Fixed staging buffers in Vulkan and D3D12 backends (https://github.com/DiligentGraphics/DiligentEngine/issues/69). Added buffer access test.

3 files changed, 29 insertions, 16 deletions

diff --git a/Graphics/GraphicsEngineVulkan/include/BufferVkImpl.h b/Graphics/GraphicsEngineVulkan/include/BufferVkImpl.h
index cf8923f3..30f8206f 100644
--- a/Graphics/GraphicsEngineVulkan/include/BufferVkImpl.h
+++ b/Graphics/GraphicsEngineVulkan/include/BufferVkImpl.h
@@ -108,13 +108,21 @@ public:
         return (GetAccessFlags() & AccessFlags) == AccessFlags;
     }
 
+    void* GetStagingCPUAddress()
+    {
+        VERIFY_EXPR(m_Desc.Usage == USAGE_STAGING);
+        return reinterpret_cast<Uint8*>(m_MemoryAllocation.Page->GetCPUMemory()) + m_BufferMemoryAlignedOffset;
+    }
+
 private:
     friend class DeviceContextVkImpl;
 
     virtual void CreateViewInternal(const struct BufferViewDesc& ViewDesc, IBufferView** ppView, bool bIsDefaultView) override;
 
     VulkanUtilities::BufferViewWrapper CreateView(struct BufferViewDesc& ViewDesc);
-    Uint32                             m_DynamicOffsetAlignment = 0;
+
+    Uint32       m_DynamicOffsetAlignment    = 0;
+    VkDeviceSize m_BufferMemoryAlignedOffset = 0;
 
     std::vector<VulkanDynamicAllocation, STDAllocatorRawMem<VulkanDynamicAllocation>> m_DynamicAllocations;
 
diff --git a/Graphics/GraphicsEngineVulkan/src/BufferVkImpl.cpp b/Graphics/GraphicsEngineVulkan/src/BufferVkImpl.cpp
index 4b34ca5f..65737f0b 100644
--- a/Graphics/GraphicsEngineVulkan/src/BufferVkImpl.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/BufferVkImpl.cpp
@@ -189,10 +189,10 @@ BufferVkImpl::BufferVkImpl(IReferenceCounters*        pRefCounters,
         VERIFY(IsPowerOfTwo(MemReqs.alignment), "Alignment is not power of 2!");
         m_MemoryAllocation = pRenderDeviceVk->AllocateMemory(MemReqs, BufferMemoryFlags);
 
-        auto AlignedOffset = Align(VkDeviceSize{m_MemoryAllocation.UnalignedOffset}, MemReqs.alignment);
-        VERIFY(m_MemoryAllocation.Size >= MemReqs.size + (AlignedOffset - m_MemoryAllocation.UnalignedOffset), "Size of memory allocation is too small");
+        m_BufferMemoryAlignedOffset = Align(VkDeviceSize{m_MemoryAllocation.UnalignedOffset}, MemReqs.alignment);
+        VERIFY(m_MemoryAllocation.Size >= MemReqs.size + (m_BufferMemoryAlignedOffset - m_MemoryAllocation.UnalignedOffset), "Size of memory allocation is too small");
         auto Memory = m_MemoryAllocation.Page->GetVkMemory();
-        auto err    = LogicalDevice.BindBufferMemory(m_VulkanBuffer, Memory, AlignedOffset);
+        auto err    = LogicalDevice.BindBufferMemory(m_VulkanBuffer, Memory, m_BufferMemoryAlignedOffset);
         CHECK_VK_ERROR_AND_THROW(err, "Failed to bind buffer memory");
 
         bool           bInitializeBuffer = (pBuffData != nullptr && pBuffData->pData != nullptr && pBuffData->DataSize > 0);
diff --git a/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp b/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
index 690b0589..6122ffda 100644
--- a/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
@@ -1297,15 +1297,22 @@ void DeviceContextVkImpl::MapBuffer(IBuffer* pBuffer, MAP_TYPE MapType, MAP_FLAG
 
     if (MapType == MAP_READ)
     {
-        LOG_ERROR("Mapping buffer for reading is not yet imlemented in Vulkan backend");
-        UNSUPPORTED("Mapping buffer for reading is not yet imlemented in Vulkan backend");
+        DEV_CHECK_ERR(BuffDesc.Usage == USAGE_STAGING, "Buffer must be created as USAGE_STAGING to be mapped for reading");
+
+        if ((MapFlags & MAP_FLAG_DO_NOT_WAIT) == 0)
+        {
+            LOG_WARNING_MESSAGE("Vulkan backend never waits for GPU when mapping staging buffers for reading. "
+                                "Applications must use fences or other synchronization methods to explicitly synchronize "
+                                "access and use MAP_FLAG_DO_NOT_WAIT flag.");
+        }
+
+        pMappedData = pBufferVk->GetStagingCPUAddress();
     }
     else if (MapType == MAP_WRITE)
     {
         if (BuffDesc.Usage == USAGE_STAGING)
         {
-            LOG_ERROR("Not implemented");
-            UNSUPPORTED("Not implemented");
+            pMappedData = pBufferVk->GetStagingCPUAddress();
         }
         else if (BuffDesc.Usage == USAGE_DYNAMIC)
         {
@@ -1340,11 +1347,11 @@ void DeviceContextVkImpl::MapBuffer(IBuffer* pBuffer, MAP_TYPE MapType, MAP_FLAG
     }
     else if (MapType == MAP_READ_WRITE)
     {
-        LOG_ERROR("MAP_READ_WRITE is not supported on Vk");
+        LOG_ERROR("MAP_READ_WRITE is not supported in Vulkan backend");
     }
     else
     {
-        LOG_ERROR("Only MAP_WRITE_DISCARD and MAP_READ are currently implemented in Vk");
+        UNEXPECTED("Unknown map type");
     }
 }
 
@@ -1356,15 +1363,13 @@ void DeviceContextVkImpl::UnmapBuffer(IBuffer* pBuffer, MAP_TYPE MapType)
 
     if (MapType == MAP_READ)
     {
-        LOG_ERROR("This map type is not yet supported");
-        UNSUPPORTED("This map type is not yet supported");
+        // We are currently using cache-coherent memory, so there is no need to invalidated mapped range
     }
     else if (MapType == MAP_WRITE)
     {
         if (BuffDesc.Usage == USAGE_STAGING)
         {
-            LOG_ERROR("This map type is not yet supported");
-            UNSUPPORTED("This map type is not yet supported");
+            // We are currently using cache-coherent memory, so there is no need to flush mapped range
         }
         else if (BuffDesc.Usage == USAGE_DYNAMIC)
         {
@@ -1864,9 +1869,9 @@ void DeviceContextVkImpl::MapTextureSubresource(ITexture*                 pTextu
         {
             if ((MapFlags & MAP_FLAG_DO_NOT_WAIT) == 0)
             {
-                LOG_WARNING_MESSAGE("Mapping staging textures for reading never blocks or waits for GPU in Vulkan backend. "
+                LOG_WARNING_MESSAGE("Vulkan backend never waits for GPU when mapping staging textures for reading. "
                                     "Applications must use fences or other synchronization methods to explicitly synchronize "
-                                    "access and map texture with MAP_FLAG_DO_NOT_WAIT flag.");
+                                    "access and use MAP_FLAG_DO_NOT_WAIT flag.");
             }
 
             DEV_CHECK_ERR((TexDesc.CPUAccessFlags & CPU_ACCESS_READ), "Texture '", TexDesc.Name, "' was not created with CPU_ACCESS_READ flag and can't be mapped for reading");