Switch uniforms to be descriptor set 0 in Vulkan

This (plus some cleanup) gives us some minor perf gains and as a side effect
the perf debug layer no longer complains when we bind certain descriptor sets.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1864303002

Review URL: https://codereview.chromium.org/1864303002

4 files changed, 22 insertions, 15 deletions

diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index 62cf58087c..e35a814b03 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -98,7 +98,7 @@ GrVkGpu::GrVkGpu(GrContext* context, const GrContextOptions& options,
                                    VK_DEBUG_REPORT_WARNING_BIT_EXT;// |
                                    //VK_DEBUG_REPORT_INFORMATION_BIT_EXT |
                                    //VK_DEBUG_REPORT_DEBUG_BIT_EXT |
-                                   //VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT;
+                                   VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT;
         callbackCreateInfo.pfnCallback = &DebugReportCallback;
         callbackCreateInfo.pUserData = nullptr;
 
diff --git a/src/gpu/vk/GrVkPipelineState.cpp b/src/gpu/vk/GrVkPipelineState.cpp
index dacd66b0e7..90a27e35a7 100644
--- a/src/gpu/vk/GrVkPipelineState.cpp
+++ b/src/gpu/vk/GrVkPipelineState.cpp
@@ -37,6 +37,8 @@ GrVkPipelineState::GrVkPipelineState(GrVkGpu* gpu,
                                      const GrGLSLFragProcs& fragmentProcessors)
     : fPipeline(pipeline)
     , fPipelineLayout(layout)
+    , fStartDS(SK_MaxS32)
+    , fDSCount(0)
     , fBuiltinUniformHandles(builtinUniformHandles)
     , fGeometryProcessor(geometryProcessor)
     , fXferProcessor(xferProcessor)
@@ -46,7 +48,8 @@ GrVkPipelineState::GrVkPipelineState(GrVkGpu* gpu,
     , fSamplerPoolManager(dsLayout[GrVkUniformHandler::kSamplerDescSet],
                           VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, numSamplers, gpu)
     , fUniformPoolManager(dsLayout[GrVkUniformHandler::kUniformBufferDescSet],
-                          VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 2, gpu) {
+                          VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER,
+                          (vertexUniformSize || fragmentUniformSize) ? 2 : 0, gpu) {
     fSamplers.setReserve(numSamplers);
     fTextureViews.setReserve(numSamplers);
     fTextures.setReserve(numSamplers);
@@ -55,8 +58,10 @@ GrVkPipelineState::GrVkPipelineState(GrVkGpu* gpu,
     fDescriptorSets[1] = VK_NULL_HANDLE;
 
     // Currently we are always binding a descriptor set for uniform buffers.
-    fStartDS = GrVkUniformHandler::kUniformBufferDescSet;
-    fDSCount = 1;
+    if (vertexUniformSize || fragmentUniformSize) {
+        fDSCount++;
+        fStartDS = GrVkUniformHandler::kUniformBufferDescSet;
+    }
     if (numSamplers) {
         fDSCount++;
         fStartDS = SkTMin(fStartDS, (int)GrVkUniformHandler::kSamplerDescSet);
@@ -189,13 +194,15 @@ void GrVkPipelineState::setData(GrVkGpu* gpu,
     if (fNumSamplers) {
         fSamplerPoolManager.getNewDescriptorSet(gpu,
                                              &fDescriptorSets[GrVkUniformHandler::kSamplerDescSet]);
+        this->writeSamplers(gpu, textureBindings);
     }
-    fUniformPoolManager.getNewDescriptorSet(gpu,
-                                       &fDescriptorSets[GrVkUniformHandler::kUniformBufferDescSet]);
 
-    this->writeUniformBuffers(gpu);
 
-    this->writeSamplers(gpu, textureBindings);
+    if (fVertexUniformBuffer.get() || fFragmentUniformBuffer.get()) {
+        fUniformPoolManager.getNewDescriptorSet(gpu,
+                                       &fDescriptorSets[GrVkUniformHandler::kUniformBufferDescSet]);
+        this->writeUniformBuffers(gpu);
+    }
 }
 
 void GrVkPipelineState::writeUniformBuffers(const GrVkGpu* gpu) {
@@ -218,7 +225,7 @@ void GrVkPipelineState::writeUniformBuffers(const GrVkGpu* gpu) {
 
         descriptorWrites[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
         descriptorWrites[0].pNext = nullptr;
-        descriptorWrites[0].dstSet = fDescriptorSets[1];
+        descriptorWrites[0].dstSet = fDescriptorSets[GrVkUniformHandler::kUniformBufferDescSet];
         descriptorWrites[0].dstBinding = GrVkUniformHandler::kVertexBinding;
         descriptorWrites[0].dstArrayElement = 0;
         descriptorWrites[0].descriptorCount = 1;
@@ -249,7 +256,7 @@ void GrVkPipelineState::writeUniformBuffers(const GrVkGpu* gpu) {
 
         descriptorWrites[1].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
         descriptorWrites[1].pNext = nullptr;
-        descriptorWrites[1].dstSet = fDescriptorSets[1];
+        descriptorWrites[1].dstSet = fDescriptorSets[GrVkUniformHandler::kUniformBufferDescSet];
         descriptorWrites[1].dstBinding = GrVkUniformHandler::kFragBinding;;
         descriptorWrites[1].dstArrayElement = 0;
         descriptorWrites[1].descriptorCount = 1;
diff --git a/src/gpu/vk/GrVkPipelineStateBuilder.cpp b/src/gpu/vk/GrVkPipelineStateBuilder.cpp
index f9654c3af5..3ea9e1b5d2 100644
--- a/src/gpu/vk/GrVkPipelineStateBuilder.cpp
+++ b/src/gpu/vk/GrVkPipelineStateBuilder.cpp
@@ -170,7 +170,7 @@ GrVkPipelineState* GrVkPipelineStateBuilder::finalize(GrPrimitiveType primitiveT
         UniformHandle uniHandle = fSamplerUniforms[i];
         GrVkUniformHandler::UniformInfo uniformInfo = fUniformHandler.getUniformInfo(uniHandle);
         SkASSERT(kSampler2D_GrSLType == uniformInfo.fVariable.getType());
-        SkASSERT(0 == uniformInfo.fSetNumber);
+        SkASSERT(GrVkUniformHandler::kSamplerDescSet == uniformInfo.fSetNumber);
         SkASSERT(uniformInfo.fBinding == i);
         dsSamplerBindings[i].binding = uniformInfo.fBinding;
         dsSamplerBindings[i].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
@@ -203,12 +203,12 @@ GrVkPipelineState* GrVkPipelineStateBuilder::finalize(GrPrimitiveType primitiveT
     memset(&dsUniBindings, 0, 2 * sizeof(VkDescriptorSetLayoutBinding));
     dsUniBindings[0].binding = GrVkUniformHandler::kVertexBinding;
     dsUniBindings[0].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
-    dsUniBindings[0].descriptorCount = fUniformHandler.hasVertexUniforms() ? 1 : 0;
+    dsUniBindings[0].descriptorCount = 1;
     dsUniBindings[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
     dsUniBindings[0].pImmutableSamplers = nullptr;
     dsUniBindings[1].binding = GrVkUniformHandler::kFragBinding;
     dsUniBindings[1].descriptorType = VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
-    dsUniBindings[1].descriptorCount = fUniformHandler.hasFragmentUniforms() ? 1 : 0;
+    dsUniBindings[1].descriptorCount = 1;
     dsUniBindings[1].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
     dsUniBindings[1].pImmutableSamplers = nullptr;
 
diff --git a/src/gpu/vk/GrVkUniformHandler.h b/src/gpu/vk/GrVkUniformHandler.h
index 8a3f314cb9..46d27cda7c 100644
--- a/src/gpu/vk/GrVkUniformHandler.h
+++ b/src/gpu/vk/GrVkUniformHandler.h
@@ -18,8 +18,8 @@ public:
     static const int kUniformsPerBlock = 8;
 
     enum {
-        kSamplerDescSet = 0,
-        kUniformBufferDescSet = 1,
+        kUniformBufferDescSet = 0,
+        kSamplerDescSet = 1,
     };
     enum {
         kVertexBinding = 0,