PixarAnimationStudios · pixar-oss · Sep 28, 2022 · Sep 15, 2022
diff --git a/pxr/imaging/hdSt/domeLightComputations.cpp b/pxr/imaging/hdSt/domeLightComputations.cpp
@@ -238,6 +238,7 @@ HdSt_DomeLightComputationGPU::Execute(
     HgiTextureBindDesc texBind0;
     texBind0.bindingIndex = 0;
     texBind0.stageUsage = HgiShaderStageCompute;
+    texBind0.writable = false;
     texBind0.textures.push_back(srcTextureName);
     texBind0.samplers.push_back(srcSamplerName);
     texBind0.resourceType = HgiBindResourceTypeCombinedSamplerImage;
@@ -246,6 +247,7 @@ HdSt_DomeLightComputationGPU::Execute(
     HgiTextureBindDesc texBind1;
     texBind1.bindingIndex = 1;
     texBind1.stageUsage = HgiShaderStageCompute;
+    texBind1.writable = true;
     texBind1.textures.push_back(dstTextureView->GetViewTexture());
     texBind1.samplers.push_back(srcSamplerName);
     texBind1.resourceType = HgiBindResourceTypeStorageImage;

diff --git a/pxr/imaging/hdSt/extCompGpuComputation.cpp b/pxr/imaging/hdSt/extCompGpuComputation.cpp
@@ -56,6 +56,7 @@ _AppendResourceBindings(
     bufBind.bindingIndex = location;
     bufBind.resourceType = HgiBindResourceTypeStorageBuffer;
     bufBind.stageUsage = HgiShaderStageCompute;
+    bufBind.writable = true;
     bufBind.offsets.push_back(0);
     bufBind.buffers.push_back(buffer);
     resourceDesc->buffers.push_back(std::move(bufBind));

diff --git a/pxr/imaging/hdSt/flatNormals.cpp b/pxr/imaging/hdSt/flatNormals.cpp
@@ -75,6 +75,7 @@ _CreateResourceBindings(
         bufBind0.bindingIndex = BufferBinding_Points;
         bufBind0.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind0.stageUsage = HgiShaderStageCompute;
+        bufBind0.writable = false;
         bufBind0.offsets.push_back(0);
         bufBind0.buffers.push_back(points);
         resourceDesc.buffers.push_back(std::move(bufBind0));
@@ -85,6 +86,7 @@ _CreateResourceBindings(
         bufBind1.bindingIndex = BufferBinding_Normals;
         bufBind1.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind1.stageUsage = HgiShaderStageCompute;
+        bufBind1.writable = true;
         bufBind1.offsets.push_back(0);
         bufBind1.buffers.push_back(normals);
         resourceDesc.buffers.push_back(std::move(bufBind1));
@@ -95,6 +97,7 @@ _CreateResourceBindings(
         bufBind2.bindingIndex = BufferBinding_Indices;
         bufBind2.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind2.stageUsage = HgiShaderStageCompute;
+        bufBind2.writable = false;
         bufBind2.offsets.push_back(0);
         bufBind2.buffers.push_back(indices);
         resourceDesc.buffers.push_back(std::move(bufBind2));
@@ -105,6 +108,7 @@ _CreateResourceBindings(
         bufBind3.bindingIndex = BufferBinding_PrimitiveParam;
         bufBind3.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind3.stageUsage = HgiShaderStageCompute;
+        bufBind3.writable = false;
         bufBind3.offsets.push_back(0);
         bufBind3.buffers.push_back(primitiveParam);
         resourceDesc.buffers.push_back(std::move(bufBind3));

diff --git a/pxr/imaging/hdSt/quadrangulate.cpp b/pxr/imaging/hdSt/quadrangulate.cpp
@@ -73,6 +73,7 @@ _CreateResourceBindings(
         bufBind0.bindingIndex = BufferBinding_Primvar;
         bufBind0.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind0.stageUsage = HgiShaderStageCompute;
+        bufBind0.writable = true;
         bufBind0.offsets.push_back(0);
         bufBind0.buffers.push_back(primvar);
         resourceDesc.buffers.push_back(std::move(bufBind0));
@@ -83,6 +84,7 @@ _CreateResourceBindings(
         bufBind1.bindingIndex = BufferBinding_Quadinfo;
         bufBind1.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind1.stageUsage = HgiShaderStageCompute;
+        bufBind1.writable = true;
         bufBind1.offsets.push_back(0);
         bufBind1.buffers.push_back(quadrangulateTable);
         resourceDesc.buffers.push_back(std::move(bufBind1));

diff --git a/pxr/imaging/hdSt/resourceBinder.cpp b/pxr/imaging/hdSt/resourceBinder.cpp
@@ -994,6 +994,7 @@ HdSt_ResourceBinder::GetBufferBindingDesc(
         HgiShaderStageVertex | HgiShaderStageFragment |
         HgiShaderStagePostTessellationVertex;
     HgiBufferBindDesc desc;
+    desc.writable = true;
 
     switch (binding.GetType()) {
     case HdBinding::SSBO:
@@ -1004,6 +1005,7 @@ HdSt_ResourceBinder::GetBufferBindingDesc(
         desc.bindingIndex = static_cast<uint32_t>(binding.GetLocation());
         desc.resourceType = HgiBindResourceTypeStorageBuffer;
         desc.stageUsage = stageUsage;
+        desc.writable = false;
         bindingsDesc->buffers.push_back(desc);
         break;
     case HdBinding::UBO:
@@ -1123,6 +1125,7 @@ HdSt_ResourceBinder::GetTextureBindingDesc(
     texelDesc.samplers = { texelSampler };
     texelDesc.resourceType = HgiBindResourceTypeSampledImage;
     texelDesc.bindingIndex = binding.GetTextureUnit();
+    texelDesc.writable = false;
     bindingsDesc->textures.push_back(std::move(texelDesc));
 }
 
@@ -1146,6 +1149,7 @@ HdSt_ResourceBinder::GetTextureWithLayoutBindingDesc(
     layoutDesc.samplers = { };
     layoutDesc.resourceType = HgiBindResourceTypeSampledImage;
     layoutDesc.bindingIndex = layoutBinding.GetTextureUnit();
+    layoutDesc.writable = false;
     bindingsDesc->textures.push_back(std::move(layoutDesc));
 }
 

diff --git a/pxr/imaging/hdSt/smoothNormals.cpp b/pxr/imaging/hdSt/smoothNormals.cpp
@@ -74,6 +74,7 @@ _CreateResourceBindings(
         bufBind0.bindingIndex = BufferBinding_Points;
         bufBind0.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind0.stageUsage = HgiShaderStageCompute;
+        bufBind0.writable = false;
         bufBind0.offsets.push_back(0);
         bufBind0.buffers.push_back(points);
         resourceDesc.buffers.push_back(std::move(bufBind0));
@@ -84,6 +85,7 @@ _CreateResourceBindings(
         bufBind1.bindingIndex = BufferBinding_Normals;
         bufBind1.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind1.stageUsage = HgiShaderStageCompute;
+        bufBind1.writable = true;
         bufBind1.offsets.push_back(0);
         bufBind1.buffers.push_back(normals);
         resourceDesc.buffers.push_back(std::move(bufBind1));
@@ -94,6 +96,7 @@ _CreateResourceBindings(
         bufBind2.bindingIndex = BufferBinding_Adjacency;
         bufBind2.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind2.stageUsage = HgiShaderStageCompute;
+        bufBind2.writable = false;
         bufBind2.offsets.push_back(0);
         bufBind2.buffers.push_back(adjacency);
         resourceDesc.buffers.push_back(std::move(bufBind2));

diff --git a/pxr/imaging/hdSt/subdivision.cpp b/pxr/imaging/hdSt/subdivision.cpp
@@ -1729,6 +1729,7 @@ _CreateResourceBindings(
         bufBind0.bindingIndex = BufferBinding_Sizes;
         bufBind0.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind0.stageUsage = HgiShaderStageCompute;
+        bufBind0.writable = false;
         bufBind0.offsets.push_back(0);
         bufBind0.buffers.push_back(sizes);
         resourceDesc.buffers.push_back(std::move(bufBind0));
@@ -1739,6 +1740,7 @@ _CreateResourceBindings(
         bufBind1.bindingIndex = BufferBinding_Offsets;
         bufBind1.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind1.stageUsage = HgiShaderStageCompute;
+        bufBind1.writable = false;
         bufBind1.offsets.push_back(0);
         bufBind1.buffers.push_back(offsets);
         resourceDesc.buffers.push_back(std::move(bufBind1));
@@ -1749,6 +1751,7 @@ _CreateResourceBindings(
         bufBind2.bindingIndex = BufferBinding_Indices;
         bufBind2.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind2.stageUsage = HgiShaderStageCompute;
+        bufBind2.writable = false;
         bufBind2.offsets.push_back(0);
         bufBind2.buffers.push_back(indices);
         resourceDesc.buffers.push_back(std::move(bufBind2));
@@ -1759,6 +1762,7 @@ _CreateResourceBindings(
         bufBind3.bindingIndex = BufferBinding_Weights;
         bufBind3.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind3.stageUsage = HgiShaderStageCompute;
+        bufBind3.writable = false;
         bufBind3.offsets.push_back(0);
         bufBind3.buffers.push_back(weights);
         resourceDesc.buffers.push_back(std::move(bufBind3));
@@ -1769,6 +1773,7 @@ _CreateResourceBindings(
         bufBind4.bindingIndex = BufferBinding_Primvar;
         bufBind4.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind4.stageUsage = HgiShaderStageCompute;
+        bufBind4.writable = true;
         bufBind4.offsets.push_back(0);
         bufBind4.buffers.push_back(primvar);
         resourceDesc.buffers.push_back(std::move(bufBind4));

diff --git a/pxr/imaging/hdSt/unitTestHelper.cpp b/pxr/imaging/hdSt/unitTestHelper.cpp
@@ -604,6 +604,7 @@ HdSt_TextureTestDriver::_CreateTextureBindings(
         HgiTextureBindDesc texBindDesc;
         texBindDesc.bindingIndex = 0;
         texBindDesc.stageUsage = HgiShaderStageFragment;
+        texBindDesc.writable = true;
         texBindDesc.textures.push_back(textureHandle);
         if (samplerHandle) {
             texBindDesc.samplers.push_back(samplerHandle);

diff --git a/pxr/imaging/hdx/boundingBoxTask.cpp b/pxr/imaging/hdx/boundingBoxTask.cpp
@@ -260,6 +260,7 @@ HdxBoundingBoxTask::_CreateResourceBindings()
     bufBind1.offsets.push_back(0);
     bufBind1.sizes.push_back(0);
     bufBind1.buffers.push_back(_transformsBuffer);
+    bufBind1.writable = false;
     resourceDesc.buffers.push_back(std::move(bufBind1));
 
     _resourceBindings = _GetHgi()->CreateResourceBindings(resourceDesc);

diff --git a/pxr/imaging/hdx/colorCorrectionTask.cpp b/pxr/imaging/hdx/colorCorrectionTask.cpp
@@ -348,6 +348,7 @@ HdxColorCorrectionTask::_CreateResourceBindings(
     HgiTextureBindDesc texBind0;
     texBind0.bindingIndex = 0;
     texBind0.stageUsage = HgiShaderStageFragment;
+    texBind0.writable = false;
     texBind0.textures.push_back(aovTexture);
     texBind0.samplers.push_back(_sampler);
     resourceDesc.textures.push_back(std::move(texBind0));
@@ -356,6 +357,7 @@ HdxColorCorrectionTask::_CreateResourceBindings(
         HgiTextureBindDesc texBind1;
         texBind1.bindingIndex = 1;
         texBind1.stageUsage = HgiShaderStageFragment;
+        texBind1.writable = false;
         texBind1.textures.push_back(_texture3dLUT);
         texBind1.samplers.push_back(_sampler);
         resourceDesc.textures.push_back(std::move(texBind1));

diff --git a/pxr/imaging/hdx/fullscreenShader.cpp b/pxr/imaging/hdx/fullscreenShader.cpp
@@ -360,6 +360,7 @@ HdxFullscreenShader::_CreateResourceBindings(TextureMap const& textures)
         HgiTextureBindDesc texBind;
         texBind.bindingIndex = bindSlots++;
         texBind.stageUsage = HgiShaderStageFragment;
+        texBind.writable = false;
         texBind.textures.push_back(texHandle);
         texBind.samplers.push_back(_sampler);
         resourceDesc.textures.push_back(std::move(texBind));
@@ -372,6 +373,7 @@ HdxFullscreenShader::_CreateResourceBindings(TextureMap const& textures)
         bufBind.bindingIndex = buffer.first;
         bufBind.resourceType = HgiBindResourceTypeStorageBuffer;
         bufBind.stageUsage = HgiShaderStageFragment;
+        bufBind.writable = false;
         bufBind.offsets.push_back(0);
         bufBind.buffers.push_back(bufferHandle);
         resourceDesc.buffers.push_back(std::move(bufBind));

diff --git a/pxr/imaging/hdx/visualizeAovTask.cpp b/pxr/imaging/hdx/visualizeAovTask.cpp
@@ -298,6 +298,7 @@ HdxVisualizeAovTask::_CreateResourceBindings(
     HgiTextureBindDesc texBind0;
     texBind0.bindingIndex = 0;
     texBind0.stageUsage = HgiShaderStageFragment;
+    texBind0.writable = false;
     texBind0.textures.push_back(inputAovTexture);
     texBind0.samplers.push_back(_sampler);
     resourceDesc.textures.push_back(std::move(texBind0));

diff --git a/pxr/imaging/hgi/resourceBindings.cpp b/pxr/imaging/hgi/resourceBindings.cpp
@@ -53,7 +53,8 @@ bool operator==(
            lhs.offsets == rhs.offsets &&
            lhs.sizes == rhs.sizes &&
            lhs.bindingIndex == rhs.bindingIndex &&
-           lhs.stageUsage == rhs.stageUsage;
+           lhs.stageUsage == rhs.stageUsage &&
+           lhs.writable == rhs.writable;
 }
 
 bool operator!=(
@@ -78,7 +79,8 @@ bool operator==(
            lhs.resourceType == rhs.resourceType &&
            lhs.bindingIndex == rhs.bindingIndex &&
            lhs.stageUsage == rhs.stageUsage &&
-           lhs.samplers == rhs.samplers;
+           lhs.samplers == rhs.samplers &&
+           lhs.writable == rhs.writable;
 }
 
 bool operator!=(

diff --git a/pxr/imaging/hgi/resourceBindings.h b/pxr/imaging/hgi/resourceBindings.h
@@ -85,6 +85,7 @@ struct HgiBufferBindDesc
     HgiBindResourceType resourceType;
     uint32_t bindingIndex;
     HgiShaderStage stageUsage;
+    bool writable;
 };
 using HgiBufferBindDescVector = std::vector<HgiBufferBindDesc>;
 
@@ -130,6 +131,7 @@ struct HgiTextureBindDesc
     HgiBindResourceType resourceType;
     uint32_t bindingIndex;
     HgiShaderStage stageUsage;
+    bool writable;
 };
 using HgiTextureBindDescVector = std::vector<HgiTextureBindDesc>;
 

diff --git a/pxr/imaging/hgiMetal/resourceBindings.mm b/pxr/imaging/hgiMetal/resourceBindings.mm
@@ -108,17 +108,20 @@
                                   atIndex:0];
         }
         if (metalTexture) {
-            if (metalSampler) {
-                [renderEncoder useResource:metalTexture
-                    usage:MTLResourceUsageSample|
-                          MTLResourceUsageRead|
-                          MTLResourceUsageWrite];
-            }
-            else {
-                [renderEncoder useResource:metalTexture
-                    usage:MTLResourceUsageRead|MTLResourceUsageWrite];
-            }
-        }
+                     MTLResourceUsage usageFlags;
+                     if (metalSampler) {
+                         usageFlags = MTLResourceUsageSample|
+                         MTLResourceUsageRead;
+                     }
+                     else {
+                         usageFlags = MTLResourceUsageRead;
+                     }
+                     if (texDesc.writable) {
+                         usageFlags = usageFlags | MTLResourceUsageWrite;
+                     }
+                     [renderEncoder useResource:metalTexture
+                         usage:usageFlags];
+                 }
     }
 
     [renderEncoder setVertexBuffer:argBuffer
@@ -151,7 +154,6 @@
 
         id<MTLBuffer> bufferId = metalbuffer->GetBufferId();
         NSUInteger offset = bufDesc.offsets.front();
-
         if ((bufDesc.stageUsage & HgiShaderStageVertex) ||
             (bufDesc.stageUsage & HgiShaderStagePostTessellationVertex)) {
             NSUInteger argBufferOffset = HgiMetalArgumentOffsetBufferVS
@@ -168,9 +170,13 @@
                                          offset:argBufferOffset];
             [argEncoderBuffer setBuffer:bufferId offset:offset atIndex:0];
         }
+        MTLResourceUsage usageFlags = MTLResourceUsageRead;
+        if (bufDesc.writable) {
+            usageFlags = usageFlags | MTLResourceUsageWrite;
+        }
 
         [renderEncoder useResource:bufferId
-                             usage:(MTLResourceUsageRead | MTLResourceUsageWrite)];
+                             usage:usageFlags];
     }
 
 
@@ -233,17 +239,19 @@
                                  + (texDesc.bindingIndex * sizeof(void*));
             [argEncoderTexture setArgumentBuffer:argBuffer
                                           offset:offsetTexture];
+            MTLResourceUsage usage = MTLResourceUsageRead;
+            if (texDesc.writable) {
+                usage = usage | MTLResourceUsageWrite;
+            }
             [argEncoderTexture setTexture:metalTexture->GetTextureId() atIndex:0];
             if (metalSmp) {
+                usage = usage | MTLResourceUsageSample;
                 [computeEncoder useResource:metalTexture->GetTextureId()
-                    usage:MTLResourceUsageSample|
-                          MTLResourceUsageRead|
-                          MTLResourceUsageWrite];
+                    usage:usage];
             }
             else {
                 [computeEncoder useResource:metalTexture->GetTextureId()
-                                      usage:MTLResourceUsageRead|
-                                            MTLResourceUsageWrite];
+                                      usage:usage];
             }
         }
     }
@@ -277,8 +285,12 @@
         [argEncoderBuffer setArgumentBuffer:argBuffer
                                      offset:argBufferOffset];
         [argEncoderBuffer setBuffer:bufferId offset:offset atIndex:0];
+        MTLResourceUsage usage = MTLResourceUsageRead;
+        if (bufDesc.writable) {
+            usage = usage | MTLResourceUsageWrite;
+        }
         [computeEncoder useResource:bufferId
-                              usage:(MTLResourceUsageRead | MTLResourceUsageWrite)];
+                              usage:usage];
     }
 
     [computeEncoder setBuffer:argBuffer

diff --git a/pxr/imaging/hgiMetal/shaderSection.mm b/pxr/imaging/hgiMetal/shaderSection.mm
@@ -676,8 +676,10 @@
 {
     if (!_writable) {
         ss << "const ";
+        ss << "constant ";
+    } else {
+        ss << "device ";
     }
-    ss << "device ";
     WriteType(ss);
 
     switch (_binding) {
@@ -702,8 +704,10 @@
 
     if (!_writable) {
         ss << "const ";
+        ss << "constant ";
+    } else {
+        ss << "device ";
     }
-    ss << "device ";
     WriteType(ss);
 
     switch (_binding) {
@@ -731,8 +735,10 @@
 
     if (!_writable) {
         ss << "const ";
+        ss << "constant ";
+    } else {
+        ss << "device ";
     }
-    ss << "device ";
     WriteType(ss);
     ss << "* _";
     WriteIdentifier(ss);