Query extensions at runtime

Don't run extensions unless they're available. This includes querying
for descriptor indexing, and running one of two versions of kernel4
depending on whether it's enabled.

Part of the support needed for #78

Cargo.lock

@@ -797,7 +797,6 @@ version = "0.1.0"
 dependencies = [
  "ash",
  "ash-window",
- "once_cell",
  "raw-window-handle",
 ]
 

piet-gpu-derive/src/glsl.rs

@@ -157,7 +157,12 @@ fn gen_enum_read(
         writeln!(r, "{}Tag {}_tag({}Ref ref) {{", name, name, name).unwrap();
         writeln!(r, "    uint tag_and_flags = {}[ref.offset >> 2];", bufname).unwrap();
     }
-    writeln!(r, "    return {}Tag(tag_and_flags & 0xffff, tag_and_flags >> 16);", name).unwrap();
+    writeln!(
+        r,
+        "    return {}Tag(tag_and_flags & 0xffff, tag_and_flags >> 16);",
+        name
+    )
+    .unwrap();
     writeln!(r, "}}\n").unwrap();
     for (var_name, payload) in variants {
         let payload_ix = if payload.len() == 1 {
@@ -564,7 +569,9 @@ fn gen_enum_write(
                 }
                 writeln!(r, "}}\n").unwrap();
             }
-        } else if payload.len() == 2 && matches!(payload[0].1.ty, GpuType::Scalar(GpuScalar::TagFlags)) {
+        } else if payload.len() == 2
+            && matches!(payload[0].1.ty, GpuType::Scalar(GpuScalar::TagFlags))
+        {
             if let GpuType::InlineStruct(structname) = &payload[1].1.ty {
                 if is_mem {
                     writeln!(

piet-gpu-hal/Cargo.toml

@@ -8,6 +8,5 @@ edition = "2018"
 
 [dependencies]
 ash = "0.31"
-once_cell = "1.3.1"
 ash-window = "0.5"
 raw-window-handle = "0.3"

piet-gpu-hal/src/hub.rs

@@ -209,6 +209,13 @@ impl Session {
     pub unsafe fn create_sampler(&self, params: SamplerParams) -> Result<Sampler, Error> {
         self.0.device.create_sampler(params)
     }
+
+    /// Report whether the device supports descriptor indexing.
+    ///
+    /// As we have more queries, we might replace this with a capabilities structure.
+    pub fn has_descriptor_indexing(&self) -> bool {
+        self.0.device.has_descriptor_indexing
+    }
 }
 
 impl CmdBuf {

piet-gpu-hal/src/vulkan.rs

@@ -2,12 +2,12 @@
 
 use std::borrow::Cow;
 use std::ffi::{CStr, CString};
+use std::os::raw::c_char;
 use std::sync::Arc;
 
 use ash::extensions::{ext::DebugUtils, khr};
 use ash::version::{DeviceV1_0, EntryV1_0, InstanceV1_0};
 use ash::{vk, Device, Entry, Instance};
-use once_cell::sync::Lazy;
 
 use crate::{Device as DeviceTrait, Error, ImageLayout, SamplerParams};
 
@@ -16,6 +16,7 @@ pub struct VkInstance {
     #[allow(unused)]
     entry: Entry,
     instance: Instance,
+    get_phys_dev_props: Option<vk::KhrGetPhysicalDeviceProperties2Fn>,
     _dbg_loader: Option<DebugUtils>,
     _dbg_callbk: Option<vk::DebugUtilsMessengerEXT>,
 }
@@ -27,6 +28,8 @@ pub struct VkDevice {
     queue: vk::Queue,
     qfi: u32,
     timestamp_period: f32,
+    /// Does the device support descriptor indexing?
+    pub has_descriptor_indexing: bool,
 }
 
 struct RawDevice {
@@ -95,6 +98,7 @@ pub struct PipelineBuilder {
     bindings: Vec<vk::DescriptorSetLayoutBinding>,
     binding_flags: Vec<vk::DescriptorBindingFlags>,
     max_textures: u32,
+    has_descriptor_indexing: bool,
 }
 
 pub struct DescriptorSetBuilder {
@@ -104,6 +108,16 @@ pub struct DescriptorSetBuilder {
     sampler: vk::Sampler,
 }
 
+struct Extensions {
+    exts: Vec<*const c_char>,
+    exist_exts: Vec<vk::ExtensionProperties>,
+}
+
+struct Layers {
+    layers: Vec<*const c_char>,
+    exist_layers: Vec<vk::LayerProperties>,
+}
+
 unsafe extern "system" fn vulkan_debug_callback(
     message_severity: vk::DebugUtilsMessageSeverityFlagsEXT,
     message_type: vk::DebugUtilsMessageTypeFlagsEXT,
@@ -133,24 +147,6 @@ unsafe extern "system" fn vulkan_debug_callback(
     vk::FALSE
 }
 
-static LAYERS: Lazy<Vec<&'static CStr>> = Lazy::new(|| {
-    let mut layers: Vec<&'static CStr> = vec![];
-    if cfg!(debug_assertions) {
-        layers.push(CStr::from_bytes_with_nul(b"VK_LAYER_KHRONOS_validation\0").unwrap());
-    }
-    layers
-});
-
-static EXTS: Lazy<Vec<&'static CStr>> = Lazy::new(|| {
-    let mut exts: Vec<&'static CStr> = vec![];
-    if cfg!(debug_assertions) {
-        exts.push(DebugUtils::name());
-    }
-    // We'll need this to do runtime query of descriptor indexing.
-    //exts.push(vk::KhrGetPhysicalDeviceProperties2Fn::name());
-    exts
-});
-
 impl VkInstance {
     /// Create a new instance.
     ///
@@ -166,50 +162,24 @@ impl VkInstance {
             let app_name = CString::new("VkToy").unwrap();
             let entry = Entry::new()?;
 
-            let exist_layers = entry.enumerate_instance_layer_properties()?;
+            let mut layers = Layers::new(entry.enumerate_instance_layer_properties()?);
-            let layers = LAYERS
+            if cfg!(debug_assertions) {
-                .iter()
+                layers
-                .filter_map(|&lyr| {
+                    .try_add(CStr::from_bytes_with_nul(b"VK_LAYER_KHRONOS_validation\0").unwrap());
-                    exist_layers
+            }
-                        .iter()
+
-                        .find(|x| CStr::from_ptr(x.layer_name.as_ptr()) == lyr)
+            let mut exts = Extensions::new(entry.enumerate_instance_extension_properties()?);
-                        .map(|_| lyr.as_ptr())
+            let mut has_debug_ext = false;
-                        .or_else(|| {
+            if cfg!(debug_assertions) {
-                            println!(
+                has_debug_ext = exts.try_add(DebugUtils::name());
-                                "Unable to find layer: {}, have you installed the Vulkan SDK?",
+            }
-                                lyr.to_string_lossy()
+            // We'll need this to do runtime query of descriptor indexing.
-                            );
+            let has_phys_dev_props = exts.try_add(vk::KhrGetPhysicalDeviceProperties2Fn::name());
-                            None
+            if let Some(ref handle) = window_handle {
-                        })
+                for ext in ash_window::enumerate_required_extensions(*handle)? {
-                })
+                    exts.try_add(ext);
-                .collect::<Vec<_>>();
+                }
-
-            let exist_exts = entry.enumerate_instance_extension_properties()?;
-            let mut exts = EXTS
-                .iter()
-                .filter_map(|&ext| {
-                    exist_exts
-                        .iter()
-                        .find(|x| CStr::from_ptr(x.extension_name.as_ptr()) == ext)
-                        .map(|_| ext.as_ptr())
-                        .or_else(|| {
-                            println!(
-                                "Unable to find extension: {}, have you installed the Vulkan SDK?",
-                                ext.to_string_lossy()
-                            );
-                            None
-                        })
-                })
-                .collect::<Vec<_>>();
-
-            let surface_extensions = match window_handle {
-                Some(ref handle) => ash_window::enumerate_required_extensions(*handle)?,
-                None => vec![],
-            };
-            for extension in surface_extensions {
-                exts.push(extension.as_ptr());
             }
-            exts.push(vk::KhrGetPhysicalDeviceProperties2Fn::name().as_ptr());
 
             let instance = entry.create_instance(
                 &vk::InstanceCreateInfo::builder()
@@ -220,12 +190,12 @@ impl VkInstance {
                             .engine_name(&app_name)
                             .api_version(vk::make_version(1, 0, 0)),
                     )
-                    .enabled_layer_names(&layers)
+                    .enabled_layer_names(layers.as_ptrs())
-                    .enabled_extension_names(&exts),
+                    .enabled_extension_names(exts.as_ptrs()),
                 None,
             )?;
 
-            let (_dbg_loader, _dbg_callbk) = if cfg!(debug_assertions) {
+            let (_dbg_loader, _dbg_callbk) = if has_debug_ext {
                 let dbg_info = vk::DebugUtilsMessengerCreateInfoEXT::builder()
                     .message_severity(
                         vk::DebugUtilsMessageSeverityFlagsEXT::ERROR
@@ -250,9 +220,20 @@ impl VkInstance {
                 None => None,
             };
 
+            let get_phys_dev_props = if has_phys_dev_props {
+                Some(vk::KhrGetPhysicalDeviceProperties2Fn::load(|name| {
+                    std::mem::transmute(
+                        entry.get_instance_proc_addr(instance.handle(), name.as_ptr()),
+                    )
+                }))
+            } else {
+                None
+            };
+
             let vk_instance = VkInstance {
                 entry,
                 instance,
+                get_phys_dev_props,
                 _dbg_loader,
                 _dbg_callbk,
             };
@@ -273,14 +254,30 @@ impl VkInstance {
         let (pdevice, qfi) =
             choose_compute_device(&self.instance, &devices, surface).ok_or("no suitable device")?;
 
+        let mut has_descriptor_indexing = false;
+        if let Some(ref get_phys_dev_props) = self.get_phys_dev_props {
+            let mut descriptor_indexing_features =
+                vk::PhysicalDeviceDescriptorIndexingFeatures::builder();
+            // See https://github.com/MaikKlein/ash/issues/325 for why we do this workaround.
+            let mut features_v2 = vk::PhysicalDeviceFeatures2::default();
+            features_v2.p_next =
+                &mut descriptor_indexing_features as *mut _ as *mut std::ffi::c_void;
+            get_phys_dev_props.get_physical_device_features2_khr(pdevice, &mut features_v2);
+            has_descriptor_indexing = descriptor_indexing_features
+                .shader_storage_image_array_non_uniform_indexing
+                == vk::TRUE
+                && descriptor_indexing_features.descriptor_binding_variable_descriptor_count
+                    == vk::TRUE
+                && descriptor_indexing_features.runtime_descriptor_array == vk::TRUE;
+        }
+
         let queue_priorities = [1.0];
         let queue_create_infos = [vk::DeviceQueueCreateInfo::builder()
             .queue_family_index(qfi)
             .queue_priorities(&queue_priorities)
             .build()];
 
-        // support for descriptor indexing (maybe should be optional for compatibility)
+        let mut descriptor_indexing = vk::PhysicalDeviceDescriptorIndexingFeatures::builder()
-        let descriptor_indexing = vk::PhysicalDeviceDescriptorIndexingFeatures::builder()
             .shader_storage_image_array_non_uniform_indexing(true)
             .descriptor_binding_variable_descriptor_count(true)
             .runtime_descriptor_array(true);
@@ -291,11 +288,12 @@ impl VkInstance {
         };
         extensions.push(vk::ExtDescriptorIndexingFn::name().as_ptr());
         extensions.push(vk::KhrMaintenance3Fn::name().as_ptr());
-        let create_info = vk::DeviceCreateInfo::builder()
+        let mut create_info = vk::DeviceCreateInfo::builder()
             .queue_create_infos(&queue_create_infos)
-            .enabled_extension_names(&extensions)
+            .enabled_extension_names(&extensions);
-            .push_next(&mut descriptor_indexing.build())
+        if has_descriptor_indexing {
-            .build();
+            create_info = create_info.push_next(&mut descriptor_indexing);
+        }
         let device = self.instance.create_device(pdevice, &create_info, None)?;
 
         let device_mem_props = self.instance.get_physical_device_memory_properties(pdevice);
@@ -315,6 +313,7 @@ impl VkInstance {
             qfi,
             queue,
             timestamp_period,
+            has_descriptor_indexing,
         })
     }
 
@@ -569,6 +568,7 @@ impl crate::Device for VkDevice {
             bindings: Vec::new(),
             binding_flags: Vec::new(),
             max_textures: 0,
+            has_descriptor_indexing: self.has_descriptor_indexing,
         }
     }
 
@@ -711,7 +711,8 @@ impl crate::Device for VkDevice {
             SamplerParams::Linear => vk::Filter::LINEAR,
             SamplerParams::Nearest => vk::Filter::NEAREST,
         };
-        let sampler = device.create_sampler(&vk::SamplerCreateInfo::builder()
+        let sampler = device.create_sampler(
+            &vk::SamplerCreateInfo::builder()
                 .mag_filter(filter)
                 .min_filter(filter)
                 .mipmap_mode(vk::SamplerMipmapMode::LINEAR)
@@ -724,8 +725,9 @@ impl crate::Device for VkDevice {
                 .max_lod(0.0)
                 .border_color(vk::BorderColor::FLOAT_TRANSPARENT_BLACK)
                 .max_anisotropy(1.0)
-            .anisotropy_enable(false)
+                .anisotropy_enable(false),
-        , None)?;
+            None,
+        )?;
         Ok(sampler)
     }
 }
@@ -1007,8 +1009,12 @@ impl crate::PipelineBuilder<VkDevice> for PipelineBuilder {
                 .stage_flags(vk::ShaderStageFlags::COMPUTE)
                 .build(),
         );
-        self.binding_flags
+        let flags = if self.has_descriptor_indexing {
-            .push(vk::DescriptorBindingFlags::VARIABLE_DESCRIPTOR_COUNT);
+            vk::DescriptorBindingFlags::VARIABLE_DESCRIPTOR_COUNT
+        } else {
+            Default::default()
+        };
+        self.binding_flags.push(flags);
         self.max_textures += max_textures;
     }
 
@@ -1231,6 +1237,64 @@ impl VkSwapchain {
     }
 }
 
+impl Extensions {
+    fn new(exist_exts: Vec<vk::ExtensionProperties>) -> Extensions {
+        Extensions {
+            exist_exts,
+            exts: vec![],
+        }
+    }
+
+    fn try_add(&mut self, ext: &'static CStr) -> bool {
+        unsafe {
+            if self
+                .exist_exts
+                .iter()
+                .find(|x| CStr::from_ptr(x.extension_name.as_ptr()) == ext)
+                .is_some()
+            {
+                self.exts.push(ext.as_ptr());
+                true
+            } else {
+                false
+            }
+        }
+    }
+
+    fn as_ptrs(&self) -> &[*const c_char] {
+        &self.exts
+    }
+}
+
+impl Layers {
+    fn new(exist_layers: Vec<vk::LayerProperties>) -> Layers {
+        Layers {
+            exist_layers,
+            layers: vec![],
+        }
+    }
+
+    fn try_add(&mut self, ext: &'static CStr) -> bool {
+        unsafe {
+            if self
+                .exist_layers
+                .iter()
+                .find(|x| CStr::from_ptr(x.layer_name.as_ptr()) == ext)
+                .is_some()
+            {
+                self.layers.push(ext.as_ptr());
+                true
+            } else {
+                false
+            }
+        }
+    }
+
+    fn as_ptrs(&self) -> &[*const c_char] {
+        &self.layers
+    }
+}
+
 unsafe fn choose_compute_device(
     instance: &Instance,
     devices: &[vk::PhysicalDevice],

piet-gpu/bin/winit.rs

@@ -25,7 +25,8 @@ fn main() -> Result<(), Error> {
     let (instance, surface) = VkInstance::new(Some(&window))?;
     unsafe {
         let device = instance.device(surface.as_ref())?;
-        let mut swapchain = instance.swapchain(WIDTH / 2, HEIGHT / 2, &device, surface.as_ref().unwrap())?;
+        let mut swapchain =
+            instance.swapchain(WIDTH / 2, HEIGHT / 2, &device, surface.as_ref().unwrap())?;
         let session = hub::Session::new(device);
 
         let mut current_frame = 0;

piet-gpu/shader/build.ninja

@@ -5,7 +5,7 @@
 glslang_validator = glslangValidator
 
 rule glsl
-  command = $glslang_validator -V -o $out $in
+  command = $glslang_validator $flags -V -o $out $in
 
 
 build elements.spv: glsl elements.comp | scene.h state.h annotated.h
@@ -21,3 +21,6 @@ build backdrop.spv: glsl backdrop.comp | annotated.h tile.h setup.h
 build coarse.spv: glsl coarse.comp | annotated.h bins.h ptcl.h setup.h
 
 build kernel4.spv: glsl kernel4.comp | ptcl.h setup.h
+
+build kernel4_idx.spv: glsl kernel4.comp | ptcl.h setup.h
+  flags = -DENABLE_IMAGE_INDICES

piet-gpu/shader/kernel4.comp

@@ -8,7 +8,9 @@
 
 #version 450
 #extension GL_GOOGLE_include_directive : enable
+#ifdef ENABLE_IMAGE_INDICES
 #extension GL_EXT_nonuniform_qualifier : enable
+#endif
 
 #include "mem.h"
 #include "setup.h"
@@ -26,7 +28,7 @@ layout(set = 0, binding = 1) readonly buffer ConfigBuf {
 
 layout(rgba8, set = 0, binding = 2) uniform writeonly image2D image;
 
-#if GL_EXT_nonuniform_qualifier
+#ifdef ENABLE_IMAGE_INDICES
 layout(rgba8, set = 0, binding = 3) uniform readonly image2D images[];
 #else
 layout(rgba8, set = 0, binding = 3) uniform readonly image2D images[1];
@@ -128,6 +130,10 @@ void main() {
         if (xy_uint.x < 1024 && xy_uint.y < 1024) {
             rgb[i] = imageLoad(images[gl_WorkGroupID.x / 64], ivec2(xy_uint + chunk_offset(i))/4).rgb;
         }
+#else
+        if (xy_uint.x < 1024 && xy_uint.y < 1024) {
+            rgb[i] = imageLoad(images[0], ivec2(xy_uint + chunk_offset(i))/4).rgb;
+        }
 #endif
     }
 

piet-gpu/shader/setup.h

@@ -15,7 +15,8 @@
 
 #define PTCL_INITIAL_ALLOC 1024
 
-#define ENABLE_IMAGE_INDICES
+// This is now set in the ninja file during compilation
+//#define ENABLE_IMAGE_INDICES
 
 // These should probably be renamed and/or reworked. In the binning
 // kernel, they represent the number of bins. Also, the workgroup size

piet-gpu/src/lib.rs

@@ -12,7 +12,7 @@ use piet::{Color, ImageFormat, RenderContext};
 
 use piet_gpu_types::encoder::Encode;
 
-use piet_gpu_hal::{hub};
+use piet_gpu_hal::hub;
 use piet_gpu_hal::{CmdBuf, Error, ImageLayout, MemFlags};
 
 use pico_svg::PicoSvg;
@@ -132,11 +132,20 @@ fn render_alpha_test(rc: &mut impl RenderContext) {
     // [α,sRGB(α⋅R),sRGB(α⋅G),sRGB(α⋅B)]
     //
     // See also http://ssp.impulsetrain.com/gamma-premult.html.
-    rc.fill(diamond(Point::new(1024.0, 100.0)), &Color::Rgba32(0xff0000ff));
+    rc.fill(
-    rc.fill(diamond(Point::new(1024.0, 125.0)), &Color::Rgba32(0x00ba0080));
+        diamond(Point::new(1024.0, 100.0)),
+        &Color::Rgba32(0xff0000ff),
+    );
+    rc.fill(
+        diamond(Point::new(1024.0, 125.0)),
+        &Color::Rgba32(0x00ba0080),
+    );
     rc.save();
     rc.clip(diamond(Point::new(1024.0, 150.0)));
-    rc.fill(diamond(Point::new(1024.0, 175.0)), &Color::Rgba32(0x0000ba80));
+    rc.fill(
+        diamond(Point::new(1024.0, 175.0)),
+        &Color::Rgba32(0x0000ba80),
+    );
     rc.restore();
 }
 
@@ -252,7 +261,7 @@ impl Renderer {
         let state_buf = session.create_buffer(1 * 1024 * 1024, dev)?;
         let image_dev = session.create_image2d(WIDTH as u32, HEIGHT as u32, dev)?;
 
-        const CONFIG_SIZE: u64 = 10*4; // Size of Config in setup.h.
+        const CONFIG_SIZE: u64 = 10 * 4; // Size of Config in setup.h.
         let mut config_buf_host = session.create_buffer(CONFIG_SIZE, host)?;
         let config_buf_dev = session.create_buffer(CONFIG_SIZE, dev)?;
 
@@ -275,9 +284,20 @@ impl Renderer {
         alloc += (n_paths * ANNO_SIZE + 3) & !3;
         let trans_base = alloc;
         alloc += (n_trans * TRANS_SIZE + 3) & !3;
-        config_buf_host.write(&[n_paths as u32, n_pathseg as u32, WIDTH_IN_TILES as u32, HEIGHT_IN_TILES as u32, tile_base as u32, bin_base as u32, ptcl_base as u32, pathseg_base as u32, anno_base as u32, trans_base as u32])?;
+        config_buf_host.write(&[
+            n_paths as u32,
+            n_pathseg as u32,
+            WIDTH_IN_TILES as u32,
+            HEIGHT_IN_TILES as u32,
+            tile_base as u32,
+            bin_base as u32,
+            ptcl_base as u32,
+            pathseg_base as u32,
+            anno_base as u32,
+            trans_base as u32,
+        ])?;
 
-        let mut memory_buf_host = session.create_buffer(2*4, host)?;
+        let mut memory_buf_host = session.create_buffer(2 * 4, host)?;
         let memory_buf_dev = session.create_buffer(128 * 1024 * 1024, dev)?;
         memory_buf_host.write(&[alloc as u32, 0 /* Overflow flag */])?;
 
@@ -290,17 +310,13 @@ impl Renderer {
 
         let tile_alloc_code = include_bytes!("../shader/tile_alloc.spv");
         let tile_pipeline = session.create_simple_compute_pipeline(tile_alloc_code, 2)?;
-        let tile_ds = session.create_simple_descriptor_set(
+        let tile_ds = session
-            &tile_pipeline,
+            .create_simple_descriptor_set(&tile_pipeline, &[&memory_buf_dev, &config_buf_dev])?;
-            &[&memory_buf_dev, &config_buf_dev],
-        )?;
 
         let path_alloc_code = include_bytes!("../shader/path_coarse.spv");
         let path_pipeline = session.create_simple_compute_pipeline(path_alloc_code, 2)?;
-        let path_ds = session.create_simple_descriptor_set(
+        let path_ds = session
-            &path_pipeline,
+            .create_simple_descriptor_set(&path_pipeline, &[&memory_buf_dev, &config_buf_dev])?;
-            &[&memory_buf_dev, &config_buf_dev],
-        )?;
 
         let backdrop_alloc_code = include_bytes!("../shader/backdrop.spv");
         let backdrop_pipeline = session.create_simple_compute_pipeline(backdrop_alloc_code, 2)?;
@@ -312,21 +328,22 @@ impl Renderer {
         // TODO: constants
         let bin_code = include_bytes!("../shader/binning.spv");
         let bin_pipeline = session.create_simple_compute_pipeline(bin_code, 2)?;
-        let bin_ds = session.create_simple_descriptor_set(
+        let bin_ds = session
-            &bin_pipeline,
+            .create_simple_descriptor_set(&bin_pipeline, &[&memory_buf_dev, &config_buf_dev])?;
-            &[&memory_buf_dev, &config_buf_dev],
-        )?;
 
         let coarse_code = include_bytes!("../shader/coarse.spv");
         let coarse_pipeline = session.create_simple_compute_pipeline(coarse_code, 2)?;
-        let coarse_ds = session.create_simple_descriptor_set(
+        let coarse_ds = session
-            &coarse_pipeline,
+            .create_simple_descriptor_set(&coarse_pipeline, &[&memory_buf_dev, &config_buf_dev])?;
-            &[&memory_buf_dev, &config_buf_dev],
-        )?;
 
         let bg_image = Self::make_test_bg_image(&session);
 
-        let k4_code = include_bytes!("../shader/kernel4.spv");
+        let k4_code = if session.has_descriptor_indexing() {
+            &include_bytes!("../shader/kernel4_idx.spv")[..]
+        } else {
+            println!("doing non-indexed k4");
+            &include_bytes!("../shader/kernel4.spv")[..]
+        };
         // This is an arbitrary limit on the number of textures that can be referenced by
         // the fine rasterizer. To set it for real, we probably want to pay attention both
         // to the device limit (maxDescriptorSetSampledImages) but also to the number of
@@ -381,7 +398,10 @@ impl Renderer {
     }
 
     pub unsafe fn record(&self, cmd_buf: &mut hub::CmdBuf, query_pool: &hub::QueryPool) {
-        cmd_buf.copy_buffer(self.scene_buf_host.vk_buffer(), self.scene_buf_dev.vk_buffer());
+        cmd_buf.copy_buffer(
+            self.scene_buf_host.vk_buffer(),
+            self.scene_buf_dev.vk_buffer(),
+        );
         cmd_buf.copy_buffer(
             self.config_buf_host.vk_buffer(),
             self.config_buf_dev.vk_buffer(),

piet-gpu/src/render_ctx.rs

@@ -3,7 +3,7 @@ use std::{borrow::Cow, ops::RangeBounds};
 use piet_gpu_types::encoder::{Encode, Encoder};
 
 use piet_gpu_types::scene::{
-    Clip, CubicSeg, Element, FillColor, SetFillMode, LineSeg, QuadSeg, SetLineWidth, Transform,
+    Clip, CubicSeg, Element, FillColor, LineSeg, QuadSeg, SetFillMode, SetLineWidth, Transform,
 };
 
 use piet::{
@@ -70,7 +70,7 @@ struct ClipElement {
     bbox: Option<Rect>,
 }
 
-#[derive(Clone,Copy,PartialEq)]
+#[derive(Clone, Copy, PartialEq)]
 enum FillMode {
     // Fill path according to the non-zero winding rule.
     Nonzero = 0,
@@ -121,8 +121,9 @@ impl PietGpuRenderContext {
 
 fn set_fill_mode(ctx: &mut PietGpuRenderContext, fill_mode: FillMode) {
     if ctx.fill_mode != fill_mode {
-        ctx.elements
+        ctx.elements.push(Element::SetFillMode(SetFillMode {
-            .push(Element::SetFillMode(SetFillMode { fill_mode: fill_mode as u32 }));
+            fill_mode: fill_mode as u32,
+        }));
         ctx.fill_mode = fill_mode;
     }
 }
@@ -322,14 +323,17 @@ impl PietGpuRenderContext {
 
     fn encode_path(&mut self, path: impl Iterator<Item = PathEl>, is_fill: bool) {
         if is_fill {
-            self.encode_path_inner(path.flat_map(|el| {
+            self.encode_path_inner(
+                path.flat_map(|el| {
                     match el {
-                    PathEl::MoveTo(..) => {
+                        PathEl::MoveTo(..) => Some(PathEl::ClosePath),
-                        Some(PathEl::ClosePath)
+                        _ => None,
                     }
-                    _ => None
+                    .into_iter()
-                }.into_iter().chain(Some(el))
+                    .chain(Some(el))
-            }).chain(Some(PathEl::ClosePath)))
+                })
+                .chain(Some(PathEl::ClosePath)),
+            )
         } else {
             self.encode_path_inner(path)
         }