Add vulkan inline constants support, emulated with uniform buffers. (PushConstants not impl yet)

Author: hzqst

Graphics/GraphicsEngineVulkan/include/DeviceContextVkImpl.hpp

@@ -555,6 +555,9 @@ class DeviceContextVkImpl final : public DeviceContextNextGenBase<EngineVkImplTr
     __forceinline ResourceBindInfo& GetBindInfo(PIPELINE_TYPE Type);
 
     __forceinline void CommitDescriptorSets(ResourceBindInfo& BindInfo, Uint32 CommitSRBMask);
+
+    void UpdateInlineConstantBuffers(ResourceBindInfo& BindInfo);
+
 #ifdef DILIGENT_DEVELOPMENT
     void DvpValidateCommittedShaderResources(ResourceBindInfo& BindInfo);
 #endif

Graphics/GraphicsEngineVulkan/include/PipelineResourceSignatureVkImpl.hpp

@@ -50,6 +50,7 @@ namespace Diligent
 
 struct SPIRVShaderResourceAttribs;
 class DeviceContextVkImpl;
+class BufferVkImpl;
 
 struct ImmutableSamplerAttribsVk
 {
@@ -58,6 +59,17 @@ struct ImmutableSamplerAttribsVk
 };
 ASSERT_SIZEOF(ImmutableSamplerAttribsVk, 8, "The struct is used in serialization and must be tightly packed");
 
+/// Inline constant buffer attributes for Vulkan backend.
+/// Since Vulkan only supports one push constant block per pipeline, inline constants
+/// are emulated using dynamic uniform buffers (similar to D3D11 backend).
+struct InlineConstantBufferAttribsVk
+{
+    Uint32                      DescrSet     = 0;  // Descriptor set index
+    Uint32                      BindingIndex = 0;  // Binding index within the descriptor set
+    Uint32                      NumConstants = 0;  // Number of 32-bit constants
+    RefCntAutoPtr<BufferVkImpl> pBuffer;           // Internal dynamic uniform buffer
+};
+
 struct PipelineResourceSignatureInternalDataVk : PipelineResourceSignatureInternalData<PipelineResourceAttribsVk, ImmutableSamplerAttribsVk>
 {
     Uint16 DynamicUniformBufferCount = 0;
@@ -134,6 +146,16 @@ class PipelineResourceSignatureVkImpl final : public PipelineResourceSignatureBa
     void CommitDynamicResources(const ShaderResourceCacheVk& ResourceCache,
                                 VkDescriptorSet              vkDynamicDescriptorSet) const;
 
+    // Updates inline constant buffers by mapping the internal buffers and copying data from the resource cache
+    void UpdateInlineConstantBuffers(const ShaderResourceCacheVk& ResourceCache,
+                                     DeviceContextVkImpl&         Ctx) const;
+
+    // Returns the number of inline constant buffers
+    Uint32 GetNumInlineConstantBuffers() const { return m_NumInlineConstantBuffers; }
+
+    // Returns the inline constant buffer attributes
+    const InlineConstantBufferAttribsVk* GetInlineConstantBuffers() const { return m_InlineConstantBuffers.get(); }
+
 #ifdef DILIGENT_DEVELOPMENT
     /// Verifies committed resource using the SPIRV resource attributes from the PSO.
     bool DvpValidateCommittedResource(const DeviceContextVkImpl*        pDeviceCtx,
@@ -193,6 +215,15 @@ class PipelineResourceSignatureVkImpl final : public PipelineResourceSignatureBa
     // The total number storage buffers with dynamic offsets in both descriptor sets,
     // accounting for array size.
     Uint16 m_DynamicStorageBufferCount = 0;
+
+    // Number of inline constant buffers
+    Uint32 m_NumInlineConstantBuffers = 0;
+    // Inline constant buffer attributes
+    std::unique_ptr<InlineConstantBufferAttribsVk[]> m_InlineConstantBuffers;
+
+    // Pointer to CPU-side staging buffer for static inline constants
+    // This memory is allocated in CreateSetLayouts and must be freed in Destruct
+    void* m_pStaticInlineConstantData = nullptr;
 };
 
 template <> Uint32 PipelineResourceSignatureVkImpl::GetDescriptorSetIndex<PipelineResourceSignatureVkImpl::DESCRIPTOR_SET_ID_STATIC_MUTABLE>() const;

Graphics/GraphicsEngineVulkan/include/ShaderResourceCacheVk.hpp

@@ -74,7 +74,8 @@ class ShaderResourceCacheVk : public ShaderResourceCacheBase
 public:
     explicit ShaderResourceCacheVk(ResourceCacheContentType ContentType) noexcept :
         m_TotalResources{0},
-        m_ContentType{static_cast<Uint32>(ContentType)}
+        m_ContentType{static_cast<Uint32>(ContentType)},
+        m_HasInlineConstants{0}
     {
         VERIFY_EXPR(GetContentType() == ContentType);
     }
@@ -93,7 +94,7 @@ class ShaderResourceCacheVk : public ShaderResourceCacheBase
     void InitializeSets(IMemoryAllocator& MemAllocator, Uint32 NumSets, const Uint32* SetSizes);
     void InitializeResources(Uint32 Set, Uint32 Offset, Uint32 ArraySize, DescriptorType Type, bool HasImmutableSampler);
 
-    // sizeof(Resource) == 32 (x64, msvc, Release)
+    // sizeof(Resource) == 40 (x64, msvc, Release)
     struct Resource
     {
         explicit Resource(DescriptorType _Type, bool _HasImmutableSampler) noexcept :
@@ -120,6 +121,10 @@ class ShaderResourceCacheVk : public ShaderResourceCacheBase
 /*16 */ Uint64                       BufferBaseOffset = 0;
 /*24 */ Uint64                       BufferRangeSize  = 0;
 
+        // For inline constants only - pointer to CPU-side staging buffer
+/*32 */ void*                        pInlineConstantData = nullptr;
+/*40 */ // End of structure
+
         VkDescriptorBufferInfo GetUniformBufferDescriptorWriteInfo()                     const;
         VkDescriptorBufferInfo GetStorageBufferDescriptorWriteInfo()                     const;
         VkDescriptorImageInfo  GetImageDescriptorWriteInfo  ()                           const;
@@ -245,13 +250,36 @@ class ShaderResourceCacheVk : public ShaderResourceCacheBase
                                 Uint32 CacheOffset,
                                 Uint32 DynamicBufferOffset);
 
+    // Sets inline constant data in the resource cache
+    void SetInlineConstants(Uint32      DescrSetIndex,
+                            Uint32      CacheOffset,
+                            const void* pConstants,
+                            Uint32      FirstConstant,
+                            Uint32      NumConstants);
+
+    // Gets the inline constant data pointer from the resource cache
+    const void* GetInlineConstantData(Uint32 DescrSetIndex, Uint32 BindingIndex) const;
+
+    // Initialize inline constant buffer in the resource cache
+    void InitializeInlineConstantBuffer(Uint32 DescrSetIndex,
+                                        Uint32 CacheOffset,
+                                        Uint32 NumConstants,
+                                        void*  pInlineConstantData);
+
+    // Sets the inline constant memory block (takes ownership, will be freed in destructor)
+    void SetInlineConstantMemory(IMemoryAllocator& Allocator, void* pMemory)
+    {
+        m_pInlineConstantMemory = decltype(m_pInlineConstantMemory){
+            pMemory,
+            STDDeleter<void, IMemoryAllocator>(Allocator)};
+    }
 
     Uint32 GetNumDescriptorSets() const { return m_NumSets; }
     bool   HasDynamicResources() const { return m_NumDynamicBuffers > 0; }
 
     bool HasInlineConstants() const
     {
-        return false;
+        return m_HasInlineConstants;
     }
 
     ResourceCacheContentType GetContentType() const { return static_cast<ResourceCacheContentType>(m_ContentType); }
@@ -287,16 +315,22 @@ class ShaderResourceCacheVk : public ShaderResourceCacheBase
 
     std::unique_ptr<void, STDDeleter<void, IMemoryAllocator>> m_pMemory;
 
+    // Memory for inline constant data (allocated separately, freed in destructor)
+    std::unique_ptr<void, STDDeleter<void, IMemoryAllocator>> m_pInlineConstantMemory;
+
     Uint16 m_NumSets = 0;
 
     // Total actual number of dynamic buffers (that were created with USAGE_DYNAMIC) bound in the resource cache
     // regardless of the variable type. Note this variable is not equal to dynamic offsets count, which is constant.
     Uint16 m_NumDynamicBuffers = 0;
-    Uint32 m_TotalResources : 31;
+    Uint32 m_TotalResources : 30;
 
     // Indicates what types of resources are stored in the cache
     const Uint32 m_ContentType : 1;
 
+    // Indicates whether the cache contains inline constants
+    Uint32 m_HasInlineConstants : 1;
+
 #ifdef DILIGENT_DEBUG
     // Debug array that stores flags indicating if resources in the cache have been initialized
     std::vector<std::vector<bool>> m_DbgInitializedResources;

Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp

@@ -415,6 +415,24 @@ DeviceContextVkImpl::ResourceBindInfo& DeviceContextVkImpl::GetBindInfo(PIPELINE
     return m_BindInfo[Indices[Uint32{Type}]];
 }
 
+void DeviceContextVkImpl::UpdateInlineConstantBuffers(ResourceBindInfo& BindInfo)
+{
+    const Uint32 SignCount = m_pPipelineState->GetResourceSignatureCount();
+    for (Uint32 i = 0; i < SignCount; ++i)
+    {
+        const PipelineResourceSignatureVkImpl* pSign = m_pPipelineState->GetResourceSignature(i);
+        if (pSign == nullptr || pSign->GetNumInlineConstantBuffers() == 0)
+            continue;
+
+        const ShaderResourceCacheVk* pResourceCache = BindInfo.ResourceCaches[i];
+        if (pResourceCache == nullptr || !pResourceCache->HasInlineConstants())
+            continue;
+
+        // Update inline constant buffers
+        pSign->UpdateInlineConstantBuffers(*pResourceCache, *this);
+    }
+}
+
 void DeviceContextVkImpl::CommitDescriptorSets(ResourceBindInfo& BindInfo, Uint32 CommitSRBMask)
 {
     VERIFY(CommitSRBMask != 0, "This method should not be called when there is nothing to commit");
@@ -758,6 +776,14 @@ void DeviceContextVkImpl::PrepareForDraw(DRAW_FLAGS Flags)
 #endif
 
     ResourceBindInfo& BindInfo = GetBindInfo(PIPELINE_TYPE_GRAPHICS);
+
+    // Update inline constant buffers before binding descriptor sets
+    const bool InlineConstantsIntact = (Flags & DRAW_FLAG_INLINE_CONSTANTS_INTACT) != 0;
+    if (!InlineConstantsIntact)
+    {
+        UpdateInlineConstantBuffers(BindInfo);
+    }
+
     // First time we must always bind descriptor sets with dynamic offsets as SRBs are stale.
     // If there are no dynamic buffers bound in the resource cache, for all subsequent
     // calls we do not need to bind the sets again.
@@ -1059,6 +1085,10 @@ void DeviceContextVkImpl::PrepareForDispatchCompute()
     EndRenderScope();
 
     ResourceBindInfo& BindInfo = GetBindInfo(PIPELINE_TYPE_COMPUTE);
+
+    // Update inline constant buffers before binding descriptor sets
+    UpdateInlineConstantBuffers(BindInfo);
+
     if (Uint32 CommitMask = BindInfo.GetCommitMask())
     {
         CommitDescriptorSets(BindInfo, CommitMask);
@@ -1075,6 +1105,10 @@ void DeviceContextVkImpl::PrepareForRayTracing()
     EnsureVkCmdBuffer();
 
     ResourceBindInfo& BindInfo = GetBindInfo(PIPELINE_TYPE_RAY_TRACING);
+
+    // Update inline constant buffers before binding descriptor sets
+    UpdateInlineConstantBuffers(BindInfo);
+
     if (Uint32 CommitMask = BindInfo.GetCommitMask())
     {
         CommitDescriptorSets(BindInfo, CommitMask);