Add Compute shaders support to WebGPU

Source/Engine/GraphicsDevice/WebGPU/GPUShaderProgramWebGPU.h

@@ -8,6 +8,42 @@
 #include "Engine/GraphicsDevice/Vulkan/Types.h"
 #include <webgpu/webgpu.h>
 
+/// <summary>
+/// Bundle of the current bound state to the Web GPU context (used to properly handle different texture layouts or samplers when building bind group layout).
+/// </summary>
+struct GPUContextBindingsWebGPU
+{
+    GPUResourceView** ShaderResources; // [GPU_MAX_SR_BINDED]
+};
+
+/// <summary>
+/// Batch of bind group descriptions for the layout. Used as a key for caching created bind groups.
+/// </summary>
+struct GPUBindGroupKeyWebGPU
+{
+    uint32 Hash;
+    WGPUBindGroupLayout Layout;
+    mutable uint64 LastFrameUsed;
+    WGPUBindGroupEntry Entries[64];
+    uint8 EntriesCount;
+    uint8 Versions[64]; // Versions of descriptors used to differentiate when texture residency gets changed
+
+    bool operator==(const GPUBindGroupKeyWebGPU& other) const;
+};
+
+/// <summary>
+/// Reusable utility for caching bind group objects. Handles reusing bind groups for the same key and releasing them when they are not used for a long time (based on the frame number).
+/// </summary>
+struct GPUBindGroupCacheWebGPU
+{
+private:
+    uint64 _lastFrameBindGroupsGC = 0;
+    Dictionary<GPUBindGroupKeyWebGPU, WGPUBindGroup> _bindGroups; // TODO: try using LRU cache
+
+public:
+    WGPUBindGroup Get(WGPUDevice device, GPUBindGroupKeyWebGPU& key, const StringAnsiView& debugName, uint64 gcFrames = 50);
+};
+
 /// <summary>
 /// Shaders base class for Web GPU backend.
 /// </summary>
@@ -69,4 +105,39 @@ public:
     }
 };
 
+/// <summary>
+/// Compute Shader for Web GPU backend.
+/// </summary>
+class GPUShaderProgramCSWebGPU : public GPUShaderProgramWebGPU<GPUShaderProgramCS>
+{
+private:
+    WGPUComputePipeline _pipeline = nullptr;
+    WGPUBindGroupLayout _bindGroupLayout = nullptr;
+    GPUBindGroupCacheWebGPU _bindGroupCache;
+
+public:
+    GPUShaderProgramCSWebGPU(const GPUShaderProgramInitializer& initializer, const SpirvShaderDescriptorInfo& descriptorInfo, WGPUShaderModule shaderModule)
+        : GPUShaderProgramWebGPU(initializer, descriptorInfo, shaderModule)
+    {
+    }
+
+    ~GPUShaderProgramCSWebGPU()
+    {
+        if (_bindGroupLayout)
+            wgpuBindGroupLayoutRelease(_bindGroupLayout);
+        if (_pipeline)
+            wgpuComputePipelineRelease(_pipeline);
+    }
+
+public:
+    // Gets the pipeline.
+    WGPUComputePipeline GetPipeline(WGPUDevice device, const GPUContextBindingsWebGPU& bindings, WGPUBindGroupLayout& resultBindGroupLayout);
+
+    // Gets the bind group for the given key (unhashed). Bind groups are cached and reused for the same key.
+    FORCE_INLINE WGPUBindGroup GetBindGroup(WGPUDevice device, GPUBindGroupKeyWebGPU& key)
+    {
+        return _bindGroupCache.Get(device, key, _name, 60 * 60);
+    }
+};
+
 #endif