VK_EXT_provoking_vertex support

include/vulkan/vk_ext_provoking_vertex.h

+// Copyright 2019 The SwiftShader Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "vulkan.h"
+
+// THIS FILE SHOULD BE DELETED IF VK_EXT_provoking_vertex IS EVER ADDED TO THE VULKAN HEADERS
+#ifdef VK_EXT_provoking_vertex
+#error "VK_EXT_provoking_vertex is already defined in the Vulkan headers, you can delete this file"
+#endif
+
+static constexpr VkStructureType VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_FEATURES_EXT = static_cast<VkStructureType>(1000254000);
+static constexpr VkStructureType VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_PROVOKING_VERTEX_STATE_CREATE_INFO_EXT = static_cast<VkStructureType>(1000254001);
+static constexpr VkStructureType VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_PROPERTIES_EXT = static_cast<VkStructureType>(1000254002);
+
+#define VK_EXT_provoking_vertex 1
+#define VK_EXT_PROVOKING_VERTEX_SPEC_VERSION 1
+#define VK_EXT_PROVOKING_VERTEX_EXTENSION_NAME "VK_EXT_provoking_vertex"
+
+typedef enum VkProvokingVertexModeEXT {
+    VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT = 0,
+    VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT = 1,
+    VK_PROVOKING_VERTEX_MODE_BEGIN_RANGE_EXT = VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT,
+    VK_PROVOKING_VERTEX_MODE_END_RANGE_EXT = VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT,
+    VK_PROVOKING_VERTEX_MODE_RANGE_SIZE_EXT = (VK_PROVOKING_VERTEX_MODE_LAST_VERTEX_EXT - VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT + 1),
+    VK_PROVOKING_VERTEX_MODE_MAX_ENUM_EXT = 0x7FFFFFFF
+} VkProvokingVertexModeEXT;
+
+typedef struct VkPhysicalDeviceProvokingVertexFeaturesEXT {
+    VkStructureType    sType;
+    void*              pNext;
+    VkBool32           provokingVertexLast;
+} VkPhysicalDeviceProvokingVertexFeaturesEXT;
+
+typedef struct VkPhysicalDeviceProvokingVertexPropertiesEXT {
+    VkStructureType    sType;
+    void*              pNext;
+    VkBool32           provokingVertexModePerPipeline;
+} VkPhysicalDeviceProvokingVertexPropertiesEXT;
+
+typedef struct VkPipelineRasterizationProvokingVertexStateCreateInfoEXT {
+    VkStructureType             sType;
+    const void*                 pNext;
+    VkProvokingVertexModeEXT    provokingVertexMode;
+} VkPipelineRasterizationProvokingVertexStateCreateInfoEXT;
+

src/Device/Context.cpp

@@ -110,6 +110,7 @@ namespace sw
 
 		cullMode = VK_CULL_MODE_FRONT_BIT;
 		frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
+		provokingVertexMode = VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT;
 		lineRasterizationMode = VK_LINE_RASTERIZATION_MODE_DEFAULT_EXT;
 
 		depthBias = 0.0f;

src/Device/Context.hpp

@@ -88,6 +88,7 @@ namespace sw
 		BlendState getBlendState(int index) const;
 
 		VkPrimitiveTopology topology;
+		VkProvokingVertexModeEXT provokingVertexMode;
 
 		bool stencilEnable;
 		VkStencilOpState frontStencil;

src/Device/Renderer.cpp

@@ -46,8 +46,10 @@ unsigned int maxPrimitives = 1 << 21;
 namespace sw
 {
 	template<typename T>
-	inline bool setBatchIndices(unsigned int batch[128][3], VkPrimitiveTopology topology, T indices, unsigned int start, unsigned int triangleCount)
+	inline bool setBatchIndices(unsigned int batch[128][3], VkPrimitiveTopology topology, VkProvokingVertexModeEXT provokingVertexMode, T indices, unsigned int start, unsigned int triangleCount)
 	{
+		bool provokeFirst = (provokingVertexMode == VK_PROVOKING_VERTEX_MODE_FIRST_VERTEX_EXT);
+
 		switch(topology)
 		{
 		case VK_PRIMITIVE_TOPOLOGY_POINT_LIST:
@@ -72,8 +74,8 @@ namespace sw
 			auto index = 2 * start;
 			for(unsigned int i = 0; i < triangleCount; i++)
 			{
-				batch[i][0] = indices[index + 0];
-				batch[i][1] = indices[index + 1];
+				batch[i][0] = indices[index + (provokeFirst ? 0 : 1)];
+				batch[i][1] = indices[index + (provokeFirst ? 1 : 0)];
 				batch[i][2] = indices[index + 1];
 
 				index += 2;
@@ -85,8 +87,8 @@ namespace sw
 			auto index = start;
 			for(unsigned int i = 0; i < triangleCount; i++)
 			{
-				batch[i][0] = indices[index + 0];
-				batch[i][1] = indices[index + 1];
+				batch[i][0] = indices[index + (provokeFirst ? 0 : 1)];
+				batch[i][1] = indices[index + (provokeFirst ? 1 : 0)];
 				batch[i][2] = indices[index + 1];
 
 				index += 1;
@@ -98,9 +100,9 @@ namespace sw
 			auto index = 3 * start;
 			for(unsigned int i = 0; i < triangleCount; i++)
 			{
-				batch[i][0] = indices[index + 0];
-				batch[i][1] = indices[index + 1];
-				batch[i][2] = indices[index + 2];
+				batch[i][0] = indices[index + (provokeFirst ? 0 : 2)];
+				batch[i][1] = indices[index + (provokeFirst ? 1 : 0)];
+				batch[i][2] = indices[index + (provokeFirst ? 2 : 1)];
 
 				index += 3;
 			}
@@ -111,9 +113,9 @@ namespace sw
 			auto index = start;
 			for(unsigned int i = 0; i < triangleCount; i++)
 			{
-				batch[i][0] = indices[index + 0];
-				batch[i][1] = indices[index + ((start + i) & 1) + 1];
-				batch[i][2] = indices[index + (~(start + i) & 1) + 1];
+				batch[i][0] = indices[index + (provokeFirst ? 0 : 2)];
+				batch[i][1] = indices[index + ((start + i) & 1) + (provokeFirst ? 1 : 0)];
+				batch[i][2] = indices[index + (~(start + i) & 1) + (provokeFirst ? 1 : 0)];
 
 				index += 1;
 			}
@@ -124,9 +126,9 @@ namespace sw
 			auto index = start + 1;
 			for(unsigned int i = 0; i < triangleCount; i++)
 			{
-				batch[i][0] = indices[index + 0];
-				batch[i][1] = indices[index + 1];
-				batch[i][2] = indices[0];
+				batch[i][provokeFirst ? 0 : 2] = indices[index + 0];
+				batch[i][provokeFirst ? 1 : 0] = indices[index + 1];
+				batch[i][provokeFirst ? 2 : 1] = indices[0];
 
 				index += 1;
 			}
@@ -260,6 +262,7 @@ namespace sw
 		draw->numPrimitivesPerBatch = numPrimitivesPerBatch;
 		draw->numBatches = (count + draw->numPrimitivesPerBatch - 1) / draw->numPrimitivesPerBatch;
 		draw->topology = context->topology;
+		draw->provokingVertexMode = context->provokingVertexMode;
 		draw->indexType = indexType;
 		draw->lineRasterizationMode = context->lineRasterizationMode;
 
@@ -498,7 +501,8 @@ namespace sw
 				draw->indexType,
 				batch->firstPrimitive,
 				batch->numPrimitives,
-				draw->topology);
+				draw->topology,
+				draw->provokingVertexMode);
 		}
 
 		auto& vertexTask = batch->vertexTask;
@@ -561,7 +565,8 @@ namespace sw
 		VkIndexType indexType,
 		unsigned int start,
 		unsigned int triangleCount,
-		VkPrimitiveTopology topology)
+		VkPrimitiveTopology topology,
+		VkProvokingVertexModeEXT provokingVertexMode)
 	{
 		if(!primitiveIndices)
 		{
@@ -570,7 +575,7 @@ namespace sw
 				unsigned int operator[](unsigned int i) { return i; }
 			};
 
-			if(!setBatchIndices(triangleIndicesOut, topology, LinearIndex(), start, triangleCount))
+			if(!setBatchIndices(triangleIndicesOut, topology, provokingVertexMode, LinearIndex(), start, triangleCount))
 			{
 				return;
 			}
@@ -580,13 +585,13 @@ namespace sw
 			switch(indexType)
 			{
 			case VK_INDEX_TYPE_UINT16:
-				if(!setBatchIndices(triangleIndicesOut, topology, static_cast<const uint16_t*>(primitiveIndices), start, triangleCount))
+				if(!setBatchIndices(triangleIndicesOut, topology, provokingVertexMode, static_cast<const uint16_t*>(primitiveIndices), start, triangleCount))
 				{
 					return;
 				}
 				break;
 			case VK_INDEX_TYPE_UINT32:
-				if(!setBatchIndices(triangleIndicesOut, topology, static_cast<const uint32_t*>(primitiveIndices), start, triangleCount))
+				if(!setBatchIndices(triangleIndicesOut, topology, provokingVertexMode, static_cast<const uint32_t*>(primitiveIndices), start, triangleCount))
 				{
 					return;
 				}

src/Device/Renderer.hpp

@@ -150,6 +150,7 @@ namespace sw
 		unsigned int numBatches;
 
 		VkPrimitiveTopology topology;
+		VkProvokingVertexModeEXT provokingVertexMode;
 		VkIndexType indexType;
 		VkLineRasterizationModeEXT lineRasterizationMode;
 
@@ -179,7 +180,8 @@ namespace sw
 				VkIndexType indexType,
 				unsigned int start,
 				unsigned int triangleCount,
-				VkPrimitiveTopology topology);
+				VkPrimitiveTopology topology,
+				VkProvokingVertexModeEXT provokingVertexMode);
 
 		static int setupSolidTriangles(Triangle* triangles, Primitive* primitives, const DrawCall* drawCall, int count);
 		static int setupWireframeTriangles(Triangle* triangles, Primitive* primitives, const DrawCall* drawCall, int count);

src/Vulkan/VkPhysicalDevice.cpp

@@ -394,6 +394,11 @@ void PhysicalDevice::getProperties(VkPhysicalDeviceLineRasterizationPropertiesEX
 	properties->lineSubPixelPrecisionBits = vk::SUBPIXEL_PRECISION_BITS;
 }
 
+void PhysicalDevice::getProperties(VkPhysicalDeviceProvokingVertexPropertiesEXT* properties) const
+{
+	properties->provokingVertexModePerPipeline = VK_TRUE;
+}
+
 bool PhysicalDevice::hasFeatures(const VkPhysicalDeviceFeatures& requestedFeatures) const
 {
 	const VkPhysicalDeviceFeatures& supportedFeatures = getFeatures();

src/Vulkan/VkPhysicalDevice.hpp

@@ -63,6 +63,7 @@ public:
 	void getProperties(const VkPhysicalDeviceExternalSemaphoreInfo* pExternalSemaphoreInfo, VkExternalSemaphoreProperties* pExternalSemaphoreProperties) const;
 	void getProperties(VkPhysicalDeviceDriverPropertiesKHR* properties) const;
 	void getProperties(VkPhysicalDeviceLineRasterizationPropertiesEXT* properties) const;
+	void getProperties(VkPhysicalDeviceProvokingVertexPropertiesEXT* properties) const;
 
 	void getFormatProperties(Format format, VkFormatProperties* pFormatProperties) const;
 	void getImageFormatProperties(Format format, VkImageType type, VkImageTiling tiling,

src/Vulkan/VkPipeline.cpp

@@ -390,6 +390,31 @@ GraphicsPipeline::GraphicsPipeline(const VkGraphicsPipelineCreateInfo* pCreateIn
 		UNIMPLEMENTED("pCreateInfo->pRasterizationState settings");
 	}
 
+	if(rasterizationState->pNext)
+	{
+		const VkBaseInStructure* extensionCreateInfo = reinterpret_cast<const VkBaseInStructure*>(rasterizationState->pNext);
+		while(extensionCreateInfo)
+		{
+			// Casting to a long since some structures, such as
+			// VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_FEATURES_EXT
+			// are not enumerated in the official Vulkan header
+			switch((long)(extensionCreateInfo->sType))
+			{
+			case VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_PROVOKING_VERTEX_STATE_CREATE_INFO_EXT:
+			{
+				const VkPipelineRasterizationProvokingVertexStateCreateInfoEXT* provokingVertexModeCreateInfo =
+					reinterpret_cast<const VkPipelineRasterizationProvokingVertexStateCreateInfoEXT*>(extensionCreateInfo);
+				context.provokingVertexMode = provokingVertexModeCreateInfo->provokingVertexMode;
+			}
+			break;
+			default:
+				UNIMPLEMENTED("extensionCreateInfo->pNext");
+			}
+
+			extensionCreateInfo = extensionCreateInfo->pNext;
+		}
+	}
+
 	context.rasterizerDiscard = (rasterizationState->rasterizerDiscardEnable == VK_TRUE);
 	context.cullMode = rasterizationState->cullMode;
 	context.frontFace = rasterizationState->frontFace;

src/Vulkan/VulkanPlatform.h

@@ -49,6 +49,7 @@ public:
 	template class VkNonDispatchableHandle<object##Ptr>;
 
 #include <vulkan/vulkan.h>
+#include <vulkan/vk_ext_provoking_vertex.h>
 
 #ifdef Bool
 #undef Bool // b/127920555

src/Vulkan/libVulkan.cpp

@@ -233,6 +233,7 @@ static const VkExtensionProperties deviceExtensionProperties[] =
 #if SWIFTSHADER_EXTERNAL_SEMAPHORE_LINUX_MEMFD
 	{ VK_KHR_EXTERNAL_SEMAPHORE_FD_EXTENSION_NAME, VK_KHR_EXTERNAL_SEMAPHORE_FD_SPEC_VERSION },
 #endif
+	{ VK_EXT_PROVOKING_VERTEX_EXTENSION_NAME, VK_EXT_PROVOKING_VERTEX_SPEC_VERSION },
 };
 
 VKAPI_ATTR VkResult VKAPI_CALL vkCreateInstance(const VkInstanceCreateInfo* pCreateInfo, const VkAllocationCallbacks* pAllocator, VkInstance* pInstance)
@@ -500,7 +501,10 @@ VKAPI_ATTR VkResult VKAPI_CALL vkCreateDevice(VkPhysicalDevice physicalDevice, c
 
 	while(extensionCreateInfo)
 	{
-		switch(extensionCreateInfo->sType)
+		// Casting to a long since some structures, such as
+		// VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_FEATURES_EXT
+		// are not enumerated in the official Vulkan header
+		switch((long)(extensionCreateInfo->sType))
 		{
 		case VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO:
 			// According to the Vulkan spec, section 2.7.2. Implicit Valid Usage:
@@ -597,6 +601,16 @@ VKAPI_ATTR VkResult VKAPI_CALL vkCreateDevice(VkPhysicalDevice physicalDevice, c
 				}
 			}
 			break;
+		case VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_FEATURES_EXT:
+			{
+				const VkPhysicalDeviceProvokingVertexFeaturesEXT* provokingVertexFeatures = reinterpret_cast<const VkPhysicalDeviceProvokingVertexFeaturesEXT*>(extensionCreateInfo);
+
+				// Provoking vertex is supported.
+				// provokingVertexFeatures->provokingVertexLast can be VK_TRUE or VK_FALSE.
+				// No action needs to be taken on our end in either case; it's the apps responsibility to check
+				// that the provokingVertexLast feature is enabled before using the provoking vertex convention.
+				(void)provokingVertexFeatures->provokingVertexLast;
+			}
 		default:
 			// "the [driver] must skip over, without processing (other than reading the sType and pNext members) any structures in the chain with sType values not defined by [supported extenions]"
 			UNIMPLEMENTED("extensionCreateInfo->sType %d", int(extensionCreateInfo->sType));   // TODO(b/119321052): UNIMPLEMENTED() should be used only for features that must still be implemented. Use a more informational macro here.
@@ -2434,7 +2448,9 @@ VKAPI_ATTR void VKAPI_CALL vkGetPhysicalDeviceProperties2(VkPhysicalDevice physi
 	VkBaseOutStructure* extensionProperties = reinterpret_cast<VkBaseOutStructure*>(pProperties->pNext);
 	while(extensionProperties)
 	{
-		// Casting to a long since some structures, such as VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PRESENTATION_PROPERTIES_ANDROID
+		// Casting to a long since some structures, such as
+		// VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PRESENTATION_PROPERTIES_ANDROID and
+		// VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_PROPERTIES_EXT
 		// are not enumerated in the official Vulkan header
 		switch((long)(extensionProperties->sType))
 		{
@@ -2503,6 +2519,12 @@ VKAPI_ATTR void VKAPI_CALL vkGetPhysicalDeviceProperties2(VkPhysicalDevice physi
 				vk::Cast(physicalDevice)->getProperties(&properties);
 			}
 			break;
+		case VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROVOKING_VERTEX_PROPERTIES_EXT:
+			{
+				auto& properties = *reinterpret_cast<VkPhysicalDeviceProvokingVertexPropertiesEXT*>(extensionProperties);
+				vk::Cast(physicalDevice)->getProperties(&properties);
+			}
+			break;
 		default:
 			// "the [driver] must skip over, without processing (other than reading the sType and pNext members) any structures in the chain with sType values not defined by [supported extenions]"
 			UNIMPLEMENTED("extensionProperties->sType");   // TODO(b/119321052): UNIMPLEMENTED() should be used only for features that must still be implemented. Use a more informational macro here.