use vk staging buffer instead of dynamic buffer to avoid dynamic buffer id reuse issue.

Author: hzqst

Graphics/GraphicsEngineVulkan/src/PipelineResourceSignatureVkImpl.cpp

@@ -417,15 +417,18 @@ void PipelineResourceSignatureVkImpl::CreateSetLayouts(const bool IsSerialized)
 
             if (!IsPushConstant && m_pDevice)
             {
-                // Create a USAGE_DYNAMIC uniform buffer for emulating inline constants
+                // Create a USAGE_STAGING uniform buffer for emulating inline constants.
+                // Using USAGE_STAGING ensures the buffer has a backing VkBuffer resource with
+                // persistently mapped host-visible memory, avoiding Dynamic Buffer ID reuse issues
+                // that can occur with USAGE_DYNAMIC buffers (which suballocate from dynamic heap).
                 // All SRBs created from this signature will share the same inline constant buffer.
                 std::string Name = m_Desc.Name;
                 Name += " - ";
                 Name += ResDesc.Name;
                 BufferDesc CBDesc;
                 CBDesc.Name           = Name.c_str();
                 CBDesc.Size           = ResDesc.ArraySize * sizeof(Uint32);
-                CBDesc.Usage          = USAGE_DYNAMIC;
+                CBDesc.Usage          = USAGE_STAGING;
                 CBDesc.BindFlags      = BIND_UNIFORM_BUFFER;
                 CBDesc.CPUAccessFlags = CPU_ACCESS_WRITE;
 
@@ -686,7 +689,7 @@ void PipelineResourceSignatureVkImpl::InitSRBResourceCache(ShaderResourceCacheVk
     {
         // Ensure the cache reports inline constants so DeviceContextVkImpl
         // updates emulated buffers even if no data has been written yet.
-        ResourceCache.MarkHasInlineConstants();
+        //ResourceCache.MarkHasInlineConstants();
 
         // Count push constant buffers and calculate total memory size
         Uint32 NumPushConstantBuffers  = 0;
@@ -1340,11 +1343,12 @@ void PipelineResourceSignatureVkImpl::UpdateInlineConstantBuffers(const ShaderRe
             const void* pInlineConstantData = ResourceCache.GetInlineConstantData(InlineCBAttr.DescrSet, InlineCBAttr.BindingIndex);
             VERIFY_EXPR(pInlineConstantData != nullptr);
 
-            // Map the buffer and copy the data
-            void* pMappedData = nullptr;
-            Ctx.MapBuffer(InlineCBAttr.pBuffer, MAP_WRITE, MAP_FLAG_DISCARD, pMappedData);
-            memcpy(pMappedData, pInlineConstantData, DataSize);
-            Ctx.UnmapBuffer(InlineCBAttr.pBuffer, MAP_WRITE);
+            // Copy data directly to the buffer's CPU address.
+            // USAGE_STAGING buffer has a backing VkBuffer resource with persistently mapped
+            // host-visible memory, so we can write directly without Map/Unmap.
+            void* pDstData = InlineCBAttr.pBuffer->GetCPUAddress();
+            VERIFY_EXPR(pDstData != nullptr);
+            memcpy(pDstData, pInlineConstantData, DataSize);
             continue;
         }
     }