vello/piet-gpu/shader/gen/draw_leaf.msl

#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)) & 28u };
}

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& _284 [[buffer(0)]], const device ConfigBuf& _92 [[buffer(1)]], const device SceneBuf& _102 [[buffer(2)]], const device ParentBuf& _202 [[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 = _92.conf.drawtag_offset >> uint(2);
    uint tag_word = _102.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 = _102.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 _205 = gl_WorkGroupID.x - 1u;
        row.path_ix = _202.parent[_205].path_ix;
        row.clip_ix = _202.parent[_205].clip_ix;
        row.scene_offset = _202.parent[_205].scene_offset;
        row.info_offset = _202.parent[_205].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 = _92.conf.drawdata_offset >> uint(2);
    uint drawinfo_base = _92.conf.drawinfo_alloc.offset >> uint(2);
    uint out_ix = gl_GlobalInvocationID.x * 8u;
    uint out_base = (_92.conf.drawmonoid_alloc.offset >> uint(2)) + (out_ix * 4u);
    uint clip_out_base = _92.conf.clip_alloc.offset >> uint(2);
    float4 mat;
    float2 translate;
    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);
        }
        _284.memory[out_base + (i_2 * 4u)] = m.path_ix;
        _284.memory[(out_base + (i_2 * 4u)) + 1u] = m.clip_ix;
        _284.memory[(out_base + (i_2 * 4u)) + 2u] = m.scene_offset;
        _284.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 = _102.scene[(drawtag_base + ix) + i_2];
        if ((((tag_word == 68u) || (tag_word == 276u)) || (tag_word == 72u)) || (tag_word == 5u))
        {
            uint bbox_offset = (_92.conf.path_bbox_alloc.offset >> uint(2)) + (6u * m.path_ix);
            float bbox_l = float(_284.memory[bbox_offset]) - 32768.0;
            float bbox_t = float(_284.memory[bbox_offset + 1u]) - 32768.0;
            float bbox_r = float(_284.memory[bbox_offset + 2u]) - 32768.0;
            float bbox_b = float(_284.memory[bbox_offset + 3u]) - 32768.0;
            float4 bbox = float4(bbox_l, bbox_t, bbox_r, bbox_b);
            float linewidth = as_type<float>(_284.memory[bbox_offset + 4u]);
            uint fill_mode = uint(linewidth >= 0.0);
            if ((linewidth >= 0.0) || (tag_word == 276u))
            {
                uint trans_ix = _284.memory[bbox_offset + 5u];
                uint t = (_92.conf.trans_alloc.offset >> uint(2)) + (6u * trans_ix);
                mat = as_type<float4>(uint4(_284.memory[t], _284.memory[t + 1u], _284.memory[t + 2u], _284.memory[t + 3u]));
                if (tag_word == 276u)
                {
                    translate = as_type<float2>(uint2(_284.memory[t + 4u], _284.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:
                {
                    _284.memory[di] = as_type<uint>(linewidth);
                    break;
                }
                case 276u:
                {
                    _284.memory[di] = as_type<uint>(linewidth);
                    uint index = _102.scene[dd];
                    float2 p0 = as_type<float2>(uint2(_102.scene[dd + 1u], _102.scene[dd + 2u]));
                    float2 p1 = as_type<float2>(uint2(_102.scene[dd + 3u], _102.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));
                    _284.memory[di + 1u] = as_type<uint>(line_x);
                    _284.memory[di + 2u] = as_type<uint>(line_y);
                    _284.memory[di + 3u] = as_type<uint>(line_c);
                    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;
            }
            _284.memory[clip_out_base + m.clip_ix] = path_ix;
        }
    }
}