
+            uint base_1 = 512u - (2u << (8u - j));
+            Bic param_2 = sh_bic[(base_1 + (ix >> j)) - 1u];
+            Bic param_3 = bic;
+            Bic test_1 = bic_combine(param_2, param_3);
+            if (test_1.b == 0u)
+            {
+                bic = test_1;
+                ix -= (1u << j);
+            }
+        }
+    }
+    if (ix > 0u)
+    {
+        return ix - 1u;
+    }
+    else
+    {
+        return 4294967295u - bic.a;
+    }
+}
+
+static inline __attribute__((always_inline))
+void store_clip_bbox(thread const uint& ix, thread const float4& bbox, const device ConfigBuf& v_80, device Memory& v_96)
+{
+    uint base = (v_80.conf.clip_bbox_alloc.offset >> uint(2)) + (4u * ix);
+    v_96.memory[base] = as_type<uint>(bbox.x);
+    v_96.memory[base + 1u] = as_type<uint>(bbox.y);
+    v_96.memory[base + 2u] = as_type<uint>(bbox.z);
+    v_96.memory[base + 3u] = as_type<uint>(bbox.w);
+}
+
+kernel void main0(device Memory& v_96 [[buffer(0)]], const device ConfigBuf& v_80 [[buffer(1)]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    threadgroup Bic sh_bic[510];
+    threadgroup uint sh_stack[256];
+    threadgroup float4 sh_stack_bbox[256];
+    threadgroup uint sh_link[256];
+    threadgroup float4 sh_bbox[256];
+    uint th = gl_LocalInvocationID.x;
+    Bic bic = Bic{ 0u, 0u };
+    if (th < gl_WorkGroupID.x)
+    {
+        uint param = th;
+        bic = load_bic(param, v_80, v_96);
+    }
+    sh_bic[th] = bic;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if ((th + (1u << i)) < 256u)
+        {
+            Bic other = sh_bic[th + (1u << i)];
+            Bic param_1 = bic;
+            Bic param_2 = other;
+            bic = bic_combine(param_1, param_2);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_bic[th] = bic;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint stack_size = sh_bic[0].b;
+    uint sp = 255u - th;
+    uint ix = 0u;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        uint probe = ix + (128u >> i_1);
+        if (sp < sh_bic[probe].b)
+        {
+            ix = probe;
+        }
+    }
+    uint b = sh_bic[ix].b;
+    float4 bbox = float4(-1000000000.0, -1000000000.0, 1000000000.0, 1000000000.0);
+    if (sp < b)
+    {
+        uint param_3 = (((ix * 256u) + b) - sp) - 1u;
+        ClipEl el = load_clip_el(param_3, v_80, v_96);
+        sh_stack[th] = el.parent_ix;
+        bbox = el.bbox;
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        sh_stack_bbox[th] = bbox;
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (th >= (1u << i_2))
+        {
+            float4 param_4 = sh_stack_bbox[th - (1u << i_2)];
+            float4 param_5 = bbox;
+            bbox = bbox_intersect(param_4, param_5);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+    }
+    sh_stack_bbox[th] = bbox;
+    uint param_6 = gl_GlobalInvocationID.x;
+    uint inp = load_path_ix(param_6, v_80, v_96);
+    bool is_push = int(inp) >= 0;
+    bic = Bic{ 1u - uint(is_push), uint(is_push) };
+    sh_bic[th] = bic;
+    if (is_push)
+    {
+        uint param_7 = inp;
+        bbox = load_path_bbox(param_7, v_80, v_96);
+    }
+    else
+    {
+        bbox = float4(-1000000000.0, -1000000000.0, 1000000000.0, 1000000000.0);
+    }
+    uint inbase = 0u;
+    for (uint i_3 = 0u; i_3 < 7u; i_3++)
+    {
+        uint outbase = 512u - (1u << (8u - i_3));
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (th < (1u << (7u - i_3)))
+        {
+            Bic param_8 = sh_bic[inbase + (th * 2u)];
+            Bic param_9 = sh_bic[(inbase + (th * 2u)) + 1u];
+            sh_bic[outbase + th] = bic_combine(param_8, param_9);
+        }
+        inbase = outbase;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    bic = Bic{ 0u, 0u };
+    Bic param_10 = bic;
+    uint _618 = search_link(param_10, gl_LocalInvocationID, sh_bic);
+    bic = param_10;
+    uint link = _618;
+    sh_link[th] = link;
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint grandparent;
+    if (int(link) >= 0)
+    {
+        grandparent = sh_link[link];
+    }
+    else
+    {
+        grandparent = link - 1u;
+    }
+    uint parent;
+    if (int(link) >= 0)
+    {
+        parent = (gl_WorkGroupID.x * 256u) + link;
+    }
+    else
+    {
+        if (int(link + stack_size) >= 0)
+        {
+            parent = sh_stack[256u + link];
+        }
+        else
+        {
+            parent = 4294967295u;
+        }
+    }
+    for (uint i_4 = 0u; i_4 < 8u; i_4++)
+    {
+        if (i_4 != 0u)
+        {
+            sh_link[th] = link;
+        }
+        sh_bbox[th] = bbox;
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (int(link) >= 0)
+        {
+            float4 param_11 = sh_bbox[link];
+            float4 param_12 = bbox;
+            bbox = bbox_intersect(param_11, param_12);
+            link = sh_link[link];
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+    }
+    if (int(link + stack_size) >= 0)
+    {
+        float4 param_13 = sh_stack_bbox[256u + link];
+        float4 param_14 = bbox;
+        bbox = bbox_intersect(param_13, param_14);
+    }
+    sh_bbox[th] = bbox;
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint path_ix = inp;
+    bool _717 = !is_push;
+    bool _725;
+    if (_717)
+    {
+        _725 = gl_GlobalInvocationID.x < v_80.conf.n_clip;
+    }
+    else
+    {
+        _725 = _717;
+    }
+    if (_725)
+    {
+        uint param_15 = parent;
+        path_ix = load_path_ix(param_15, v_80, v_96);
+        uint drawmonoid_out_base = (v_80.conf.drawmonoid_alloc.offset >> uint(2)) + (4u * (~inp));
+        v_96.memory[drawmonoid_out_base] = path_ix;
+        if (int(grandparent) >= 0)
+        {
+            bbox = sh_bbox[grandparent];
+        }
+        else
+        {
+            if (int(grandparent + stack_size) >= 0)
+            {
+                bbox = sh_stack_bbox[256u + grandparent];
+            }
+            else
+            {
+                bbox = float4(-1000000000.0, -1000000000.0, 1000000000.0, 1000000000.0);
+            }
+        }
+    }
+    uint param_16 = gl_GlobalInvocationID.x;
+    float4 param_17 = bbox;
+    store_clip_bbox(param_16, param_17, v_80, v_96);
+}
+

piet-gpu/shader/gen/clip_reduce.hlsl

@@ -0,0 +1,181 @@
+struct Bic
+{
+    uint a;
+    uint b;
+};
+
+struct ClipEl
+{
+    uint parent_ix;
+    float4 bbox;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const Bic _267 = { 0u, 0u };
+
+ByteAddressBuffer _64 : register(t1, space0);
+RWByteAddressBuffer _80 : register(u0, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared Bic sh_bic[256];
+groupshared uint sh_parent[256];
+groupshared uint sh_path_ix[256];
+groupshared float4 sh_bbox[256];
+
+Bic bic_combine(Bic x, Bic y)
+{
+    uint m = min(x.b, y.a);
+    Bic _56 = { (x.a + y.a) - m, (x.b + y.b) - m };
+    return _56;
+}
+
+void store_bic(uint ix, Bic bic)
+{
+    uint base = (_64.Load(52) >> uint(2)) + (2u * ix);
+    _80.Store(base * 4 + 8, bic.a);
+    _80.Store((base + 1u) * 4 + 8, bic.b);
+}
+
+float4 load_path_bbox(uint path_ix)
+{
+    uint base = (_64.Load(40) >> uint(2)) + (6u * path_ix);
+    float bbox_l = float(_80.Load(base * 4 + 8)) - 32768.0f;
+    float bbox_t = float(_80.Load((base + 1u) * 4 + 8)) - 32768.0f;
+    float bbox_r = float(_80.Load((base + 2u) * 4 + 8)) - 32768.0f;
+    float bbox_b = float(_80.Load((base + 3u) * 4 + 8)) - 32768.0f;
+    float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+    return bbox;
+}
+
+void store_clip_el(uint ix, ClipEl el)
+{
+    uint base = (_64.Load(56) >> uint(2)) + (5u * ix);
+    _80.Store(base * 4 + 8, el.parent_ix);
+    _80.Store((base + 1u) * 4 + 8, asuint(el.bbox.x));
+    _80.Store((base + 2u) * 4 + 8, asuint(el.bbox.y));
+    _80.Store((base + 3u) * 4 + 8, asuint(el.bbox.z));
+    _80.Store((base + 4u) * 4 + 8, asuint(el.bbox.w));
+}
+
+void comp_main()
+{
+    uint th = gl_LocalInvocationID.x;
+    uint inp = _80.Load(((_64.Load(48) >> uint(2)) + gl_GlobalInvocationID.x) * 4 + 8);
+    bool is_push = int(inp) >= 0;
+    Bic _207 = { 1u - uint(is_push), uint(is_push) };
+    Bic bic = _207;
+    sh_bic[gl_LocalInvocationID.x] = bic;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if ((th + (1u << i)) < 256u)
+        {
+            Bic other = sh_bic[gl_LocalInvocationID.x + (1u << i)];
+            Bic param = bic;
+            Bic param_1 = other;
+            bic = bic_combine(param, param_1);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_bic[th] = bic;
+    }
+    if (th == 0u)
+    {
+        uint param_2 = gl_WorkGroupID.x;
+        Bic param_3 = bic;
+        store_bic(param_2, param_3);
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint size = sh_bic[0].b;
+    bic = _267;
+    if ((th + 1u) < 256u)
+    {
+        bic = sh_bic[th + 1u];
+    }
+    bool _283;
+    if (is_push)
+    {
+        _283 = bic.a == 0u;
+    }
+    else
+    {
+        _283 = is_push;
+    }
+    if (_283)
+    {
+        uint local_ix = (size - bic.b) - 1u;
+        sh_parent[local_ix] = th;
+        sh_path_ix[local_ix] = inp;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    float4 bbox;
+    if (th < size)
+    {
+        uint path_ix = sh_path_ix[th];
+        uint param_4 = path_ix;
+        bbox = load_path_bbox(param_4);
+    }
+    if (th < size)
+    {
+        uint parent_ix = sh_parent[th] + (gl_WorkGroupID.x * 256u);
+        ClipEl _331 = { parent_ix, bbox };
+        ClipEl el = _331;
+        uint param_5 = gl_GlobalInvocationID.x;
+        ClipEl param_6 = el;
+        store_clip_el(param_5, param_6);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/clip_reduce.msl

@@ -0,0 +1,177 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct Bic
+{
+    uint a;
+    uint b;
+};
+
+struct ClipEl
+{
+    uint parent_ix;
+    float4 bbox;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+Bic bic_combine(thread const Bic& x, thread const Bic& y)
+{
+    uint m = min(x.b, y.a);
+    return Bic{ (x.a + y.a) - m, (x.b + y.b) - m };
+}
+
+static inline __attribute__((always_inline))
+void store_bic(thread const uint& ix, thread const Bic& bic, const device ConfigBuf& v_64, device Memory& v_80)
+{
+    uint base = (v_64.conf.clip_bic_alloc.offset >> uint(2)) + (2u * ix);
+    v_80.memory[base] = bic.a;
+    v_80.memory[base + 1u] = bic.b;
+}
+
+static inline __attribute__((always_inline))
+float4 load_path_bbox(thread const uint& path_ix, const device ConfigBuf& v_64, device Memory& v_80)
+{
+    uint base = (v_64.conf.path_bbox_alloc.offset >> uint(2)) + (6u * path_ix);
+    float bbox_l = float(v_80.memory[base]) - 32768.0;
+    float bbox_t = float(v_80.memory[base + 1u]) - 32768.0;
+    float bbox_r = float(v_80.memory[base + 2u]) - 32768.0;
+    float bbox_b = float(v_80.memory[base + 3u]) - 32768.0;
+    float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+    return bbox;
+}
+
+static inline __attribute__((always_inline))
+void store_clip_el(thread const uint& ix, thread const ClipEl& el, const device ConfigBuf& v_64, device Memory& v_80)
+{
+    uint base = (v_64.conf.clip_stack_alloc.offset >> uint(2)) + (5u * ix);
+    v_80.memory[base] = el.parent_ix;
+    v_80.memory[base + 1u] = as_type<uint>(el.bbox.x);
+    v_80.memory[base + 2u] = as_type<uint>(el.bbox.y);
+    v_80.memory[base + 3u] = as_type<uint>(el.bbox.z);
+    v_80.memory[base + 4u] = as_type<uint>(el.bbox.w);
+}
+
+kernel void main0(device Memory& v_80 [[buffer(0)]], const device ConfigBuf& v_64 [[buffer(1)]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup Bic sh_bic[256];
+    threadgroup uint sh_parent[256];
+    threadgroup uint sh_path_ix[256];
+    threadgroup float4 sh_bbox[256];
+    uint th = gl_LocalInvocationID.x;
+    uint inp = v_80.memory[(v_64.conf.clip_alloc.offset >> uint(2)) + gl_GlobalInvocationID.x];
+    bool is_push = int(inp) >= 0;
+    Bic bic = Bic{ 1u - uint(is_push), uint(is_push) };
+    sh_bic[gl_LocalInvocationID.x] = bic;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if ((th + (1u << i)) < 256u)
+        {
+            Bic other = sh_bic[gl_LocalInvocationID.x + (1u << i)];
+            Bic param = bic;
+            Bic param_1 = other;
+            bic = bic_combine(param, param_1);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_bic[th] = bic;
+    }
+    if (th == 0u)
+    {
+        uint param_2 = gl_WorkGroupID.x;
+        Bic param_3 = bic;
+        store_bic(param_2, param_3, v_64, v_80);
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint size = sh_bic[0].b;
+    bic = Bic{ 0u, 0u };
+    if ((th + 1u) < 256u)
+    {
+        bic = sh_bic[th + 1u];
+    }
+    bool _283;
+    if (is_push)
+    {
+        _283 = bic.a == 0u;
+    }
+    else
+    {
+        _283 = is_push;
+    }
+    if (_283)
+    {
+        uint local_ix = (size - bic.b) - 1u;
+        sh_parent[local_ix] = th;
+        sh_path_ix[local_ix] = inp;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    float4 bbox;
+    if (th < size)
+    {
+        uint path_ix = sh_path_ix[th];
+        uint param_4 = path_ix;
+        bbox = load_path_bbox(param_4, v_64, v_80);
+    }
+    if (th < size)
+    {
+        uint parent_ix = sh_parent[th] + (gl_WorkGroupID.x * 256u);
+        ClipEl el = ClipEl{ parent_ix, bbox };
+        uint param_5 = gl_GlobalInvocationID.x;
+        ClipEl param_6 = el;
+        store_clip_el(param_5, param_6, v_64, v_80);
+    }
+}
+

piet-gpu/shader/gen/draw_leaf.hlsl

@@ -0,0 +1,268 @@
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const DrawMonoid _23 = { 0u, 0u, 0u, 0u };
+
+ByteAddressBuffer _93 : register(t1, space0);
+ByteAddressBuffer _103 : register(t2, space0);
+ByteAddressBuffer _203 : register(t3, space0);
+RWByteAddressBuffer _285 : register(u0, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared DrawMonoid sh_scratch[256];
+
+DrawMonoid map_tag(uint tag_word)
+{
+    uint has_path = uint(tag_word != 0u);
+    DrawMonoid _76 = { has_path, tag_word & 1u, tag_word & 28u, (tag_word >> uint(4)) & 60u };
+    return _76;
+}
+
+DrawMonoid combine_draw_monoid(DrawMonoid a, DrawMonoid b)
+{
+    DrawMonoid c;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.clip_ix = a.clip_ix + b.clip_ix;
+    c.scene_offset = a.scene_offset + b.scene_offset;
+    c.info_offset = a.info_offset + b.info_offset;
+    return c;
+}
+
+DrawMonoid draw_monoid_identity()
+{
+    return _23;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    uint drawtag_base = _93.Load(100) >> uint(2);
+    uint tag_word = _103.Load((drawtag_base + ix) * 4 + 0);
+    uint param = tag_word;
+    DrawMonoid agg = map_tag(param);
+    DrawMonoid local[8];
+    local[0] = agg;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        tag_word = _103.Load(((drawtag_base + ix) + i) * 4 + 0);
+        uint param_1 = tag_word;
+        DrawMonoid param_2 = agg;
+        DrawMonoid param_3 = map_tag(param_1);
+        agg = combine_draw_monoid(param_2, param_3);
+        local[i] = agg;
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            DrawMonoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            DrawMonoid param_4 = other;
+            DrawMonoid param_5 = agg;
+            agg = combine_draw_monoid(param_4, param_5);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    DrawMonoid row = draw_monoid_identity();
+    if (gl_WorkGroupID.x > 0u)
+    {
+        DrawMonoid _209;
+        _209.path_ix = _203.Load((gl_WorkGroupID.x - 1u) * 16 + 0);
+        _209.clip_ix = _203.Load((gl_WorkGroupID.x - 1u) * 16 + 4);
+        _209.scene_offset = _203.Load((gl_WorkGroupID.x - 1u) * 16 + 8);
+        _209.info_offset = _203.Load((gl_WorkGroupID.x - 1u) * 16 + 12);
+        row.path_ix = _209.path_ix;
+        row.clip_ix = _209.clip_ix;
+        row.scene_offset = _209.scene_offset;
+        row.info_offset = _209.info_offset;
+    }
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        DrawMonoid param_6 = row;
+        DrawMonoid param_7 = sh_scratch[gl_LocalInvocationID.x - 1u];
+        row = combine_draw_monoid(param_6, param_7);
+    }
+    uint drawdata_base = _93.Load(104) >> uint(2);
+    uint drawinfo_base = _93.Load(68) >> uint(2);
+    uint out_ix = gl_GlobalInvocationID.x * 8u;
+    uint out_base = (_93.Load(44) >> uint(2)) + (out_ix * 4u);
+    uint clip_out_base = _93.Load(48) >> uint(2);
+    float4 mat;
+    float2 translate;
+    float2 p0;
+    float2 p1;
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        DrawMonoid m = row;
+        if (i_2 > 0u)
+        {
+            DrawMonoid param_8 = m;
+            DrawMonoid param_9 = local[i_2 - 1u];
+            m = combine_draw_monoid(param_8, param_9);
+        }
+        _285.Store((out_base + (i_2 * 4u)) * 4 + 8, m.path_ix);
+        _285.Store(((out_base + (i_2 * 4u)) + 1u) * 4 + 8, m.clip_ix);
+        _285.Store(((out_base + (i_2 * 4u)) + 2u) * 4 + 8, m.scene_offset);
+        _285.Store(((out_base + (i_2 * 4u)) + 3u) * 4 + 8, m.info_offset);
+        uint dd = drawdata_base + (m.scene_offset >> uint(2));
+        uint di = drawinfo_base + (m.info_offset >> uint(2));
+        tag_word = _103.Load(((drawtag_base + ix) + i_2) * 4 + 0);
+        if (((((tag_word == 68u) || (tag_word == 276u)) || (tag_word == 732u)) || (tag_word == 72u)) || (tag_word == 5u))
+        {
+            uint bbox_offset = (_93.Load(40) >> uint(2)) + (6u * m.path_ix);
+            float bbox_l = float(_285.Load(bbox_offset * 4 + 8)) - 32768.0f;
+            float bbox_t = float(_285.Load((bbox_offset + 1u) * 4 + 8)) - 32768.0f;
+            float bbox_r = float(_285.Load((bbox_offset + 2u) * 4 + 8)) - 32768.0f;
+            float bbox_b = float(_285.Load((bbox_offset + 3u) * 4 + 8)) - 32768.0f;
+            float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+            float linewidth = asfloat(_285.Load((bbox_offset + 4u) * 4 + 8));
+            uint fill_mode = uint(linewidth >= 0.0f);
+            if (((linewidth >= 0.0f) || (tag_word == 276u)) || (tag_word == 732u))
+            {
+                uint trans_ix = _285.Load((bbox_offset + 5u) * 4 + 8);
+                uint t = (_93.Load(36) >> uint(2)) + (6u * trans_ix);
+                mat = asfloat(uint4(_285.Load(t * 4 + 8), _285.Load((t + 1u) * 4 + 8), _285.Load((t + 2u) * 4 + 8), _285.Load((t + 3u) * 4 + 8)));
+                if ((tag_word == 276u) || (tag_word == 732u))
+                {
+                    translate = asfloat(uint2(_285.Load((t + 4u) * 4 + 8), _285.Load((t + 5u) * 4 + 8)));
+                }
+            }
+            if (linewidth >= 0.0f)
+            {
+                linewidth *= sqrt(abs((mat.x * mat.w) - (mat.y * mat.z)));
+            }
+            switch (tag_word)
+            {
+                case 68u:
+                case 72u:
+                {
+                    _285.Store(di * 4 + 8, asuint(linewidth));
+                    break;
+                }
+                case 276u:
+                {
+                    _285.Store(di * 4 + 8, asuint(linewidth));
+                    p0 = asfloat(uint2(_103.Load((dd + 1u) * 4 + 0), _103.Load((dd + 2u) * 4 + 0)));
+                    p1 = asfloat(uint2(_103.Load((dd + 3u) * 4 + 0), _103.Load((dd + 4u) * 4 + 0)));
+                    p0 = ((mat.xy * p0.x) + (mat.zw * p0.y)) + translate;
+                    p1 = ((mat.xy * p1.x) + (mat.zw * p1.y)) + translate;
+                    float2 dxy = p1 - p0;
+                    float scale = 1.0f / ((dxy.x * dxy.x) + (dxy.y * dxy.y));
+                    float line_x = dxy.x * scale;
+                    float line_y = dxy.y * scale;
+                    float line_c = -((p0.x * line_x) + (p0.y * line_y));
+                    _285.Store((di + 1u) * 4 + 8, asuint(line_x));
+                    _285.Store((di + 2u) * 4 + 8, asuint(line_y));
+                    _285.Store((di + 3u) * 4 + 8, asuint(line_c));
+                    break;
+                }
+                case 732u:
+                {
+                    p0 = asfloat(uint2(_103.Load((dd + 1u) * 4 + 0), _103.Load((dd + 2u) * 4 + 0)));
+                    p1 = asfloat(uint2(_103.Load((dd + 3u) * 4 + 0), _103.Load((dd + 4u) * 4 + 0)));
+                    float r0 = asfloat(_103.Load((dd + 5u) * 4 + 0));
+                    float r1 = asfloat(_103.Load((dd + 6u) * 4 + 0));
+                    float inv_det = 1.0f / ((mat.x * mat.w) - (mat.y * mat.z));
+                    float4 inv_mat = float4(mat.w, -mat.y, -mat.z, mat.x) * inv_det;
+                    float2 inv_tr = (inv_mat.xz * translate.x) + (inv_mat.yw * translate.y);
+                    inv_tr += p0;
+                    float2 center1 = p1 - p0;
+                    float rr = r1 / (r1 - r0);
+                    float rainv = rr / ((r1 * r1) - dot(center1, center1));
+                    float2 c1 = center1 * rainv;
+                    float ra = rr * rainv;
+                    float roff = rr - 1.0f;
+                    _285.Store(di * 4 + 8, asuint(linewidth));
+                    _285.Store((di + 1u) * 4 + 8, asuint(inv_mat.x));
+                    _285.Store((di + 2u) * 4 + 8, asuint(inv_mat.y));
+                    _285.Store((di + 3u) * 4 + 8, asuint(inv_mat.z));
+                    _285.Store((di + 4u) * 4 + 8, asuint(inv_mat.w));
+                    _285.Store((di + 5u) * 4 + 8, asuint(inv_tr.x));
+                    _285.Store((di + 6u) * 4 + 8, asuint(inv_tr.y));
+                    _285.Store((di + 7u) * 4 + 8, asuint(c1.x));
+                    _285.Store((di + 8u) * 4 + 8, asuint(c1.y));
+                    _285.Store((di + 9u) * 4 + 8, asuint(ra));
+                    _285.Store((di + 10u) * 4 + 8, asuint(roff));
+                    break;
+                }
+                case 5u:
+                {
+                    break;
+                }
+            }
+        }
+        if ((tag_word == 5u) || (tag_word == 37u))
+        {
+            uint path_ix = ~(out_ix + i_2);
+            if (tag_word == 5u)
+            {
+                path_ix = m.path_ix;
+            }
+            _285.Store((clip_out_base + m.clip_ix) * 4 + 8, path_ix);
+        }
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/draw_leaf.msl

@@ -0,0 +1,316 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+struct DrawMonoid_1
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct ParentBuf
+{
+    DrawMonoid_1 parent[1];
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+DrawMonoid map_tag(thread const uint& tag_word)
+{
+    uint has_path = uint(tag_word != 0u);
+    return DrawMonoid{ has_path, tag_word & 1u, tag_word & 28u, (tag_word >> uint(4)) & 60u };
+}
+
+static inline __attribute__((always_inline))
+DrawMonoid combine_draw_monoid(thread const DrawMonoid& a, thread const DrawMonoid& b)
+{
+    DrawMonoid c;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.clip_ix = a.clip_ix + b.clip_ix;
+    c.scene_offset = a.scene_offset + b.scene_offset;
+    c.info_offset = a.info_offset + b.info_offset;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+DrawMonoid draw_monoid_identity()
+{
+    return DrawMonoid{ 0u, 0u, 0u, 0u };
+}
+
+kernel void main0(device Memory& _285 [[buffer(0)]], const device ConfigBuf& _93 [[buffer(1)]], const device SceneBuf& _103 [[buffer(2)]], const device ParentBuf& _203 [[buffer(3)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup DrawMonoid sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    uint drawtag_base = _93.conf.drawtag_offset >> uint(2);
+    uint tag_word = _103.scene[drawtag_base + ix];
+    uint param = tag_word;
+    DrawMonoid agg = map_tag(param);
+    spvUnsafeArray<DrawMonoid, 8> local;
+    local[0] = agg;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        tag_word = _103.scene[(drawtag_base + ix) + i];
+        uint param_1 = tag_word;
+        DrawMonoid param_2 = agg;
+        DrawMonoid param_3 = map_tag(param_1);
+        agg = combine_draw_monoid(param_2, param_3);
+        local[i] = agg;
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            DrawMonoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            DrawMonoid param_4 = other;
+            DrawMonoid param_5 = agg;
+            agg = combine_draw_monoid(param_4, param_5);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    DrawMonoid row = draw_monoid_identity();
+    if (gl_WorkGroupID.x > 0u)
+    {
+        uint _206 = gl_WorkGroupID.x - 1u;
+        row.path_ix = _203.parent[_206].path_ix;
+        row.clip_ix = _203.parent[_206].clip_ix;
+        row.scene_offset = _203.parent[_206].scene_offset;
+        row.info_offset = _203.parent[_206].info_offset;
+    }
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        DrawMonoid param_6 = row;
+        DrawMonoid param_7 = sh_scratch[gl_LocalInvocationID.x - 1u];
+        row = combine_draw_monoid(param_6, param_7);
+    }
+    uint drawdata_base = _93.conf.drawdata_offset >> uint(2);
+    uint drawinfo_base = _93.conf.drawinfo_alloc.offset >> uint(2);
+    uint out_ix = gl_GlobalInvocationID.x * 8u;
+    uint out_base = (_93.conf.drawmonoid_alloc.offset >> uint(2)) + (out_ix * 4u);
+    uint clip_out_base = _93.conf.clip_alloc.offset >> uint(2);
+    float4 mat;
+    float2 translate;
+    float2 p0;
+    float2 p1;
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        DrawMonoid m = row;
+        if (i_2 > 0u)
+        {
+            DrawMonoid param_8 = m;
+            DrawMonoid param_9 = local[i_2 - 1u];
+            m = combine_draw_monoid(param_8, param_9);
+        }
+        _285.memory[out_base + (i_2 * 4u)] = m.path_ix;
+        _285.memory[(out_base + (i_2 * 4u)) + 1u] = m.clip_ix;
+        _285.memory[(out_base + (i_2 * 4u)) + 2u] = m.scene_offset;
+        _285.memory[(out_base + (i_2 * 4u)) + 3u] = m.info_offset;
+        uint dd = drawdata_base + (m.scene_offset >> uint(2));
+        uint di = drawinfo_base + (m.info_offset >> uint(2));
+        tag_word = _103.scene[(drawtag_base + ix) + i_2];
+        if (((((tag_word == 68u) || (tag_word == 276u)) || (tag_word == 732u)) || (tag_word == 72u)) || (tag_word == 5u))
+        {
+            uint bbox_offset = (_93.conf.path_bbox_alloc.offset >> uint(2)) + (6u * m.path_ix);
+            float bbox_l = float(_285.memory[bbox_offset]) - 32768.0;
+            float bbox_t = float(_285.memory[bbox_offset + 1u]) - 32768.0;
+            float bbox_r = float(_285.memory[bbox_offset + 2u]) - 32768.0;
+            float bbox_b = float(_285.memory[bbox_offset + 3u]) - 32768.0;
+            float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
+            float linewidth = as_type<float>(_285.memory[bbox_offset + 4u]);
+            uint fill_mode = uint(linewidth >= 0.0);
+            if (((linewidth >= 0.0) || (tag_word == 276u)) || (tag_word == 732u))
+            {
+                uint trans_ix = _285.memory[bbox_offset + 5u];
+                uint t = (_93.conf.trans_alloc.offset >> uint(2)) + (6u * trans_ix);
+                mat = as_type<float4>(uint4(_285.memory[t], _285.memory[t + 1u], _285.memory[t + 2u], _285.memory[t + 3u]));
+                if ((tag_word == 276u) || (tag_word == 732u))
+                {
+                    translate = as_type<float2>(uint2(_285.memory[t + 4u], _285.memory[t + 5u]));
+                }
+            }
+            if (linewidth >= 0.0)
+            {
+                linewidth *= sqrt(abs((mat.x * mat.w) - (mat.y * mat.z)));
+            }
+            switch (tag_word)
+            {
+                case 68u:
+                case 72u:
+                {
+                    _285.memory[di] = as_type<uint>(linewidth);
+                    break;
+                }
+                case 276u:
+                {
+                    _285.memory[di] = as_type<uint>(linewidth);
+                    p0 = as_type<float2>(uint2(_103.scene[dd + 1u], _103.scene[dd + 2u]));
+                    p1 = as_type<float2>(uint2(_103.scene[dd + 3u], _103.scene[dd + 4u]));
+                    p0 = ((mat.xy * p0.x) + (mat.zw * p0.y)) + translate;
+                    p1 = ((mat.xy * p1.x) + (mat.zw * p1.y)) + translate;
+                    float2 dxy = p1 - p0;
+                    float scale = 1.0 / ((dxy.x * dxy.x) + (dxy.y * dxy.y));
+                    float line_x = dxy.x * scale;
+                    float line_y = dxy.y * scale;
+                    float line_c = -((p0.x * line_x) + (p0.y * line_y));
+                    _285.memory[di + 1u] = as_type<uint>(line_x);
+                    _285.memory[di + 2u] = as_type<uint>(line_y);
+                    _285.memory[di + 3u] = as_type<uint>(line_c);
+                    break;
+                }
+                case 732u:
+                {
+                    p0 = as_type<float2>(uint2(_103.scene[dd + 1u], _103.scene[dd + 2u]));
+                    p1 = as_type<float2>(uint2(_103.scene[dd + 3u], _103.scene[dd + 4u]));
+                    float r0 = as_type<float>(_103.scene[dd + 5u]);
+                    float r1 = as_type<float>(_103.scene[dd + 6u]);
+                    float inv_det = 1.0 / ((mat.x * mat.w) - (mat.y * mat.z));
+                    float4 inv_mat = float4(mat.w, -mat.y, -mat.z, mat.x) * inv_det;
+                    float2 inv_tr = (inv_mat.xz * translate.x) + (inv_mat.yw * translate.y);
+                    inv_tr += p0;
+                    float2 center1 = p1 - p0;
+                    float rr = r1 / (r1 - r0);
+                    float rainv = rr / ((r1 * r1) - dot(center1, center1));
+                    float2 c1 = center1 * rainv;
+                    float ra = rr * rainv;
+                    float roff = rr - 1.0;
+                    _285.memory[di] = as_type<uint>(linewidth);
+                    _285.memory[di + 1u] = as_type<uint>(inv_mat.x);
+                    _285.memory[di + 2u] = as_type<uint>(inv_mat.y);
+                    _285.memory[di + 3u] = as_type<uint>(inv_mat.z);
+                    _285.memory[di + 4u] = as_type<uint>(inv_mat.w);
+                    _285.memory[di + 5u] = as_type<uint>(inv_tr.x);
+                    _285.memory[di + 6u] = as_type<uint>(inv_tr.y);
+                    _285.memory[di + 7u] = as_type<uint>(c1.x);
+                    _285.memory[di + 8u] = as_type<uint>(c1.y);
+                    _285.memory[di + 9u] = as_type<uint>(ra);
+                    _285.memory[di + 10u] = as_type<uint>(roff);
+                    break;
+                }
+                case 5u:
+                {
+                    break;
+                }
+            }
+        }
+        if ((tag_word == 5u) || (tag_word == 37u))
+        {
+            uint path_ix = ~(out_ix + i_2);
+            if (tag_word == 5u)
+            {
+                path_ix = m.path_ix;
+            }
+            _285.memory[clip_out_base + m.clip_ix] = path_ix;
+        }
+    }
+}
+

piet-gpu/shader/gen/draw_reduce.hlsl

@@ -0,0 +1,126 @@
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+ByteAddressBuffer _87 : register(t1, space0);
+ByteAddressBuffer _97 : register(t2, space0);
+RWByteAddressBuffer _188 : register(u3, space0);
+RWByteAddressBuffer _206 : register(u0, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared DrawMonoid sh_scratch[256];
+
+DrawMonoid map_tag(uint tag_word)
+{
+    uint has_path = uint(tag_word != 0u);
+    DrawMonoid _70 = { has_path, tag_word & 1u, tag_word & 28u, (tag_word >> uint(4)) & 60u };
+    return _70;
+}
+
+DrawMonoid combine_draw_monoid(DrawMonoid a, DrawMonoid b)
+{
+    DrawMonoid c;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.clip_ix = a.clip_ix + b.clip_ix;
+    c.scene_offset = a.scene_offset + b.scene_offset;
+    c.info_offset = a.info_offset + b.info_offset;
+    return c;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    uint drawtag_base = _87.Load(100) >> uint(2);
+    uint tag_word = _97.Load((drawtag_base + ix) * 4 + 0);
+    uint param = tag_word;
+    DrawMonoid agg = map_tag(param);
+    for (uint i = 1u; i < 8u; i++)
+    {
+        uint tag_word_1 = _97.Load(((drawtag_base + ix) + i) * 4 + 0);
+        uint param_1 = tag_word_1;
+        DrawMonoid param_2 = agg;
+        DrawMonoid param_3 = map_tag(param_1);
+        agg = combine_draw_monoid(param_2, param_3);
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if ((gl_LocalInvocationID.x + (1u << i_1)) < 256u)
+        {
+            DrawMonoid other = sh_scratch[gl_LocalInvocationID.x + (1u << i_1)];
+            DrawMonoid param_4 = agg;
+            DrawMonoid param_5 = other;
+            agg = combine_draw_monoid(param_4, param_5);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        _188.Store(gl_WorkGroupID.x * 16 + 0, agg.path_ix);
+        _188.Store(gl_WorkGroupID.x * 16 + 4, agg.clip_ix);
+        _188.Store(gl_WorkGroupID.x * 16 + 8, agg.scene_offset);
+        _188.Store(gl_WorkGroupID.x * 16 + 12, agg.info_offset);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/draw_reduce.msl

@@ -0,0 +1,140 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+struct DrawMonoid_1
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct OutBuf
+{
+    DrawMonoid_1 outbuf[1];
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+DrawMonoid map_tag(thread const uint& tag_word)
+{
+    uint has_path = uint(tag_word != 0u);
+    return DrawMonoid{ has_path, tag_word & 1u, tag_word & 28u, (tag_word >> uint(4)) & 60u };
+}
+
+static inline __attribute__((always_inline))
+DrawMonoid combine_draw_monoid(thread const DrawMonoid& a, thread const DrawMonoid& b)
+{
+    DrawMonoid c;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.clip_ix = a.clip_ix + b.clip_ix;
+    c.scene_offset = a.scene_offset + b.scene_offset;
+    c.info_offset = a.info_offset + b.info_offset;
+    return c;
+}
+
+kernel void main0(const device ConfigBuf& _87 [[buffer(1)]], const device SceneBuf& _97 [[buffer(2)]], device OutBuf& _188 [[buffer(3)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup DrawMonoid sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    uint drawtag_base = _87.conf.drawtag_offset >> uint(2);
+    uint tag_word = _97.scene[drawtag_base + ix];
+    uint param = tag_word;
+    DrawMonoid agg = map_tag(param);
+    for (uint i = 1u; i < 8u; i++)
+    {
+        uint tag_word_1 = _97.scene[(drawtag_base + ix) + i];
+        uint param_1 = tag_word_1;
+        DrawMonoid param_2 = agg;
+        DrawMonoid param_3 = map_tag(param_1);
+        agg = combine_draw_monoid(param_2, param_3);
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if ((gl_LocalInvocationID.x + (1u << i_1)) < 256u)
+        {
+            DrawMonoid other = sh_scratch[gl_LocalInvocationID.x + (1u << i_1)];
+            DrawMonoid param_4 = agg;
+            DrawMonoid param_5 = other;
+            agg = combine_draw_monoid(param_4, param_5);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        _188.outbuf[gl_WorkGroupID.x].path_ix = agg.path_ix;
+        _188.outbuf[gl_WorkGroupID.x].clip_ix = agg.clip_ix;
+        _188.outbuf[gl_WorkGroupID.x].scene_offset = agg.scene_offset;
+        _188.outbuf[gl_WorkGroupID.x].info_offset = agg.info_offset;
+    }
+}
+

piet-gpu/shader/gen/draw_root.hlsl

@@ -0,0 +1,108 @@
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const DrawMonoid _18 = { 0u, 0u, 0u, 0u };
+
+RWByteAddressBuffer _71 : register(u0, space0);
+
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared DrawMonoid sh_scratch[256];
+
+DrawMonoid combine_draw_monoid(DrawMonoid a, DrawMonoid b)
+{
+    DrawMonoid c;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.clip_ix = a.clip_ix + b.clip_ix;
+    c.scene_offset = a.scene_offset + b.scene_offset;
+    c.info_offset = a.info_offset + b.info_offset;
+    return c;
+}
+
+DrawMonoid draw_monoid_identity()
+{
+    return _18;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    DrawMonoid _75;
+    _75.path_ix = _71.Load(ix * 16 + 0);
+    _75.clip_ix = _71.Load(ix * 16 + 4);
+    _75.scene_offset = _71.Load(ix * 16 + 8);
+    _75.info_offset = _71.Load(ix * 16 + 12);
+    DrawMonoid local[8];
+    local[0].path_ix = _75.path_ix;
+    local[0].clip_ix = _75.clip_ix;
+    local[0].scene_offset = _75.scene_offset;
+    local[0].info_offset = _75.info_offset;
+    DrawMonoid param_1;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        DrawMonoid param = local[i - 1u];
+        DrawMonoid _106;
+        _106.path_ix = _71.Load((ix + i) * 16 + 0);
+        _106.clip_ix = _71.Load((ix + i) * 16 + 4);
+        _106.scene_offset = _71.Load((ix + i) * 16 + 8);
+        _106.info_offset = _71.Load((ix + i) * 16 + 12);
+        param_1.path_ix = _106.path_ix;
+        param_1.clip_ix = _106.clip_ix;
+        param_1.scene_offset = _106.scene_offset;
+        param_1.info_offset = _106.info_offset;
+        local[i] = combine_draw_monoid(param, param_1);
+    }
+    DrawMonoid agg = local[7];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            DrawMonoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            DrawMonoid param_2 = other;
+            DrawMonoid param_3 = agg;
+            agg = combine_draw_monoid(param_2, param_3);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    DrawMonoid row = draw_monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        DrawMonoid param_4 = row;
+        DrawMonoid param_5 = local[i_2];
+        DrawMonoid m = combine_draw_monoid(param_4, param_5);
+        uint _199 = ix + i_2;
+        _71.Store(_199 * 16 + 0, m.path_ix);
+        _71.Store(_199 * 16 + 4, m.clip_ix);
+        _71.Store(_199 * 16 + 8, m.scene_offset);
+        _71.Store(_199 * 16 + 12, m.info_offset);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/draw_root.msl

@@ -0,0 +1,140 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct DrawMonoid
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct DrawMonoid_1
+{
+    uint path_ix;
+    uint clip_ix;
+    uint scene_offset;
+    uint info_offset;
+};
+
+struct DataBuf
+{
+    DrawMonoid_1 data[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+DrawMonoid combine_draw_monoid(thread const DrawMonoid& a, thread const DrawMonoid& b)
+{
+    DrawMonoid c;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.clip_ix = a.clip_ix + b.clip_ix;
+    c.scene_offset = a.scene_offset + b.scene_offset;
+    c.info_offset = a.info_offset + b.info_offset;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+DrawMonoid draw_monoid_identity()
+{
+    return DrawMonoid{ 0u, 0u, 0u, 0u };
+}
+
+kernel void main0(device DataBuf& _71 [[buffer(0)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]])
+{
+    threadgroup DrawMonoid sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    spvUnsafeArray<DrawMonoid, 8> local;
+    local[0].path_ix = _71.data[ix].path_ix;
+    local[0].clip_ix = _71.data[ix].clip_ix;
+    local[0].scene_offset = _71.data[ix].scene_offset;
+    local[0].info_offset = _71.data[ix].info_offset;
+    DrawMonoid param_1;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        uint _100 = ix + i;
+        DrawMonoid param = local[i - 1u];
+        param_1.path_ix = _71.data[_100].path_ix;
+        param_1.clip_ix = _71.data[_100].clip_ix;
+        param_1.scene_offset = _71.data[_100].scene_offset;
+        param_1.info_offset = _71.data[_100].info_offset;
+        local[i] = combine_draw_monoid(param, param_1);
+    }
+    DrawMonoid agg = local[7];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            DrawMonoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            DrawMonoid param_2 = other;
+            DrawMonoid param_3 = agg;
+            agg = combine_draw_monoid(param_2, param_3);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    DrawMonoid row = draw_monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        DrawMonoid param_4 = row;
+        DrawMonoid param_5 = local[i_2];
+        DrawMonoid m = combine_draw_monoid(param_4, param_5);
+        uint _199 = ix + i_2;
+        _71.data[_199].path_ix = m.path_ix;
+        _71.data[_199].clip_ix = m.clip_ix;
+        _71.data[_199].scene_offset = m.scene_offset;
+        _71.data[_199].info_offset = m.info_offset;
+    }
+}
+

piet-gpu/shader/gen/path_coarse.hlsl

@@ -0,0 +1,673 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct MallocResult
+{
+    Alloc alloc;
+    bool failed;
+};
+
+struct PathCubicRef
+{
+    uint offset;
+};
+
+struct PathCubic
+{
+    float2 p0;
+    float2 p1;
+    float2 p2;
+    float2 p3;
+    uint path_ix;
+    uint trans_ix;
+    float2 stroke;
+};
+
+struct PathSegRef
+{
+    uint offset;
+};
+
+struct PathSegTag
+{
+    uint tag;
+    uint flags;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct TileSegRef
+{
+    uint offset;
+};
+
+struct TileSeg
+{
+    float2 origin;
+    float2 _vector;
+    float y_edge;
+    TileSegRef next;
+};
+
+struct SubdivResult
+{
+    float val;
+    float a0;
+    float a2;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(32u, 1u, 1u);
+
+static const PathSegTag _721 = { 0u, 0u };
+
+RWByteAddressBuffer _136 : register(u0, space0);
+ByteAddressBuffer _710 : register(t1, space0);
+
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+uint read_mem(Alloc alloc, uint offset)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = _136.Load(offset * 4 + 8);
+    return v;
+}
+
+PathSegTag PathSeg_tag(Alloc a, PathSegRef ref)
+{
+    Alloc param = a;
+    uint param_1 = ref.offset >> uint(2);
+    uint tag_and_flags = read_mem(param, param_1);
+    PathSegTag _367 = { tag_and_flags & 65535u, tag_and_flags >> uint(16) };
+    return _367;
+}
+
+PathCubic PathCubic_read(Alloc a, PathCubicRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5);
+    Alloc param_6 = a;
+    uint param_7 = ix + 3u;
+    uint raw3 = read_mem(param_6, param_7);
+    Alloc param_8 = a;
+    uint param_9 = ix + 4u;
+    uint raw4 = read_mem(param_8, param_9);
+    Alloc param_10 = a;
+    uint param_11 = ix + 5u;
+    uint raw5 = read_mem(param_10, param_11);
+    Alloc param_12 = a;
+    uint param_13 = ix + 6u;
+    uint raw6 = read_mem(param_12, param_13);
+    Alloc param_14 = a;
+    uint param_15 = ix + 7u;
+    uint raw7 = read_mem(param_14, param_15);
+    Alloc param_16 = a;
+    uint param_17 = ix + 8u;
+    uint raw8 = read_mem(param_16, param_17);
+    Alloc param_18 = a;
+    uint param_19 = ix + 9u;
+    uint raw9 = read_mem(param_18, param_19);
+    Alloc param_20 = a;
+    uint param_21 = ix + 10u;
+    uint raw10 = read_mem(param_20, param_21);
+    Alloc param_22 = a;
+    uint param_23 = ix + 11u;
+    uint raw11 = read_mem(param_22, param_23);
+    PathCubic s;
+    s.p0 = float2(asfloat(raw0), asfloat(raw1));
+    s.p1 = float2(asfloat(raw2), asfloat(raw3));
+    s.p2 = float2(asfloat(raw4), asfloat(raw5));
+    s.p3 = float2(asfloat(raw6), asfloat(raw7));
+    s.path_ix = raw8;
+    s.trans_ix = raw9;
+    s.stroke = float2(asfloat(raw10), asfloat(raw11));
+    return s;
+}
+
+PathCubic PathSeg_Cubic_read(Alloc a, PathSegRef ref)
+{
+    PathCubicRef _373 = { ref.offset + 4u };
+    Alloc param = a;
+    PathCubicRef param_1 = _373;
+    return PathCubic_read(param, param_1);
+}
+
+float2 eval_cubic(float2 p0, float2 p1, float2 p2, float2 p3, float t)
+{
+    float mt = 1.0f - t;
+    return (p0 * ((mt * mt) * mt)) + (((p1 * ((mt * mt) * 3.0f)) + (((p2 * (mt * 3.0f)) + (p3 * t)) * t)) * t);
+}
+
+float approx_parabola_integral(float x)
+{
+    return x * rsqrt(sqrt(0.3300000131130218505859375f + (0.201511204242706298828125f + ((0.25f * x) * x))));
+}
+
+SubdivResult estimate_subdiv(float2 p0, float2 p1, float2 p2, float sqrt_tol)
+{
+    float2 d01 = p1 - p0;
+    float2 d12 = p2 - p1;
+    float2 dd = d01 - d12;
+    float _cross = ((p2.x - p0.x) * dd.y) - ((p2.y - p0.y) * dd.x);
+    float x0 = ((d01.x * dd.x) + (d01.y * dd.y)) / _cross;
+    float x2 = ((d12.x * dd.x) + (d12.y * dd.y)) / _cross;
+    float scale = abs(_cross / (length(dd) * (x2 - x0)));
+    float param = x0;
+    float a0 = approx_parabola_integral(param);
+    float param_1 = x2;
+    float a2 = approx_parabola_integral(param_1);
+    float val = 0.0f;
+    if (scale < 1000000000.0f)
+    {
+        float da = abs(a2 - a0);
+        float sqrt_scale = sqrt(scale);
+        if (sign(x0) == sign(x2))
+        {
+            val = da * sqrt_scale;
+        }
+        else
+        {
+            float xmin = sqrt_tol / sqrt_scale;
+            float param_2 = xmin;
+            val = (sqrt_tol * da) / approx_parabola_integral(param_2);
+        }
+    }
+    SubdivResult _695 = { val, a0, a2 };
+    return _695;
+}
+
+uint fill_mode_from_flags(uint flags)
+{
+    return flags & 1u;
+}
+
+Path Path_read(Alloc a, PathRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5);
+    Path s;
+    s.bbox = uint4(raw0 & 65535u, raw0 >> uint(16), raw1 & 65535u, raw1 >> uint(16));
+    TileRef _427 = { raw2 };
+    s.tiles = _427;
+    return s;
+}
+
+Alloc new_alloc(uint offset, uint size, bool mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+float approx_parabola_inv_integral(float x)
+{
+    return x * sqrt(0.61000001430511474609375f + (0.1520999968051910400390625f + ((0.25f * x) * x)));
+}
+
+float2 eval_quad(float2 p0, float2 p1, float2 p2, float t)
+{
+    float mt = 1.0f - t;
+    return (p0 * (mt * mt)) + (((p1 * (mt * 2.0f)) + (p2 * t)) * t);
+}
+
+MallocResult malloc(uint size)
+{
+    uint _142;
+    _136.InterlockedAdd(0, size, _142);
+    uint offset = _142;
+    uint _149;
+    _136.GetDimensions(_149);
+    _149 = (_149 - 8) / 4;
+    MallocResult r;
+    r.failed = (offset + size) > uint(int(_149) * 4);
+    uint param = offset;
+    uint param_1 = size;
+    bool param_2 = !r.failed;
+    r.alloc = new_alloc(param, param_1, param_2);
+    if (r.failed)
+    {
+        uint _171;
+        _136.InterlockedMax(4, 1u, _171);
+        return r;
+    }
+    return r;
+}
+
+TileRef Tile_index(TileRef ref, uint index)
+{
+    TileRef _385 = { ref.offset + (index * 8u) };
+    return _385;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _136.Store(offset * 4 + 8, val);
+}
+
+void TileSeg_write(Alloc a, TileSegRef ref, TileSeg s)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = asuint(s.origin.x);
+    write_mem(param, param_1, param_2);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = asuint(s.origin.y);
+    write_mem(param_3, param_4, param_5);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = asuint(s._vector.x);
+    write_mem(param_6, param_7, param_8);
+    Alloc param_9 = a;
+    uint param_10 = ix + 3u;
+    uint param_11 = asuint(s._vector.y);
+    write_mem(param_9, param_10, param_11);
+    Alloc param_12 = a;
+    uint param_13 = ix + 4u;
+    uint param_14 = asuint(s.y_edge);
+    write_mem(param_12, param_13, param_14);
+    Alloc param_15 = a;
+    uint param_16 = ix + 5u;
+    uint param_17 = s.next.offset;
+    write_mem(param_15, param_16, param_17);
+}
+
+void comp_main()
+{
+    uint element_ix = gl_GlobalInvocationID.x;
+    PathSegRef _718 = { _710.Load(28) + (element_ix * 52u) };
+    PathSegRef ref = _718;
+    PathSegTag tag = _721;
+    if (element_ix < _710.Load(4))
+    {
+        Alloc _731;
+        _731.offset = _710.Load(28);
+        Alloc param;
+        param.offset = _731.offset;
+        PathSegRef param_1 = ref;
+        tag = PathSeg_tag(param, param_1);
+    }
+    bool mem_ok = _136.Load(4) == 0u;
+    switch (tag.tag)
+    {
+        case 1u:
+        {
+            Alloc _748;
+            _748.offset = _710.Load(28);
+            Alloc param_2;
+            param_2.offset = _748.offset;
+            PathSegRef param_3 = ref;
+            PathCubic cubic = PathSeg_Cubic_read(param_2, param_3);
+            float2 err_v = (((cubic.p2 - cubic.p1) * 3.0f) + cubic.p0) - cubic.p3;
+            float err = (err_v.x * err_v.x) + (err_v.y * err_v.y);
+            uint n_quads = max(uint(ceil(pow(err * 3.7037036418914794921875f, 0.16666667163372039794921875f))), 1u);
+            n_quads = min(n_quads, 16u);
+            float val = 0.0f;
+            float2 qp0 = cubic.p0;
+            float _step = 1.0f / float(n_quads);
+            SubdivResult keep_params[16];
+            for (uint i = 0u; i < n_quads; i++)
+            {
+                float t = float(i + 1u) * _step;
+                float2 param_4 = cubic.p0;
+                float2 param_5 = cubic.p1;
+                float2 param_6 = cubic.p2;
+                float2 param_7 = cubic.p3;
+                float param_8 = t;
+                float2 qp2 = eval_cubic(param_4, param_5, param_6, param_7, param_8);
+                float2 param_9 = cubic.p0;
+                float2 param_10 = cubic.p1;
+                float2 param_11 = cubic.p2;
+                float2 param_12 = cubic.p3;
+                float param_13 = t - (0.5f * _step);
+                float2 qp1 = eval_cubic(param_9, param_10, param_11, param_12, param_13);
+                qp1 = (qp1 * 2.0f) - ((qp0 + qp2) * 0.5f);
+                float2 param_14 = qp0;
+                float2 param_15 = qp1;
+                float2 param_16 = qp2;
+                float param_17 = 0.4743416607379913330078125f;
+                SubdivResult params = estimate_subdiv(param_14, param_15, param_16, param_17);
+                keep_params[i] = params;
+                val += params.val;
+                qp0 = qp2;
+            }
+            uint n = max(uint(ceil((val * 0.5f) / 0.4743416607379913330078125f)), 1u);
+            uint param_18 = tag.flags;
+            bool is_stroke = fill_mode_from_flags(param_18) == 1u;
+            uint path_ix = cubic.path_ix;
+            PathRef _904 = { _710.Load(16) + (path_ix * 12u) };
+            Alloc _907;
+            _907.offset = _710.Load(16);
+            Alloc param_19;
+            param_19.offset = _907.offset;
+            PathRef param_20 = _904;
+            Path path = Path_read(param_19, param_20);
+            uint param_21 = path.tiles.offset;
+            uint param_22 = ((path.bbox.z - path.bbox.x) * (path.bbox.w - path.bbox.y)) * 8u;
+            bool param_23 = mem_ok;
+            Alloc path_alloc = new_alloc(param_21, param_22, param_23);
+            int4 bbox = int4(path.bbox);
+            float2 p0 = cubic.p0;
+            qp0 = cubic.p0;
+            float v_step = val / float(n);
+            int n_out = 1;
+            float val_sum = 0.0f;
+            float2 p1;
+            float _1147;
+            TileSeg tile_seg;
+            for (uint i_1 = 0u; i_1 < n_quads; i_1++)
+            {
+                float t_1 = float(i_1 + 1u) * _step;
+                float2 param_24 = cubic.p0;
+                float2 param_25 = cubic.p1;
+                float2 param_26 = cubic.p2;
+                float2 param_27 = cubic.p3;
+                float param_28 = t_1;
+                float2 qp2_1 = eval_cubic(param_24, param_25, param_26, param_27, param_28);
+                float2 param_29 = cubic.p0;
+                float2 param_30 = cubic.p1;
+                float2 param_31 = cubic.p2;
+                float2 param_32 = cubic.p3;
+                float param_33 = t_1 - (0.5f * _step);
+                float2 qp1_1 = eval_cubic(param_29, param_30, param_31, param_32, param_33);
+                qp1_1 = (qp1_1 * 2.0f) - ((qp0 + qp2_1) * 0.5f);
+                SubdivResult params_1 = keep_params[i_1];
+                float param_34 = params_1.a0;
+                float u0 = approx_parabola_inv_integral(param_34);
+                float param_35 = params_1.a2;
+                float u2 = approx_parabola_inv_integral(param_35);
+                float uscale = 1.0f / (u2 - u0);
+                float target = float(n_out) * v_step;
+                for (;;)
+                {
+                    bool _1040 = uint(n_out) == n;
+                    bool _1050;
+                    if (!_1040)
+                    {
+                        _1050 = target < (val_sum + params_1.val);
+                    }
+                    else
+                    {
+                        _1050 = _1040;
+                    }
+                    if (_1050)
+                    {
+                        if (uint(n_out) == n)
+                        {
+                            p1 = cubic.p3;
+                        }
+                        else
+                        {
+                            float u = (target - val_sum) / params_1.val;
+                            float a = lerp(params_1.a0, params_1.a2, u);
+                            float param_36 = a;
+                            float au = approx_parabola_inv_integral(param_36);
+                            float t_2 = (au - u0) * uscale;
+                            float2 param_37 = qp0;
+                            float2 param_38 = qp1_1;
+                            float2 param_39 = qp2_1;
+                            float param_40 = t_2;
+                            p1 = eval_quad(param_37, param_38, param_39, param_40);
+                        }
+                        float xmin = min(p0.x, p1.x) - cubic.stroke.x;
+                        float xmax = max(p0.x, p1.x) + cubic.stroke.x;
+                        float ymin = min(p0.y, p1.y) - cubic.stroke.y;
+                        float ymax = max(p0.y, p1.y) + cubic.stroke.y;
+                        float dx = p1.x - p0.x;
+                        float dy = p1.y - p0.y;
+                        if (abs(dy) < 9.999999717180685365747194737196e-10f)
+                        {
+                            _1147 = 1000000000.0f;
+                        }
+                        else
+                        {
+                            _1147 = dx / dy;
+                        }
+                        float invslope = _1147;
+                        float c = (cubic.stroke.x + (abs(invslope) * (8.0f + cubic.stroke.y))) * 0.0625f;
+                        float b = invslope;
+                        float a_1 = (p0.x - ((p0.y - 8.0f) * b)) * 0.0625f;
+                        int x0 = int(floor(xmin * 0.0625f));
+                        int x1 = int(floor(xmax * 0.0625f) + 1.0f);
+                        int y0 = int(floor(ymin * 0.0625f));
+                        int y1 = int(floor(ymax * 0.0625f) + 1.0f);
+                        x0 = clamp(x0, bbox.x, bbox.z);
+                        y0 = clamp(y0, bbox.y, bbox.w);
+                        x1 = clamp(x1, bbox.x, bbox.z);
+                        y1 = clamp(y1, bbox.y, bbox.w);
+                        float xc = a_1 + (b * float(y0));
+                        int stride = bbox.z - bbox.x;
+                        int base = ((y0 - bbox.y) * stride) - bbox.x;
+                        uint n_tile_alloc = uint((x1 - x0) * (y1 - y0));
+                        uint param_41 = n_tile_alloc * 24u;
+                        MallocResult _1263 = malloc(param_41);
+                        MallocResult tile_alloc = _1263;
+                        if (tile_alloc.failed || (!mem_ok))
+                        {
+                            return;
+                        }
+                        uint tile_offset = tile_alloc.alloc.offset;
+                        int xray = int(floor(p0.x * 0.0625f));
+                        int last_xray = int(floor(p1.x * 0.0625f));
+                        if (p0.y > p1.y)
+                        {
+                            int tmp = xray;
+                            xray = last_xray;
+                            last_xray = tmp;
+                        }
+                        for (int y = y0; y < y1; y++)
+                        {
+                            float tile_y0 = float(y * 16);
+                            int xbackdrop = max((xray + 1), bbox.x);
+                            bool _1319 = !is_stroke;
+                            bool _1329;
+                            if (_1319)
+                            {
+                                _1329 = min(p0.y, p1.y) < tile_y0;
+                            }
+                            else
+                            {
+                                _1329 = _1319;
+                            }
+                            bool _1336;
+                            if (_1329)
+                            {
+                                _1336 = xbackdrop < bbox.z;
+                            }
+                            else
+                            {
+                                _1336 = _1329;
+                            }
+                            if (_1336)
+                            {
+                                int backdrop = (p1.y < p0.y) ? 1 : (-1);
+                                TileRef param_42 = path.tiles;
+                                uint param_43 = uint(base + xbackdrop);
+                                TileRef tile_ref = Tile_index(param_42, param_43);
+                                uint tile_el = tile_ref.offset >> uint(2);
+                                Alloc param_44 = path_alloc;
+                                uint param_45 = tile_el + 1u;
+                                if (touch_mem(param_44, param_45))
+                                {
+                                    uint _1374;
+                                    _136.InterlockedAdd((tile_el + 1u) * 4 + 8, uint(backdrop), _1374);
+                                }
+                            }
+                            int next_xray = last_xray;
+                            if (y < (y1 - 1))
+                            {
+                                float tile_y1 = float((y + 1) * 16);
+                                float x_edge = lerp(p0.x, p1.x, (tile_y1 - p0.y) / dy);
+                                next_xray = int(floor(x_edge * 0.0625f));
+                            }
+                            int min_xray = min(xray, next_xray);
+                            int max_xray = max(xray, next_xray);
+                            int xx0 = min(int(floor(xc - c)), min_xray);
+                            int xx1 = max(int(ceil(xc + c)), (max_xray + 1));
+                            xx0 = clamp(xx0, x0, x1);
+                            xx1 = clamp(xx1, x0, x1);
+                            for (int x = xx0; x < xx1; x++)
+                            {
+                                float tile_x0 = float(x * 16);
+                                TileRef _1454 = { path.tiles.offset };
+                                TileRef param_46 = _1454;
+                                uint param_47 = uint(base + x);
+                                TileRef tile_ref_1 = Tile_index(param_46, param_47);
+                                uint tile_el_1 = tile_ref_1.offset >> uint(2);
+                                uint old = 0u;
+                                Alloc param_48 = path_alloc;
+                                uint param_49 = tile_el_1;
+                                if (touch_mem(param_48, param_49))
+                                {
+                                    uint _1477;
+                                    _136.InterlockedExchange(tile_el_1 * 4 + 8, tile_offset, _1477);
+                                    old = _1477;
+                                }
+                                tile_seg.origin = p0;
+                                tile_seg._vector = p1 - p0;
+                                float y_edge = 0.0f;
+                                if (!is_stroke)
+                                {
+                                    y_edge = lerp(p0.y, p1.y, (tile_x0 - p0.x) / dx);
+                                    if (min(p0.x, p1.x) < tile_x0)
+                                    {
+                                        float2 p = float2(tile_x0, y_edge);
+                                        if (p0.x > p1.x)
+                                        {
+                                            tile_seg._vector = p - p0;
+                                        }
+                                        else
+                                        {
+                                            tile_seg.origin = p;
+                                            tile_seg._vector = p1 - p;
+                                        }
+                                        if (tile_seg._vector.x == 0.0f)
+                                        {
+                                            tile_seg._vector.x = sign(p1.x - p0.x) * 9.999999717180685365747194737196e-10f;
+                                        }
+                                    }
+                                    if ((x <= min_xray) || (max_xray < x))
+                                    {
+                                        y_edge = 1000000000.0f;
+                                    }
+                                }
+                                tile_seg.y_edge = y_edge;
+                                tile_seg.next.offset = old;
+                                TileSegRef _1559 = { tile_offset };
+                                Alloc param_50 = tile_alloc.alloc;
+                                TileSegRef param_51 = _1559;
+                                TileSeg param_52 = tile_seg;
+                                TileSeg_write(param_50, param_51, param_52);
+                                tile_offset += 24u;
+                            }
+                            xc += b;
+                            base += stride;
+                            xray = next_xray;
+                        }
+                        n_out++;
+                        target += v_step;
+                        p0 = p1;
+                        continue;
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+                val_sum += params_1.val;
+                qp0 = qp2_1;
+            }
+            break;
+        }
+    }
+}
+
+[numthreads(32, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/path_coarse.msl

@@ -0,0 +1,717 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_atomic>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct MallocResult
+{
+    Alloc alloc;
+    bool failed;
+};
+
+struct PathCubicRef
+{
+    uint offset;
+};
+
+struct PathCubic
+{
+    float2 p0;
+    float2 p1;
+    float2 p2;
+    float2 p3;
+    uint path_ix;
+    uint trans_ix;
+    float2 stroke;
+};
+
+struct PathSegRef
+{
+    uint offset;
+};
+
+struct PathSegTag
+{
+    uint tag;
+    uint flags;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct TileSegRef
+{
+    uint offset;
+};
+
+struct TileSeg
+{
+    float2 origin;
+    float2 vector;
+    float y_edge;
+    TileSegRef next;
+};
+
+struct SubdivResult
+{
+    float val;
+    float a0;
+    float a2;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(32u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+uint read_mem(thread const Alloc& alloc, thread const uint& offset, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = v_136.memory[offset];
+    return v;
+}
+
+static inline __attribute__((always_inline))
+PathSegTag PathSeg_tag(thread const Alloc& a, thread const PathSegRef& ref, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    Alloc param = a;
+    uint param_1 = ref.offset >> uint(2);
+    uint tag_and_flags = read_mem(param, param_1, v_136, v_136BufferSize);
+    return PathSegTag{ tag_and_flags & 65535u, tag_and_flags >> uint(16) };
+}
+
+static inline __attribute__((always_inline))
+PathCubic PathCubic_read(thread const Alloc& a, thread const PathCubicRef& ref, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1, v_136, v_136BufferSize);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3, v_136, v_136BufferSize);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5, v_136, v_136BufferSize);
+    Alloc param_6 = a;
+    uint param_7 = ix + 3u;
+    uint raw3 = read_mem(param_6, param_7, v_136, v_136BufferSize);
+    Alloc param_8 = a;
+    uint param_9 = ix + 4u;
+    uint raw4 = read_mem(param_8, param_9, v_136, v_136BufferSize);
+    Alloc param_10 = a;
+    uint param_11 = ix + 5u;
+    uint raw5 = read_mem(param_10, param_11, v_136, v_136BufferSize);
+    Alloc param_12 = a;
+    uint param_13 = ix + 6u;
+    uint raw6 = read_mem(param_12, param_13, v_136, v_136BufferSize);
+    Alloc param_14 = a;
+    uint param_15 = ix + 7u;
+    uint raw7 = read_mem(param_14, param_15, v_136, v_136BufferSize);
+    Alloc param_16 = a;
+    uint param_17 = ix + 8u;
+    uint raw8 = read_mem(param_16, param_17, v_136, v_136BufferSize);
+    Alloc param_18 = a;
+    uint param_19 = ix + 9u;
+    uint raw9 = read_mem(param_18, param_19, v_136, v_136BufferSize);
+    Alloc param_20 = a;
+    uint param_21 = ix + 10u;
+    uint raw10 = read_mem(param_20, param_21, v_136, v_136BufferSize);
+    Alloc param_22 = a;
+    uint param_23 = ix + 11u;
+    uint raw11 = read_mem(param_22, param_23, v_136, v_136BufferSize);
+    PathCubic s;
+    s.p0 = float2(as_type<float>(raw0), as_type<float>(raw1));
+    s.p1 = float2(as_type<float>(raw2), as_type<float>(raw3));
+    s.p2 = float2(as_type<float>(raw4), as_type<float>(raw5));
+    s.p3 = float2(as_type<float>(raw6), as_type<float>(raw7));
+    s.path_ix = raw8;
+    s.trans_ix = raw9;
+    s.stroke = float2(as_type<float>(raw10), as_type<float>(raw11));
+    return s;
+}
+
+static inline __attribute__((always_inline))
+PathCubic PathSeg_Cubic_read(thread const Alloc& a, thread const PathSegRef& ref, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    Alloc param = a;
+    PathCubicRef param_1 = PathCubicRef{ ref.offset + 4u };
+    return PathCubic_read(param, param_1, v_136, v_136BufferSize);
+}
+
+static inline __attribute__((always_inline))
+float2 eval_cubic(thread const float2& p0, thread const float2& p1, thread const float2& p2, thread const float2& p3, thread const float& t)
+{
+    float mt = 1.0 - t;
+    return (p0 * ((mt * mt) * mt)) + (((p1 * ((mt * mt) * 3.0)) + (((p2 * (mt * 3.0)) + (p3 * t)) * t)) * t);
+}
+
+static inline __attribute__((always_inline))
+float approx_parabola_integral(thread const float& x)
+{
+    return x * rsqrt(sqrt(0.3300000131130218505859375 + (0.201511204242706298828125 + ((0.25 * x) * x))));
+}
+
+static inline __attribute__((always_inline))
+SubdivResult estimate_subdiv(thread const float2& p0, thread const float2& p1, thread const float2& p2, thread const float& sqrt_tol)
+{
+    float2 d01 = p1 - p0;
+    float2 d12 = p2 - p1;
+    float2 dd = d01 - d12;
+    float _cross = ((p2.x - p0.x) * dd.y) - ((p2.y - p0.y) * dd.x);
+    float x0 = ((d01.x * dd.x) + (d01.y * dd.y)) / _cross;
+    float x2 = ((d12.x * dd.x) + (d12.y * dd.y)) / _cross;
+    float scale = abs(_cross / (length(dd) * (x2 - x0)));
+    float param = x0;
+    float a0 = approx_parabola_integral(param);
+    float param_1 = x2;
+    float a2 = approx_parabola_integral(param_1);
+    float val = 0.0;
+    if (scale < 1000000000.0)
+    {
+        float da = abs(a2 - a0);
+        float sqrt_scale = sqrt(scale);
+        if (sign(x0) == sign(x2))
+        {
+            val = da * sqrt_scale;
+        }
+        else
+        {
+            float xmin = sqrt_tol / sqrt_scale;
+            float param_2 = xmin;
+            val = (sqrt_tol * da) / approx_parabola_integral(param_2);
+        }
+    }
+    return SubdivResult{ val, a0, a2 };
+}
+
+static inline __attribute__((always_inline))
+uint fill_mode_from_flags(thread const uint& flags)
+{
+    return flags & 1u;
+}
+
+static inline __attribute__((always_inline))
+Path Path_read(thread const Alloc& a, thread const PathRef& ref, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1, v_136, v_136BufferSize);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3, v_136, v_136BufferSize);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5, v_136, v_136BufferSize);
+    Path s;
+    s.bbox = uint4(raw0 & 65535u, raw0 >> uint(16), raw1 & 65535u, raw1 >> uint(16));
+    s.tiles = TileRef{ raw2 };
+    return s;
+}
+
+static inline __attribute__((always_inline))
+Alloc new_alloc(thread const uint& offset, thread const uint& size, thread const bool& mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+static inline __attribute__((always_inline))
+float approx_parabola_inv_integral(thread const float& x)
+{
+    return x * sqrt(0.61000001430511474609375 + (0.1520999968051910400390625 + ((0.25 * x) * x)));
+}
+
+static inline __attribute__((always_inline))
+float2 eval_quad(thread const float2& p0, thread const float2& p1, thread const float2& p2, thread const float& t)
+{
+    float mt = 1.0 - t;
+    return (p0 * (mt * mt)) + (((p1 * (mt * 2.0)) + (p2 * t)) * t);
+}
+
+static inline __attribute__((always_inline))
+MallocResult malloc(thread const uint& size, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    uint _142 = atomic_fetch_add_explicit((device atomic_uint*)&v_136.mem_offset, size, memory_order_relaxed);
+    uint offset = _142;
+    MallocResult r;
+    r.failed = (offset + size) > uint(int((v_136BufferSize - 8) / 4) * 4);
+    uint param = offset;
+    uint param_1 = size;
+    bool param_2 = !r.failed;
+    r.alloc = new_alloc(param, param_1, param_2);
+    if (r.failed)
+    {
+        uint _171 = atomic_fetch_max_explicit((device atomic_uint*)&v_136.mem_error, 1u, memory_order_relaxed);
+        return r;
+    }
+    return r;
+}
+
+static inline __attribute__((always_inline))
+TileRef Tile_index(thread const TileRef& ref, thread const uint& index)
+{
+    return TileRef{ ref.offset + (index * 8u) };
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_136.memory[offset] = val;
+}
+
+static inline __attribute__((always_inline))
+void TileSeg_write(thread const Alloc& a, thread const TileSegRef& ref, thread const TileSeg& s, device Memory& v_136, constant uint& v_136BufferSize)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = as_type<uint>(s.origin.x);
+    write_mem(param, param_1, param_2, v_136, v_136BufferSize);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = as_type<uint>(s.origin.y);
+    write_mem(param_3, param_4, param_5, v_136, v_136BufferSize);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = as_type<uint>(s.vector.x);
+    write_mem(param_6, param_7, param_8, v_136, v_136BufferSize);
+    Alloc param_9 = a;
+    uint param_10 = ix + 3u;
+    uint param_11 = as_type<uint>(s.vector.y);
+    write_mem(param_9, param_10, param_11, v_136, v_136BufferSize);
+    Alloc param_12 = a;
+    uint param_13 = ix + 4u;
+    uint param_14 = as_type<uint>(s.y_edge);
+    write_mem(param_12, param_13, param_14, v_136, v_136BufferSize);
+    Alloc param_15 = a;
+    uint param_16 = ix + 5u;
+    uint param_17 = s.next.offset;
+    write_mem(param_15, param_16, param_17, v_136, v_136BufferSize);
+}
+
+kernel void main0(constant uint* spvBufferSizeConstants [[buffer(25)]], device Memory& v_136 [[buffer(0)]], const device ConfigBuf& _710 [[buffer(1)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    constant uint& v_136BufferSize = spvBufferSizeConstants[0];
+    uint element_ix = gl_GlobalInvocationID.x;
+    PathSegRef ref = PathSegRef{ _710.conf.pathseg_alloc.offset + (element_ix * 52u) };
+    PathSegTag tag = PathSegTag{ 0u, 0u };
+    if (element_ix < _710.conf.n_pathseg)
+    {
+        Alloc param;
+        param.offset = _710.conf.pathseg_alloc.offset;
+        PathSegRef param_1 = ref;
+        tag = PathSeg_tag(param, param_1, v_136, v_136BufferSize);
+    }
+    bool mem_ok = v_136.mem_error == 0u;
+    switch (tag.tag)
+    {
+        case 1u:
+        {
+            Alloc param_2;
+            param_2.offset = _710.conf.pathseg_alloc.offset;
+            PathSegRef param_3 = ref;
+            PathCubic cubic = PathSeg_Cubic_read(param_2, param_3, v_136, v_136BufferSize);
+            float2 err_v = (((cubic.p2 - cubic.p1) * 3.0) + cubic.p0) - cubic.p3;
+            float err = (err_v.x * err_v.x) + (err_v.y * err_v.y);
+            uint n_quads = max(uint(ceil(pow(err * 3.7037036418914794921875, 0.16666667163372039794921875))), 1u);
+            n_quads = min(n_quads, 16u);
+            float val = 0.0;
+            float2 qp0 = cubic.p0;
+            float _step = 1.0 / float(n_quads);
+            spvUnsafeArray<SubdivResult, 16> keep_params;
+            for (uint i = 0u; i < n_quads; i++)
+            {
+                float t = float(i + 1u) * _step;
+                float2 param_4 = cubic.p0;
+                float2 param_5 = cubic.p1;
+                float2 param_6 = cubic.p2;
+                float2 param_7 = cubic.p3;
+                float param_8 = t;
+                float2 qp2 = eval_cubic(param_4, param_5, param_6, param_7, param_8);
+                float2 param_9 = cubic.p0;
+                float2 param_10 = cubic.p1;
+                float2 param_11 = cubic.p2;
+                float2 param_12 = cubic.p3;
+                float param_13 = t - (0.5 * _step);
+                float2 qp1 = eval_cubic(param_9, param_10, param_11, param_12, param_13);
+                qp1 = (qp1 * 2.0) - ((qp0 + qp2) * 0.5);
+                float2 param_14 = qp0;
+                float2 param_15 = qp1;
+                float2 param_16 = qp2;
+                float param_17 = 0.4743416607379913330078125;
+                SubdivResult params = estimate_subdiv(param_14, param_15, param_16, param_17);
+                keep_params[i] = params;
+                val += params.val;
+                qp0 = qp2;
+            }
+            uint n = max(uint(ceil((val * 0.5) / 0.4743416607379913330078125)), 1u);
+            uint param_18 = tag.flags;
+            bool is_stroke = fill_mode_from_flags(param_18) == 1u;
+            uint path_ix = cubic.path_ix;
+            Alloc param_19;
+            param_19.offset = _710.conf.tile_alloc.offset;
+            PathRef param_20 = PathRef{ _710.conf.tile_alloc.offset + (path_ix * 12u) };
+            Path path = Path_read(param_19, param_20, v_136, v_136BufferSize);
+            uint param_21 = path.tiles.offset;
+            uint param_22 = ((path.bbox.z - path.bbox.x) * (path.bbox.w - path.bbox.y)) * 8u;
+            bool param_23 = mem_ok;
+            Alloc path_alloc = new_alloc(param_21, param_22, param_23);
+            int4 bbox = int4(path.bbox);
+            float2 p0 = cubic.p0;
+            qp0 = cubic.p0;
+            float v_step = val / float(n);
+            int n_out = 1;
+            float val_sum = 0.0;
+            float2 p1;
+            float _1147;
+            TileSeg tile_seg;
+            for (uint i_1 = 0u; i_1 < n_quads; i_1++)
+            {
+                float t_1 = float(i_1 + 1u) * _step;
+                float2 param_24 = cubic.p0;
+                float2 param_25 = cubic.p1;
+                float2 param_26 = cubic.p2;
+                float2 param_27 = cubic.p3;
+                float param_28 = t_1;
+                float2 qp2_1 = eval_cubic(param_24, param_25, param_26, param_27, param_28);
+                float2 param_29 = cubic.p0;
+                float2 param_30 = cubic.p1;
+                float2 param_31 = cubic.p2;
+                float2 param_32 = cubic.p3;
+                float param_33 = t_1 - (0.5 * _step);
+                float2 qp1_1 = eval_cubic(param_29, param_30, param_31, param_32, param_33);
+                qp1_1 = (qp1_1 * 2.0) - ((qp0 + qp2_1) * 0.5);
+                SubdivResult params_1 = keep_params[i_1];
+                float param_34 = params_1.a0;
+                float u0 = approx_parabola_inv_integral(param_34);
+                float param_35 = params_1.a2;
+                float u2 = approx_parabola_inv_integral(param_35);
+                float uscale = 1.0 / (u2 - u0);
+                float target = float(n_out) * v_step;
+                for (;;)
+                {
+                    bool _1040 = uint(n_out) == n;
+                    bool _1050;
+                    if (!_1040)
+                    {
+                        _1050 = target < (val_sum + params_1.val);
+                    }
+                    else
+                    {
+                        _1050 = _1040;
+                    }
+                    if (_1050)
+                    {
+                        if (uint(n_out) == n)
+                        {
+                            p1 = cubic.p3;
+                        }
+                        else
+                        {
+                            float u = (target - val_sum) / params_1.val;
+                            float a = mix(params_1.a0, params_1.a2, u);
+                            float param_36 = a;
+                            float au = approx_parabola_inv_integral(param_36);
+                            float t_2 = (au - u0) * uscale;
+                            float2 param_37 = qp0;
+                            float2 param_38 = qp1_1;
+                            float2 param_39 = qp2_1;
+                            float param_40 = t_2;
+                            p1 = eval_quad(param_37, param_38, param_39, param_40);
+                        }
+                        float xmin = fast::min(p0.x, p1.x) - cubic.stroke.x;
+                        float xmax = fast::max(p0.x, p1.x) + cubic.stroke.x;
+                        float ymin = fast::min(p0.y, p1.y) - cubic.stroke.y;
+                        float ymax = fast::max(p0.y, p1.y) + cubic.stroke.y;
+                        float dx = p1.x - p0.x;
+                        float dy = p1.y - p0.y;
+                        if (abs(dy) < 9.999999717180685365747194737196e-10)
+                        {
+                            _1147 = 1000000000.0;
+                        }
+                        else
+                        {
+                            _1147 = dx / dy;
+                        }
+                        float invslope = _1147;
+                        float c = (cubic.stroke.x + (abs(invslope) * (8.0 + cubic.stroke.y))) * 0.0625;
+                        float b = invslope;
+                        float a_1 = (p0.x - ((p0.y - 8.0) * b)) * 0.0625;
+                        int x0 = int(floor(xmin * 0.0625));
+                        int x1 = int(floor(xmax * 0.0625) + 1.0);
+                        int y0 = int(floor(ymin * 0.0625));
+                        int y1 = int(floor(ymax * 0.0625) + 1.0);
+                        x0 = clamp(x0, bbox.x, bbox.z);
+                        y0 = clamp(y0, bbox.y, bbox.w);
+                        x1 = clamp(x1, bbox.x, bbox.z);
+                        y1 = clamp(y1, bbox.y, bbox.w);
+                        float xc = a_1 + (b * float(y0));
+                        int stride = bbox.z - bbox.x;
+                        int base = ((y0 - bbox.y) * stride) - bbox.x;
+                        uint n_tile_alloc = uint((x1 - x0) * (y1 - y0));
+                        uint param_41 = n_tile_alloc * 24u;
+                        MallocResult _1263 = malloc(param_41, v_136, v_136BufferSize);
+                        MallocResult tile_alloc = _1263;
+                        if (tile_alloc.failed || (!mem_ok))
+                        {
+                            return;
+                        }
+                        uint tile_offset = tile_alloc.alloc.offset;
+                        int xray = int(floor(p0.x * 0.0625));
+                        int last_xray = int(floor(p1.x * 0.0625));
+                        if (p0.y > p1.y)
+                        {
+                            int tmp = xray;
+                            xray = last_xray;
+                            last_xray = tmp;
+                        }
+                        for (int y = y0; y < y1; y++)
+                        {
+                            float tile_y0 = float(y * 16);
+                            int xbackdrop = max((xray + 1), bbox.x);
+                            bool _1319 = !is_stroke;
+                            bool _1329;
+                            if (_1319)
+                            {
+                                _1329 = fast::min(p0.y, p1.y) < tile_y0;
+                            }
+                            else
+                            {
+                                _1329 = _1319;
+                            }
+                            bool _1336;
+                            if (_1329)
+                            {
+                                _1336 = xbackdrop < bbox.z;
+                            }
+                            else
+                            {
+                                _1336 = _1329;
+                            }
+                            if (_1336)
+                            {
+                                int backdrop = (p1.y < p0.y) ? 1 : (-1);
+                                TileRef param_42 = path.tiles;
+                                uint param_43 = uint(base + xbackdrop);
+                                TileRef tile_ref = Tile_index(param_42, param_43);
+                                uint tile_el = tile_ref.offset >> uint(2);
+                                Alloc param_44 = path_alloc;
+                                uint param_45 = tile_el + 1u;
+                                if (touch_mem(param_44, param_45))
+                                {
+                                    uint _1374 = atomic_fetch_add_explicit((device atomic_uint*)&v_136.memory[tile_el + 1u], uint(backdrop), memory_order_relaxed);
+                                }
+                            }
+                            int next_xray = last_xray;
+                            if (y < (y1 - 1))
+                            {
+                                float tile_y1 = float((y + 1) * 16);
+                                float x_edge = mix(p0.x, p1.x, (tile_y1 - p0.y) / dy);
+                                next_xray = int(floor(x_edge * 0.0625));
+                            }
+                            int min_xray = min(xray, next_xray);
+                            int max_xray = max(xray, next_xray);
+                            int xx0 = min(int(floor(xc - c)), min_xray);
+                            int xx1 = max(int(ceil(xc + c)), (max_xray + 1));
+                            xx0 = clamp(xx0, x0, x1);
+                            xx1 = clamp(xx1, x0, x1);
+                            for (int x = xx0; x < xx1; x++)
+                            {
+                                float tile_x0 = float(x * 16);
+                                TileRef param_46 = TileRef{ path.tiles.offset };
+                                uint param_47 = uint(base + x);
+                                TileRef tile_ref_1 = Tile_index(param_46, param_47);
+                                uint tile_el_1 = tile_ref_1.offset >> uint(2);
+                                uint old = 0u;
+                                Alloc param_48 = path_alloc;
+                                uint param_49 = tile_el_1;
+                                if (touch_mem(param_48, param_49))
+                                {
+                                    uint _1477 = atomic_exchange_explicit((device atomic_uint*)&v_136.memory[tile_el_1], tile_offset, memory_order_relaxed);
+                                    old = _1477;
+                                }
+                                tile_seg.origin = p0;
+                                tile_seg.vector = p1 - p0;
+                                float y_edge = 0.0;
+                                if (!is_stroke)
+                                {
+                                    y_edge = mix(p0.y, p1.y, (tile_x0 - p0.x) / dx);
+                                    if (fast::min(p0.x, p1.x) < tile_x0)
+                                    {
+                                        float2 p = float2(tile_x0, y_edge);
+                                        if (p0.x > p1.x)
+                                        {
+                                            tile_seg.vector = p - p0;
+                                        }
+                                        else
+                                        {
+                                            tile_seg.origin = p;
+                                            tile_seg.vector = p1 - p;
+                                        }
+                                        if (tile_seg.vector.x == 0.0)
+                                        {
+                                            tile_seg.vector.x = sign(p1.x - p0.x) * 9.999999717180685365747194737196e-10;
+                                        }
+                                    }
+                                    if ((x <= min_xray) || (max_xray < x))
+                                    {
+                                        y_edge = 1000000000.0;
+                                    }
+                                }
+                                tile_seg.y_edge = y_edge;
+                                tile_seg.next.offset = old;
+                                Alloc param_50 = tile_alloc.alloc;
+                                TileSegRef param_51 = TileSegRef{ tile_offset };
+                                TileSeg param_52 = tile_seg;
+                                TileSeg_write(param_50, param_51, param_52, v_136, v_136BufferSize);
+                                tile_offset += 24u;
+                            }
+                            xc += b;
+                            base += stride;
+                            xray = next_xray;
+                        }
+                        n_out++;
+                        target += v_step;
+                        p0 = p1;
+                        continue;
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+                val_sum += params_1.val;
+                qp0 = qp2_1;
+            }
+            break;
+        }
+    }
+}
+

piet-gpu/shader/gen/pathseg.hlsl

@@ -0,0 +1,661 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct TagMonoid
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct TransformSegRef
+{
+    uint offset;
+};
+
+struct TransformSeg
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct PathCubicRef
+{
+    uint offset;
+};
+
+struct PathCubic
+{
+    float2 p0;
+    float2 p1;
+    float2 p2;
+    float2 p3;
+    uint path_ix;
+    uint trans_ix;
+    float2 stroke;
+};
+
+struct PathSegRef
+{
+    uint offset;
+};
+
+struct Monoid
+{
+    float4 bbox;
+    uint flags;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const TagMonoid _135 = { 0u, 0u, 0u, 0u, 0u };
+static const Monoid _567 = { 0.0f.xxxx, 0u };
+
+RWByteAddressBuffer _111 : register(u0, space0);
+ByteAddressBuffer _574 : register(t2, space0);
+ByteAddressBuffer _639 : register(t1, space0);
+ByteAddressBuffer _710 : register(t3, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared TagMonoid sh_tag[256];
+groupshared Monoid sh_scratch[256];
+
+TagMonoid reduce_tag(uint tag_word)
+{
+    uint point_count = tag_word & 50529027u;
+    TagMonoid c;
+    c.pathseg_ix = uint(int(countbits((point_count * 7u) & 67372036u)));
+    c.linewidth_ix = uint(int(countbits(tag_word & 1077952576u)));
+    c.path_ix = uint(int(countbits(tag_word & 269488144u)));
+    c.trans_ix = uint(int(countbits(tag_word & 538976288u)));
+    uint n_points = point_count + ((tag_word >> uint(2)) & 16843009u);
+    uint a = n_points + (n_points & (((tag_word >> uint(3)) & 16843009u) * 15u));
+    a += (a >> uint(8));
+    a += (a >> uint(16));
+    c.pathseg_offset = a & 255u;
+    return c;
+}
+
+TagMonoid combine_tag_monoid(TagMonoid a, TagMonoid b)
+{
+    TagMonoid c;
+    c.trans_ix = a.trans_ix + b.trans_ix;
+    c.linewidth_ix = a.linewidth_ix + b.linewidth_ix;
+    c.pathseg_ix = a.pathseg_ix + b.pathseg_ix;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.pathseg_offset = a.pathseg_offset + b.pathseg_offset;
+    return c;
+}
+
+TagMonoid tag_monoid_identity()
+{
+    return _135;
+}
+
+float2 read_f32_point(uint ix)
+{
+    float x = asfloat(_574.Load(ix * 4 + 0));
+    float y = asfloat(_574.Load((ix + 1u) * 4 + 0));
+    return float2(x, y);
+}
+
+float2 read_i16_point(uint ix)
+{
+    uint raw = _574.Load(ix * 4 + 0);
+    float x = float(int(raw << uint(16)) >> 16);
+    float y = float(int(raw) >> 16);
+    return float2(x, y);
+}
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+uint read_mem(Alloc alloc, uint offset)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = _111.Load(offset * 4 + 8);
+    return v;
+}
+
+TransformSeg TransformSeg_read(Alloc a, TransformSegRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5);
+    Alloc param_6 = a;
+    uint param_7 = ix + 3u;
+    uint raw3 = read_mem(param_6, param_7);
+    Alloc param_8 = a;
+    uint param_9 = ix + 4u;
+    uint raw4 = read_mem(param_8, param_9);
+    Alloc param_10 = a;
+    uint param_11 = ix + 5u;
+    uint raw5 = read_mem(param_10, param_11);
+    TransformSeg s;
+    s.mat = float4(asfloat(raw0), asfloat(raw1), asfloat(raw2), asfloat(raw3));
+    s.translate = float2(asfloat(raw4), asfloat(raw5));
+    return s;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _111.Store(offset * 4 + 8, val);
+}
+
+void PathCubic_write(Alloc a, PathCubicRef ref, PathCubic s)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = asuint(s.p0.x);
+    write_mem(param, param_1, param_2);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = asuint(s.p0.y);
+    write_mem(param_3, param_4, param_5);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = asuint(s.p1.x);
+    write_mem(param_6, param_7, param_8);
+    Alloc param_9 = a;
+    uint param_10 = ix + 3u;
+    uint param_11 = asuint(s.p1.y);
+    write_mem(param_9, param_10, param_11);
+    Alloc param_12 = a;
+    uint param_13 = ix + 4u;
+    uint param_14 = asuint(s.p2.x);
+    write_mem(param_12, param_13, param_14);
+    Alloc param_15 = a;
+    uint param_16 = ix + 5u;
+    uint param_17 = asuint(s.p2.y);
+    write_mem(param_15, param_16, param_17);
+    Alloc param_18 = a;
+    uint param_19 = ix + 6u;
+    uint param_20 = asuint(s.p3.x);
+    write_mem(param_18, param_19, param_20);
+    Alloc param_21 = a;
+    uint param_22 = ix + 7u;
+    uint param_23 = asuint(s.p3.y);
+    write_mem(param_21, param_22, param_23);
+    Alloc param_24 = a;
+    uint param_25 = ix + 8u;
+    uint param_26 = s.path_ix;
+    write_mem(param_24, param_25, param_26);
+    Alloc param_27 = a;
+    uint param_28 = ix + 9u;
+    uint param_29 = s.trans_ix;
+    write_mem(param_27, param_28, param_29);
+    Alloc param_30 = a;
+    uint param_31 = ix + 10u;
+    uint param_32 = asuint(s.stroke.x);
+    write_mem(param_30, param_31, param_32);
+    Alloc param_33 = a;
+    uint param_34 = ix + 11u;
+    uint param_35 = asuint(s.stroke.y);
+    write_mem(param_33, param_34, param_35);
+}
+
+void PathSeg_Cubic_write(Alloc a, PathSegRef ref, uint flags, PathCubic s)
+{
+    Alloc param = a;
+    uint param_1 = ref.offset >> uint(2);
+    uint param_2 = (flags << uint(16)) | 1u;
+    write_mem(param, param_1, param_2);
+    PathCubicRef _458 = { ref.offset + 4u };
+    Alloc param_3 = a;
+    PathCubicRef param_4 = _458;
+    PathCubic param_5 = s;
+    PathCubic_write(param_3, param_4, param_5);
+}
+
+Monoid combine_monoid(Monoid a, Monoid b)
+{
+    Monoid c;
+    c.bbox = b.bbox;
+    bool _472 = (a.flags & 1u) == 0u;
+    bool _480;
+    if (_472)
+    {
+        _480 = b.bbox.z <= b.bbox.x;
+    }
+    else
+    {
+        _480 = _472;
+    }
+    bool _488;
+    if (_480)
+    {
+        _488 = b.bbox.w <= b.bbox.y;
+    }
+    else
+    {
+        _488 = _480;
+    }
+    if (_488)
+    {
+        c.bbox = a.bbox;
+    }
+    else
+    {
+        bool _498 = (a.flags & 1u) == 0u;
+        bool _505;
+        if (_498)
+        {
+            _505 = (b.flags & 2u) == 0u;
+        }
+        else
+        {
+            _505 = _498;
+        }
+        bool _522;
+        if (_505)
+        {
+            bool _512 = a.bbox.z > a.bbox.x;
+            bool _521;
+            if (!_512)
+            {
+                _521 = a.bbox.w > a.bbox.y;
+            }
+            else
+            {
+                _521 = _512;
+            }
+            _522 = _521;
+        }
+        else
+        {
+            _522 = _505;
+        }
+        if (_522)
+        {
+            float4 _529 = c.bbox;
+            float2 _531 = min(a.bbox.xy, _529.xy);
+            c.bbox.x = _531.x;
+            c.bbox.y = _531.y;
+            float4 _540 = c.bbox;
+            float2 _542 = max(a.bbox.zw, _540.zw);
+            c.bbox.z = _542.x;
+            c.bbox.w = _542.y;
+        }
+    }
+    c.flags = (a.flags & 2u) | b.flags;
+    c.flags |= ((a.flags & 1u) << uint(1));
+    return c;
+}
+
+Monoid monoid_identity()
+{
+    return _567;
+}
+
+uint round_down(float x)
+{
+    return uint(max(0.0f, floor(x) + 32768.0f));
+}
+
+uint round_up(float x)
+{
+    return uint(min(65535.0f, ceil(x) + 32768.0f));
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 4u;
+    uint tag_word = _574.Load(((_639.Load(92) >> uint(2)) + (ix >> uint(2))) * 4 + 0);
+    uint param = tag_word;
+    TagMonoid local_tm = reduce_tag(param);
+    sh_tag[gl_LocalInvocationID.x] = local_tm;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i))
+        {
+            TagMonoid other = sh_tag[gl_LocalInvocationID.x - (1u << i)];
+            TagMonoid param_1 = other;
+            TagMonoid param_2 = local_tm;
+            local_tm = combine_tag_monoid(param_1, param_2);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_tag[gl_LocalInvocationID.x] = local_tm;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    TagMonoid tm = tag_monoid_identity();
+    if (gl_WorkGroupID.x > 0u)
+    {
+        TagMonoid _716;
+        _716.trans_ix = _710.Load((gl_WorkGroupID.x - 1u) * 20 + 0);
+        _716.linewidth_ix = _710.Load((gl_WorkGroupID.x - 1u) * 20 + 4);
+        _716.pathseg_ix = _710.Load((gl_WorkGroupID.x - 1u) * 20 + 8);
+        _716.path_ix = _710.Load((gl_WorkGroupID.x - 1u) * 20 + 12);
+        _716.pathseg_offset = _710.Load((gl_WorkGroupID.x - 1u) * 20 + 16);
+        tm.trans_ix = _716.trans_ix;
+        tm.linewidth_ix = _716.linewidth_ix;
+        tm.pathseg_ix = _716.pathseg_ix;
+        tm.path_ix = _716.path_ix;
+        tm.pathseg_offset = _716.pathseg_offset;
+    }
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        TagMonoid param_3 = tm;
+        TagMonoid param_4 = sh_tag[gl_LocalInvocationID.x - 1u];
+        tm = combine_tag_monoid(param_3, param_4);
+    }
+    uint ps_ix = (_639.Load(96) >> uint(2)) + tm.pathseg_offset;
+    uint lw_ix = (_639.Load(88) >> uint(2)) + tm.linewidth_ix;
+    uint save_path_ix = tm.path_ix;
+    uint trans_ix = tm.trans_ix;
+    TransformSegRef _771 = { _639.Load(36) + (trans_ix * 24u) };
+    TransformSegRef trans_ref = _771;
+    PathSegRef _781 = { _639.Load(28) + (tm.pathseg_ix * 52u) };
+    PathSegRef ps_ref = _781;
+    float linewidth[4];
+    uint save_trans_ix[4];
+    float2 p0;
+    float2 p1;
+    float2 p2;
+    float2 p3;
+    Alloc param_13;
+    Monoid local[4];
+    PathCubic cubic;
+    Alloc param_15;
+    for (uint i_1 = 0u; i_1 < 4u; i_1++)
+    {
+        linewidth[i_1] = asfloat(_574.Load(lw_ix * 4 + 0));
+        save_trans_ix[i_1] = trans_ix;
+        uint tag_byte = tag_word >> (i_1 * 8u);
+        uint seg_type = tag_byte & 3u;
+        if (seg_type != 0u)
+        {
+            if ((tag_byte & 8u) != 0u)
+            {
+                uint param_5 = ps_ix;
+                p0 = read_f32_point(param_5);
+                uint param_6 = ps_ix + 2u;
+                p1 = read_f32_point(param_6);
+                if (seg_type >= 2u)
+                {
+                    uint param_7 = ps_ix + 4u;
+                    p2 = read_f32_point(param_7);
+                    if (seg_type == 3u)
+                    {
+                        uint param_8 = ps_ix + 6u;
+                        p3 = read_f32_point(param_8);
+                    }
+                }
+            }
+            else
+            {
+                uint param_9 = ps_ix;
+                p0 = read_i16_point(param_9);
+                uint param_10 = ps_ix + 1u;
+                p1 = read_i16_point(param_10);
+                if (seg_type >= 2u)
+                {
+                    uint param_11 = ps_ix + 2u;
+                    p2 = read_i16_point(param_11);
+                    if (seg_type == 3u)
+                    {
+                        uint param_12 = ps_ix + 3u;
+                        p3 = read_i16_point(param_12);
+                    }
+                }
+            }
+            Alloc _877;
+            _877.offset = _639.Load(36);
+            param_13.offset = _877.offset;
+            TransformSegRef param_14 = trans_ref;
+            TransformSeg transform = TransformSeg_read(param_13, param_14);
+            p0 = ((transform.mat.xy * p0.x) + (transform.mat.zw * p0.y)) + transform.translate;
+            p1 = ((transform.mat.xy * p1.x) + (transform.mat.zw * p1.y)) + transform.translate;
+            float4 bbox = float4(min(p0, p1), max(p0, p1));
+            if (seg_type >= 2u)
+            {
+                p2 = ((transform.mat.xy * p2.x) + (transform.mat.zw * p2.y)) + transform.translate;
+                float4 _947 = bbox;
+                float2 _950 = min(_947.xy, p2);
+                bbox.x = _950.x;
+                bbox.y = _950.y;
+                float4 _955 = bbox;
+                float2 _958 = max(_955.zw, p2);
+                bbox.z = _958.x;
+                bbox.w = _958.y;
+                if (seg_type == 3u)
+                {
+                    p3 = ((transform.mat.xy * p3.x) + (transform.mat.zw * p3.y)) + transform.translate;
+                    float4 _983 = bbox;
+                    float2 _986 = min(_983.xy, p3);
+                    bbox.x = _986.x;
+                    bbox.y = _986.y;
+                    float4 _991 = bbox;
+                    float2 _994 = max(_991.zw, p3);
+                    bbox.z = _994.x;
+                    bbox.w = _994.y;
+                }
+                else
+                {
+                    p3 = p2;
+                    p2 = lerp(p1, p2, 0.3333333432674407958984375f.xx);
+                    p1 = lerp(p1, p0, 0.3333333432674407958984375f.xx);
+                }
+            }
+            else
+            {
+                p3 = p1;
+                p2 = lerp(p3, p0, 0.3333333432674407958984375f.xx);
+                p1 = lerp(p0, p3, 0.3333333432674407958984375f.xx);
+            }
+            float2 stroke = 0.0f.xx;
+            if (linewidth[i_1] >= 0.0f)
+            {
+                stroke = float2(length(transform.mat.xz), length(transform.mat.yw)) * (0.5f * linewidth[i_1]);
+                bbox += float4(-stroke, stroke);
+            }
+            local[i_1].bbox = bbox;
+            local[i_1].flags = 0u;
+            cubic.p0 = p0;
+            cubic.p1 = p1;
+            cubic.p2 = p2;
+            cubic.p3 = p3;
+            cubic.path_ix = tm.path_ix;
+            cubic.trans_ix = (gl_GlobalInvocationID.x * 4u) + i_1;
+            cubic.stroke = stroke;
+            uint fill_mode = uint(linewidth[i_1] >= 0.0f);
+            Alloc _1089;
+            _1089.offset = _639.Load(28);
+            param_15.offset = _1089.offset;
+            PathSegRef param_16 = ps_ref;
+            uint param_17 = fill_mode;
+            PathCubic param_18 = cubic;
+            PathSeg_Cubic_write(param_15, param_16, param_17, param_18);
+            ps_ref.offset += 52u;
+            uint n_points = (tag_byte & 3u) + ((tag_byte >> uint(2)) & 1u);
+            uint n_words = n_points + (n_points & (((tag_byte >> uint(3)) & 1u) * 15u));
+            ps_ix += n_words;
+        }
+        else
+        {
+            local[i_1].bbox = 0.0f.xxxx;
+            uint is_path = (tag_byte >> uint(4)) & 1u;
+            local[i_1].flags = is_path;
+            tm.path_ix += is_path;
+            trans_ix += ((tag_byte >> uint(5)) & 1u);
+            trans_ref.offset += (((tag_byte >> uint(5)) & 1u) * 24u);
+            lw_ix += ((tag_byte >> uint(6)) & 1u);
+        }
+    }
+    Monoid agg = local[0];
+    for (uint i_2 = 1u; i_2 < 4u; i_2++)
+    {
+        Monoid param_19 = agg;
+        Monoid param_20 = local[i_2];
+        agg = combine_monoid(param_19, param_20);
+        local[i_2] = agg;
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_3 = 0u; i_3 < 8u; i_3++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_3))
+        {
+            Monoid other_1 = sh_scratch[gl_LocalInvocationID.x - (1u << i_3)];
+            Monoid param_21 = other_1;
+            Monoid param_22 = agg;
+            agg = combine_monoid(param_21, param_22);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint path_ix = save_path_ix;
+    uint bbox_out_ix = (_639.Load(40) >> uint(2)) + (path_ix * 6u);
+    Monoid row = monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_4 = 0u; i_4 < 4u; i_4++)
+    {
+        Monoid param_23 = row;
+        Monoid param_24 = local[i_4];
+        Monoid m = combine_monoid(param_23, param_24);
+        bool do_atomic = false;
+        bool _1264 = i_4 == 3u;
+        bool _1270;
+        if (_1264)
+        {
+            _1270 = gl_LocalInvocationID.x == 255u;
+        }
+        else
+        {
+            _1270 = _1264;
+        }
+        if (_1270)
+        {
+            do_atomic = true;
+        }
+        if ((m.flags & 1u) != 0u)
+        {
+            _111.Store((bbox_out_ix + 4u) * 4 + 8, asuint(linewidth[i_4]));
+            _111.Store((bbox_out_ix + 5u) * 4 + 8, save_trans_ix[i_4]);
+            if ((m.flags & 2u) == 0u)
+            {
+                do_atomic = true;
+            }
+            else
+            {
+                float param_25 = m.bbox.x;
+                _111.Store(bbox_out_ix * 4 + 8, round_down(param_25));
+                float param_26 = m.bbox.y;
+                _111.Store((bbox_out_ix + 1u) * 4 + 8, round_down(param_26));
+                float param_27 = m.bbox.z;
+                _111.Store((bbox_out_ix + 2u) * 4 + 8, round_up(param_27));
+                float param_28 = m.bbox.w;
+                _111.Store((bbox_out_ix + 3u) * 4 + 8, round_up(param_28));
+                bbox_out_ix += 6u;
+                do_atomic = false;
+            }
+        }
+        if (do_atomic)
+        {
+            bool _1335 = m.bbox.z > m.bbox.x;
+            bool _1344;
+            if (!_1335)
+            {
+                _1344 = m.bbox.w > m.bbox.y;
+            }
+            else
+            {
+                _1344 = _1335;
+            }
+            if (_1344)
+            {
+                float param_29 = m.bbox.x;
+                uint _1353;
+                _111.InterlockedMin(bbox_out_ix * 4 + 8, round_down(param_29), _1353);
+                float param_30 = m.bbox.y;
+                uint _1361;
+                _111.InterlockedMin((bbox_out_ix + 1u) * 4 + 8, round_down(param_30), _1361);
+                float param_31 = m.bbox.z;
+                uint _1369;
+                _111.InterlockedMax((bbox_out_ix + 2u) * 4 + 8, round_up(param_31), _1369);
+                float param_32 = m.bbox.w;
+                uint _1377;
+                _111.InterlockedMax((bbox_out_ix + 3u) * 4 + 8, round_up(param_32), _1377);
+            }
+            bbox_out_ix += 6u;
+        }
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/pathseg.msl

@@ -0,0 +1,717 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_atomic>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct TagMonoid
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct TransformSegRef
+{
+    uint offset;
+};
+
+struct TransformSeg
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct PathCubicRef
+{
+    uint offset;
+};
+
+struct PathCubic
+{
+    float2 p0;
+    float2 p1;
+    float2 p2;
+    float2 p3;
+    uint path_ix;
+    uint trans_ix;
+    float2 stroke;
+};
+
+struct PathSegRef
+{
+    uint offset;
+};
+
+struct Monoid
+{
+    float4 bbox;
+    uint flags;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct TagMonoid_1
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct ParentBuf
+{
+    TagMonoid_1 parent[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+TagMonoid reduce_tag(thread const uint& tag_word)
+{
+    uint point_count = tag_word & 50529027u;
+    TagMonoid c;
+    c.pathseg_ix = uint(int(popcount((point_count * 7u) & 67372036u)));
+    c.linewidth_ix = uint(int(popcount(tag_word & 1077952576u)));
+    c.path_ix = uint(int(popcount(tag_word & 269488144u)));
+    c.trans_ix = uint(int(popcount(tag_word & 538976288u)));
+    uint n_points = point_count + ((tag_word >> uint(2)) & 16843009u);
+    uint a = n_points + (n_points & (((tag_word >> uint(3)) & 16843009u) * 15u));
+    a += (a >> uint(8));
+    a += (a >> uint(16));
+    c.pathseg_offset = a & 255u;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+TagMonoid combine_tag_monoid(thread const TagMonoid& a, thread const TagMonoid& b)
+{
+    TagMonoid c;
+    c.trans_ix = a.trans_ix + b.trans_ix;
+    c.linewidth_ix = a.linewidth_ix + b.linewidth_ix;
+    c.pathseg_ix = a.pathseg_ix + b.pathseg_ix;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.pathseg_offset = a.pathseg_offset + b.pathseg_offset;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+TagMonoid tag_monoid_identity()
+{
+    return TagMonoid{ 0u, 0u, 0u, 0u, 0u };
+}
+
+static inline __attribute__((always_inline))
+float2 read_f32_point(thread const uint& ix, const device SceneBuf& v_574)
+{
+    float x = as_type<float>(v_574.scene[ix]);
+    float y = as_type<float>(v_574.scene[ix + 1u]);
+    return float2(x, y);
+}
+
+static inline __attribute__((always_inline))
+float2 read_i16_point(thread const uint& ix, const device SceneBuf& v_574)
+{
+    uint raw = v_574.scene[ix];
+    float x = float(int(raw << uint(16)) >> 16);
+    float y = float(int(raw) >> 16);
+    return float2(x, y);
+}
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+uint read_mem(thread const Alloc& alloc, thread const uint& offset, device Memory& v_111)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return 0u;
+    }
+    uint v = v_111.memory[offset];
+    return v;
+}
+
+static inline __attribute__((always_inline))
+TransformSeg TransformSeg_read(thread const Alloc& a, thread const TransformSegRef& ref, device Memory& v_111)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint raw0 = read_mem(param, param_1, v_111);
+    Alloc param_2 = a;
+    uint param_3 = ix + 1u;
+    uint raw1 = read_mem(param_2, param_3, v_111);
+    Alloc param_4 = a;
+    uint param_5 = ix + 2u;
+    uint raw2 = read_mem(param_4, param_5, v_111);
+    Alloc param_6 = a;
+    uint param_7 = ix + 3u;
+    uint raw3 = read_mem(param_6, param_7, v_111);
+    Alloc param_8 = a;
+    uint param_9 = ix + 4u;
+    uint raw4 = read_mem(param_8, param_9, v_111);
+    Alloc param_10 = a;
+    uint param_11 = ix + 5u;
+    uint raw5 = read_mem(param_10, param_11, v_111);
+    TransformSeg s;
+    s.mat = float4(as_type<float>(raw0), as_type<float>(raw1), as_type<float>(raw2), as_type<float>(raw3));
+    s.translate = float2(as_type<float>(raw4), as_type<float>(raw5));
+    return s;
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_111)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_111.memory[offset] = val;
+}
+
+static inline __attribute__((always_inline))
+void PathCubic_write(thread const Alloc& a, thread const PathCubicRef& ref, thread const PathCubic& s, device Memory& v_111)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = as_type<uint>(s.p0.x);
+    write_mem(param, param_1, param_2, v_111);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = as_type<uint>(s.p0.y);
+    write_mem(param_3, param_4, param_5, v_111);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = as_type<uint>(s.p1.x);
+    write_mem(param_6, param_7, param_8, v_111);
+    Alloc param_9 = a;
+    uint param_10 = ix + 3u;
+    uint param_11 = as_type<uint>(s.p1.y);
+    write_mem(param_9, param_10, param_11, v_111);
+    Alloc param_12 = a;
+    uint param_13 = ix + 4u;
+    uint param_14 = as_type<uint>(s.p2.x);
+    write_mem(param_12, param_13, param_14, v_111);
+    Alloc param_15 = a;
+    uint param_16 = ix + 5u;
+    uint param_17 = as_type<uint>(s.p2.y);
+    write_mem(param_15, param_16, param_17, v_111);
+    Alloc param_18 = a;
+    uint param_19 = ix + 6u;
+    uint param_20 = as_type<uint>(s.p3.x);
+    write_mem(param_18, param_19, param_20, v_111);
+    Alloc param_21 = a;
+    uint param_22 = ix + 7u;
+    uint param_23 = as_type<uint>(s.p3.y);
+    write_mem(param_21, param_22, param_23, v_111);
+    Alloc param_24 = a;
+    uint param_25 = ix + 8u;
+    uint param_26 = s.path_ix;
+    write_mem(param_24, param_25, param_26, v_111);
+    Alloc param_27 = a;
+    uint param_28 = ix + 9u;
+    uint param_29 = s.trans_ix;
+    write_mem(param_27, param_28, param_29, v_111);
+    Alloc param_30 = a;
+    uint param_31 = ix + 10u;
+    uint param_32 = as_type<uint>(s.stroke.x);
+    write_mem(param_30, param_31, param_32, v_111);
+    Alloc param_33 = a;
+    uint param_34 = ix + 11u;
+    uint param_35 = as_type<uint>(s.stroke.y);
+    write_mem(param_33, param_34, param_35, v_111);
+}
+
+static inline __attribute__((always_inline))
+void PathSeg_Cubic_write(thread const Alloc& a, thread const PathSegRef& ref, thread const uint& flags, thread const PathCubic& s, device Memory& v_111)
+{
+    Alloc param = a;
+    uint param_1 = ref.offset >> uint(2);
+    uint param_2 = (flags << uint(16)) | 1u;
+    write_mem(param, param_1, param_2, v_111);
+    Alloc param_3 = a;
+    PathCubicRef param_4 = PathCubicRef{ ref.offset + 4u };
+    PathCubic param_5 = s;
+    PathCubic_write(param_3, param_4, param_5, v_111);
+}
+
+static inline __attribute__((always_inline))
+Monoid combine_monoid(thread const Monoid& a, thread const Monoid& b)
+{
+    Monoid c;
+    c.bbox = b.bbox;
+    bool _472 = (a.flags & 1u) == 0u;
+    bool _480;
+    if (_472)
+    {
+        _480 = b.bbox.z <= b.bbox.x;
+    }
+    else
+    {
+        _480 = _472;
+    }
+    bool _488;
+    if (_480)
+    {
+        _488 = b.bbox.w <= b.bbox.y;
+    }
+    else
+    {
+        _488 = _480;
+    }
+    if (_488)
+    {
+        c.bbox = a.bbox;
+    }
+    else
+    {
+        bool _498 = (a.flags & 1u) == 0u;
+        bool _505;
+        if (_498)
+        {
+            _505 = (b.flags & 2u) == 0u;
+        }
+        else
+        {
+            _505 = _498;
+        }
+        bool _522;
+        if (_505)
+        {
+            bool _512 = a.bbox.z > a.bbox.x;
+            bool _521;
+            if (!_512)
+            {
+                _521 = a.bbox.w > a.bbox.y;
+            }
+            else
+            {
+                _521 = _512;
+            }
+            _522 = _521;
+        }
+        else
+        {
+            _522 = _505;
+        }
+        if (_522)
+        {
+            float4 _529 = c.bbox;
+            float2 _531 = fast::min(a.bbox.xy, _529.xy);
+            c.bbox.x = _531.x;
+            c.bbox.y = _531.y;
+            float4 _540 = c.bbox;
+            float2 _542 = fast::max(a.bbox.zw, _540.zw);
+            c.bbox.z = _542.x;
+            c.bbox.w = _542.y;
+        }
+    }
+    c.flags = (a.flags & 2u) | b.flags;
+    c.flags |= ((a.flags & 1u) << uint(1));
+    return c;
+}
+
+static inline __attribute__((always_inline))
+Monoid monoid_identity()
+{
+    return Monoid{ float4(0.0), 0u };
+}
+
+static inline __attribute__((always_inline))
+uint round_down(thread const float& x)
+{
+    return uint(fast::max(0.0, floor(x) + 32768.0));
+}
+
+static inline __attribute__((always_inline))
+uint round_up(thread const float& x)
+{
+    return uint(fast::min(65535.0, ceil(x) + 32768.0));
+}
+
+kernel void main0(device Memory& v_111 [[buffer(0)]], const device ConfigBuf& _639 [[buffer(1)]], const device SceneBuf& v_574 [[buffer(2)]], const device ParentBuf& _710 [[buffer(3)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup TagMonoid sh_tag[256];
+    threadgroup Monoid sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 4u;
+    uint tag_word = v_574.scene[(_639.conf.pathtag_offset >> uint(2)) + (ix >> uint(2))];
+    uint param = tag_word;
+    TagMonoid local_tm = reduce_tag(param);
+    sh_tag[gl_LocalInvocationID.x] = local_tm;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i))
+        {
+            TagMonoid other = sh_tag[gl_LocalInvocationID.x - (1u << i)];
+            TagMonoid param_1 = other;
+            TagMonoid param_2 = local_tm;
+            local_tm = combine_tag_monoid(param_1, param_2);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_tag[gl_LocalInvocationID.x] = local_tm;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    TagMonoid tm = tag_monoid_identity();
+    if (gl_WorkGroupID.x > 0u)
+    {
+        uint _713 = gl_WorkGroupID.x - 1u;
+        tm.trans_ix = _710.parent[_713].trans_ix;
+        tm.linewidth_ix = _710.parent[_713].linewidth_ix;
+        tm.pathseg_ix = _710.parent[_713].pathseg_ix;
+        tm.path_ix = _710.parent[_713].path_ix;
+        tm.pathseg_offset = _710.parent[_713].pathseg_offset;
+    }
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        TagMonoid param_3 = tm;
+        TagMonoid param_4 = sh_tag[gl_LocalInvocationID.x - 1u];
+        tm = combine_tag_monoid(param_3, param_4);
+    }
+    uint ps_ix = (_639.conf.pathseg_offset >> uint(2)) + tm.pathseg_offset;
+    uint lw_ix = (_639.conf.linewidth_offset >> uint(2)) + tm.linewidth_ix;
+    uint save_path_ix = tm.path_ix;
+    uint trans_ix = tm.trans_ix;
+    TransformSegRef trans_ref = TransformSegRef{ _639.conf.trans_alloc.offset + (trans_ix * 24u) };
+    PathSegRef ps_ref = PathSegRef{ _639.conf.pathseg_alloc.offset + (tm.pathseg_ix * 52u) };
+    spvUnsafeArray<float, 4> linewidth;
+    spvUnsafeArray<uint, 4> save_trans_ix;
+    float2 p0;
+    float2 p1;
+    float2 p2;
+    float2 p3;
+    Alloc param_13;
+    spvUnsafeArray<Monoid, 4> local;
+    PathCubic cubic;
+    Alloc param_15;
+    for (uint i_1 = 0u; i_1 < 4u; i_1++)
+    {
+        linewidth[i_1] = as_type<float>(v_574.scene[lw_ix]);
+        save_trans_ix[i_1] = trans_ix;
+        uint tag_byte = tag_word >> (i_1 * 8u);
+        uint seg_type = tag_byte & 3u;
+        if (seg_type != 0u)
+        {
+            if ((tag_byte & 8u) != 0u)
+            {
+                uint param_5 = ps_ix;
+                p0 = read_f32_point(param_5, v_574);
+                uint param_6 = ps_ix + 2u;
+                p1 = read_f32_point(param_6, v_574);
+                if (seg_type >= 2u)
+                {
+                    uint param_7 = ps_ix + 4u;
+                    p2 = read_f32_point(param_7, v_574);
+                    if (seg_type == 3u)
+                    {
+                        uint param_8 = ps_ix + 6u;
+                        p3 = read_f32_point(param_8, v_574);
+                    }
+                }
+            }
+            else
+            {
+                uint param_9 = ps_ix;
+                p0 = read_i16_point(param_9, v_574);
+                uint param_10 = ps_ix + 1u;
+                p1 = read_i16_point(param_10, v_574);
+                if (seg_type >= 2u)
+                {
+                    uint param_11 = ps_ix + 2u;
+                    p2 = read_i16_point(param_11, v_574);
+                    if (seg_type == 3u)
+                    {
+                        uint param_12 = ps_ix + 3u;
+                        p3 = read_i16_point(param_12, v_574);
+                    }
+                }
+            }
+            param_13.offset = _639.conf.trans_alloc.offset;
+            TransformSegRef param_14 = trans_ref;
+            TransformSeg transform = TransformSeg_read(param_13, param_14, v_111);
+            p0 = ((transform.mat.xy * p0.x) + (transform.mat.zw * p0.y)) + transform.translate;
+            p1 = ((transform.mat.xy * p1.x) + (transform.mat.zw * p1.y)) + transform.translate;
+            float4 bbox = float4(fast::min(p0, p1), fast::max(p0, p1));
+            if (seg_type >= 2u)
+            {
+                p2 = ((transform.mat.xy * p2.x) + (transform.mat.zw * p2.y)) + transform.translate;
+                float4 _947 = bbox;
+                float2 _950 = fast::min(_947.xy, p2);
+                bbox.x = _950.x;
+                bbox.y = _950.y;
+                float4 _955 = bbox;
+                float2 _958 = fast::max(_955.zw, p2);
+                bbox.z = _958.x;
+                bbox.w = _958.y;
+                if (seg_type == 3u)
+                {
+                    p3 = ((transform.mat.xy * p3.x) + (transform.mat.zw * p3.y)) + transform.translate;
+                    float4 _983 = bbox;
+                    float2 _986 = fast::min(_983.xy, p3);
+                    bbox.x = _986.x;
+                    bbox.y = _986.y;
+                    float4 _991 = bbox;
+                    float2 _994 = fast::max(_991.zw, p3);
+                    bbox.z = _994.x;
+                    bbox.w = _994.y;
+                }
+                else
+                {
+                    p3 = p2;
+                    p2 = mix(p1, p2, float2(0.3333333432674407958984375));
+                    p1 = mix(p1, p0, float2(0.3333333432674407958984375));
+                }
+            }
+            else
+            {
+                p3 = p1;
+                p2 = mix(p3, p0, float2(0.3333333432674407958984375));
+                p1 = mix(p0, p3, float2(0.3333333432674407958984375));
+            }
+            float2 stroke = float2(0.0);
+            if (linewidth[i_1] >= 0.0)
+            {
+                stroke = float2(length(transform.mat.xz), length(transform.mat.yw)) * (0.5 * linewidth[i_1]);
+                bbox += float4(-stroke, stroke);
+            }
+            local[i_1].bbox = bbox;
+            local[i_1].flags = 0u;
+            cubic.p0 = p0;
+            cubic.p1 = p1;
+            cubic.p2 = p2;
+            cubic.p3 = p3;
+            cubic.path_ix = tm.path_ix;
+            cubic.trans_ix = (gl_GlobalInvocationID.x * 4u) + i_1;
+            cubic.stroke = stroke;
+            uint fill_mode = uint(linewidth[i_1] >= 0.0);
+            param_15.offset = _639.conf.pathseg_alloc.offset;
+            PathSegRef param_16 = ps_ref;
+            uint param_17 = fill_mode;
+            PathCubic param_18 = cubic;
+            PathSeg_Cubic_write(param_15, param_16, param_17, param_18, v_111);
+            ps_ref.offset += 52u;
+            uint n_points = (tag_byte & 3u) + ((tag_byte >> uint(2)) & 1u);
+            uint n_words = n_points + (n_points & (((tag_byte >> uint(3)) & 1u) * 15u));
+            ps_ix += n_words;
+        }
+        else
+        {
+            local[i_1].bbox = float4(0.0);
+            uint is_path = (tag_byte >> uint(4)) & 1u;
+            local[i_1].flags = is_path;
+            tm.path_ix += is_path;
+            trans_ix += ((tag_byte >> uint(5)) & 1u);
+            trans_ref.offset += (((tag_byte >> uint(5)) & 1u) * 24u);
+            lw_ix += ((tag_byte >> uint(6)) & 1u);
+        }
+    }
+    Monoid agg = local[0];
+    for (uint i_2 = 1u; i_2 < 4u; i_2++)
+    {
+        Monoid param_19 = agg;
+        Monoid param_20 = local[i_2];
+        agg = combine_monoid(param_19, param_20);
+        local[i_2] = agg;
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_3 = 0u; i_3 < 8u; i_3++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i_3))
+        {
+            Monoid other_1 = sh_scratch[gl_LocalInvocationID.x - (1u << i_3)];
+            Monoid param_21 = other_1;
+            Monoid param_22 = agg;
+            agg = combine_monoid(param_21, param_22);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    uint path_ix = save_path_ix;
+    uint bbox_out_ix = (_639.conf.path_bbox_alloc.offset >> uint(2)) + (path_ix * 6u);
+    Monoid row = monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_4 = 0u; i_4 < 4u; i_4++)
+    {
+        Monoid param_23 = row;
+        Monoid param_24 = local[i_4];
+        Monoid m = combine_monoid(param_23, param_24);
+        bool do_atomic = false;
+        bool _1264 = i_4 == 3u;
+        bool _1270;
+        if (_1264)
+        {
+            _1270 = gl_LocalInvocationID.x == 255u;
+        }
+        else
+        {
+            _1270 = _1264;
+        }
+        if (_1270)
+        {
+            do_atomic = true;
+        }
+        if ((m.flags & 1u) != 0u)
+        {
+            v_111.memory[bbox_out_ix + 4u] = as_type<uint>(linewidth[i_4]);
+            v_111.memory[bbox_out_ix + 5u] = save_trans_ix[i_4];
+            if ((m.flags & 2u) == 0u)
+            {
+                do_atomic = true;
+            }
+            else
+            {
+                float param_25 = m.bbox.x;
+                v_111.memory[bbox_out_ix] = round_down(param_25);
+                float param_26 = m.bbox.y;
+                v_111.memory[bbox_out_ix + 1u] = round_down(param_26);
+                float param_27 = m.bbox.z;
+                v_111.memory[bbox_out_ix + 2u] = round_up(param_27);
+                float param_28 = m.bbox.w;
+                v_111.memory[bbox_out_ix + 3u] = round_up(param_28);
+                bbox_out_ix += 6u;
+                do_atomic = false;
+            }
+        }
+        if (do_atomic)
+        {
+            bool _1335 = m.bbox.z > m.bbox.x;
+            bool _1344;
+            if (!_1335)
+            {
+                _1344 = m.bbox.w > m.bbox.y;
+            }
+            else
+            {
+                _1344 = _1335;
+            }
+            if (_1344)
+            {
+                float param_29 = m.bbox.x;
+                uint _1353 = atomic_fetch_min_explicit((device atomic_uint*)&v_111.memory[bbox_out_ix], round_down(param_29), memory_order_relaxed);
+                float param_30 = m.bbox.y;
+                uint _1361 = atomic_fetch_min_explicit((device atomic_uint*)&v_111.memory[bbox_out_ix + 1u], round_down(param_30), memory_order_relaxed);
+                float param_31 = m.bbox.z;
+                uint _1369 = atomic_fetch_max_explicit((device atomic_uint*)&v_111.memory[bbox_out_ix + 2u], round_up(param_31), memory_order_relaxed);
+                float param_32 = m.bbox.w;
+                uint _1377 = atomic_fetch_max_explicit((device atomic_uint*)&v_111.memory[bbox_out_ix + 3u], round_up(param_32), memory_order_relaxed);
+            }
+            bbox_out_ix += 6u;
+        }
+    }
+}
+

piet-gpu/shader/gen/pathtag_reduce.hlsl

@@ -0,0 +1,138 @@
+struct TagMonoid
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(128u, 1u, 1u);
+
+ByteAddressBuffer _139 : register(t1, space0);
+ByteAddressBuffer _151 : register(t2, space0);
+RWByteAddressBuffer _238 : register(u3, space0);
+RWByteAddressBuffer _258 : register(u0, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared TagMonoid sh_scratch[128];
+
+TagMonoid reduce_tag(uint tag_word)
+{
+    uint point_count = tag_word & 50529027u;
+    TagMonoid c;
+    c.pathseg_ix = uint(int(countbits((point_count * 7u) & 67372036u)));
+    c.linewidth_ix = uint(int(countbits(tag_word & 1077952576u)));
+    c.path_ix = uint(int(countbits(tag_word & 269488144u)));
+    c.trans_ix = uint(int(countbits(tag_word & 538976288u)));
+    uint n_points = point_count + ((tag_word >> uint(2)) & 16843009u);
+    uint a = n_points + (n_points & (((tag_word >> uint(3)) & 16843009u) * 15u));
+    a += (a >> uint(8));
+    a += (a >> uint(16));
+    c.pathseg_offset = a & 255u;
+    return c;
+}
+
+TagMonoid combine_tag_monoid(TagMonoid a, TagMonoid b)
+{
+    TagMonoid c;
+    c.trans_ix = a.trans_ix + b.trans_ix;
+    c.linewidth_ix = a.linewidth_ix + b.linewidth_ix;
+    c.pathseg_ix = a.pathseg_ix + b.pathseg_ix;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.pathseg_offset = a.pathseg_offset + b.pathseg_offset;
+    return c;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 2u;
+    uint scene_ix = (_139.Load(92) >> uint(2)) + ix;
+    uint tag_word = _151.Load(scene_ix * 4 + 0);
+    uint param = tag_word;
+    TagMonoid agg = reduce_tag(param);
+    for (uint i = 1u; i < 2u; i++)
+    {
+        tag_word = _151.Load((scene_ix + i) * 4 + 0);
+        uint param_1 = tag_word;
+        TagMonoid param_2 = agg;
+        TagMonoid param_3 = reduce_tag(param_1);
+        agg = combine_tag_monoid(param_2, param_3);
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 7u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if ((gl_LocalInvocationID.x + (1u << i_1)) < 128u)
+        {
+            TagMonoid other = sh_scratch[gl_LocalInvocationID.x + (1u << i_1)];
+            TagMonoid param_4 = agg;
+            TagMonoid param_5 = other;
+            agg = combine_tag_monoid(param_4, param_5);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        _238.Store(gl_WorkGroupID.x * 20 + 0, agg.trans_ix);
+        _238.Store(gl_WorkGroupID.x * 20 + 4, agg.linewidth_ix);
+        _238.Store(gl_WorkGroupID.x * 20 + 8, agg.pathseg_ix);
+        _238.Store(gl_WorkGroupID.x * 20 + 12, agg.path_ix);
+        _238.Store(gl_WorkGroupID.x * 20 + 16, agg.pathseg_offset);
+    }
+}
+
+[numthreads(128, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/pathtag_reduce.msl

@@ -0,0 +1,154 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct TagMonoid
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+struct TagMonoid_1
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct OutBuf
+{
+    TagMonoid_1 outbuf[1];
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(128u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+TagMonoid reduce_tag(thread const uint& tag_word)
+{
+    uint point_count = tag_word & 50529027u;
+    TagMonoid c;
+    c.pathseg_ix = uint(int(popcount((point_count * 7u) & 67372036u)));
+    c.linewidth_ix = uint(int(popcount(tag_word & 1077952576u)));
+    c.path_ix = uint(int(popcount(tag_word & 269488144u)));
+    c.trans_ix = uint(int(popcount(tag_word & 538976288u)));
+    uint n_points = point_count + ((tag_word >> uint(2)) & 16843009u);
+    uint a = n_points + (n_points & (((tag_word >> uint(3)) & 16843009u) * 15u));
+    a += (a >> uint(8));
+    a += (a >> uint(16));
+    c.pathseg_offset = a & 255u;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+TagMonoid combine_tag_monoid(thread const TagMonoid& a, thread const TagMonoid& b)
+{
+    TagMonoid c;
+    c.trans_ix = a.trans_ix + b.trans_ix;
+    c.linewidth_ix = a.linewidth_ix + b.linewidth_ix;
+    c.pathseg_ix = a.pathseg_ix + b.pathseg_ix;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.pathseg_offset = a.pathseg_offset + b.pathseg_offset;
+    return c;
+}
+
+kernel void main0(const device ConfigBuf& _139 [[buffer(1)]], const device SceneBuf& _151 [[buffer(2)]], device OutBuf& _238 [[buffer(3)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup TagMonoid sh_scratch[128];
+    uint ix = gl_GlobalInvocationID.x * 2u;
+    uint scene_ix = (_139.conf.pathtag_offset >> uint(2)) + ix;
+    uint tag_word = _151.scene[scene_ix];
+    uint param = tag_word;
+    TagMonoid agg = reduce_tag(param);
+    for (uint i = 1u; i < 2u; i++)
+    {
+        tag_word = _151.scene[scene_ix + i];
+        uint param_1 = tag_word;
+        TagMonoid param_2 = agg;
+        TagMonoid param_3 = reduce_tag(param_1);
+        agg = combine_tag_monoid(param_2, param_3);
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 7u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if ((gl_LocalInvocationID.x + (1u << i_1)) < 128u)
+        {
+            TagMonoid other = sh_scratch[gl_LocalInvocationID.x + (1u << i_1)];
+            TagMonoid param_4 = agg;
+            TagMonoid param_5 = other;
+            agg = combine_tag_monoid(param_4, param_5);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        _238.outbuf[gl_WorkGroupID.x].trans_ix = agg.trans_ix;
+        _238.outbuf[gl_WorkGroupID.x].linewidth_ix = agg.linewidth_ix;
+        _238.outbuf[gl_WorkGroupID.x].pathseg_ix = agg.pathseg_ix;
+        _238.outbuf[gl_WorkGroupID.x].path_ix = agg.path_ix;
+        _238.outbuf[gl_WorkGroupID.x].pathseg_offset = agg.pathseg_offset;
+    }
+}
+

piet-gpu/shader/gen/pathtag_root.hlsl

@@ -0,0 +1,115 @@
+struct TagMonoid
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const TagMonoid _18 = { 0u, 0u, 0u, 0u, 0u };
+
+RWByteAddressBuffer _78 : register(u0, space0);
+
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared TagMonoid sh_scratch[256];
+
+TagMonoid combine_tag_monoid(TagMonoid a, TagMonoid b)
+{
+    TagMonoid c;
+    c.trans_ix = a.trans_ix + b.trans_ix;
+    c.linewidth_ix = a.linewidth_ix + b.linewidth_ix;
+    c.pathseg_ix = a.pathseg_ix + b.pathseg_ix;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.pathseg_offset = a.pathseg_offset + b.pathseg_offset;
+    return c;
+}
+
+TagMonoid tag_monoid_identity()
+{
+    return _18;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    TagMonoid _82;
+    _82.trans_ix = _78.Load(ix * 20 + 0);
+    _82.linewidth_ix = _78.Load(ix * 20 + 4);
+    _82.pathseg_ix = _78.Load(ix * 20 + 8);
+    _82.path_ix = _78.Load(ix * 20 + 12);
+    _82.pathseg_offset = _78.Load(ix * 20 + 16);
+    TagMonoid local[8];
+    local[0].trans_ix = _82.trans_ix;
+    local[0].linewidth_ix = _82.linewidth_ix;
+    local[0].pathseg_ix = _82.pathseg_ix;
+    local[0].path_ix = _82.path_ix;
+    local[0].pathseg_offset = _82.pathseg_offset;
+    TagMonoid param_1;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        TagMonoid param = local[i - 1u];
+        TagMonoid _115;
+        _115.trans_ix = _78.Load((ix + i) * 20 + 0);
+        _115.linewidth_ix = _78.Load((ix + i) * 20 + 4);
+        _115.pathseg_ix = _78.Load((ix + i) * 20 + 8);
+        _115.path_ix = _78.Load((ix + i) * 20 + 12);
+        _115.pathseg_offset = _78.Load((ix + i) * 20 + 16);
+        param_1.trans_ix = _115.trans_ix;
+        param_1.linewidth_ix = _115.linewidth_ix;
+        param_1.pathseg_ix = _115.pathseg_ix;
+        param_1.path_ix = _115.path_ix;
+        param_1.pathseg_offset = _115.pathseg_offset;
+        local[i] = combine_tag_monoid(param, param_1);
+    }
+    TagMonoid agg = local[7];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            TagMonoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            TagMonoid param_2 = other;
+            TagMonoid param_3 = agg;
+            agg = combine_tag_monoid(param_2, param_3);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    TagMonoid row = tag_monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        TagMonoid param_4 = row;
+        TagMonoid param_5 = local[i_2];
+        TagMonoid m = combine_tag_monoid(param_4, param_5);
+        uint _210 = ix + i_2;
+        _78.Store(_210 * 20 + 0, m.trans_ix);
+        _78.Store(_210 * 20 + 4, m.linewidth_ix);
+        _78.Store(_210 * 20 + 8, m.pathseg_ix);
+        _78.Store(_210 * 20 + 12, m.path_ix);
+        _78.Store(_210 * 20 + 16, m.pathseg_offset);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/pathtag_root.msl

@@ -0,0 +1,146 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct TagMonoid
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct TagMonoid_1
+{
+    uint trans_ix;
+    uint linewidth_ix;
+    uint pathseg_ix;
+    uint path_ix;
+    uint pathseg_offset;
+};
+
+struct DataBuf
+{
+    TagMonoid_1 data[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+TagMonoid combine_tag_monoid(thread const TagMonoid& a, thread const TagMonoid& b)
+{
+    TagMonoid c;
+    c.trans_ix = a.trans_ix + b.trans_ix;
+    c.linewidth_ix = a.linewidth_ix + b.linewidth_ix;
+    c.pathseg_ix = a.pathseg_ix + b.pathseg_ix;
+    c.path_ix = a.path_ix + b.path_ix;
+    c.pathseg_offset = a.pathseg_offset + b.pathseg_offset;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+TagMonoid tag_monoid_identity()
+{
+    return TagMonoid{ 0u, 0u, 0u, 0u, 0u };
+}
+
+kernel void main0(device DataBuf& _78 [[buffer(0)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]])
+{
+    threadgroup TagMonoid sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    spvUnsafeArray<TagMonoid, 8> local;
+    local[0].trans_ix = _78.data[ix].trans_ix;
+    local[0].linewidth_ix = _78.data[ix].linewidth_ix;
+    local[0].pathseg_ix = _78.data[ix].pathseg_ix;
+    local[0].path_ix = _78.data[ix].path_ix;
+    local[0].pathseg_offset = _78.data[ix].pathseg_offset;
+    TagMonoid param_1;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        uint _109 = ix + i;
+        TagMonoid param = local[i - 1u];
+        param_1.trans_ix = _78.data[_109].trans_ix;
+        param_1.linewidth_ix = _78.data[_109].linewidth_ix;
+        param_1.pathseg_ix = _78.data[_109].pathseg_ix;
+        param_1.path_ix = _78.data[_109].path_ix;
+        param_1.pathseg_offset = _78.data[_109].pathseg_offset;
+        local[i] = combine_tag_monoid(param, param_1);
+    }
+    TagMonoid agg = local[7];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            TagMonoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            TagMonoid param_2 = other;
+            TagMonoid param_3 = agg;
+            agg = combine_tag_monoid(param_2, param_3);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    TagMonoid row = tag_monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        TagMonoid param_4 = row;
+        TagMonoid param_5 = local[i_2];
+        TagMonoid m = combine_tag_monoid(param_4, param_5);
+        uint _210 = ix + i_2;
+        _78.data[_210].trans_ix = m.trans_ix;
+        _78.data[_210].linewidth_ix = m.linewidth_ix;
+        _78.data[_210].pathseg_ix = m.pathseg_ix;
+        _78.data[_210].path_ix = m.path_ix;
+        _78.data[_210].pathseg_offset = m.pathseg_offset;
+    }
+}
+

piet-gpu/shader/gen/tile_alloc.hlsl

@@ -0,0 +1,264 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct MallocResult
+{
+    Alloc alloc;
+    bool failed;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+RWByteAddressBuffer _70 : register(u0, space0);
+ByteAddressBuffer _181 : register(t1, space0);
+ByteAddressBuffer _257 : register(t2, space0);
+
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared uint sh_tile_count[256];
+groupshared MallocResult sh_tile_alloc;
+
+float4 load_draw_bbox(uint draw_ix)
+{
+    uint base = (_181.Load(64) >> uint(2)) + (4u * draw_ix);
+    float x0 = asfloat(_70.Load(base * 4 + 8));
+    float y0 = asfloat(_70.Load((base + 1u) * 4 + 8));
+    float x1 = asfloat(_70.Load((base + 2u) * 4 + 8));
+    float y1 = asfloat(_70.Load((base + 3u) * 4 + 8));
+    float4 bbox = float4(x0, y0, x1, y1);
+    return bbox;
+}
+
+Alloc new_alloc(uint offset, uint size, bool mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+MallocResult malloc(uint size)
+{
+    uint _76;
+    _70.InterlockedAdd(0, size, _76);
+    uint offset = _76;
+    uint _83;
+    _70.GetDimensions(_83);
+    _83 = (_83 - 8) / 4;
+    MallocResult r;
+    r.failed = (offset + size) > uint(int(_83) * 4);
+    uint param = offset;
+    uint param_1 = size;
+    bool param_2 = !r.failed;
+    r.alloc = new_alloc(param, param_1, param_2);
+    if (r.failed)
+    {
+        uint _105;
+        _70.InterlockedMax(4, 1u, _105);
+        return r;
+    }
+    return r;
+}
+
+Alloc slice_mem(Alloc a, uint offset, uint size)
+{
+    Alloc _131 = { a.offset + offset };
+    return _131;
+}
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _70.Store(offset * 4 + 8, val);
+}
+
+void Path_write(Alloc a, PathRef ref, Path s)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = s.bbox.x | (s.bbox.y << uint(16));
+    write_mem(param, param_1, param_2);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = s.bbox.z | (s.bbox.w << uint(16));
+    write_mem(param_3, param_4, param_5);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = s.tiles.offset;
+    write_mem(param_6, param_7, param_8);
+}
+
+void comp_main()
+{
+    uint th_ix = gl_LocalInvocationID.x;
+    uint element_ix = gl_GlobalInvocationID.x;
+    PathRef _241 = { _181.Load(16) + (element_ix * 12u) };
+    PathRef path_ref = _241;
+    uint drawtag_base = _181.Load(100) >> uint(2);
+    uint drawtag = 0u;
+    if (element_ix < _181.Load(0))
+    {
+        drawtag = _257.Load((drawtag_base + element_ix) * 4 + 0);
+    }
+    int x0 = 0;
+    int y0 = 0;
+    int x1 = 0;
+    int y1 = 0;
+    if ((drawtag != 0u) && (drawtag != 37u))
+    {
+        uint param = element_ix;
+        float4 bbox = load_draw_bbox(param);
+        x0 = int(floor(bbox.x * 0.0625f));
+        y0 = int(floor(bbox.y * 0.0625f));
+        x1 = int(ceil(bbox.z * 0.0625f));
+        y1 = int(ceil(bbox.w * 0.0625f));
+    }
+    x0 = clamp(x0, 0, int(_181.Load(8)));
+    y0 = clamp(y0, 0, int(_181.Load(12)));
+    x1 = clamp(x1, 0, int(_181.Load(8)));
+    y1 = clamp(y1, 0, int(_181.Load(12)));
+    Path path;
+    path.bbox = uint4(uint(x0), uint(y0), uint(x1), uint(y1));
+    uint tile_count = uint((x1 - x0) * (y1 - y0));
+    sh_tile_count[th_ix] = tile_count;
+    uint total_tile_count = tile_count;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (th_ix >= (1u << i))
+        {
+            total_tile_count += sh_tile_count[th_ix - (1u << i)];
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_tile_count[th_ix] = total_tile_count;
+    }
+    if (th_ix == 255u)
+    {
+        uint param_1 = total_tile_count * 8u;
+        MallocResult _392 = malloc(param_1);
+        sh_tile_alloc = _392;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    MallocResult alloc_start = sh_tile_alloc;
+    bool _403;
+    if (!alloc_start.failed)
+    {
+        _403 = _70.Load(4) != 0u;
+    }
+    else
+    {
+        _403 = alloc_start.failed;
+    }
+    if (_403)
+    {
+        return;
+    }
+    if (element_ix < _181.Load(0))
+    {
+        uint _416;
+        if (th_ix > 0u)
+        {
+            _416 = sh_tile_count[th_ix - 1u];
+        }
+        else
+        {
+            _416 = 0u;
+        }
+        uint tile_subix = _416;
+        Alloc param_2 = alloc_start.alloc;
+        uint param_3 = 8u * tile_subix;
+        uint param_4 = 8u * tile_count;
+        Alloc tiles_alloc = slice_mem(param_2, param_3, param_4);
+        TileRef _438 = { tiles_alloc.offset };
+        path.tiles = _438;
+        Alloc _444;
+        _444.offset = _181.Load(16);
+        Alloc param_5;
+        param_5.offset = _444.offset;
+        PathRef param_6 = path_ref;
+        Path param_7 = path;
+        Path_write(param_5, param_6, param_7);
+    }
+    uint total_count = sh_tile_count[255] * 2u;
+    uint start_ix = alloc_start.alloc.offset >> uint(2);
+    for (uint i_1 = th_ix; i_1 < total_count; i_1 += 256u)
+    {
+        Alloc param_8 = alloc_start.alloc;
+        uint param_9 = start_ix + i_1;
+        uint param_10 = 0u;
+        write_mem(param_8, param_9, param_10);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/tile_alloc.msl

@@ -0,0 +1,273 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_atomic>
+
+using namespace metal;
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct MallocResult
+{
+    Alloc alloc;
+    bool failed;
+};
+
+struct PathRef
+{
+    uint offset;
+};
+
+struct TileRef
+{
+    uint offset;
+};
+
+struct Path
+{
+    uint4 bbox;
+    TileRef tiles;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+float4 load_draw_bbox(thread const uint& draw_ix, device Memory& v_70, constant uint& v_70BufferSize, const device ConfigBuf& v_181)
+{
+    uint base = (v_181.conf.draw_bbox_alloc.offset >> uint(2)) + (4u * draw_ix);
+    float x0 = as_type<float>(v_70.memory[base]);
+    float y0 = as_type<float>(v_70.memory[base + 1u]);
+    float x1 = as_type<float>(v_70.memory[base + 2u]);
+    float y1 = as_type<float>(v_70.memory[base + 3u]);
+    float4 bbox = float4(x0, y0, x1, y1);
+    return bbox;
+}
+
+static inline __attribute__((always_inline))
+Alloc new_alloc(thread const uint& offset, thread const uint& size, thread const bool& mem_ok)
+{
+    Alloc a;
+    a.offset = offset;
+    return a;
+}
+
+static inline __attribute__((always_inline))
+MallocResult malloc(thread const uint& size, device Memory& v_70, constant uint& v_70BufferSize)
+{
+    uint _76 = atomic_fetch_add_explicit((device atomic_uint*)&v_70.mem_offset, size, memory_order_relaxed);
+    uint offset = _76;
+    MallocResult r;
+    r.failed = (offset + size) > uint(int((v_70BufferSize - 8) / 4) * 4);
+    uint param = offset;
+    uint param_1 = size;
+    bool param_2 = !r.failed;
+    r.alloc = new_alloc(param, param_1, param_2);
+    if (r.failed)
+    {
+        uint _105 = atomic_fetch_max_explicit((device atomic_uint*)&v_70.mem_error, 1u, memory_order_relaxed);
+        return r;
+    }
+    return r;
+}
+
+static inline __attribute__((always_inline))
+Alloc slice_mem(thread const Alloc& a, thread const uint& offset, thread const uint& size)
+{
+    return Alloc{ a.offset + offset };
+}
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_70, constant uint& v_70BufferSize)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_70.memory[offset] = val;
+}
+
+static inline __attribute__((always_inline))
+void Path_write(thread const Alloc& a, thread const PathRef& ref, thread const Path& s, device Memory& v_70, constant uint& v_70BufferSize)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = s.bbox.x | (s.bbox.y << uint(16));
+    write_mem(param, param_1, param_2, v_70, v_70BufferSize);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = s.bbox.z | (s.bbox.w << uint(16));
+    write_mem(param_3, param_4, param_5, v_70, v_70BufferSize);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = s.tiles.offset;
+    write_mem(param_6, param_7, param_8, v_70, v_70BufferSize);
+}
+
+kernel void main0(constant uint* spvBufferSizeConstants [[buffer(25)]], device Memory& v_70 [[buffer(0)]], const device ConfigBuf& v_181 [[buffer(1)]], const device SceneBuf& _257 [[buffer(2)]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    threadgroup uint sh_tile_count[256];
+    threadgroup MallocResult sh_tile_alloc;
+    constant uint& v_70BufferSize = spvBufferSizeConstants[0];
+    uint th_ix = gl_LocalInvocationID.x;
+    uint element_ix = gl_GlobalInvocationID.x;
+    PathRef path_ref = PathRef{ v_181.conf.tile_alloc.offset + (element_ix * 12u) };
+    uint drawtag_base = v_181.conf.drawtag_offset >> uint(2);
+    uint drawtag = 0u;
+    if (element_ix < v_181.conf.n_elements)
+    {
+        drawtag = _257.scene[drawtag_base + element_ix];
+    }
+    int x0 = 0;
+    int y0 = 0;
+    int x1 = 0;
+    int y1 = 0;
+    if ((drawtag != 0u) && (drawtag != 37u))
+    {
+        uint param = element_ix;
+        float4 bbox = load_draw_bbox(param, v_70, v_70BufferSize, v_181);
+        x0 = int(floor(bbox.x * 0.0625));
+        y0 = int(floor(bbox.y * 0.0625));
+        x1 = int(ceil(bbox.z * 0.0625));
+        y1 = int(ceil(bbox.w * 0.0625));
+    }
+    x0 = clamp(x0, 0, int(v_181.conf.width_in_tiles));
+    y0 = clamp(y0, 0, int(v_181.conf.height_in_tiles));
+    x1 = clamp(x1, 0, int(v_181.conf.width_in_tiles));
+    y1 = clamp(y1, 0, int(v_181.conf.height_in_tiles));
+    Path path;
+    path.bbox = uint4(uint(x0), uint(y0), uint(x1), uint(y1));
+    uint tile_count = uint((x1 - x0) * (y1 - y0));
+    sh_tile_count[th_ix] = tile_count;
+    uint total_tile_count = tile_count;
+    for (uint i = 0u; i < 8u; i++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (th_ix >= (1u << i))
+        {
+            total_tile_count += sh_tile_count[th_ix - (1u << i)];
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_tile_count[th_ix] = total_tile_count;
+    }
+    if (th_ix == 255u)
+    {
+        uint param_1 = total_tile_count * 8u;
+        MallocResult _392 = malloc(param_1, v_70, v_70BufferSize);
+        sh_tile_alloc = _392;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    MallocResult alloc_start = sh_tile_alloc;
+    bool _403;
+    if (!alloc_start.failed)
+    {
+        _403 = v_70.mem_error != 0u;
+    }
+    else
+    {
+        _403 = alloc_start.failed;
+    }
+    if (_403)
+    {
+        return;
+    }
+    if (element_ix < v_181.conf.n_elements)
+    {
+        uint _416;
+        if (th_ix > 0u)
+        {
+            _416 = sh_tile_count[th_ix - 1u];
+        }
+        else
+        {
+            _416 = 0u;
+        }
+        uint tile_subix = _416;
+        Alloc param_2 = alloc_start.alloc;
+        uint param_3 = 8u * tile_subix;
+        uint param_4 = 8u * tile_count;
+        Alloc tiles_alloc = slice_mem(param_2, param_3, param_4);
+        path.tiles = TileRef{ tiles_alloc.offset };
+        Alloc param_5;
+        param_5.offset = v_181.conf.tile_alloc.offset;
+        PathRef param_6 = path_ref;
+        Path param_7 = path;
+        Path_write(param_5, param_6, param_7, v_70, v_70BufferSize);
+    }
+    uint total_count = sh_tile_count[255] * 2u;
+    uint start_ix = alloc_start.alloc.offset >> uint(2);
+    for (uint i_1 = th_ix; i_1 < total_count; i_1 += 256u)
+    {
+        Alloc param_8 = alloc_start.alloc;
+        uint param_9 = start_ix + i_1;
+        uint param_10 = 0u;
+        write_mem(param_8, param_9, param_10, v_70, v_70BufferSize);
+    }
+}
+

piet-gpu/shader/gen/transform_leaf.hlsl

@@ -0,0 +1,234 @@
+struct Alloc
+{
+    uint offset;
+};
+
+struct TransformRef
+{
+    uint offset;
+};
+
+struct Transform
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct TransformSegRef
+{
+    uint offset;
+};
+
+struct TransformSeg
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const Transform _224 = { float4(1.0f, 0.0f, 0.0f, 1.0f), 0.0f.xx };
+
+RWByteAddressBuffer _71 : register(u0, space0);
+ByteAddressBuffer _96 : register(t2, space0);
+ByteAddressBuffer _278 : register(t1, space0);
+ByteAddressBuffer _376 : register(t3, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared Transform sh_scratch[256];
+
+Transform Transform_read(TransformRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    uint raw0 = _96.Load((ix + 0u) * 4 + 0);
+    uint raw1 = _96.Load((ix + 1u) * 4 + 0);
+    uint raw2 = _96.Load((ix + 2u) * 4 + 0);
+    uint raw3 = _96.Load((ix + 3u) * 4 + 0);
+    uint raw4 = _96.Load((ix + 4u) * 4 + 0);
+    uint raw5 = _96.Load((ix + 5u) * 4 + 0);
+    Transform s;
+    s.mat = float4(asfloat(raw0), asfloat(raw1), asfloat(raw2), asfloat(raw3));
+    s.translate = float2(asfloat(raw4), asfloat(raw5));
+    return s;
+}
+
+TransformRef Transform_index(TransformRef ref, uint index)
+{
+    TransformRef _85 = { ref.offset + (index * 24u) };
+    return _85;
+}
+
+Transform combine_monoid(Transform a, Transform b)
+{
+    Transform c;
+    c.mat = (a.mat.xyxy * b.mat.xxzz) + (a.mat.zwzw * b.mat.yyww);
+    c.translate = ((a.mat.xy * b.translate.x) + (a.mat.zw * b.translate.y)) + a.translate;
+    return c;
+}
+
+Transform monoid_identity()
+{
+    return _224;
+}
+
+bool touch_mem(Alloc alloc, uint offset)
+{
+    return true;
+}
+
+void write_mem(Alloc alloc, uint offset, uint val)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    _71.Store(offset * 4 + 8, val);
+}
+
+void TransformSeg_write(Alloc a, TransformSegRef ref, TransformSeg s)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = asuint(s.mat.x);
+    write_mem(param, param_1, param_2);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = asuint(s.mat.y);
+    write_mem(param_3, param_4, param_5);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = asuint(s.mat.z);
+    write_mem(param_6, param_7, param_8);
+    Alloc param_9 = a;
+    uint param_10 = ix + 3u;
+    uint param_11 = asuint(s.mat.w);
+    write_mem(param_9, param_10, param_11);
+    Alloc param_12 = a;
+    uint param_13 = ix + 4u;
+    uint param_14 = asuint(s.translate.x);
+    write_mem(param_12, param_13, param_14);
+    Alloc param_15 = a;
+    uint param_16 = ix + 5u;
+    uint param_17 = asuint(s.translate.y);
+    write_mem(param_15, param_16, param_17);
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    TransformRef _285 = { _278.Load(84) + (ix * 24u) };
+    TransformRef ref = _285;
+    TransformRef param = ref;
+    Transform agg = Transform_read(param);
+    Transform local[8];
+    local[0] = agg;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        TransformRef param_1 = ref;
+        uint param_2 = i;
+        TransformRef param_3 = Transform_index(param_1, param_2);
+        Transform param_4 = agg;
+        Transform param_5 = Transform_read(param_3);
+        agg = combine_monoid(param_4, param_5);
+        local[i] = agg;
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            Transform other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            Transform param_6 = other;
+            Transform param_7 = agg;
+            agg = combine_monoid(param_6, param_7);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    Transform row = monoid_identity();
+    if (gl_WorkGroupID.x > 0u)
+    {
+        Transform _382;
+        _382.mat = asfloat(_376.Load4((gl_WorkGroupID.x - 1u) * 32 + 0));
+        _382.translate = asfloat(_376.Load2((gl_WorkGroupID.x - 1u) * 32 + 16));
+        row.mat = _382.mat;
+        row.translate = _382.translate;
+    }
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        Transform param_8 = row;
+        Transform param_9 = sh_scratch[gl_LocalInvocationID.x - 1u];
+        row = combine_monoid(param_8, param_9);
+    }
+    Alloc param_12;
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        Transform param_10 = row;
+        Transform param_11 = local[i_2];
+        Transform m = combine_monoid(param_10, param_11);
+        TransformSeg _422 = { m.mat, m.translate };
+        TransformSeg transform = _422;
+        TransformSegRef _432 = { _278.Load(36) + ((ix + i_2) * 24u) };
+        TransformSegRef trans_ref = _432;
+        Alloc _436;
+        _436.offset = _278.Load(36);
+        param_12.offset = _436.offset;
+        TransformSegRef param_13 = trans_ref;
+        TransformSeg param_14 = transform;
+        TransformSeg_write(param_12, param_13, param_14);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/transform_leaf.msl

@@ -0,0 +1,287 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct TransformRef
+{
+    uint offset;
+};
+
+struct Transform
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct TransformSegRef
+{
+    uint offset;
+};
+
+struct TransformSeg
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+struct Alloc_1
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc_1 tile_alloc;
+    Alloc_1 bin_alloc;
+    Alloc_1 ptcl_alloc;
+    Alloc_1 pathseg_alloc;
+    Alloc_1 anno_alloc;
+    Alloc_1 trans_alloc;
+    Alloc_1 path_bbox_alloc;
+    Alloc_1 drawmonoid_alloc;
+    Alloc_1 clip_alloc;
+    Alloc_1 clip_bic_alloc;
+    Alloc_1 clip_stack_alloc;
+    Alloc_1 clip_bbox_alloc;
+    Alloc_1 draw_bbox_alloc;
+    Alloc_1 drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct Transform_1
+{
+    float4 mat;
+    float2 translate;
+    char _m0_final_padding[8];
+};
+
+struct ParentBuf
+{
+    Transform_1 parent[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+Transform Transform_read(thread const TransformRef& ref, const device SceneBuf& v_96)
+{
+    uint ix = ref.offset >> uint(2);
+    uint raw0 = v_96.scene[ix + 0u];
+    uint raw1 = v_96.scene[ix + 1u];
+    uint raw2 = v_96.scene[ix + 2u];
+    uint raw3 = v_96.scene[ix + 3u];
+    uint raw4 = v_96.scene[ix + 4u];
+    uint raw5 = v_96.scene[ix + 5u];
+    Transform s;
+    s.mat = float4(as_type<float>(raw0), as_type<float>(raw1), as_type<float>(raw2), as_type<float>(raw3));
+    s.translate = float2(as_type<float>(raw4), as_type<float>(raw5));
+    return s;
+}
+
+static inline __attribute__((always_inline))
+TransformRef Transform_index(thread const TransformRef& ref, thread const uint& index)
+{
+    return TransformRef{ ref.offset + (index * 24u) };
+}
+
+static inline __attribute__((always_inline))
+Transform combine_monoid(thread const Transform& a, thread const Transform& b)
+{
+    Transform c;
+    c.mat = (a.mat.xyxy * b.mat.xxzz) + (a.mat.zwzw * b.mat.yyww);
+    c.translate = ((a.mat.xy * b.translate.x) + (a.mat.zw * b.translate.y)) + a.translate;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+Transform monoid_identity()
+{
+    return Transform{ float4(1.0, 0.0, 0.0, 1.0), float2(0.0) };
+}
+
+static inline __attribute__((always_inline))
+bool touch_mem(thread const Alloc& alloc, thread const uint& offset)
+{
+    return true;
+}
+
+static inline __attribute__((always_inline))
+void write_mem(thread const Alloc& alloc, thread const uint& offset, thread const uint& val, device Memory& v_71)
+{
+    Alloc param = alloc;
+    uint param_1 = offset;
+    if (!touch_mem(param, param_1))
+    {
+        return;
+    }
+    v_71.memory[offset] = val;
+}
+
+static inline __attribute__((always_inline))
+void TransformSeg_write(thread const Alloc& a, thread const TransformSegRef& ref, thread const TransformSeg& s, device Memory& v_71)
+{
+    uint ix = ref.offset >> uint(2);
+    Alloc param = a;
+    uint param_1 = ix + 0u;
+    uint param_2 = as_type<uint>(s.mat.x);
+    write_mem(param, param_1, param_2, v_71);
+    Alloc param_3 = a;
+    uint param_4 = ix + 1u;
+    uint param_5 = as_type<uint>(s.mat.y);
+    write_mem(param_3, param_4, param_5, v_71);
+    Alloc param_6 = a;
+    uint param_7 = ix + 2u;
+    uint param_8 = as_type<uint>(s.mat.z);
+    write_mem(param_6, param_7, param_8, v_71);
+    Alloc param_9 = a;
+    uint param_10 = ix + 3u;
+    uint param_11 = as_type<uint>(s.mat.w);
+    write_mem(param_9, param_10, param_11, v_71);
+    Alloc param_12 = a;
+    uint param_13 = ix + 4u;
+    uint param_14 = as_type<uint>(s.translate.x);
+    write_mem(param_12, param_13, param_14, v_71);
+    Alloc param_15 = a;
+    uint param_16 = ix + 5u;
+    uint param_17 = as_type<uint>(s.translate.y);
+    write_mem(param_15, param_16, param_17, v_71);
+}
+
+kernel void main0(device Memory& v_71 [[buffer(0)]], const device ConfigBuf& _278 [[buffer(1)]], const device SceneBuf& v_96 [[buffer(2)]], const device ParentBuf& _376 [[buffer(3)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup Transform sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    TransformRef ref = TransformRef{ _278.conf.trans_offset + (ix * 24u) };
+    TransformRef param = ref;
+    Transform agg = Transform_read(param, v_96);
+    spvUnsafeArray<Transform, 8> local;
+    local[0] = agg;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        TransformRef param_1 = ref;
+        uint param_2 = i;
+        TransformRef param_3 = Transform_index(param_1, param_2);
+        Transform param_4 = agg;
+        Transform param_5 = Transform_read(param_3, v_96);
+        agg = combine_monoid(param_4, param_5);
+        local[i] = agg;
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            Transform other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            Transform param_6 = other;
+            Transform param_7 = agg;
+            agg = combine_monoid(param_6, param_7);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    Transform row = monoid_identity();
+    if (gl_WorkGroupID.x > 0u)
+    {
+        uint _379 = gl_WorkGroupID.x - 1u;
+        row.mat = _376.parent[_379].mat;
+        row.translate = _376.parent[_379].translate;
+    }
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        Transform param_8 = row;
+        Transform param_9 = sh_scratch[gl_LocalInvocationID.x - 1u];
+        row = combine_monoid(param_8, param_9);
+    }
+    Alloc param_12;
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        Transform param_10 = row;
+        Transform param_11 = local[i_2];
+        Transform m = combine_monoid(param_10, param_11);
+        TransformSeg transform = TransformSeg{ m.mat, m.translate };
+        TransformSegRef trans_ref = TransformSegRef{ _278.conf.trans_alloc.offset + ((ix + i_2) * 24u) };
+        param_12.offset = _278.conf.trans_alloc.offset;
+        TransformSegRef param_13 = trans_ref;
+        TransformSeg param_14 = transform;
+        TransformSeg_write(param_12, param_13, param_14, v_71);
+    }
+}
+

piet-gpu/shader/gen/transform_reduce.hlsl

@@ -0,0 +1,140 @@
+struct TransformRef
+{
+    uint offset;
+};
+
+struct Transform
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+ByteAddressBuffer _49 : register(t2, space0);
+ByteAddressBuffer _161 : register(t1, space0);
+RWByteAddressBuffer _250 : register(u3, space0);
+RWByteAddressBuffer _266 : register(u0, space0);
+
+static uint3 gl_WorkGroupID;
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_WorkGroupID : SV_GroupID;
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared Transform sh_scratch[256];
+
+Transform Transform_read(TransformRef ref)
+{
+    uint ix = ref.offset >> uint(2);
+    uint raw0 = _49.Load((ix + 0u) * 4 + 0);
+    uint raw1 = _49.Load((ix + 1u) * 4 + 0);
+    uint raw2 = _49.Load((ix + 2u) * 4 + 0);
+    uint raw3 = _49.Load((ix + 3u) * 4 + 0);
+    uint raw4 = _49.Load((ix + 4u) * 4 + 0);
+    uint raw5 = _49.Load((ix + 5u) * 4 + 0);
+    Transform s;
+    s.mat = float4(asfloat(raw0), asfloat(raw1), asfloat(raw2), asfloat(raw3));
+    s.translate = float2(asfloat(raw4), asfloat(raw5));
+    return s;
+}
+
+TransformRef Transform_index(TransformRef ref, uint index)
+{
+    TransformRef _37 = { ref.offset + (index * 24u) };
+    return _37;
+}
+
+Transform combine_monoid(Transform a, Transform b)
+{
+    Transform c;
+    c.mat = (a.mat.xyxy * b.mat.xxzz) + (a.mat.zwzw * b.mat.yyww);
+    c.translate = ((a.mat.xy * b.translate.x) + (a.mat.zw * b.translate.y)) + a.translate;
+    return c;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    TransformRef _168 = { _161.Load(84) + (ix * 24u) };
+    TransformRef ref = _168;
+    TransformRef param = ref;
+    Transform agg = Transform_read(param);
+    for (uint i = 1u; i < 8u; i++)
+    {
+        TransformRef param_1 = ref;
+        uint param_2 = i;
+        TransformRef param_3 = Transform_index(param_1, param_2);
+        Transform param_4 = agg;
+        Transform param_5 = Transform_read(param_3);
+        agg = combine_monoid(param_4, param_5);
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if ((gl_LocalInvocationID.x + (1u << i_1)) < 256u)
+        {
+            Transform other = sh_scratch[gl_LocalInvocationID.x + (1u << i_1)];
+            Transform param_6 = agg;
+            Transform param_7 = other;
+            agg = combine_monoid(param_6, param_7);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        _250.Store4(gl_WorkGroupID.x * 32 + 0, asuint(agg.mat));
+        _250.Store2(gl_WorkGroupID.x * 32 + 16, asuint(agg.translate));
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_WorkGroupID = stage_input.gl_WorkGroupID;
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/transform_reduce.msl

@@ -0,0 +1,153 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct TransformRef
+{
+    uint offset;
+};
+
+struct Transform
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct SceneBuf
+{
+    uint scene[1];
+};
+
+struct Alloc
+{
+    uint offset;
+};
+
+struct Config
+{
+    uint n_elements;
+    uint n_pathseg;
+    uint width_in_tiles;
+    uint height_in_tiles;
+    Alloc tile_alloc;
+    Alloc bin_alloc;
+    Alloc ptcl_alloc;
+    Alloc pathseg_alloc;
+    Alloc anno_alloc;
+    Alloc trans_alloc;
+    Alloc path_bbox_alloc;
+    Alloc drawmonoid_alloc;
+    Alloc clip_alloc;
+    Alloc clip_bic_alloc;
+    Alloc clip_stack_alloc;
+    Alloc clip_bbox_alloc;
+    Alloc draw_bbox_alloc;
+    Alloc drawinfo_alloc;
+    uint n_trans;
+    uint n_path;
+    uint n_clip;
+    uint trans_offset;
+    uint linewidth_offset;
+    uint pathtag_offset;
+    uint pathseg_offset;
+    uint drawtag_offset;
+    uint drawdata_offset;
+};
+
+struct ConfigBuf
+{
+    Config conf;
+};
+
+struct Transform_1
+{
+    float4 mat;
+    float2 translate;
+    char _m0_final_padding[8];
+};
+
+struct OutBuf
+{
+    Transform_1 outbuf[1];
+};
+
+struct Memory
+{
+    uint mem_offset;
+    uint mem_error;
+    uint memory[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+Transform Transform_read(thread const TransformRef& ref, const device SceneBuf& v_49)
+{
+    uint ix = ref.offset >> uint(2);
+    uint raw0 = v_49.scene[ix + 0u];
+    uint raw1 = v_49.scene[ix + 1u];
+    uint raw2 = v_49.scene[ix + 2u];
+    uint raw3 = v_49.scene[ix + 3u];
+    uint raw4 = v_49.scene[ix + 4u];
+    uint raw5 = v_49.scene[ix + 5u];
+    Transform s;
+    s.mat = float4(as_type<float>(raw0), as_type<float>(raw1), as_type<float>(raw2), as_type<float>(raw3));
+    s.translate = float2(as_type<float>(raw4), as_type<float>(raw5));
+    return s;
+}
+
+static inline __attribute__((always_inline))
+TransformRef Transform_index(thread const TransformRef& ref, thread const uint& index)
+{
+    return TransformRef{ ref.offset + (index * 24u) };
+}
+
+static inline __attribute__((always_inline))
+Transform combine_monoid(thread const Transform& a, thread const Transform& b)
+{
+    Transform c;
+    c.mat = (a.mat.xyxy * b.mat.xxzz) + (a.mat.zwzw * b.mat.yyww);
+    c.translate = ((a.mat.xy * b.translate.x) + (a.mat.zw * b.translate.y)) + a.translate;
+    return c;
+}
+
+kernel void main0(const device ConfigBuf& _161 [[buffer(1)]], const device SceneBuf& v_49 [[buffer(2)]], device OutBuf& _250 [[buffer(3)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]], uint3 gl_WorkGroupID [[threadgroup_position_in_grid]])
+{
+    threadgroup Transform sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    TransformRef ref = TransformRef{ _161.conf.trans_offset + (ix * 24u) };
+    TransformRef param = ref;
+    Transform agg = Transform_read(param, v_49);
+    for (uint i = 1u; i < 8u; i++)
+    {
+        TransformRef param_1 = ref;
+        uint param_2 = i;
+        TransformRef param_3 = Transform_index(param_1, param_2);
+        Transform param_4 = agg;
+        Transform param_5 = Transform_read(param_3, v_49);
+        agg = combine_monoid(param_4, param_5);
+    }
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if ((gl_LocalInvocationID.x + (1u << i_1)) < 256u)
+        {
+            Transform other = sh_scratch[gl_LocalInvocationID.x + (1u << i_1)];
+            Transform param_6 = agg;
+            Transform param_7 = other;
+            agg = combine_monoid(param_6, param_7);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        _250.outbuf[gl_WorkGroupID.x].mat = agg.mat;
+        _250.outbuf[gl_WorkGroupID.x].translate = agg.translate;
+    }
+}
+

piet-gpu/shader/gen/transform_root.hlsl

@@ -0,0 +1,94 @@
+struct Transform
+{
+    float4 mat;
+    float2 translate;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+static const Transform _23 = { float4(1.0f, 0.0f, 0.0f, 1.0f), 0.0f.xx };
+
+RWByteAddressBuffer _89 : register(u0, space0);
+
+static uint3 gl_LocalInvocationID;
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+groupshared Transform sh_scratch[256];
+
+Transform combine_monoid(Transform a, Transform b)
+{
+    Transform c;
+    c.mat = (a.mat.xyxy * b.mat.xxzz) + (a.mat.zwzw * b.mat.yyww);
+    c.translate = ((a.mat.xy * b.translate.x) + (a.mat.zw * b.translate.y)) + a.translate;
+    return c;
+}
+
+Transform monoid_identity()
+{
+    return _23;
+}
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    Transform _93;
+    _93.mat = asfloat(_89.Load4(ix * 32 + 0));
+    _93.translate = asfloat(_89.Load2(ix * 32 + 16));
+    Transform local[8];
+    local[0].mat = _93.mat;
+    local[0].translate = _93.translate;
+    Transform param_1;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        Transform param = local[i - 1u];
+        Transform _119;
+        _119.mat = asfloat(_89.Load4((ix + i) * 32 + 0));
+        _119.translate = asfloat(_89.Load2((ix + i) * 32 + 16));
+        param_1.mat = _119.mat;
+        param_1.translate = _119.translate;
+        local[i] = combine_monoid(param, param_1);
+    }
+    Transform agg = local[7];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            Transform other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            Transform param_2 = other;
+            Transform param_3 = agg;
+            agg = combine_monoid(param_2, param_3);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    Transform row = monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        Transform param_4 = row;
+        Transform param_5 = local[i_2];
+        Transform m = combine_monoid(param_4, param_5);
+        uint _208 = ix + i_2;
+        _89.Store4(_208 * 32 + 0, asuint(m.mat));
+        _89.Store2(_208 * 32 + 16, asuint(m.translate));
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

piet-gpu/shader/gen/transform_root.msl

@@ -0,0 +1,129 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wmissing-braces"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+template<typename T, size_t Num>
+struct spvUnsafeArray
+{
+    T elements[Num ? Num : 1];
+    
+    thread T& operator [] (size_t pos) thread
+    {
+        return elements[pos];
+    }
+    constexpr const thread T& operator [] (size_t pos) const thread
+    {
+        return elements[pos];
+    }
+    
+    device T& operator [] (size_t pos) device
+    {
+        return elements[pos];
+    }
+    constexpr const device T& operator [] (size_t pos) const device
+    {
+        return elements[pos];
+    }
+    
+    constexpr const constant T& operator [] (size_t pos) const constant
+    {
+        return elements[pos];
+    }
+    
+    threadgroup T& operator [] (size_t pos) threadgroup
+    {
+        return elements[pos];
+    }
+    constexpr const threadgroup T& operator [] (size_t pos) const threadgroup
+    {
+        return elements[pos];
+    }
+};
+
+struct Transform
+{
+    float4 mat;
+    float2 translate;
+};
+
+struct Transform_1
+{
+    float4 mat;
+    float2 translate;
+    char _m0_final_padding[8];
+};
+
+struct DataBuf
+{
+    Transform_1 data[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+Transform combine_monoid(thread const Transform& a, thread const Transform& b)
+{
+    Transform c;
+    c.mat = (a.mat.xyxy * b.mat.xxzz) + (a.mat.zwzw * b.mat.yyww);
+    c.translate = ((a.mat.xy * b.translate.x) + (a.mat.zw * b.translate.y)) + a.translate;
+    return c;
+}
+
+static inline __attribute__((always_inline))
+Transform monoid_identity()
+{
+    return Transform{ float4(1.0, 0.0, 0.0, 1.0), float2(0.0) };
+}
+
+kernel void main0(device DataBuf& _89 [[buffer(0)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]], uint3 gl_LocalInvocationID [[thread_position_in_threadgroup]])
+{
+    threadgroup Transform sh_scratch[256];
+    uint ix = gl_GlobalInvocationID.x * 8u;
+    spvUnsafeArray<Transform, 8> local;
+    local[0].mat = _89.data[ix].mat;
+    local[0].translate = _89.data[ix].translate;
+    Transform param_1;
+    for (uint i = 1u; i < 8u; i++)
+    {
+        uint _113 = ix + i;
+        Transform param = local[i - 1u];
+        param_1.mat = _89.data[_113].mat;
+        param_1.translate = _89.data[_113].translate;
+        local[i] = combine_monoid(param, param_1);
+    }
+    Transform agg = local[7];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 8u; i_1++)
+    {
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            Transform other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            Transform param_2 = other;
+            Transform param_3 = agg;
+            agg = combine_monoid(param_2, param_3);
+        }
+        threadgroup_barrier(mem_flags::mem_threadgroup);
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    threadgroup_barrier(mem_flags::mem_threadgroup);
+    Transform row = monoid_identity();
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        row = sh_scratch[gl_LocalInvocationID.x - 1u];
+    }
+    for (uint i_2 = 0u; i_2 < 8u; i_2++)
+    {
+        Transform param_4 = row;
+        Transform param_5 = local[i_2];
+        Transform m = combine_monoid(param_4, param_5);
+        uint _208 = ix + i_2;
+        _89.data[_208].mat = m.mat;
+        _89.data[_208].translate = m.translate;
+    }
+}
+

tests/shader/gen/clear.hlsl

@@ -0,0 +1,26 @@
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+ByteAddressBuffer _19 : register(t0);
+RWByteAddressBuffer _32 : register(u1);
+
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+void comp_main()
+{
+    uint ix = gl_GlobalInvocationID.x;
+    if (ix < _19.Load(0))
+    {
+        _32.Store(ix * 4 + 0, _19.Load(4));
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

tests/shader/gen/clear.msl

@@ -0,0 +1,27 @@
+#include <metal_stdlib>
+#include <simd/simd.h>
+
+using namespace metal;
+
+struct ConfigBuf
+{
+    uint size;
+    uint value;
+};
+
+struct TargetBuf
+{
+    uint data[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+kernel void main0(const device ConfigBuf& _19 [[buffer(0)]], device TargetBuf& _32 [[buffer(1)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    uint ix = gl_GlobalInvocationID.x;
+    if (ix < _19.size)
+    {
+        _32.data[ix] = _19.value;
+    }
+}
+

tests/shader/gen/linkedlist.hlsl

@@ -0,0 +1,39 @@
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+RWByteAddressBuffer _56 : register(u0);
+
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+void comp_main()
+{
+    uint rng = gl_GlobalInvocationID.x + 1u;
+    for (uint i = 0u; i < 100u; i++)
+    {
+        rng ^= (rng << uint(13));
+        rng ^= (rng >> uint(17));
+        rng ^= (rng << uint(5));
+        uint bucket = rng % 65536u;
+        if (bucket != 0u)
+        {
+            uint _61;
+            _56.InterlockedAdd(0, 2u, _61);
+            uint alloc = _61 + 65536u;
+            uint _67;
+            _56.InterlockedExchange(bucket * 4 + 0, alloc, _67);
+            uint old = _67;
+            _56.Store(alloc * 4 + 0, old);
+            _56.Store((alloc + 1u) * 4 + 0, gl_GlobalInvocationID.x);
+        }
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

tests/shader/gen/linkedlist.msl

@@ -0,0 +1,36 @@
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_atomic>
+
+using namespace metal;
+
+struct MemBuf
+{
+    uint mem[1];
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+kernel void main0(device MemBuf& _56 [[buffer(0)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    uint rng = gl_GlobalInvocationID.x + 1u;
+    for (uint i = 0u; i < 100u; i++)
+    {
+        rng ^= (rng << uint(13));
+        rng ^= (rng >> uint(17));
+        rng ^= (rng << uint(5));
+        uint bucket = rng % 65536u;
+        if (bucket != 0u)
+        {
+            uint _61 = atomic_fetch_add_explicit((device atomic_uint*)&_56.mem[0], 2u, memory_order_relaxed);
+            uint alloc = _61 + 65536u;
+            uint _67 = atomic_exchange_explicit((device atomic_uint*)&_56.mem[bucket], alloc, memory_order_relaxed);
+            uint old = _67;
+            _56.mem[alloc] = old;
+            _56.mem[alloc + 1u] = gl_GlobalInvocationID.x;
+        }
+    }
+}
+

tests/shader/gen/message_passing.hlsl

@@ -0,0 +1,54 @@
+struct Element
+{
+    uint data;
+    uint flag;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(256u, 1u, 1u);
+
+RWByteAddressBuffer data_buf : register(u0);
+RWByteAddressBuffer control_buf : register(u1);
+
+static uint3 gl_GlobalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_GlobalInvocationID : SV_DispatchThreadID;
+};
+
+uint permute_flag_ix(uint data_ix)
+{
+    return (data_ix * 419u) & 65535u;
+}
+
+void comp_main()
+{
+    uint _76;
+    data_buf.InterlockedExchange(gl_GlobalInvocationID.x * 8 + 0, 1u, _76);
+    DeviceMemoryBarrier();
+    uint param = gl_GlobalInvocationID.x;
+    uint write_flag_ix = permute_flag_ix(param);
+    uint _77;
+    data_buf.InterlockedExchange(write_flag_ix * 8 + 4, 1u, _77);
+    uint read_ix = (gl_GlobalInvocationID.x * 4099u) & 65535u;
+    uint param_1 = read_ix;
+    uint read_flag_ix = permute_flag_ix(param_1);
+    uint _58;
+    data_buf.InterlockedAdd(read_flag_ix * 8 + 4, 0, _58);
+    uint flag = _58;
+    DeviceMemoryBarrier();
+    uint _62;
+    data_buf.InterlockedAdd(read_ix * 8 + 0, 0, _62);
+    uint data = _62;
+    if (flag > data)
+    {
+        uint _73;
+        control_buf.InterlockedAdd(0, 1u, _73);
+    }
+}
+
+[numthreads(256, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_GlobalInvocationID = stage_input.gl_GlobalInvocationID;
+    comp_main();
+}

tests/shader/gen/message_passing.msl

@@ -0,0 +1,54 @@
+#pragma clang diagnostic ignored "-Wmissing-prototypes"
+#pragma clang diagnostic ignored "-Wunused-variable"
+
+#include <metal_stdlib>
+#include <simd/simd.h>
+#include <metal_atomic>
+
+using namespace metal;
+
+struct Element
+{
+    uint data;
+    uint flag;
+};
+
+struct DataBuf
+{
+    Element data[1];
+};
+
+struct ControlBuf
+{
+    uint failures;
+};
+
+constant uint3 gl_WorkGroupSize [[maybe_unused]] = uint3(256u, 1u, 1u);
+
+static inline __attribute__((always_inline))
+uint permute_flag_ix(thread const uint& data_ix)
+{
+    return (data_ix * 419u) & 65535u;
+}
+
+kernel void main0(device DataBuf& data_buf [[buffer(0)]], device ControlBuf& control_buf [[buffer(1)]], uint3 gl_GlobalInvocationID [[thread_position_in_grid]])
+{
+    atomic_store_explicit((device atomic_uint*)&data_buf.data[gl_GlobalInvocationID.x].data, 1u, memory_order_relaxed);
+    threadgroup_barrier(mem_flags::mem_device);
+    uint param = gl_GlobalInvocationID.x;
+    uint write_flag_ix = permute_flag_ix(param);
+    atomic_store_explicit((device atomic_uint*)&data_buf.data[write_flag_ix].flag, 1u, memory_order_relaxed);
+    uint read_ix = (gl_GlobalInvocationID.x * 4099u) & 65535u;
+    uint param_1 = read_ix;
+    uint read_flag_ix = permute_flag_ix(param_1);
+    uint _58 = atomic_load_explicit((device atomic_uint*)&data_buf.data[read_flag_ix].flag, memory_order_relaxed);
+    uint flag = _58;
+    threadgroup_barrier(mem_flags::mem_device);
+    uint _62 = atomic_load_explicit((device atomic_uint*)&data_buf.data[read_ix].data, memory_order_relaxed);
+    uint data = _62;
+    if (flag > data)
+    {
+        uint _73 = atomic_fetch_add_explicit((device atomic_uint*)&control_buf.failures, 1u, memory_order_relaxed);
+    }
+}
+

tests/shader/gen/prefix.hlsl

@@ -0,0 +1,225 @@
+struct Monoid
+{
+    uint element;
+};
+
+struct State
+{
+    uint flag;
+    Monoid aggregate;
+    Monoid prefix;
+};
+
+static const uint3 gl_WorkGroupSize = uint3(512u, 1u, 1u);
+
+static const Monoid _185 = { 0u };
+
+globallycoherent RWByteAddressBuffer _43 : register(u2);
+ByteAddressBuffer _67 : register(t0);
+RWByteAddressBuffer _372 : register(u1);
+
+static uint3 gl_LocalInvocationID;
+struct SPIRV_Cross_Input
+{
+    uint3 gl_LocalInvocationID : SV_GroupThreadID;
+};
+
+groupshared uint sh_part_ix;
+groupshared Monoid sh_scratch[512];
+groupshared uint sh_flag;
+groupshared Monoid sh_prefix;
+
+Monoid combine_monoid(Monoid a, Monoid b)
+{
+    Monoid _22 = { a.element + b.element };
+    return _22;
+}
+
+void comp_main()
+{
+    if (gl_LocalInvocationID.x == 0u)
+    {
+        uint _47;
+        _43.InterlockedAdd(0, 1u, _47);
+        sh_part_ix = _47;
+    }
+    GroupMemoryBarrierWithGroupSync();
+    uint part_ix = sh_part_ix;
+    uint ix = (part_ix * 8192u) + (gl_LocalInvocationID.x * 16u);
+    Monoid _71;
+    _71.element = _67.Load(ix * 4 + 0);
+    Monoid local[16];
+    local[0].element = _71.element;
+    Monoid param_1;
+    for (uint i = 1u; i < 16u; i++)
+    {
+        Monoid param = local[i - 1u];
+        Monoid _94;
+        _94.element = _67.Load((ix + i) * 4 + 0);
+        param_1.element = _94.element;
+        local[i] = combine_monoid(param, param_1);
+    }
+    Monoid agg = local[15];
+    sh_scratch[gl_LocalInvocationID.x] = agg;
+    for (uint i_1 = 0u; i_1 < 9u; i_1++)
+    {
+        GroupMemoryBarrierWithGroupSync();
+        if (gl_LocalInvocationID.x >= (1u << i_1))
+        {
+            Monoid other = sh_scratch[gl_LocalInvocationID.x - (1u << i_1)];
+            Monoid param_2 = other;
+            Monoid param_3 = agg;
+            agg = combine_monoid(param_2, param_3);
+        }
+        GroupMemoryBarrierWithGroupSync();
+        sh_scratch[gl_LocalInvocationID.x] = agg;
+    }
+    if (gl_LocalInvocationID.x == 511u)
+    {
+        _43.Store(part_ix * 12 + 8, agg.element);
+        if (part_ix == 0u)
+        {
+            _43.Store(12, agg.element);
+        }
+    }
+    DeviceMemoryBarrier();
+    if (gl_LocalInvocationID.x == 511u)
+    {
+        uint flag = 1u;
+        if (part_ix == 0u)
+        {
+            flag = 2u;
+        }
+        _43.Store(part_ix * 12 + 4, flag);
+    }
+    Monoid exclusive = _185;
+    if (part_ix != 0u)
+    {
+        uint look_back_ix = part_ix - 1u;
+        uint their_ix = 0u;
+        Monoid their_prefix;
+        Monoid their_agg;
+        Monoid m;
+        while (true)
+        {
+            if (gl_LocalInvocationID.x == 511u)
+            {
+                sh_flag = _43.Load(look_back_ix * 12 + 4);
+            }
+            GroupMemoryBarrierWithGroupSync();
+            DeviceMemoryBarrier();
+            uint flag_1 = sh_flag;
+            GroupMemoryBarrierWithGroupSync();
+            if (flag_1 == 2u)
+            {
+                if (gl_LocalInvocationID.x == 511u)
+                {
+                    Monoid _223;
+                    _223.element = _43.Load(look_back_ix * 12 + 12);
+                    their_prefix.element = _223.element;
+                    Monoid param_4 = their_prefix;
+                    Monoid param_5 = exclusive;
+                    exclusive = combine_monoid(param_4, param_5);
+                }
+                break;
+            }
+            else
+            {
+                if (flag_1 == 1u)
+                {
+                    if (gl_LocalInvocationID.x == 511u)
+                    {
+                        Monoid _245;
+                        _245.element = _43.Load(look_back_ix * 12 + 8);
+                        their_agg.element = _245.element;
+                        Monoid param_6 = their_agg;
+                        Monoid param_7 = exclusive;
+                        exclusive = combine_monoid(param_6, param_7);
+                    }
+                    look_back_ix--;
+                    their_ix = 0u;
+                    continue;
+                }
+            }
+            if (gl_LocalInvocationID.x == 511u)
+            {
+                Monoid _267;
+                _267.element = _67.Load(((look_back_ix * 8192u) + their_ix) * 4 + 0);
+                m.element = _267.element;
+                if (their_ix == 0u)
+                {
+                    their_agg = m;
+                }
+                else
+                {
+                    Monoid param_8 = their_agg;
+                    Monoid param_9 = m;
+                    their_agg = combine_monoid(param_8, param_9);
+                }
+                their_ix++;
+                if (their_ix == 8192u)
+                {
+                    Monoid param_10 = their_agg;
+                    Monoid param_11 = exclusive;
+                    exclusive = combine_monoid(param_10, param_11);
+                    if (look_back_ix == 0u)
+                    {
+                        sh_flag = 2u;
+                    }
+                    else
+                    {
+                        look_back_ix--;
+                        their_ix = 0u;
+                    }
+                }
+            }
+            GroupMemoryBarrierWithGroupSync();
+            flag_1 = sh_flag;
+            GroupMemoryBarrierWithGroupSync();
+            if (flag_1 == 2u)
+            {
+                break;
+            }
+        }
+        if (gl_LocalInvocationID.x == 511u)
+        {
+            Monoid param_12 = exclusive;
+            Monoid param_13 = agg;
+            Monoid inclusive_prefix = combine_monoid(param_12, param_13);
+            sh_prefix = exclusive;
+            _43.Store(part_ix * 12 + 12, inclusive_prefix.element);
+        }
+        DeviceMemoryBarrier();
+        if (gl_LocalInvocationID.x == 511u)
+        {
+            _43.Store(part_ix * 12 + 4, 2u);
+        }
+    }
+    GroupMemoryBarrierWithGroupSync();
+    if (part_ix != 0u)
+    {
+        exclusive = sh_prefix;
+    }
+    Monoid row = exclusive;
+    if (gl_LocalInvocationID.x > 0u)
+    {
+        Monoid other_1 = sh_scratch[gl_LocalInvocationID.x - 1u];
+        Monoid param_14 = row;
+        Monoid param_15 = other_1;
+        row = combine_monoid(param_14, param_15);
+    }
+    for (uint i_2 = 0u; i_2 < 16u; i_2++)
+    {
+        Monoid param_16 = row;
+        Monoid param_17 = local[i_2];
+        Monoid m_1 = combine_monoid(param_16, param_17);
+        _372.Store((ix + i_2) * 4 + 0, m_1.element);
+    }
+}
+
+[numthreads(512, 1, 1)]
+void main(SPIRV_Cross_Input stage_input)
+{
+    gl_LocalInvocationID = stage_input.gl_LocalInvocationID;
+    comp_main();
+}