src/Device/Context.cpp - SwiftShader - Git at Google

 // Copyright 2016 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 "Context.hpp"

 #include "Primitive.hpp"
 #include "Surface.hpp"
 #include "Pipeline/PixelShader.hpp"
 #include "Pipeline/VertexShader.hpp"
 #include "System/Memory.hpp"
 #include "System/Debug.hpp"

 #include <string.h>

 namespace sw
 {
 	extern bool perspectiveCorrection;

 	bool halfIntegerCoordinates = false;     // Pixel centers are not at integer coordinates
 	bool symmetricNormalizedDepth = false;   // [-1, 1] instead of [0, 1]
 	bool booleanFaceRegister = false;
 	bool fullPixelPositionRegister = false;
 	bool leadingVertexFirst = false;         // Flat shading uses first vertex, else last
 	bool secondaryColor = false;             // Specular lighting is applied after texturing
 	bool colorsDefaultToZero = false;

 	bool forceWindowed = false;
 	bool quadLayoutEnabled = false;
 	bool veryEarlyDepthTest = true;
 	bool complementaryDepthBuffer = false;
 	bool postBlendSRGB = false;
 	bool exactColorRounding = false;
 	TransparencyAntialiasing transparencyAntialiasing = TRANSPARENCY_NONE;
 	bool forceClearRegisters = false;

 	Context::Context()
 	{
 		init();
 	}

 	Context::~Context()
 	{
 	}

 	void *Context::operator new(size_t bytes)
 	{
 		return allocate((unsigned int)bytes);
 	}

 	void Context::operator delete(void *pointer, size_t bytes)
 	{
 		deallocate(pointer);
 	}

 	bool Context::isDrawPoint() const
 	{
 		switch(drawType)
 		{
 		case DRAW_POINTLIST:
 		case DRAW_INDEXEDPOINTLIST16:
 		case DRAW_INDEXEDPOINTLIST32:
 			return true;
 		case DRAW_LINELIST:
 		case DRAW_LINESTRIP:
 		case DRAW_INDEXEDLINELIST16:
 		case DRAW_INDEXEDLINESTRIP16:
 		case DRAW_INDEXEDLINELIST32:
 		case DRAW_INDEXEDLINESTRIP32:
 			return false;
 		case DRAW_TRIANGLELIST:
 		case DRAW_TRIANGLESTRIP:
 		case DRAW_TRIANGLEFAN:
 		case DRAW_INDEXEDTRIANGLELIST16:
 		case DRAW_INDEXEDTRIANGLESTRIP16:
 		case DRAW_INDEXEDTRIANGLEFAN16:
 		case DRAW_INDEXEDTRIANGLELIST32:
 		case DRAW_INDEXEDTRIANGLESTRIP32:
 		case DRAW_INDEXEDTRIANGLEFAN32:
 			return false;
 		default:
 			ASSERT(false);
 		}

 		return false;
 	}

 	bool Context::isDrawLine() const
 	{
 		switch(drawType)
 		{
 		case DRAW_POINTLIST:
 		case DRAW_INDEXEDPOINTLIST16:
 		case DRAW_INDEXEDPOINTLIST32:
 			return false;
 		case DRAW_LINELIST:
 		case DRAW_LINESTRIP:
 		case DRAW_INDEXEDLINELIST16:
 		case DRAW_INDEXEDLINESTRIP16:
 		case DRAW_INDEXEDLINELIST32:
 		case DRAW_INDEXEDLINESTRIP32:
 			return true;
 		case DRAW_TRIANGLELIST:
 		case DRAW_TRIANGLESTRIP:
 		case DRAW_TRIANGLEFAN:
 		case DRAW_INDEXEDTRIANGLELIST16:
 		case DRAW_INDEXEDTRIANGLESTRIP16:
 		case DRAW_INDEXEDTRIANGLEFAN16:
 		case DRAW_INDEXEDTRIANGLELIST32:
 		case DRAW_INDEXEDTRIANGLESTRIP32:
 		case DRAW_INDEXEDTRIANGLEFAN32:
 			return false;
 		default:
 			ASSERT(false);
 		}

 		return false;
 	}

 	bool Context::isDrawTriangle() const
 	{
 		switch(drawType)
 		{
 		case DRAW_POINTLIST:
 		case DRAW_INDEXEDPOINTLIST16:
 		case DRAW_INDEXEDPOINTLIST32:
 			return false;
 		case DRAW_LINELIST:
 		case DRAW_LINESTRIP:
 		case DRAW_INDEXEDLINELIST16:
 		case DRAW_INDEXEDLINESTRIP16:
 		case DRAW_INDEXEDLINELIST32:
 		case DRAW_INDEXEDLINESTRIP32:
 			return false;
 		case DRAW_TRIANGLELIST:
 		case DRAW_TRIANGLESTRIP:
 		case DRAW_TRIANGLEFAN:
 		case DRAW_INDEXEDTRIANGLELIST16:
 		case DRAW_INDEXEDTRIANGLESTRIP16:
 		case DRAW_INDEXEDTRIANGLEFAN16:
 		case DRAW_INDEXEDTRIANGLELIST32:
 		case DRAW_INDEXEDTRIANGLESTRIP32:
 		case DRAW_INDEXEDTRIANGLEFAN32:
 			return true;
 		default:
 			ASSERT(false);
 		}

 		return true;
 	}

 	void Context::init()
 	{
 		// Set vertex streams to null stream
 		for(int i = 0; i < MAX_VERTEX_INPUTS; i++)
 		{
 			input[i].defaults();
 		}

 		for(int i = 0; i < RENDERTARGETS; ++i)
 		{
 			renderTarget[i] = nullptr;
 		}
 		depthBuffer = nullptr;
 		stencilBuffer = nullptr;

 		stencilEnable = false;
 		stencilCompareMode = VK_COMPARE_OP_ALWAYS;
 		stencilReference = 0;
 		stencilMask = 0xFFFFFFFF;
 		stencilFailOperation = VK_STENCIL_OP_KEEP;
 		stencilPassOperation = VK_STENCIL_OP_KEEP;
 		stencilZFailOperation = VK_STENCIL_OP_KEEP;
 		stencilWriteMask = 0xFFFFFFFF;

 		twoSidedStencil = false;
 		stencilCompareModeCCW = VK_COMPARE_OP_ALWAYS;
 		stencilReferenceCCW = 0;
 		stencilMaskCCW = 0xFFFFFFFF;
 		stencilFailOperationCCW = VK_STENCIL_OP_KEEP;
 		stencilPassOperationCCW = VK_STENCIL_OP_KEEP;
 		stencilZFailOperationCCW = VK_STENCIL_OP_KEEP;
 		stencilWriteMaskCCW = 0xFFFFFFFF;

 		alphaCompareMode = VK_COMPARE_OP_ALWAYS;
 		alphaTestEnable = false;

 		rasterizerDiscard = false;

 		depthCompareMode = VK_COMPARE_OP_LESS;
 		depthBufferEnable = true;
 		depthWriteEnable = true;

 		alphaBlendEnable = false;
 		sourceBlendFactorState = VK_BLEND_FACTOR_ONE;
 		destBlendFactorState = VK_BLEND_FACTOR_ZERO;
 		blendOperationState = VK_BLEND_OP_ADD;

 		separateAlphaBlendEnable = false;
 		sourceBlendFactorStateAlpha = VK_BLEND_FACTOR_ONE;
 		destBlendFactorStateAlpha = VK_BLEND_FACTOR_ZERO;
 		blendOperationStateAlpha = VK_BLEND_OP_ADD;

 		cullMode = CULL_CLOCKWISE;
 		frontFacingCCW = true;
 		alphaReference = 0.0f;

 		depthBias = 0.0f;
 		slopeDepthBias = 0.0f;

 		for(int i = 0; i < RENDERTARGETS; i++)
 		{
 			colorWriteMask[i] = 0x0000000F;
 		}

 		pixelShader = nullptr;
 		vertexShader = nullptr;

 		instanceID = 0;

 		occlusionEnabled = false;
 		transformFeedbackQueryEnabled = false;
 		transformFeedbackEnabled = 0;

 		lineWidth = 1.0f;

 		writeSRGB = false;
 		sampleMask = 0xFFFFFFFF;

 		colorLogicOpEnabled = false;
 		logicalOperation = VK_LOGIC_OP_COPY;
 	}

 	bool Context::setDepthBufferEnable(bool depthBufferEnable)
 	{
 		bool modified = (Context::depthBufferEnable != depthBufferEnable);
 		Context::depthBufferEnable = depthBufferEnable;
 		return modified;
 	}

 	bool Context::setAlphaBlendEnable(bool alphaBlendEnable)
 	{
 		bool modified = (Context::alphaBlendEnable != alphaBlendEnable);
 		Context::alphaBlendEnable = alphaBlendEnable;
 		return modified;
 	}

 	bool Context::setSourceBlendFactor(VkBlendFactor sourceBlendFactor)
 	{
 		bool modified = (Context::sourceBlendFactorState != sourceBlendFactor);
 		Context::sourceBlendFactorState = sourceBlendFactor;
 		return modified;
 	}

 	bool Context::setDestBlendFactor(VkBlendFactor destBlendFactor)
 	{
 		bool modified = (Context::destBlendFactorState != destBlendFactor);
 		Context::destBlendFactorState = destBlendFactor;
 		return modified;
 	}

 	bool Context::setBlendOperation(VkBlendOp blendOperation)
 	{
 		bool modified = (Context::blendOperationState != blendOperation);
 		Context::blendOperationState = blendOperation;
 		return modified;
 	}

 	bool Context::setSeparateAlphaBlendEnable(bool separateAlphaBlendEnable)
 	{
 		bool modified = (Context::separateAlphaBlendEnable != separateAlphaBlendEnable);
 		Context::separateAlphaBlendEnable = separateAlphaBlendEnable;
 		return modified;
 	}

 	bool Context::setSourceBlendFactorAlpha(VkBlendFactor sourceBlendFactorAlpha)
 	{
 		bool modified = (Context::sourceBlendFactorStateAlpha != sourceBlendFactorAlpha);
 		Context::sourceBlendFactorStateAlpha = sourceBlendFactorAlpha;
 		return modified;
 	}

 	bool Context::setDestBlendFactorAlpha(VkBlendFactor destBlendFactorAlpha)
 	{
 		bool modified = (Context::destBlendFactorStateAlpha != destBlendFactorAlpha);
 		Context::destBlendFactorStateAlpha = destBlendFactorAlpha;
 		return modified;
 	}

 	bool Context::setBlendOperationAlpha(VkBlendOp blendOperationAlpha)
 	{
 		bool modified = (Context::blendOperationStateAlpha != blendOperationAlpha);
 		Context::blendOperationStateAlpha = blendOperationAlpha;
 		return modified;
 	}

 	bool Context::setColorWriteMask(int index, int colorWriteMask)
 	{
 		bool modified = (Context::colorWriteMask[index] != colorWriteMask);
 		Context::colorWriteMask[index] = colorWriteMask;
 		return modified;
 	}

 	bool Context::setWriteSRGB(bool sRGB)
 	{
 		bool modified = (Context::writeSRGB != sRGB);
 		Context::writeSRGB = sRGB;
 		return modified;
 	}

 	bool Context::setColorLogicOpEnabled(bool enabled)
 	{
 		bool modified = (Context::colorLogicOpEnabled != enabled);
 		Context::colorLogicOpEnabled = enabled;
 		return modified;
 	}

 	bool Context::setLogicalOperation(VkLogicOp logicalOperation)
 	{
 		bool modified = (Context::logicalOperation != logicalOperation);
 		Context::logicalOperation = logicalOperation;
 		return modified;
 	}

 	bool Context::depthWriteActive()
 	{
 		if(!depthBufferActive()) return false;

 		return depthWriteEnable;
 	}

 	bool Context::alphaTestActive()
 	{
 		if(transparencyAntialiasing != TRANSPARENCY_NONE) return true;
 		if(!alphaTestEnable) return false;
 		if(alphaCompareMode == VK_COMPARE_OP_ALWAYS) return false;
 		if(alphaReference == 0.0f && alphaCompareMode == VK_COMPARE_OP_GREATER_OR_EQUAL) return false;

 		return true;
 	}

 	bool Context::depthBufferActive()
 	{
 		return depthBuffer && depthBufferEnable;
 	}

 	bool Context::stencilActive()
 	{
 		return stencilBuffer && stencilEnable;
 	}

 	bool Context::alphaBlendActive()
 	{
 		if(!alphaBlendEnable)
 		{
 			return false;
 		}

 		if(!colorUsed())
 		{
 			return false;
 		}

 		bool colorBlend = !(blendOperation() == VK_BLEND_OP_SRC_EXT && sourceBlendFactor() == VK_BLEND_FACTOR_ONE);
 		bool alphaBlend = separateAlphaBlendEnable ? !(blendOperationAlpha() == VK_BLEND_OP_SRC_EXT && sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE) : colorBlend;

 		return colorBlend || alphaBlend;
 	}

 	VkLogicOp Context::colorLogicOp()
 	{
 		return colorLogicOpEnabled ? logicalOperation : VK_LOGIC_OP_COPY;
 	}

 	VkBlendFactor Context::sourceBlendFactor()
 	{
 		if(!alphaBlendEnable) return VK_BLEND_FACTOR_ONE;

 		switch(blendOperationState)
 		{
 		case VK_BLEND_OP_ADD:
 		case VK_BLEND_OP_SUBTRACT:
 		case VK_BLEND_OP_REVERSE_SUBTRACT:
 			return sourceBlendFactorState;
 		case VK_BLEND_OP_MIN:
 			return VK_BLEND_FACTOR_ONE;
 		case VK_BLEND_OP_MAX:
 			return VK_BLEND_FACTOR_ONE;
 		default:
 			ASSERT(false);
 		}

 		return sourceBlendFactorState;
 	}

 	VkBlendFactor Context::destBlendFactor()
 	{
 		if(!alphaBlendEnable) return VK_BLEND_FACTOR_ONE;

 		switch(blendOperationState)
 		{
 		case VK_BLEND_OP_ADD:
 		case VK_BLEND_OP_SUBTRACT:
 		case VK_BLEND_OP_REVERSE_SUBTRACT:
 			return destBlendFactorState;
 		case VK_BLEND_OP_MIN:
 			return VK_BLEND_FACTOR_ONE;
 		case VK_BLEND_OP_MAX:
 			return VK_BLEND_FACTOR_ONE;
 		default:
 			ASSERT(false);
 		}

 		return destBlendFactorState;
 	}

 	VkBlendOp Context::blendOperation()
 	{
 		if(!alphaBlendEnable) return VK_BLEND_OP_SRC_EXT;

 		switch(blendOperationState)
 		{
 		case VK_BLEND_OP_ADD:
 			if(sourceBlendFactor() == VK_BLEND_FACTOR_ZERO)
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_ZERO_EXT;
 				}
 				else
 				{
 					return VK_BLEND_OP_DST_EXT;
 				}
 			}
 			else if(sourceBlendFactor() == VK_BLEND_FACTOR_ONE)
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_SRC_EXT;
 				}
 				else
 				{
 					return VK_BLEND_OP_ADD;
 				}
 			}
 			else
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_SRC_EXT;
 				}
 				else
 				{
 					return VK_BLEND_OP_ADD;
 				}
 			}
 		case VK_BLEND_OP_SUBTRACT:
 			if(sourceBlendFactor() == VK_BLEND_FACTOR_ZERO)
 			{
 				return VK_BLEND_OP_ZERO_EXT;   // Negative, clamped to zero
 			}
 			else if(sourceBlendFactor() == VK_BLEND_FACTOR_ONE)
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_SRC_EXT;
 				}
 				else
 				{
 					return VK_BLEND_OP_SUBTRACT;
 				}
 			}
 			else
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_SRC_EXT;
 				}
 				else
 				{
 					return VK_BLEND_OP_SUBTRACT;
 				}
 			}
 		case VK_BLEND_OP_REVERSE_SUBTRACT:
 			if(sourceBlendFactor() == VK_BLEND_FACTOR_ZERO)
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_ZERO_EXT;
 				}
 				else
 				{
 					return VK_BLEND_OP_DST_EXT;
 				}
 			}
 			else if(sourceBlendFactor() == VK_BLEND_FACTOR_ONE)
 			{
 				if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_ZERO_EXT;   // Negative, clamped to zero
 				}
 				else
 				{
 					return VK_BLEND_OP_REVERSE_SUBTRACT;
 				}
 			}
 			else
 			{
 				if(destBlendFactor() == VK_BLEND_OP_ZERO_EXT)
 				{
 					return VK_BLEND_OP_ZERO_EXT;   // Negative, clamped to zero
 				}
 				else
 				{
 					return VK_BLEND_OP_REVERSE_SUBTRACT;
 				}
 			}
 		case VK_BLEND_OP_MIN:
 			return VK_BLEND_OP_MIN;
 		case VK_BLEND_OP_MAX:
 			return VK_BLEND_OP_MAX;
 		default:
 			ASSERT(false);
 		}

 		return blendOperationState;
 	}

 	VkBlendFactor Context::sourceBlendFactorAlpha()
 	{
 		if(!separateAlphaBlendEnable)
 		{
 			return sourceBlendFactor();
 		}
 		else
 		{
 			switch(blendOperationStateAlpha)
 			{
 			case VK_BLEND_OP_ADD:
 			case VK_BLEND_OP_SUBTRACT:
 			case VK_BLEND_OP_REVERSE_SUBTRACT:
 				return sourceBlendFactorStateAlpha;
 			case VK_BLEND_OP_MIN:
 				return VK_BLEND_FACTOR_ONE;
 			case VK_BLEND_OP_MAX:
 				return VK_BLEND_FACTOR_ONE;
 			default:
 				ASSERT(false);
 			}

 			return sourceBlendFactorStateAlpha;
 		}
 	}

 	VkBlendFactor Context::destBlendFactorAlpha()
 	{
 		if(!separateAlphaBlendEnable)
 		{
 			return destBlendFactor();
 		}
 		else
 		{
 			switch(blendOperationStateAlpha)
 			{
 			case VK_BLEND_OP_ADD:
 			case VK_BLEND_OP_SUBTRACT:
 			case VK_BLEND_OP_REVERSE_SUBTRACT:
 				return destBlendFactorStateAlpha;
 			case VK_BLEND_OP_MIN:
 				return VK_BLEND_FACTOR_ONE;
 			case VK_BLEND_OP_MAX:
 				return VK_BLEND_FACTOR_ONE;
 			default:
 				ASSERT(false);
 			}

 			return destBlendFactorStateAlpha;
 		}
 	}

 	VkBlendOp Context::blendOperationAlpha()
 	{
 		if(!separateAlphaBlendEnable)
 		{
 			return blendOperation();
 		}
 		else
 		{
 			switch(blendOperationStateAlpha)
 			{
 			case VK_BLEND_OP_ADD:
 				if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_ZERO_EXT;
 					}
 					else
 					{
 						return VK_BLEND_OP_DST_EXT;
 					}
 				}
 				else if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_SRC_EXT;
 					}
 					else
 					{
 						return VK_BLEND_OP_ADD;
 					}
 				}
 				else
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_SRC_EXT;
 					}
 					else
 					{
 						return VK_BLEND_OP_ADD;
 					}
 				}
 			case VK_BLEND_OP_SUBTRACT:
 				if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 				{
 					return VK_BLEND_OP_ZERO_EXT;   // Negative, clamped to zero
 				}
 				else if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_SRC_EXT;
 					}
 					else
 					{
 						return VK_BLEND_OP_SUBTRACT;
 					}
 				}
 				else
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_SRC_EXT;
 					}
 					else
 					{
 						return VK_BLEND_OP_SUBTRACT;
 					}
 				}
 			case VK_BLEND_OP_REVERSE_SUBTRACT:
 				if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_ZERO_EXT;
 					}
 					else
 					{
 						return VK_BLEND_OP_DST_EXT;
 					}
 				}
 				else if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
 					{
 						return VK_BLEND_OP_ZERO_EXT;   // Negative, clamped to zero
 					}
 					else
 					{
 						return VK_BLEND_OP_REVERSE_SUBTRACT;
 					}
 				}
 				else
 				{
 					if(destBlendFactorAlpha() == VK_BLEND_OP_ZERO_EXT)
 					{
 						return VK_BLEND_OP_ZERO_EXT;   // Negative, clamped to zero
 					}
 					else
 					{
 						return VK_BLEND_OP_ZERO_EXT;
 					}
 				}
 			case VK_BLEND_OP_MIN:
 				return VK_BLEND_OP_MIN;
 			case VK_BLEND_OP_MAX:
 				return VK_BLEND_OP_MAX;
 			default:
 				ASSERT(false);
 			}

 			return blendOperationStateAlpha;
 		}
 	}

 	bool Context::perspectiveActive()
 	{
 		if(!colorUsed())
 		{
 			return false;
 		}

 		if(!perspectiveCorrection)
 		{
 			return false;
 		}

 		if(isDrawPoint())
 		{
 			return false;
 		}

 		return true;
 	}

 	unsigned short Context::pixelShaderModel() const
 	{
 		return pixelShader ? pixelShader->getShaderModel() : 0x0000;
 	}

 	unsigned short Context::vertexShaderModel() const
 	{
 		return vertexShader ? vertexShader->getShaderModel() : 0x0000;
 	}

 	int Context::getMultiSampleCount() const
 	{
 		return renderTarget[0] ? renderTarget[0]->getMultiSampleCount() : 1;
 	}

 	VkFormat Context::renderTargetInternalFormat(int index)
 	{
 		if(renderTarget[index])
 		{
 			return renderTarget[index]->getInternalFormat();
 		}
 		else
 		{
 			return VK_FORMAT_UNDEFINED;
 		}
 	}

 	int Context::colorWriteActive()
 	{
 		return colorWriteActive(0) | colorWriteActive(1) | colorWriteActive(2) | colorWriteActive(3);
 	}

 	int Context::colorWriteActive(int index)
 	{
 		if(!renderTarget[index] || renderTarget[index]->getInternalFormat() == VK_FORMAT_UNDEFINED)
 		{
 			return 0;
 		}

 		if(blendOperation() == VK_BLEND_OP_DST_EXT && destBlendFactor() == VK_BLEND_FACTOR_ONE &&
 		   (!separateAlphaBlendEnable || (blendOperationAlpha() == VK_BLEND_OP_DST_EXT && destBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)))
 		{
 			return 0;
 		}

 		return colorWriteMask[index];
 	}

 	bool Context::colorUsed()
 	{
 		return colorWriteActive() || alphaTestActive() || (pixelShader && pixelShader->containsKill());
 	}
 }
	// Copyright 2016 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 "Context.hpp"

	#include "Primitive.hpp"
	#include "Surface.hpp"
	#include "Pipeline/PixelShader.hpp"
	#include "Pipeline/VertexShader.hpp"
	#include "System/Memory.hpp"
	#include "System/Debug.hpp"

	#include <string.h>

	namespace sw
	{
	extern bool perspectiveCorrection;

	bool halfIntegerCoordinates = false; // Pixel centers are not at integer coordinates
	bool symmetricNormalizedDepth = false; // [-1, 1] instead of [0, 1]
	bool booleanFaceRegister = false;
	bool fullPixelPositionRegister = false;
	bool leadingVertexFirst = false; // Flat shading uses first vertex, else last
	bool secondaryColor = false; // Specular lighting is applied after texturing
	bool colorsDefaultToZero = false;

	bool forceWindowed = false;
	bool quadLayoutEnabled = false;
	bool veryEarlyDepthTest = true;
	bool complementaryDepthBuffer = false;
	bool postBlendSRGB = false;
	bool exactColorRounding = false;
	TransparencyAntialiasing transparencyAntialiasing = TRANSPARENCY_NONE;
	bool forceClearRegisters = false;

	Context::Context()
	{
	init();
	}

	Context::~Context()
	{
	}

	void *Context::operator new(size_t bytes)
	{
	return allocate((unsigned int)bytes);
	}

	void Context::operator delete(void *pointer, size_t bytes)
	{
	deallocate(pointer);
	}

	bool Context::isDrawPoint() const
	{
	switch(drawType)
	{
	case DRAW_POINTLIST:
	case DRAW_INDEXEDPOINTLIST16:
	case DRAW_INDEXEDPOINTLIST32:
	return true;
	case DRAW_LINELIST:
	case DRAW_LINESTRIP:
	case DRAW_INDEXEDLINELIST16:
	case DRAW_INDEXEDLINESTRIP16:
	case DRAW_INDEXEDLINELIST32:
	case DRAW_INDEXEDLINESTRIP32:
	return false;
	case DRAW_TRIANGLELIST:
	case DRAW_TRIANGLESTRIP:
	case DRAW_TRIANGLEFAN:
	case DRAW_INDEXEDTRIANGLELIST16:
	case DRAW_INDEXEDTRIANGLESTRIP16:
	case DRAW_INDEXEDTRIANGLEFAN16:
	case DRAW_INDEXEDTRIANGLELIST32:
	case DRAW_INDEXEDTRIANGLESTRIP32:
	case DRAW_INDEXEDTRIANGLEFAN32:
	return false;
	default:
	ASSERT(false);
	}

	return false;
	}

	bool Context::isDrawLine() const
	{
	switch(drawType)
	{
	case DRAW_POINTLIST:
	case DRAW_INDEXEDPOINTLIST16:
	case DRAW_INDEXEDPOINTLIST32:
	return false;
	case DRAW_LINELIST:
	case DRAW_LINESTRIP:
	case DRAW_INDEXEDLINELIST16:
	case DRAW_INDEXEDLINESTRIP16:
	case DRAW_INDEXEDLINELIST32:
	case DRAW_INDEXEDLINESTRIP32:
	return true;
	case DRAW_TRIANGLELIST:
	case DRAW_TRIANGLESTRIP:
	case DRAW_TRIANGLEFAN:
	case DRAW_INDEXEDTRIANGLELIST16:
	case DRAW_INDEXEDTRIANGLESTRIP16:
	case DRAW_INDEXEDTRIANGLEFAN16:
	case DRAW_INDEXEDTRIANGLELIST32:
	case DRAW_INDEXEDTRIANGLESTRIP32:
	case DRAW_INDEXEDTRIANGLEFAN32:
	return false;
	default:
	ASSERT(false);
	}

	return false;
	}

	bool Context::isDrawTriangle() const
	{
	switch(drawType)
	{
	case DRAW_POINTLIST:
	case DRAW_INDEXEDPOINTLIST16:
	case DRAW_INDEXEDPOINTLIST32:
	return false;
	case DRAW_LINELIST:
	case DRAW_LINESTRIP:
	case DRAW_INDEXEDLINELIST16:
	case DRAW_INDEXEDLINESTRIP16:
	case DRAW_INDEXEDLINELIST32:
	case DRAW_INDEXEDLINESTRIP32:
	return false;
	case DRAW_TRIANGLELIST:
	case DRAW_TRIANGLESTRIP:
	case DRAW_TRIANGLEFAN:
	case DRAW_INDEXEDTRIANGLELIST16:
	case DRAW_INDEXEDTRIANGLESTRIP16:
	case DRAW_INDEXEDTRIANGLEFAN16:
	case DRAW_INDEXEDTRIANGLELIST32:
	case DRAW_INDEXEDTRIANGLESTRIP32:
	case DRAW_INDEXEDTRIANGLEFAN32:
	return true;
	default:
	ASSERT(false);
	}

	return true;
	}

	void Context::init()
	{
	// Set vertex streams to null stream
	for(int i = 0; i < MAX_VERTEX_INPUTS; i++)
	{
	input[i].defaults();
	}

	for(int i = 0; i < RENDERTARGETS; ++i)
	{
	renderTarget[i] = nullptr;
	}
	depthBuffer = nullptr;
	stencilBuffer = nullptr;

	stencilEnable = false;
	stencilCompareMode = VK_COMPARE_OP_ALWAYS;
	stencilReference = 0;
	stencilMask = 0xFFFFFFFF;
	stencilFailOperation = VK_STENCIL_OP_KEEP;
	stencilPassOperation = VK_STENCIL_OP_KEEP;
	stencilZFailOperation = VK_STENCIL_OP_KEEP;
	stencilWriteMask = 0xFFFFFFFF;

	twoSidedStencil = false;
	stencilCompareModeCCW = VK_COMPARE_OP_ALWAYS;
	stencilReferenceCCW = 0;
	stencilMaskCCW = 0xFFFFFFFF;
	stencilFailOperationCCW = VK_STENCIL_OP_KEEP;
	stencilPassOperationCCW = VK_STENCIL_OP_KEEP;
	stencilZFailOperationCCW = VK_STENCIL_OP_KEEP;
	stencilWriteMaskCCW = 0xFFFFFFFF;

	alphaCompareMode = VK_COMPARE_OP_ALWAYS;
	alphaTestEnable = false;

	rasterizerDiscard = false;

	depthCompareMode = VK_COMPARE_OP_LESS;
	depthBufferEnable = true;
	depthWriteEnable = true;

	alphaBlendEnable = false;
	sourceBlendFactorState = VK_BLEND_FACTOR_ONE;
	destBlendFactorState = VK_BLEND_FACTOR_ZERO;
	blendOperationState = VK_BLEND_OP_ADD;

	separateAlphaBlendEnable = false;
	sourceBlendFactorStateAlpha = VK_BLEND_FACTOR_ONE;
	destBlendFactorStateAlpha = VK_BLEND_FACTOR_ZERO;
	blendOperationStateAlpha = VK_BLEND_OP_ADD;

	cullMode = CULL_CLOCKWISE;
	frontFacingCCW = true;
	alphaReference = 0.0f;

	depthBias = 0.0f;
	slopeDepthBias = 0.0f;

	for(int i = 0; i < RENDERTARGETS; i++)
	{
	colorWriteMask[i] = 0x0000000F;
	}

	pixelShader = nullptr;
	vertexShader = nullptr;

	instanceID = 0;

	occlusionEnabled = false;
	transformFeedbackQueryEnabled = false;
	transformFeedbackEnabled = 0;

	lineWidth = 1.0f;

	writeSRGB = false;
	sampleMask = 0xFFFFFFFF;

	colorLogicOpEnabled = false;
	logicalOperation = VK_LOGIC_OP_COPY;
	}

	bool Context::setDepthBufferEnable(bool depthBufferEnable)
	{
	bool modified = (Context::depthBufferEnable != depthBufferEnable);
	Context::depthBufferEnable = depthBufferEnable;
	return modified;
	}

	bool Context::setAlphaBlendEnable(bool alphaBlendEnable)
	{
	bool modified = (Context::alphaBlendEnable != alphaBlendEnable);
	Context::alphaBlendEnable = alphaBlendEnable;
	return modified;
	}

	bool Context::setSourceBlendFactor(VkBlendFactor sourceBlendFactor)
	{
	bool modified = (Context::sourceBlendFactorState != sourceBlendFactor);
	Context::sourceBlendFactorState = sourceBlendFactor;
	return modified;
	}

	bool Context::setDestBlendFactor(VkBlendFactor destBlendFactor)
	{
	bool modified = (Context::destBlendFactorState != destBlendFactor);
	Context::destBlendFactorState = destBlendFactor;
	return modified;
	}

	bool Context::setBlendOperation(VkBlendOp blendOperation)
	{
	bool modified = (Context::blendOperationState != blendOperation);
	Context::blendOperationState = blendOperation;
	return modified;
	}

	bool Context::setSeparateAlphaBlendEnable(bool separateAlphaBlendEnable)
	{
	bool modified = (Context::separateAlphaBlendEnable != separateAlphaBlendEnable);
	Context::separateAlphaBlendEnable = separateAlphaBlendEnable;
	return modified;
	}

	bool Context::setSourceBlendFactorAlpha(VkBlendFactor sourceBlendFactorAlpha)
	{
	bool modified = (Context::sourceBlendFactorStateAlpha != sourceBlendFactorAlpha);
	Context::sourceBlendFactorStateAlpha = sourceBlendFactorAlpha;
	return modified;
	}

	bool Context::setDestBlendFactorAlpha(VkBlendFactor destBlendFactorAlpha)
	{
	bool modified = (Context::destBlendFactorStateAlpha != destBlendFactorAlpha);
	Context::destBlendFactorStateAlpha = destBlendFactorAlpha;
	return modified;
	}

	bool Context::setBlendOperationAlpha(VkBlendOp blendOperationAlpha)
	{
	bool modified = (Context::blendOperationStateAlpha != blendOperationAlpha);
	Context::blendOperationStateAlpha = blendOperationAlpha;
	return modified;
	}

	bool Context::setColorWriteMask(int index, int colorWriteMask)
	{
	bool modified = (Context::colorWriteMask[index] != colorWriteMask);
	Context::colorWriteMask[index] = colorWriteMask;
	return modified;
	}

	bool Context::setWriteSRGB(bool sRGB)
	{
	bool modified = (Context::writeSRGB != sRGB);
	Context::writeSRGB = sRGB;
	return modified;
	}

	bool Context::setColorLogicOpEnabled(bool enabled)
	{
	bool modified = (Context::colorLogicOpEnabled != enabled);
	Context::colorLogicOpEnabled = enabled;
	return modified;
	}

	bool Context::setLogicalOperation(VkLogicOp logicalOperation)
	{
	bool modified = (Context::logicalOperation != logicalOperation);
	Context::logicalOperation = logicalOperation;
	return modified;
	}

	bool Context::depthWriteActive()
	{
	if(!depthBufferActive()) return false;

	return depthWriteEnable;
	}

	bool Context::alphaTestActive()
	{
	if(transparencyAntialiasing != TRANSPARENCY_NONE) return true;
	if(!alphaTestEnable) return false;
	if(alphaCompareMode == VK_COMPARE_OP_ALWAYS) return false;
	if(alphaReference == 0.0f && alphaCompareMode == VK_COMPARE_OP_GREATER_OR_EQUAL) return false;

	return true;
	}

	bool Context::depthBufferActive()
	{
	return depthBuffer && depthBufferEnable;
	}

	bool Context::stencilActive()
	{
	return stencilBuffer && stencilEnable;
	}

	bool Context::alphaBlendActive()
	{
	if(!alphaBlendEnable)
	{
	return false;
	}

	if(!colorUsed())
	{
	return false;
	}

	bool colorBlend = !(blendOperation() == VK_BLEND_OP_SRC_EXT && sourceBlendFactor() == VK_BLEND_FACTOR_ONE);
	bool alphaBlend = separateAlphaBlendEnable ? !(blendOperationAlpha() == VK_BLEND_OP_SRC_EXT && sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE) : colorBlend;

	return colorBlend \|\| alphaBlend;
	}

	VkLogicOp Context::colorLogicOp()
	{
	return colorLogicOpEnabled ? logicalOperation : VK_LOGIC_OP_COPY;
	}

	VkBlendFactor Context::sourceBlendFactor()
	{
	if(!alphaBlendEnable) return VK_BLEND_FACTOR_ONE;

	switch(blendOperationState)
	{
	case VK_BLEND_OP_ADD:
	case VK_BLEND_OP_SUBTRACT:
	case VK_BLEND_OP_REVERSE_SUBTRACT:
	return sourceBlendFactorState;
	case VK_BLEND_OP_MIN:
	return VK_BLEND_FACTOR_ONE;
	case VK_BLEND_OP_MAX:
	return VK_BLEND_FACTOR_ONE;
	default:
	ASSERT(false);
	}

	return sourceBlendFactorState;
	}

	VkBlendFactor Context::destBlendFactor()
	{
	if(!alphaBlendEnable) return VK_BLEND_FACTOR_ONE;

	switch(blendOperationState)
	{
	case VK_BLEND_OP_ADD:
	case VK_BLEND_OP_SUBTRACT:
	case VK_BLEND_OP_REVERSE_SUBTRACT:
	return destBlendFactorState;
	case VK_BLEND_OP_MIN:
	return VK_BLEND_FACTOR_ONE;
	case VK_BLEND_OP_MAX:
	return VK_BLEND_FACTOR_ONE;
	default:
	ASSERT(false);
	}

	return destBlendFactorState;
	}

	VkBlendOp Context::blendOperation()
	{
	if(!alphaBlendEnable) return VK_BLEND_OP_SRC_EXT;

	switch(blendOperationState)
	{
	case VK_BLEND_OP_ADD:
	if(sourceBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT;
	}
	else
	{
	return VK_BLEND_OP_DST_EXT;
	}
	}
	else if(sourceBlendFactor() == VK_BLEND_FACTOR_ONE)
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_ADD;
	}
	}
	else
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_ADD;
	}
	}
	case VK_BLEND_OP_SUBTRACT:
	if(sourceBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT; // Negative, clamped to zero
	}
	else if(sourceBlendFactor() == VK_BLEND_FACTOR_ONE)
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_SUBTRACT;
	}
	}
	else
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_SUBTRACT;
	}
	}
	case VK_BLEND_OP_REVERSE_SUBTRACT:
	if(sourceBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT;
	}
	else
	{
	return VK_BLEND_OP_DST_EXT;
	}
	}
	else if(sourceBlendFactor() == VK_BLEND_FACTOR_ONE)
	{
	if(destBlendFactor() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT; // Negative, clamped to zero
	}
	else
	{
	return VK_BLEND_OP_REVERSE_SUBTRACT;
	}
	}
	else
	{
	if(destBlendFactor() == VK_BLEND_OP_ZERO_EXT)
	{
	return VK_BLEND_OP_ZERO_EXT; // Negative, clamped to zero
	}
	else
	{
	return VK_BLEND_OP_REVERSE_SUBTRACT;
	}
	}
	case VK_BLEND_OP_MIN:
	return VK_BLEND_OP_MIN;
	case VK_BLEND_OP_MAX:
	return VK_BLEND_OP_MAX;
	default:
	ASSERT(false);
	}

	return blendOperationState;
	}

	VkBlendFactor Context::sourceBlendFactorAlpha()
	{
	if(!separateAlphaBlendEnable)
	{
	return sourceBlendFactor();
	}
	else
	{
	switch(blendOperationStateAlpha)
	{
	case VK_BLEND_OP_ADD:
	case VK_BLEND_OP_SUBTRACT:
	case VK_BLEND_OP_REVERSE_SUBTRACT:
	return sourceBlendFactorStateAlpha;
	case VK_BLEND_OP_MIN:
	return VK_BLEND_FACTOR_ONE;
	case VK_BLEND_OP_MAX:
	return VK_BLEND_FACTOR_ONE;
	default:
	ASSERT(false);
	}

	return sourceBlendFactorStateAlpha;
	}
	}

	VkBlendFactor Context::destBlendFactorAlpha()
	{
	if(!separateAlphaBlendEnable)
	{
	return destBlendFactor();
	}
	else
	{
	switch(blendOperationStateAlpha)
	{
	case VK_BLEND_OP_ADD:
	case VK_BLEND_OP_SUBTRACT:
	case VK_BLEND_OP_REVERSE_SUBTRACT:
	return destBlendFactorStateAlpha;
	case VK_BLEND_OP_MIN:
	return VK_BLEND_FACTOR_ONE;
	case VK_BLEND_OP_MAX:
	return VK_BLEND_FACTOR_ONE;
	default:
	ASSERT(false);
	}

	return destBlendFactorStateAlpha;
	}
	}

	VkBlendOp Context::blendOperationAlpha()
	{
	if(!separateAlphaBlendEnable)
	{
	return blendOperation();
	}
	else
	{
	switch(blendOperationStateAlpha)
	{
	case VK_BLEND_OP_ADD:
	if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT;
	}
	else
	{
	return VK_BLEND_OP_DST_EXT;
	}
	}
	else if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_ADD;
	}
	}
	else
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_ADD;
	}
	}
	case VK_BLEND_OP_SUBTRACT:
	if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT; // Negative, clamped to zero
	}
	else if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_SUBTRACT;
	}
	}
	else
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_SRC_EXT;
	}
	else
	{
	return VK_BLEND_OP_SUBTRACT;
	}
	}
	case VK_BLEND_OP_REVERSE_SUBTRACT:
	if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT;
	}
	else
	{
	return VK_BLEND_OP_DST_EXT;
	}
	}
	else if(sourceBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)
	{
	if(destBlendFactorAlpha() == VK_BLEND_FACTOR_ZERO)
	{
	return VK_BLEND_OP_ZERO_EXT; // Negative, clamped to zero
	}
	else
	{
	return VK_BLEND_OP_REVERSE_SUBTRACT;
	}
	}
	else
	{
	if(destBlendFactorAlpha() == VK_BLEND_OP_ZERO_EXT)
	{
	return VK_BLEND_OP_ZERO_EXT; // Negative, clamped to zero
	}
	else
	{
	return VK_BLEND_OP_ZERO_EXT;
	}
	}
	case VK_BLEND_OP_MIN:
	return VK_BLEND_OP_MIN;
	case VK_BLEND_OP_MAX:
	return VK_BLEND_OP_MAX;
	default:
	ASSERT(false);
	}

	return blendOperationStateAlpha;
	}
	}

	bool Context::perspectiveActive()
	{
	if(!colorUsed())
	{
	return false;
	}

	if(!perspectiveCorrection)
	{
	return false;
	}

	if(isDrawPoint())
	{
	return false;
	}

	return true;
	}

	unsigned short Context::pixelShaderModel() const
	{
	return pixelShader ? pixelShader->getShaderModel() : 0x0000;
	}

	unsigned short Context::vertexShaderModel() const
	{
	return vertexShader ? vertexShader->getShaderModel() : 0x0000;
	}

	int Context::getMultiSampleCount() const
	{
	return renderTarget[0] ? renderTarget[0]->getMultiSampleCount() : 1;
	}

	VkFormat Context::renderTargetInternalFormat(int index)
	{
	if(renderTarget[index])
	{
	return renderTarget[index]->getInternalFormat();
	}
	else
	{
	return VK_FORMAT_UNDEFINED;
	}
	}

	int Context::colorWriteActive()
	{
	return colorWriteActive(0) \| colorWriteActive(1) \| colorWriteActive(2) \| colorWriteActive(3);
	}

	int Context::colorWriteActive(int index)
	{
	if(!renderTarget[index] \|\| renderTarget[index]->getInternalFormat() == VK_FORMAT_UNDEFINED)
	{
	return 0;
	}

	if(blendOperation() == VK_BLEND_OP_DST_EXT && destBlendFactor() == VK_BLEND_FACTOR_ONE &&
	(!separateAlphaBlendEnable \|\| (blendOperationAlpha() == VK_BLEND_OP_DST_EXT && destBlendFactorAlpha() == VK_BLEND_FACTOR_ONE)))
	{
	return 0;
	}

	return colorWriteMask[index];
	}

	bool Context::colorUsed()
	{
	return colorWriteActive() \|\| alphaTestActive() \|\| (pixelShader && pixelShader->containsKill());
	}
	}