Add docs and helpers for WebGPU shaders & backend

Author: JimBobSquarePants

src/ImageSharp.Drawing.WebGPU/RemoteExecutor/Program.cs

@@ -10,6 +10,9 @@ namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 /// </summary>
 internal static class Program
 {
+    /// <summary>
+    /// Dispatches the requested probe method inside the child process.
+    /// </summary>
     private static int Main(string[] args)
     {
         if (args.Length < 1)

src/ImageSharp.Drawing.WebGPU/Shaders/BackdropComputeShader.cs

@@ -11,14 +11,26 @@ namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 /// </summary>
 internal static unsafe class BackdropComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the dynamic backdrop stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.BackdropDynCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Gets the X workgroup count required to process every draw object in the scene.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static uint GetDispatchX(uint drawObjectCount)
         => drawObjectCount;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the dynamic backdrop stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/BboxClearComputeShader.cs

@@ -6,16 +6,31 @@
 
 namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 
+/// <summary>
+/// GPU stage that clears path bounding boxes before flatten repopulates them.
+/// </summary>
 internal static unsafe class BboxClearComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the bbox-clear stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.BboxClearCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Gets the X workgroup count required to clear every path bounding box.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static uint GetDispatchX(uint pathCount)
         => (pathCount + 255U) / 256U;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the bbox-clear stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/BinningComputeShader.cs

@@ -11,14 +11,26 @@ namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 /// </summary>
 internal static unsafe class BinningComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the binning stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.BinningCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Gets the X workgroup count required to bin every draw object in the scene.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static uint GetDispatchX(uint drawObjectCount)
         => (drawObjectCount + 255U) / 256U;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the binning stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/ClipLeafComputeShader.cs

@@ -5,12 +5,24 @@
 
 namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 
+/// <summary>
+/// GPU stage that resolves clip leaves into concrete clip bounding boxes.
+/// </summary>
 internal static unsafe class ClipLeafComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the clip-leaf stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.ClipLeafCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the clip-leaf stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/ClipReduceComputeShader.cs

@@ -5,12 +5,24 @@
 
 namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 
+/// <summary>
+/// GPU stage that reduces clip inputs into the binary-interval-combination structure consumed by clip leaf expansion.
+/// </summary>
 internal static unsafe class ClipReduceComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the clip-reduce stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.ClipReduceCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the clip-reduce stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/CoarseComputeShader.cs

@@ -11,16 +11,31 @@ namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 /// </summary>
 internal static unsafe class CoarseComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the coarse stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.CoarseCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Gets the X workgroup count required to cover the bin grid width.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static uint GetDispatchX(uint widthInBins) => widthInBins;
 
+    /// <summary>
+    /// Gets the Y workgroup count required to cover the bin grid height.
+    /// </summary>
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static uint GetDispatchY(uint heightInBins) => heightInBins;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the coarse stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/DrawLeafComputeShader.cs

@@ -5,12 +5,24 @@
 
 namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 
+/// <summary>
+/// GPU stage that expands reduced draw metadata into concrete draw and clip inputs.
+/// </summary>
 internal static unsafe class DrawLeafComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the draw-leaf stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.DrawLeafCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the draw-leaf stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/DrawReduceComputeShader.cs

@@ -5,12 +5,24 @@
 
 namespace SixLabors.ImageSharp.Drawing.Processing.Backends;
 
+/// <summary>
+/// GPU stage that scans draw tags into draw-object offsets and counts.
+/// </summary>
 internal static unsafe class DrawReduceComputeShader
 {
+    /// <summary>
+    /// Gets the generated WGSL source bytes for the draw-reduce stage.
+    /// </summary>
     public static ReadOnlySpan<byte> ShaderCode => GeneratedWgslShaderSources.DrawReduceCode;
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Creates the bind-group layout required by the draw-reduce stage.
+    /// </summary>
     public static bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,

src/ImageSharp.Drawing.WebGPU/Shaders/FineAreaComputeShader.cs

@@ -19,8 +19,14 @@ internal static class FineAreaComputeShader
     private static readonly object CacheSync = new();
     private static readonly Dictionary<TextureFormat, byte[]> ShaderCache = [];
 
+    /// <summary>
+    /// Gets the WGSL entry point used by this shader.
+    /// </summary>
     public static ReadOnlySpan<byte> EntryPoint => "main\0"u8;
 
+    /// <summary>
+    /// Gets or generates the fine-pass shader specialized for the requested output texture format.
+    /// </summary>
     public static bool TryGetCode(TextureFormat textureFormat, out byte[] code, out string? error)
     {
         if (!TryGetTraits(textureFormat, out ShaderTraits traits))
@@ -55,6 +61,9 @@ public static bool TryGetCode(TextureFormat textureFormat, out byte[] code, out
         return true;
     }
 
+    /// <summary>
+    /// Creates the bind-group layout required by the fine area shader.
+    /// </summary>
     public static unsafe bool TryCreateBindGroupLayout(
         WebGPU api,
         Device* device,