D3D12 and VK backends: disallowed mapping structured and formatted dynamic buffers with MAP_FLAG_NO_OVERWRITE flag

1 files changed, 10 insertions, 0 deletions

diff --git a/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp b/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
index 1681b456..76163513 100644
--- a/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
@@ -1318,6 +1318,16 @@ void DeviceContextVkImpl::MapBuffer(IBuffer* pBuffer, MAP_TYPE MapType, MAP_FLAG
             else
             {
                 VERIFY_EXPR(MapFlags & MAP_FLAG_NO_OVERWRITE);
+
+                if (pBufferVk->m_VulkanBuffer != VK_NULL_HANDLE)
+                {
+                    LOG_ERROR("Formatted or structured buffers require actual Vulkan backing resource and cannot be suballocated "
+                              "from dynamic heap. In current implementation, the entire contents of the backing buffer is updated when the buffer is unmapped. "
+                              "As a consequence, the buffer cannot be mapped with MAP_FLAG_NO_OVERWRITE flag because updating the whole "
+                              "buffer will overwrite regions that may still be in use by the GPU.");
+                    return;
+                }
+
                 // Reuse the same allocation
             }