Reland "Add ComparisonSampler binding type and validation tests"

This is a reland of 6d9e4f8076
Now that the Chromium-side API change has landed, this CL can land.

Original change's description:
> Add ComparisonSampler binding type and validation tests
>
> Bug: dawn:367
> Change-Id: Iba1d3d03f6247a356b6f3fabfe7a7ba3c0753171
> Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/18423
> Reviewed-by: Austin Eng <enga@chromium.org>
> Commit-Queue: Austin Eng <enga@chromium.org>

Bug: dawn:367
TBR=cwallez@chromium.org,kainino@chromium.org
Change-Id: I325d096e7ce092d17833429c3f54ef7c71189739
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/20045
Reviewed-by: Austin Eng <enga@chromium.org>
Commit-Queue: Austin Eng <enga@chromium.org>

dawn.json

@@ -115,10 +115,11 @@
             {"value": 1, "name": "storage buffer"},
             {"value": 2, "name": "readonly storage buffer"},
             {"value": 3, "name": "sampler"},
-            {"value": 4, "name": "sampled texture"},
+            {"value": 4, "name": "comparison sampler"},
-            {"value": 5, "name": "storage texture"},
+            {"value": 5, "name": "sampled texture"},
-            {"value": 6, "name": "readonly storage texture"},
+            {"value": 6, "name": "storage texture"},
-            {"value": 7, "name": "writeonly storage texture"}
+            {"value": 7, "name": "readonly storage texture"},
+            {"value": 8, "name": "writeonly storage texture"}
         ]
     },
     "blend descriptor": {

src/dawn_native/BindGroup.cpp

@@ -117,13 +117,30 @@ namespace dawn_native {
             return {};
         }
 
-        MaybeError ValidateSamplerBinding(const DeviceBase* device, const BindGroupEntry& binding) {
+        MaybeError ValidateSamplerBinding(const DeviceBase* device,
+                                          const BindGroupEntry& binding,
+                                          wgpu::BindingType bindingType) {
             if (binding.sampler == nullptr || binding.textureView != nullptr ||
                 binding.buffer != nullptr) {
                 return DAWN_VALIDATION_ERROR("expected sampler binding");
             }
             DAWN_TRY(device->ValidateObject(binding.sampler));
 
+            switch (bindingType) {
+                case wgpu::BindingType::Sampler:
+                    if (binding.sampler->HasCompareFunction()) {
+                        return DAWN_VALIDATION_ERROR("Did not expect comparison sampler");
+                    }
+                    break;
+                case wgpu::BindingType::ComparisonSampler:
+                    if (!binding.sampler->HasCompareFunction()) {
+                        return DAWN_VALIDATION_ERROR("Expected comparison sampler");
+                    }
+                    break;
+                default:
+                    UNREACHABLE();
+            }
+
             return {};
         }
 
@@ -174,7 +191,8 @@ namespace dawn_native {
                                                     bindingInfo));
                     break;
                 case wgpu::BindingType::Sampler:
-                    DAWN_TRY(ValidateSamplerBinding(device, binding));
+                case wgpu::BindingType::ComparisonSampler:
+                    DAWN_TRY(ValidateSamplerBinding(device, binding, bindingInfo.type));
                     break;
                 // TODO(jiawei.shao@intel.com): support creating bind group with read-only and
                 // write-only storage textures.
@@ -294,7 +312,8 @@ namespace dawn_native {
     SamplerBase* BindGroupBase::GetBindingAsSampler(BindingIndex bindingIndex) {
         ASSERT(!IsError());
         ASSERT(bindingIndex < mLayout->GetBindingCount());
-        ASSERT(mLayout->GetBindingInfo(bindingIndex).type == wgpu::BindingType::Sampler);
+        ASSERT(mLayout->GetBindingInfo(bindingIndex).type == wgpu::BindingType::Sampler ||
+               mLayout->GetBindingInfo(bindingIndex).type == wgpu::BindingType::ComparisonSampler);
         return static_cast<SamplerBase*>(mBindingData.bindings[bindingIndex].Get());
     }
 

src/dawn_native/BindGroupAndStorageBarrierTracker.h

@@ -52,6 +52,7 @@ namespace dawn_native {
                         case wgpu::BindingType::UniformBuffer:
                         case wgpu::BindingType::ReadonlyStorageBuffer:
                         case wgpu::BindingType::Sampler:
+                        case wgpu::BindingType::ComparisonSampler:
                         case wgpu::BindingType::SampledTexture:
                             // Don't require barriers.
                             break;

src/dawn_native/BindGroupLayout.cpp

@@ -53,6 +53,7 @@ namespace dawn_native {
             case wgpu::BindingType::UniformBuffer:
             case wgpu::BindingType::ReadonlyStorageBuffer:
             case wgpu::BindingType::Sampler:
+            case wgpu::BindingType::ComparisonSampler:
             case wgpu::BindingType::SampledTexture:
             case wgpu::BindingType::ReadonlyStorageTexture:
                 break;
@@ -82,6 +83,7 @@ namespace dawn_native {
             case wgpu::BindingType::UniformBuffer:
             case wgpu::BindingType::ReadonlyStorageBuffer:
             case wgpu::BindingType::Sampler:
+            case wgpu::BindingType::ComparisonSampler:
             case wgpu::BindingType::SampledTexture:
                 break;
             default:
@@ -151,6 +153,7 @@ namespace dawn_native {
                     break;
                 case wgpu::BindingType::SampledTexture:
                 case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler:
                 case wgpu::BindingType::ReadonlyStorageTexture:
                 case wgpu::BindingType::WriteonlyStorageTexture:
                     if (binding.hasDynamicOffset) {
@@ -248,6 +251,7 @@ namespace dawn_native {
                         break;
                     case wgpu::BindingType::SampledTexture:
                     case wgpu::BindingType::Sampler:
+                    case wgpu::BindingType::ComparisonSampler:
                     case wgpu::BindingType::StorageTexture:
                     case wgpu::BindingType::ReadonlyStorageTexture:
                     case wgpu::BindingType::WriteonlyStorageTexture:
@@ -320,6 +324,7 @@ namespace dawn_native {
                         break;
                     case wgpu::BindingType::SampledTexture:
                     case wgpu::BindingType::Sampler:
+                    case wgpu::BindingType::ComparisonSampler:
                     case wgpu::BindingType::StorageTexture:
                     case wgpu::BindingType::ReadonlyStorageTexture:
                     case wgpu::BindingType::WriteonlyStorageTexture:

src/dawn_native/PipelineLayout.cpp

@@ -48,6 +48,7 @@ namespace dawn_native {
                 case wgpu::BindingType::UniformBuffer:
                 case wgpu::BindingType::ReadonlyStorageBuffer:
                 case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler:
                 case wgpu::BindingType::SampledTexture:
                 case wgpu::BindingType::ReadonlyStorageTexture:
                     return wgpu::ShaderStage::Vertex | wgpu::ShaderStage::Fragment |

src/dawn_native/ProgrammablePassEncoder.cpp

@@ -60,6 +60,7 @@ namespace dawn_native {
                     }
 
                     case wgpu::BindingType::Sampler:
+                    case wgpu::BindingType::ComparisonSampler:
                         break;
 
                     case wgpu::BindingType::StorageTexture:

src/dawn_native/Sampler.cpp

@@ -80,6 +80,10 @@ namespace dawn_native {
         return new SamplerBase(device, ObjectBase::kError);
     }
 
+    bool SamplerBase::HasCompareFunction() const {
+        return mCompareFunction != wgpu::CompareFunction::Undefined;
+    }
+
     size_t SamplerBase::HashFunc::operator()(const SamplerBase* module) const {
         size_t hash = 0;
 

src/dawn_native/Sampler.h

@@ -33,6 +33,8 @@ namespace dawn_native {
 
         static SamplerBase* MakeError(DeviceBase* device);
 
+        bool HasCompareFunction() const;
+
         // Functors necessary for the unordered_set<SamplerBase*>-based cache.
         struct HashFunc {
             size_t operator()(const SamplerBase* module) const;

src/dawn_native/ShaderModule.cpp

@@ -110,10 +110,9 @@ namespace dawn_native {
                 case shaderc_spvc_binding_type_readonly_storage_buffer:
                     return wgpu::BindingType::ReadonlyStorageBuffer;
                 case shaderc_spvc_binding_type_sampler:
-                case shaderc_spvc_binding_type_comparison_sampler:
-                    // TODO: Break out comparison sampler into its own case, once Dawn has seperate
-                    // handling
                     return wgpu::BindingType::Sampler;
+                case shaderc_spvc_binding_type_comparison_sampler:
+                    return wgpu::BindingType::ComparisonSampler;
                 case shaderc_spvc_binding_type_sampled_texture:
                     return wgpu::BindingType::SampledTexture;
                 case shaderc_spvc_binding_type_readonly_storage_texture:
@@ -773,6 +772,16 @@ namespace dawn_native {
                 bool validBindingConversion =
                     bindingInfo.type == wgpu::BindingType::StorageBuffer &&
                     moduleInfo.type == wgpu::BindingType::ReadonlyStorageBuffer;
+
+                // TODO(crbug.com/dawn/367): Temporarily allow using either a sampler or a
+                // comparison sampler until we can perform the proper shader analysis of what type
+                // is used in the shader module.
+                validBindingConversion |= (bindingInfo.type == wgpu::BindingType::Sampler &&
+                                           moduleInfo.type == wgpu::BindingType::ComparisonSampler);
+                validBindingConversion |=
+                    (bindingInfo.type == wgpu::BindingType::ComparisonSampler &&
+                     moduleInfo.type == wgpu::BindingType::Sampler);
+
                 if (!validBindingConversion) {
                     return false;
                 }
@@ -811,6 +820,7 @@ namespace dawn_native {
                 case wgpu::BindingType::ReadonlyStorageBuffer:
                 case wgpu::BindingType::StorageBuffer:
                 case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler:
                     break;
 
                 case wgpu::BindingType::StorageTexture:

src/dawn_native/d3d12/BindGroupD3D12.cpp

@@ -123,7 +123,8 @@ namespace dawn_native { namespace d3d12 {
                         viewAllocation.OffsetFrom(viewSizeIncrement, bindingOffsets[bindingIndex]));
                     break;
                 }
-                case wgpu::BindingType::Sampler: {
+                case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler: {
                     auto* sampler = ToBackend(GetBindingAsSampler(bindingIndex));
                     auto& samplerDesc = sampler->GetSamplerDescriptor();
                     d3d12Device->CreateSampler(

src/dawn_native/d3d12/BindGroupLayoutD3D12.cpp

@@ -34,6 +34,7 @@ namespace dawn_native { namespace d3d12 {
                 case wgpu::BindingType::ReadonlyStorageTexture:
                     return BindGroupLayout::DescriptorType::SRV;
                 case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler:
                     return BindGroupLayout::DescriptorType::Sampler;
                 case wgpu::BindingType::StorageTexture:
                     UNREACHABLE();
@@ -116,6 +117,7 @@ namespace dawn_native { namespace d3d12 {
                         break;
                     case wgpu::BindingType::SampledTexture:
                     case wgpu::BindingType::Sampler:
+                    case wgpu::BindingType::ComparisonSampler:
                     case wgpu::BindingType::StorageTexture:
                     case wgpu::BindingType::ReadonlyStorageTexture:
                     case wgpu::BindingType::WriteonlyStorageTexture:

src/dawn_native/d3d12/CommandBufferD3D12.cpp

@@ -165,6 +165,7 @@ namespace dawn_native { namespace d3d12 {
                             case wgpu::BindingType::UniformBuffer:
                             case wgpu::BindingType::ReadonlyStorageBuffer:
                             case wgpu::BindingType::Sampler:
+                            case wgpu::BindingType::ComparisonSampler:
                             case wgpu::BindingType::SampledTexture:
                                 // Don't require barriers.
 
@@ -246,6 +247,7 @@ namespace dawn_native { namespace d3d12 {
                             break;
                         case wgpu::BindingType::SampledTexture:
                         case wgpu::BindingType::Sampler:
+                        case wgpu::BindingType::ComparisonSampler:
                         case wgpu::BindingType::StorageTexture:
                         case wgpu::BindingType::ReadonlyStorageTexture:
                         case wgpu::BindingType::WriteonlyStorageTexture:

src/dawn_native/d3d12/PipelineLayoutD3D12.cpp

@@ -50,6 +50,7 @@ namespace dawn_native { namespace d3d12 {
                     return D3D12_ROOT_PARAMETER_TYPE_SRV;
                 case wgpu::BindingType::SampledTexture:
                 case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler:
                 case wgpu::BindingType::StorageTexture:
                 case wgpu::BindingType::ReadonlyStorageTexture:
                 case wgpu::BindingType::WriteonlyStorageTexture:

src/dawn_native/metal/CommandBufferMTL.mm

@@ -571,7 +571,8 @@ namespace dawn_native { namespace metal {
                             break;
                         }
 
-                        case wgpu::BindingType::Sampler: {
+                        case wgpu::BindingType::Sampler:
+                        case wgpu::BindingType::ComparisonSampler: {
                             auto sampler = ToBackend(group->GetBindingAsSampler(bindingIndex));
                             if (hasVertStage) {
                                 [render setVertexSamplerState:sampler->GetMTLSamplerState()

src/dawn_native/metal/PipelineLayoutMTL.mm

@@ -45,6 +45,7 @@ namespace dawn_native { namespace metal {
                             bufferIndex++;
                             break;
                         case wgpu::BindingType::Sampler:
+                        case wgpu::BindingType::ComparisonSampler:
                             mIndexInfo[stage][group][bindingIndex] = samplerIndex;
                             samplerIndex++;
                             break;

src/dawn_native/opengl/CommandBufferGL.cpp

@@ -280,7 +280,8 @@ namespace dawn_native { namespace opengl {
                             break;
                         }
 
-                        case wgpu::BindingType::Sampler: {
+                        case wgpu::BindingType::Sampler:
+                        case wgpu::BindingType::ComparisonSampler: {
                             Sampler* sampler = ToBackend(group->GetBindingAsSampler(bindingIndex));
                             GLuint samplerIndex = indices[bindingIndex];
 

src/dawn_native/opengl/PipelineGL.cpp

@@ -136,6 +136,7 @@ namespace dawn_native { namespace opengl {
                     }
 
                     case wgpu::BindingType::Sampler:
+                    case wgpu::BindingType::ComparisonSampler:
                     case wgpu::BindingType::SampledTexture:
                         // These binding types are handled in the separate sampler and texture
                         // emulation

src/dawn_native/opengl/PipelineLayoutGL.cpp

@@ -38,6 +38,7 @@ namespace dawn_native { namespace opengl {
                         uboIndex++;
                         break;
                     case wgpu::BindingType::Sampler:
+                    case wgpu::BindingType::ComparisonSampler:
                         mIndexInfo[group][bindingIndex] = samplerIndex;
                         samplerIndex++;
                         break;

src/dawn_native/vulkan/BindGroupLayoutVk.cpp

@@ -53,6 +53,7 @@ namespace dawn_native { namespace vulkan {
                 }
                 return VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER;
             case wgpu::BindingType::Sampler:
+            case wgpu::BindingType::ComparisonSampler:
                 return VK_DESCRIPTOR_TYPE_SAMPLER;
             case wgpu::BindingType::SampledTexture:
                 return VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE;

src/dawn_native/vulkan/BindGroupVk.cpp

@@ -71,7 +71,8 @@ namespace dawn_native { namespace vulkan {
                     break;
                 }
 
-                case wgpu::BindingType::Sampler: {
+                case wgpu::BindingType::Sampler:
+                case wgpu::BindingType::ComparisonSampler: {
                     Sampler* sampler = ToBackend(GetBindingAsSampler(bindingIndex));
                     writeImageInfo[numWrites].sampler = sampler->GetHandle();
                     write.pImageInfo = &writeImageInfo[numWrites];

src/dawn_native/vulkan/CommandBufferVk.cpp

@@ -156,6 +156,7 @@ namespace dawn_native { namespace vulkan {
                             case wgpu::BindingType::UniformBuffer:
                             case wgpu::BindingType::ReadonlyStorageBuffer:
                             case wgpu::BindingType::Sampler:
+                            case wgpu::BindingType::ComparisonSampler:
                             case wgpu::BindingType::SampledTexture:
                                 // Don't require barriers.
 

src/tests/end2end/BindGroupTests.cpp

@@ -264,16 +264,13 @@ TEST_P(BindGroupTests, UBOSamplerAndTexture) {
     wgpu::Buffer buffer = utils::CreateBufferFromData(device, &transform, sizeof(transform),
                                                       wgpu::BufferUsage::Uniform);
 
-    wgpu::SamplerDescriptor samplerDescriptor;
+    wgpu::SamplerDescriptor samplerDescriptor = {};
     samplerDescriptor.minFilter = wgpu::FilterMode::Nearest;
     samplerDescriptor.magFilter = wgpu::FilterMode::Nearest;
     samplerDescriptor.mipmapFilter = wgpu::FilterMode::Nearest;
     samplerDescriptor.addressModeU = wgpu::AddressMode::ClampToEdge;
     samplerDescriptor.addressModeV = wgpu::AddressMode::ClampToEdge;
     samplerDescriptor.addressModeW = wgpu::AddressMode::ClampToEdge;
-    samplerDescriptor.lodMinClamp = kLodMin;
-    samplerDescriptor.lodMaxClamp = kLodMax;
-    samplerDescriptor.compare = wgpu::CompareFunction::Never;
 
     wgpu::Sampler sampler = device.CreateSampler(&samplerDescriptor);
 

src/tests/end2end/SamplerTests.cpp

@@ -122,16 +122,13 @@ protected:
     void TestAddressModes(AddressModeTestCase u, AddressModeTestCase v, AddressModeTestCase w) {
         wgpu::Sampler sampler;
         {
-            wgpu::SamplerDescriptor descriptor;
+            wgpu::SamplerDescriptor descriptor = {};
             descriptor.minFilter = wgpu::FilterMode::Nearest;
             descriptor.magFilter = wgpu::FilterMode::Nearest;
             descriptor.mipmapFilter = wgpu::FilterMode::Nearest;
             descriptor.addressModeU = u.mMode;
             descriptor.addressModeV = v.mMode;
             descriptor.addressModeW = w.mMode;
-            descriptor.lodMinClamp = kLodMin;
-            descriptor.lodMaxClamp = kLodMax;
-            descriptor.compare = wgpu::CompareFunction::Never;
             sampler = device.CreateSampler(&descriptor);
         }
 

src/tests/end2end/TextureViewTests.cpp

@@ -86,16 +86,13 @@ protected:
         wgpu::FilterMode kFilterMode = wgpu::FilterMode::Nearest;
         wgpu::AddressMode kAddressMode = wgpu::AddressMode::ClampToEdge;
 
-        wgpu::SamplerDescriptor samplerDescriptor;
+        wgpu::SamplerDescriptor samplerDescriptor = {};
         samplerDescriptor.minFilter = kFilterMode;
         samplerDescriptor.magFilter = kFilterMode;
         samplerDescriptor.mipmapFilter = kFilterMode;
         samplerDescriptor.addressModeU = kAddressMode;
         samplerDescriptor.addressModeV = kAddressMode;
         samplerDescriptor.addressModeW = kAddressMode;
-        samplerDescriptor.lodMinClamp = kLodMin;
-        samplerDescriptor.lodMaxClamp = kLodMax;
-        samplerDescriptor.compare = wgpu::CompareFunction::Never;
         mSampler = device.CreateSampler(&samplerDescriptor);
 
         mVSModule = CreateDefaultVertexShaderModule(device);

src/tests/unittests/validation/BindGroupValidationTests.cpp

@@ -1506,3 +1506,126 @@ TEST_F(BindingsValidationTest, BindGroupsWithLessBindingsThanPipelineLayout) {
 
     TestComputePassBindings(bg.data(), kBindingNum, computePipeline, false);
 }
+
+class ComparisonSamplerBindingTest : public ValidationTest {
+  protected:
+    wgpu::RenderPipeline CreateFragmentPipeline(wgpu::BindGroupLayout* bindGroupLayout,
+                                                const char* fragmentSource) {
+        wgpu::ShaderModule vsModule =
+            utils::CreateShaderModule(device, utils::SingleShaderStage::Vertex, R"(
+                #version 450
+                void main() {
+                })");
+
+        wgpu::ShaderModule fsModule =
+            utils::CreateShaderModule(device, utils::SingleShaderStage::Fragment, fragmentSource);
+
+        utils::ComboRenderPipelineDescriptor pipelineDescriptor(device);
+        pipelineDescriptor.vertexStage.module = vsModule;
+        pipelineDescriptor.cFragmentStage.module = fsModule;
+        wgpu::PipelineLayout pipelineLayout =
+            utils::MakeBasicPipelineLayout(device, bindGroupLayout);
+        pipelineDescriptor.layout = pipelineLayout;
+        return device.CreateRenderPipeline(&pipelineDescriptor);
+    }
+};
+
+// TODO(crbug.com/dawn/367): Disabled until we can perform shader analysis
+// of which samplers are comparison samplers.
+TEST_F(ComparisonSamplerBindingTest, DISABLED_ShaderAndBGLMatches) {
+    // Test that sampler binding works with normal sampler in the shader.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::Sampler}});
+
+        CreateFragmentPipeline(&bindGroupLayout, R"(
+        #version 450
+        layout(set = 0, binding = 0) uniform sampler samp;
+
+        void main() {
+        })");
+    }
+
+    // Test that comparison sampler binding works with shadow sampler in the shader.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::ComparisonSampler}});
+
+        CreateFragmentPipeline(&bindGroupLayout, R"(
+        #version 450
+        layout(set = 0, binding = 0) uniform samplerShadow samp;
+
+        void main() {
+        })");
+    }
+
+    // Test that sampler binding does not work with comparison sampler in the shader.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::Sampler}});
+
+        ASSERT_DEVICE_ERROR(CreateFragmentPipeline(&bindGroupLayout, R"(
+        #version 450
+        layout(set = 0, binding = 0) uniform samplerShadow samp;
+
+        void main() {
+        })"));
+    }
+
+    // Test that comparison sampler binding does not work with normal sampler in the shader.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::ComparisonSampler}});
+
+        ASSERT_DEVICE_ERROR(CreateFragmentPipeline(&bindGroupLayout, R"(
+        #version 450
+        layout(set = 0, binding = 0) uniform sampler samp;
+
+        void main() {
+        })"));
+    }
+}
+
+TEST_F(ComparisonSamplerBindingTest, SamplerAndBindGroupMatches) {
+    // Test that sampler binding works with normal sampler.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::Sampler}});
+
+        wgpu::SamplerDescriptor desc = {};
+        utils::MakeBindGroup(device, bindGroupLayout, {{0, device.CreateSampler(&desc)}});
+    }
+
+    // Test that comparison sampler binding works with sampler w/ compare function.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::ComparisonSampler}});
+
+        wgpu::SamplerDescriptor desc = {
+            .compare = wgpu::CompareFunction::Never,
+        };
+        utils::MakeBindGroup(device, bindGroupLayout, {{0, device.CreateSampler(&desc)}});
+    }
+
+    // Test that sampler binding does not work with sampler w/ compare function.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::Sampler}});
+
+        wgpu::SamplerDescriptor desc = {
+            .compare = wgpu::CompareFunction::Never,
+        };
+        ASSERT_DEVICE_ERROR(
+            utils::MakeBindGroup(device, bindGroupLayout, {{0, device.CreateSampler(&desc)}}));
+    }
+
+    // Test that comparison sampler binding does not work with normal sampler.
+    {
+        wgpu::BindGroupLayout bindGroupLayout = utils::MakeBindGroupLayout(
+            device, {{0, wgpu::ShaderStage::Fragment, wgpu::BindingType::ComparisonSampler}});
+
+        wgpu::SamplerDescriptor desc = {};
+        ASSERT_DEVICE_ERROR(
+            utils::MakeBindGroup(device, bindGroupLayout, {{0, device.CreateSampler(&desc)}}));
+    }
+}

src/utils/WGPUHelpers.cpp

@@ -244,7 +244,7 @@ namespace utils {
     }
 
     wgpu::SamplerDescriptor GetDefaultSamplerDescriptor() {
-        wgpu::SamplerDescriptor desc;
+        wgpu::SamplerDescriptor desc = {};
 
         desc.minFilter = wgpu::FilterMode::Linear;
         desc.magFilter = wgpu::FilterMode::Linear;
@@ -252,9 +252,6 @@ namespace utils {
         desc.addressModeU = wgpu::AddressMode::Repeat;
         desc.addressModeV = wgpu::AddressMode::Repeat;
         desc.addressModeW = wgpu::AddressMode::Repeat;
-        desc.lodMinClamp = kLodMin;
-        desc.lodMaxClamp = kLodMax;
-        desc.compare = wgpu::CompareFunction::Never;
 
         return desc;
     }