some improvements for ray tracing

7 files changed, 59 insertions, 29 deletions

diff --git a/Graphics/GraphicsEngineVulkan/include/RenderDeviceVkImpl.hpp b/Graphics/GraphicsEngineVulkan/include/RenderDeviceVkImpl.hpp
index 2aaf4c69..2b8408ce 100644
--- a/Graphics/GraphicsEngineVulkan/include/RenderDeviceVkImpl.hpp
+++ b/Graphics/GraphicsEngineVulkan/include/RenderDeviceVkImpl.hpp
@@ -215,6 +215,8 @@ public:
         const Uint32 MaxShaderRecordStride;
         const Uint32 ShaderGroupBaseAlignment;
         const Uint32 MaxDrawMeshTasksCount;
+        const Uint32 MaxRayTracingRecursionDepth;
+        const Uint32 MaxRayGenThreads;
     };
 
     const Properties& GetProperties() const
diff --git a/Graphics/GraphicsEngineVulkan/include/VulkanTypeConversions.hpp b/Graphics/GraphicsEngineVulkan/include/VulkanTypeConversions.hpp
index 8f90a914..405e9bfa 100644
--- a/Graphics/GraphicsEngineVulkan/include/VulkanTypeConversions.hpp
+++ b/Graphics/GraphicsEngineVulkan/include/VulkanTypeConversions.hpp
@@ -67,6 +67,7 @@ VkBorderColor        BorderColorToVkBorderColor(const Float32 BorderColor[]);
 
 VkPipelineStageFlags ResourceStateFlagsToVkPipelineStageFlags(RESOURCE_STATE StateFlags, VkPipelineStageFlags ShaderStages);
 VkAccessFlags        ResourceStateFlagsToVkAccessFlags(RESOURCE_STATE StateFlags);
+VkAccessFlags        AccelStructStateFlagsToVkAccessFlags(RESOURCE_STATE StateFlags);
 VkImageLayout        ResourceStateToVkImageLayout(RESOURCE_STATE StateFlag, bool IsInsideRenderPass = false);
 
 RESOURCE_STATE VkAccessFlagsToResourceStates(VkAccessFlags AccessFlags);
diff --git a/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp b/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
index e34f52f2..48b7df04 100644
--- a/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/DeviceContextVkImpl.cpp
@@ -2514,8 +2514,8 @@ void DeviceContextVkImpl::TransitionBLASState(BottomLevelASVkImpl& BLAS,
     if ((OldState & NewState) != NewState || AfterWrite)
     {
         EnsureVkCmdBuffer();
-        auto OldAccessFlags = ResourceStateFlagsToVkAccessFlags(OldState);
-        auto NewAccessFlags = ResourceStateFlagsToVkAccessFlags(NewState);
+        auto OldAccessFlags = AccelStructStateFlagsToVkAccessFlags(OldState);
+        auto NewAccessFlags = AccelStructStateFlagsToVkAccessFlags(NewState);
         auto OldStages      = ResourceStateFlagsToVkPipelineStageFlags(OldState, m_CommandBuffer.GetEnabledShaderStages());
         auto NewStages      = ResourceStateFlagsToVkPipelineStageFlags(NewState, m_CommandBuffer.GetEnabledShaderStages());
         m_CommandBuffer.ASMemoryBarrier(OldAccessFlags, NewAccessFlags, OldStages, NewStages);
@@ -2560,8 +2560,8 @@ void DeviceContextVkImpl::TransitionTLASState(TopLevelASVkImpl& TLAS,
     if ((OldState & NewState) != NewState || AfterWrite)
     {
         EnsureVkCmdBuffer();
-        auto OldAccessFlags = ResourceStateFlagsToVkAccessFlags(OldState);
-        auto NewAccessFlags = ResourceStateFlagsToVkAccessFlags(NewState);
+        auto OldAccessFlags = AccelStructStateFlagsToVkAccessFlags(OldState);
+        auto NewAccessFlags = AccelStructStateFlagsToVkAccessFlags(NewState);
         auto OldStages      = ResourceStateFlagsToVkPipelineStageFlags(OldState, m_CommandBuffer.GetEnabledShaderStages());
         auto NewStages      = ResourceStateFlagsToVkPipelineStageFlags(NewState, m_CommandBuffer.GetEnabledShaderStages());
         m_CommandBuffer.ASMemoryBarrier(OldAccessFlags, NewAccessFlags, OldStages, NewStages);
@@ -2792,7 +2792,7 @@ void DeviceContextVkImpl::BuildBLAS(const BuildBLASAttribs& Attribs)
             vkTris.maxVertex                = SrcTris.VertexCount;
             vkTris.vertexData.deviceAddress = pVB->GetVkDeviceAddress() + SrcTris.VertexOffset;
 
-            TransitionOrVerifyBufferState(*pVB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR, OpName);
+            TransitionOrVerifyBufferState(*pVB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_SHADER_READ_BIT, OpName);
 
             if (SrcTris.pIndexBuffer)
             {
@@ -2802,7 +2802,7 @@ void DeviceContextVkImpl::BuildBLAS(const BuildBLASAttribs& Attribs)
                 vkTris.indexType               = TypeToVkIndexType(TriDesc.IndexType);
                 vkTris.indexData.deviceAddress = pIB->GetVkDeviceAddress() + SrcTris.IndexOffset;
 
-                TransitionOrVerifyBufferState(*pIB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR, OpName);
+                TransitionOrVerifyBufferState(*pIB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_SHADER_READ_BIT, OpName);
             }
             else
             {
@@ -2815,7 +2815,7 @@ void DeviceContextVkImpl::BuildBLAS(const BuildBLASAttribs& Attribs)
                 auto* const pTB                    = ValidatedCast<BufferVkImpl>(SrcTris.pTransformBuffer);
                 vkTris.transformData.deviceAddress = pTB->GetVkDeviceAddress() + SrcTris.TransformBufferOffset;
 
-                TransitionOrVerifyBufferState(*pTB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR, OpName);
+                TransitionOrVerifyBufferState(*pTB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_SHADER_READ_BIT, OpName);
             }
             else
             {
@@ -2863,7 +2863,7 @@ void DeviceContextVkImpl::BuildBLAS(const BuildBLASAttribs& Attribs)
 
             VERIFY(vkAABBs.data.deviceAddress % 8 == 0, "AABB start address is not properly aligned");
 
-            TransitionOrVerifyBufferState(*pBB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR, OpName);
+            TransitionOrVerifyBufferState(*pBB, Attribs.GeometryTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_SHADER_READ_BIT, OpName);
 
             off.firstVertex     = 0;
             off.transformOffset = 0;
@@ -2956,7 +2956,7 @@ void DeviceContextVkImpl::BuildTLAS(const BuildTLASAttribs& Attribs)
 
         UpdateBufferRegion(pInstancesVk, Attribs.InstanceBufferOffset, Size, TmpSpace.vkBuffer, TmpSpace.AlignedOffset, Attribs.InstanceBufferTransitionMode);
     }
-    TransitionOrVerifyBufferState(*pInstancesVk, Attribs.InstanceBufferTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR, OpName);
+    TransitionOrVerifyBufferState(*pInstancesVk, Attribs.InstanceBufferTransitionMode, RESOURCE_STATE_BUILD_AS_READ, VK_ACCESS_SHADER_READ_BIT, OpName);
 
     VkAccelerationStructureBuildGeometryInfoKHR     vkASBuildInfo = {};
     VkAccelerationStructureBuildRangeInfoKHR        vkRange       = {};
@@ -3128,10 +3128,10 @@ void DeviceContextVkImpl::TraceRays(const TraceRaysAttribs& Attribs)
 
     pSBTVk->GetData(pBuffer, RayGenShaderRecord, MissShaderTable, HitGroupTable, CallableShaderTable);
 
-    auto* pBufferVk = ValidatedCast<BufferVkImpl>(pBuffer);
+    auto* pSBTBufferVk = ValidatedCast<BufferVkImpl>(pBuffer);
 
     const char* OpName = "Trace rays (DeviceContextVkImpl::TraceRays)";
-    TransitionOrVerifyBufferState(*pBufferVk, Attribs.SBTTransitionMode, RESOURCE_STATE_COPY_DEST, VK_ACCESS_TRANSFER_WRITE_BIT, OpName);
+    TransitionOrVerifyBufferState(*pSBTBufferVk, Attribs.SBTTransitionMode, RESOURCE_STATE_COPY_DEST, VK_ACCESS_TRANSFER_WRITE_BIT, OpName);
 
     // buffer ranges are not intersected, so we don't need to add barriers between them
     if (RayGenShaderRecord.pData)
@@ -3146,13 +3146,13 @@ void DeviceContextVkImpl::TraceRays(const TraceRaysAttribs& Attribs)
     if (CallableShaderTable.pData)
         UpdateBuffer(pBuffer, CallableShaderTable.Offset, CallableShaderTable.Size, CallableShaderTable.pData, RESOURCE_STATE_TRANSITION_MODE_VERIFY);
 
-    TransitionOrVerifyBufferState(*pBufferVk, Attribs.SBTTransitionMode, RESOURCE_STATE_RAY_TRACING, VK_ACCESS_SHADER_READ_BIT, OpName);
+    TransitionOrVerifyBufferState(*pSBTBufferVk, Attribs.SBTTransitionMode, RESOURCE_STATE_RAY_TRACING, VK_ACCESS_SHADER_READ_BIT, OpName);
 
     // clang-format off
-    VkStridedDeviceAddressRegionKHR RaygenShaderBindingTable   = {pBufferVk->GetVkDeviceAddress() + RayGenShaderRecord.Offset,  RayGenShaderRecord.Stride,  RayGenShaderRecord.Size };
-    VkStridedDeviceAddressRegionKHR MissShaderBindingTable     = {pBufferVk->GetVkDeviceAddress() + MissShaderTable.Offset,     MissShaderTable.Stride,     MissShaderTable.Size    };
-    VkStridedDeviceAddressRegionKHR HitShaderBindingTable      = {pBufferVk->GetVkDeviceAddress() + HitGroupTable.Offset,       HitGroupTable.Stride,       HitGroupTable.Size      };
-    VkStridedDeviceAddressRegionKHR CallableShaderBindingTable = {pBufferVk->GetVkDeviceAddress() + CallableShaderTable.Offset, CallableShaderTable.Stride, CallableShaderTable.Size};
+    VkStridedDeviceAddressRegionKHR RaygenShaderBindingTable   = {pSBTBufferVk->GetVkDeviceAddress() + RayGenShaderRecord.Offset,  RayGenShaderRecord.Stride,  RayGenShaderRecord.Size };
+    VkStridedDeviceAddressRegionKHR MissShaderBindingTable     = {pSBTBufferVk->GetVkDeviceAddress() + MissShaderTable.Offset,     MissShaderTable.Stride,     MissShaderTable.Size    };
+    VkStridedDeviceAddressRegionKHR HitShaderBindingTable      = {pSBTBufferVk->GetVkDeviceAddress() + HitGroupTable.Offset,       HitGroupTable.Stride,       HitGroupTable.Size      };
+    VkStridedDeviceAddressRegionKHR CallableShaderBindingTable = {pSBTBufferVk->GetVkDeviceAddress() + CallableShaderTable.Offset, CallableShaderTable.Stride, CallableShaderTable.Size};
     // clang-format on
 
     PrepareForRayTracing();
diff --git a/Graphics/GraphicsEngineVulkan/src/EngineFactoryVk.cpp b/Graphics/GraphicsEngineVulkan/src/EngineFactoryVk.cpp
index 514ca01d..ed537333 100644
--- a/Graphics/GraphicsEngineVulkan/src/EngineFactoryVk.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/EngineFactoryVk.cpp
@@ -418,7 +418,6 @@ void EngineFactoryVkImpl::CreateDeviceAndContextsVk(const EngineVkCreateInfo& _E
                 DeviceExtensions.push_back(VK_EXT_DESCRIPTOR_INDEXING_EXTENSION_NAME);      // required for VK_KHR_acceleration_structure
                 DeviceExtensions.push_back(VK_KHR_BUFFER_DEVICE_ADDRESS_EXTENSION_NAME);    // required for VK_KHR_acceleration_structure
                 DeviceExtensions.push_back(VK_KHR_DEFERRED_HOST_OPERATIONS_EXTENSION_NAME); // required for VK_KHR_acceleration_structure
-                DeviceExtensions.push_back(VK_KHR_PIPELINE_LIBRARY_EXTENSION_NAME);         // required for VK_KHR_ray_tracing_pipeline
                 DeviceExtensions.push_back(VK_KHR_ACCELERATION_STRUCTURE_EXTENSION_NAME);   // required for ray tracing
                 DeviceExtensions.push_back(VK_KHR_RAY_TRACING_PIPELINE_EXTENSION_NAME);     // required for ray tracing
 
diff --git a/Graphics/GraphicsEngineVulkan/src/PipelineStateVkImpl.cpp b/Graphics/GraphicsEngineVulkan/src/PipelineStateVkImpl.cpp
index 00bb54d9..7d846b90 100644
--- a/Graphics/GraphicsEngineVulkan/src/PipelineStateVkImpl.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/PipelineStateVkImpl.cpp
@@ -346,12 +346,7 @@ static void CreateRayTracingPipeline(RenderDeviceVkImpl*
                                      const RayTracingPipelineDesc&                            RayTracingPipeline,
                                      VulkanUtilities::PipelineWrapper&                        Pipeline)
 {
-    const auto& LogicalDevice  = pDeviceVk->GetLogicalDevice();
-    const auto& PhysicalDevice = pDeviceVk->GetPhysicalDevice();
-    const auto& RTLimits       = PhysicalDevice.GetExtProperties().RayTracingPipeline;
-
-    DEV_CHECK_ERR(RayTracingPipeline.MaxRecursionDepth <= RTLimits.maxRayRecursionDepth,
-                  "RayTracingPipeline.MaxRecursionDepth must not exceed ", RTLimits.maxRayRecursionDepth);
+    const auto& LogicalDevice = pDeviceVk->GetLogicalDevice();
 
     VkRayTracingPipelineCreateInfoKHR PipelineCI = {};
 
@@ -365,7 +360,7 @@ static void CreateRayTracingPipeline(RenderDeviceVkImpl*
     PipelineCI.pStages                      = Stages.data();
     PipelineCI.groupCount                   = static_cast<Uint32>(ShaderGroups.size());
     PipelineCI.pGroups                      = ShaderGroups.data();
-    PipelineCI.maxPipelineRayRecursionDepth = RayTracingPipeline.MaxRecursionDepth;
+    PipelineCI.maxPipelineRayRecursionDepth = std::max(1u, Uint32{RayTracingPipeline.MaxRecursionDepth}) - 1; // for compatibility with D3D12, zero means only one ray tracing depth.
     PipelineCI.pLibraryInfo                 = nullptr;
     PipelineCI.pLibraryInterface            = nullptr;
     PipelineCI.pDynamicState                = nullptr;
diff --git a/Graphics/GraphicsEngineVulkan/src/RenderDeviceVkImpl.cpp b/Graphics/GraphicsEngineVulkan/src/RenderDeviceVkImpl.cpp
index c44d5642..44bc0eb8 100644
--- a/Graphics/GraphicsEngineVulkan/src/RenderDeviceVkImpl.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/RenderDeviceVkImpl.cpp
@@ -165,13 +165,21 @@ RenderDeviceVkImpl::RenderDeviceVkImpl(IReferenceCounters*
         m_PhysicalDevice->GetExtProperties().RayTracingPipeline.shaderGroupHandleSize,
         m_PhysicalDevice->GetExtProperties().RayTracingPipeline.maxShaderGroupStride,
         m_PhysicalDevice->GetExtProperties().RayTracingPipeline.shaderGroupBaseAlignment,
-        m_PhysicalDevice->GetExtProperties().MeshShader.maxDrawMeshTasksCount
+        m_PhysicalDevice->GetExtProperties().MeshShader.maxDrawMeshTasksCount,
+        m_PhysicalDevice->GetExtProperties().RayTracingPipeline.maxRayRecursionDepth + 1, // for compatibility with D3D12
+        m_PhysicalDevice->GetExtProperties().RayTracingPipeline.maxRayDispatchInvocationCount
     }
 // clang-format on
 {
     static_assert(sizeof(VulkanDescriptorPoolSize) == sizeof(Uint32) * 11, "Please add new descriptors to m_DescriptorSetAllocator and m_DynamicDescriptorPool constructors");
     static_assert(sizeof(DeviceObjectSizes) == sizeof(size_t) * 15, "Please add new objects to DeviceObjectSizes constructor");
 
+    // set device properties
+    {
+        static_assert(sizeof(DeviceProperties) == sizeof(Uint32) * 1, "Please set new properties below");
+        m_DeviceProperties.MaxRayTracingRecursionDepth = m_Properties.MaxRayTracingRecursionDepth;
+    }
+
     m_DeviceCaps.DevType      = RENDER_DEVICE_TYPE_VULKAN;
     m_DeviceCaps.MajorVersion = 1;
     m_DeviceCaps.MinorVersion = 0;
diff --git a/Graphics/GraphicsEngineVulkan/src/VulkanTypeConversions.cpp b/Graphics/GraphicsEngineVulkan/src/VulkanTypeConversions.cpp
index edfa7625..17c129c1 100644
--- a/Graphics/GraphicsEngineVulkan/src/VulkanTypeConversions.cpp
+++ b/Graphics/GraphicsEngineVulkan/src/VulkanTypeConversions.cpp
@@ -1239,9 +1239,9 @@ static VkAccessFlags ResourceStateFlagToVkAccessFlags(RESOURCE_STATE StateFlag)
         case RESOURCE_STATE_RESOLVE_SOURCE:    return VK_ACCESS_TRANSFER_READ_BIT;
         case RESOURCE_STATE_INPUT_ATTACHMENT:  return VK_ACCESS_INPUT_ATTACHMENT_READ_BIT;
         case RESOURCE_STATE_PRESENT:           return 0;
-        case RESOURCE_STATE_BUILD_AS_READ:     return VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR;
-        case RESOURCE_STATE_BUILD_AS_WRITE:    return VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR | VK_ACCESS_ACCELERATION_STRUCTURE_WRITE_BIT_KHR;
-        case RESOURCE_STATE_RAY_TRACING:       return VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR | VK_ACCESS_SHADER_READ_BIT; // for TLAS & SBT
+        case RESOURCE_STATE_BUILD_AS_READ:     return VK_ACCESS_SHADER_READ_BIT; // for vertex, index, transform, AABB, instance buffers
+        case RESOURCE_STATE_BUILD_AS_WRITE:    return VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR | VK_ACCESS_ACCELERATION_STRUCTURE_WRITE_BIT_KHR; // for scratch buffer
+        case RESOURCE_STATE_RAY_TRACING:       return VK_ACCESS_SHADER_READ_BIT; // for SBT
             // clang-format on
 
         default:
@@ -1290,6 +1290,30 @@ VkAccessFlags ResourceStateFlagsToVkAccessFlags(RESOURCE_STATE StateFlags)
     return AccessFlags;
 }
 
+VkAccessFlags AccelStructStateFlagsToVkAccessFlags(RESOURCE_STATE StateFlags)
+{
+    VERIFY(Uint32{StateFlags} < (RESOURCE_STATE_MAX_BIT << 1), "Resource state flags are out of range");
+    static_assert(RESOURCE_STATE_MAX_BIT == RESOURCE_STATE_RAY_TRACING, "This function must be updated to handle new resource state flag");
+
+    VkAccessFlags AccessFlags = 0;
+    Uint32        Bits        = StateFlags;
+    while (Bits != 0)
+    {
+        auto Bit = static_cast<RESOURCE_STATE>(1 << PlatformMisc::GetLSB(Bits));
+        switch (Bit)
+        {
+            // clang-format off
+            case RESOURCE_STATE_BUILD_AS_READ:  AccessFlags |= VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR; break;
+            case RESOURCE_STATE_BUILD_AS_WRITE: AccessFlags |= VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR | VK_ACCESS_ACCELERATION_STRUCTURE_WRITE_BIT_KHR; break;
+            case RESOURCE_STATE_RAY_TRACING:    AccessFlags |= VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR; break;
+            default:                            UNEXPECTED("Unexpected resource state flag");
+                // clang-format on
+        }
+        Bits &= ~Bit;
+    }
+    return AccessFlags;
+}
+
 static RESOURCE_STATE VkAccessFlagToResourceStates(VkAccessFlagBits AccessFlagBit)
 {
     VERIFY((AccessFlagBit & (AccessFlagBit - 1)) == 0, "Single access flag bit is expected");
@@ -1302,7 +1326,7 @@ static RESOURCE_STATE VkAccessFlagToResourceStates(VkAccessFlagBits AccessFlagBi
         case VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT:                 return RESOURCE_STATE_VERTEX_BUFFER;
         case VK_ACCESS_UNIFORM_READ_BIT:                          return RESOURCE_STATE_CONSTANT_BUFFER;
         case VK_ACCESS_INPUT_ATTACHMENT_READ_BIT:                 return RESOURCE_STATE_INPUT_ATTACHMENT;
-        case VK_ACCESS_SHADER_READ_BIT:                           return RESOURCE_STATE_SHADER_RESOURCE;
+        case VK_ACCESS_SHADER_READ_BIT:                           return RESOURCE_STATE_SHADER_RESOURCE; // or RESOURCE_STATE_BUILD_AS_READ
         case VK_ACCESS_SHADER_WRITE_BIT:                          return RESOURCE_STATE_UNORDERED_ACCESS;
         case VK_ACCESS_COLOR_ATTACHMENT_READ_BIT:                 return RESOURCE_STATE_RENDER_TARGET;
         case VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT:                return RESOURCE_STATE_RENDER_TARGET;
@@ -1310,6 +1334,7 @@ static RESOURCE_STATE VkAccessFlagToResourceStates(VkAccessFlagBits AccessFlagBi
         case VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT:        return RESOURCE_STATE_DEPTH_WRITE;
         case VK_ACCESS_TRANSFER_READ_BIT:                         return RESOURCE_STATE_COPY_SOURCE;
         case VK_ACCESS_TRANSFER_WRITE_BIT:                        return RESOURCE_STATE_COPY_DEST;
+        case VK_ACCESS_ACCELERATION_STRUCTURE_WRITE_BIT_KHR:      return RESOURCE_STATE_BUILD_AS_WRITE;
         case VK_ACCESS_HOST_READ_BIT:                             return RESOURCE_STATE_UNKNOWN;
         case VK_ACCESS_HOST_WRITE_BIT:                            return RESOURCE_STATE_UNKNOWN;
         case VK_ACCESS_MEMORY_READ_BIT:                           return RESOURCE_STATE_UNKNOWN;