Mesh shaders MSL writer (gfx-rs#8739)

* Single squashed commit

* Updated changelog

* Fixed stupid changelog thing

* If I have to do this one more fucking time I'm gonna lose it

* Removed some pub(super)'s

* Thing

---------

Co-authored-by: Andreas Reich <[email protected]>

Author: inner-daemons

CHANGELOG.md

@@ -54,6 +54,7 @@ Bottom level categories:
 #### Metal
 
 - Unconditionally enable `Features::CLIP_DISTANCES`. By @ErichDonGubler in [#9270](https://github.com/gfx-rs/wgpu/pull/9270).
+- Added full support for mesh shaders, including in WGSL shaders. By @inner-daemons in [#8739](https://github.com/gfx-rs/wgpu/pull/8739).
 
 #### DX12
 
@@ -68,6 +69,7 @@ Bottom level categories:
 #### General
 
 - `Features::CLIP_DISTANCE`, `naga::Capabilities::CLIP_DISTANCE`, and `naga::BuiltIn::ClipDistance` have been renamed to `CLIP_DISTANCES` and `ClipDistances` (viz., pluralized) as appropriate, to match the WebGPU spec. By @ErichDonGubler in [#9267](https://github.com/gfx-rs/wgpu/pull/9267).
+- Added more granular limits for mesh shaders. By @inner-daemons in [#8739](https://github.com/gfx-rs/wgpu/pull/8739).
 - Added new `InvalidWorkgroupSizeError`, which is now used by `DrawError::InvalidGroupSize` and `StageError::InvalidWorkgroupSize`. By @andyleiserson in [#9357](https://github.com/gfx-rs/wgpu/pull/9357).
 
 #### Validation

examples/features/src/mesh_shader/mod.rs

@@ -12,17 +12,6 @@ fn compile_wgsl(device: &wgpu::Device) -> wgpu::ShaderModule {
     }
 }
 
-fn compile_msl(device: &wgpu::Device) -> wgpu::ShaderModule {
-    unsafe {
-        device.create_shader_module_passthrough(wgpu::ShaderModuleDescriptorPassthrough {
-            label: None,
-            msl: Some(std::borrow::Cow::Borrowed(include_str!("shader.metal"))),
-            num_workgroups: (1, 1, 1),
-            ..Default::default()
-        })
-    }
-}
-
 struct Shaders {
     ts: wgpu::ShaderModule,
     ms: wgpu::ShaderModule,
@@ -32,33 +21,15 @@ struct Shaders {
     fs_name: &'static str,
 }
 
-fn get_shaders(device: &wgpu::Device, backend: wgpu::Backend) -> Shaders {
-    // In the case that the platform does support mesh shaders, the dummy
-    // shader is used to avoid requiring PASSTHROUGH_SHADERS.
-    match backend {
-        wgpu::Backend::Vulkan | wgpu::Backend::Dx12 => {
-            let compiled = compile_wgsl(device);
-            Shaders {
-                ts: compiled.clone(),
-                ms: compiled.clone(),
-                fs: compiled.clone(),
-                ts_name: "ts_main",
-                ms_name: "ms_main",
-                fs_name: "fs_main",
-            }
-        }
-        wgpu::Backend::Metal => {
-            let compiled = compile_msl(device);
-            Shaders {
-                ts: compiled.clone(),
-                ms: compiled.clone(),
-                fs: compiled.clone(),
-                ts_name: "taskShader",
-                ms_name: "meshShader",
-                fs_name: "fragShader",
-            }
-        }
-        _ => unreachable!(),
+fn get_shaders(device: &wgpu::Device) -> Shaders {
+    let compiled = compile_wgsl(device);
+    Shaders {
+        ts: compiled.clone(),
+        ms: compiled.clone(),
+        fs: compiled.clone(),
+        ts_name: "ts_main",
+        ms_name: "ms_main",
+        fs_name: "fs_main",
     }
 }
 
@@ -68,7 +39,7 @@ pub struct Example {
 impl crate::framework::Example for Example {
     fn init(
         config: &wgpu::SurfaceConfiguration,
-        adapter: &wgpu::Adapter,
+        _adapter: &wgpu::Adapter,
         device: &wgpu::Device,
         _queue: &wgpu::Queue,
     ) -> Self {
@@ -79,7 +50,7 @@ impl crate::framework::Example for Example {
             ts_name,
             ms_name,
             fs_name,
-        } = get_shaders(device, adapter.get_info().backend);
+        } = get_shaders(device);
         let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
             label: None,
             bind_group_layouts: &[],

examples/features/src/mesh_shader/shader.metal

@@ -575,6 +575,8 @@ fn run() -> anyhow::Result<()> {
 
     params.spv_out.mesh_shader_primitive_indices_clamp = args.validate_mesh_output;
     params.spv_out.task_dispatch_limits = args.task_limits.0;
+    params.msl.mesh_shader_primitive_indices_clamp = args.validate_mesh_output;
+    params.msl.task_dispatch_limits = args.task_limits.0;
     params.hlsl.mesh_shader_primitive_indices_clamp = args.validate_mesh_output;
     params.hlsl.task_dispatch_limits = args.task_limits.0;
 

naga-cli/src/bin/naga.rs

@@ -344,7 +344,7 @@ const RESERVED: &[&str] = &[
     // Naga utilities
     "DefaultConstructible",
     // Naga builtin names
-    "__local_invocation_id",
+    "__local_invocation_index",
     super::writer::FREXP_FUNCTION,
     super::writer::MODF_FUNCTION,
     super::writer::ABS_FUNCTION,