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kc3-lang/angle/src/libGLESv2/Context.cpp

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  • Author : shannon.woods%transgaming.com@gtempaccount.com
    Date : 2013-04-13 03:42:30
    Hash : 4760c563
    Message : Added depth parameters to all image loading functions. TRAC #22705 Signed-off-by: Jamie Madill Signed-off-by: Shannon Woods Author: Geoff Lang git-svn-id: https://angleproject.googlecode.com/svn/branches/es3proto@2159 736b8ea6-26fd-11df-bfd4-992fa37f6226

  • src/libGLESv2/Context.cpp
  • #include "precompiled.h"
    //
    // Copyright (c) 2002-2013 The ANGLE Project Authors. All rights reserved.
    // Use of this source code is governed by a BSD-style license that can be
    // found in the LICENSE file.
    //
    
    // Context.cpp: Implements the gl::Context class, managing all GL state and performing
    // rendering operations. It is the GLES2 specific implementation of EGLContext.
    
    #include "libGLESv2/Context.h"
    
    #include "libGLESv2/main.h"
    #include "libGLESv2/utilities.h"
    #include "libGLESv2/Buffer.h"
    #include "libGLESv2/Fence.h"
    #include "libGLESv2/Framebuffer.h"
    #include "libGLESv2/Renderbuffer.h"
    #include "libGLESv2/Program.h"
    #include "libGLESv2/ProgramBinary.h"
    #include "libGLESv2/Query.h"
    #include "libGLESv2/Texture.h"
    #include "libGLESv2/ResourceManager.h"
    #include "libGLESv2/renderer/IndexDataManager.h"
    #include "libGLESv2/renderer/RenderTarget.h"
    #include "libGLESv2/renderer/Renderer.h"
    
    #include "libEGL/Surface.h"
    
    #undef near
    #undef far
    
    namespace gl
    {
    static const char* makeStaticString(const std::string& str)
    {
        static std::set<std::string> strings;
        std::set<std::string>::iterator it = strings.find(str);
        if (it != strings.end())
          return it->c_str();
    
        return strings.insert(str).first->c_str();
    }
    
    Context::Context(int clientVersion, const gl::Context *shareContext, rx::Renderer *renderer, bool notifyResets, bool robustAccess) : mRenderer(renderer)
    {
        ASSERT(robustAccess == false);   // Unimplemented
    
        mFenceHandleAllocator.setBaseHandle(0);
    
        setClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    
        mClientVersion = clientVersion;
    
        mState.depthClearValue = 1.0f;
        mState.stencilClearValue = 0;
    
        mState.rasterizer.cullFace = false;
        mState.rasterizer.cullMode = GL_BACK;
        mState.rasterizer.frontFace = GL_CCW;
        mState.rasterizer.polygonOffsetFill = false;
        mState.rasterizer.polygonOffsetFactor = 0.0f;
        mState.rasterizer.polygonOffsetUnits = 0.0f;
        mState.rasterizer.pointDrawMode = false;
        mState.scissorTest = false;
        mState.scissor.x = 0;
        mState.scissor.y = 0;
        mState.scissor.width = 0;
        mState.scissor.height = 0;
    
        mState.blend.blend = false;
        mState.blend.sourceBlendRGB = GL_ONE;
        mState.blend.sourceBlendAlpha = GL_ONE;
        mState.blend.destBlendRGB = GL_ZERO;
        mState.blend.destBlendAlpha = GL_ZERO;
        mState.blend.blendEquationRGB = GL_FUNC_ADD;
        mState.blend.blendEquationAlpha = GL_FUNC_ADD;
        mState.blend.sampleAlphaToCoverage = false;
        mState.blend.dither = true;
    
        mState.blendColor.red = 0;
        mState.blendColor.green = 0;
        mState.blendColor.blue = 0;
        mState.blendColor.alpha = 0;
    
        mState.depthStencil.depthTest = false;
        mState.depthStencil.depthFunc = GL_LESS;
        mState.depthStencil.depthMask = true;
        mState.depthStencil.stencilTest = false;
        mState.depthStencil.stencilFunc = GL_ALWAYS;
        mState.depthStencil.stencilMask = -1;
        mState.depthStencil.stencilWritemask = -1;
        mState.depthStencil.stencilBackFunc = GL_ALWAYS;
        mState.depthStencil.stencilBackMask = - 1;
        mState.depthStencil.stencilBackWritemask = -1;
        mState.depthStencil.stencilFail = GL_KEEP;
        mState.depthStencil.stencilPassDepthFail = GL_KEEP;
        mState.depthStencil.stencilPassDepthPass = GL_KEEP;
        mState.depthStencil.stencilBackFail = GL_KEEP;
        mState.depthStencil.stencilBackPassDepthFail = GL_KEEP;
        mState.depthStencil.stencilBackPassDepthPass = GL_KEEP;
    
        mState.stencilRef = 0;
        mState.stencilBackRef = 0;
    
        mState.sampleCoverage = false;
        mState.sampleCoverageValue = 1.0f;
        mState.sampleCoverageInvert = false;
        mState.generateMipmapHint = GL_DONT_CARE;
        mState.fragmentShaderDerivativeHint = GL_DONT_CARE;
    
        mState.lineWidth = 1.0f;
    
        mState.viewport.x = 0;
        mState.viewport.y = 0;
        mState.viewport.width = 0;
        mState.viewport.height = 0;
        mState.zNear = 0.0f;
        mState.zFar = 1.0f;
    
        mState.blend.colorMaskRed = true;
        mState.blend.colorMaskGreen = true;
        mState.blend.colorMaskBlue = true;
        mState.blend.colorMaskAlpha = true;
    
        if (shareContext != NULL)
        {
            mResourceManager = shareContext->mResourceManager;
            mResourceManager->addRef();
        }
        else
        {
            mResourceManager = new ResourceManager(mRenderer);
        }
    
        // [OpenGL ES 2.0.24] section 3.7 page 83:
        // In the initial state, TEXTURE_2D and TEXTURE_CUBE_MAP have twodimensional
        // and cube map texture state vectors respectively associated with them.
        // In order that access to these initial textures not be lost, they are treated as texture
        // objects all of whose names are 0.
    
        mTexture2DZero.set(new Texture2D(mRenderer, 0));
        mTextureCubeMapZero.set(new TextureCubeMap(mRenderer, 0));
    
        mState.activeSampler = 0;
        bindArrayBuffer(0);
        bindElementArrayBuffer(0);
        bindTextureCubeMap(0);
        bindTexture2D(0);
        bindReadFramebuffer(0);
        bindDrawFramebuffer(0);
        bindRenderbuffer(0);
    
        bindGenericUniformBuffer(0);
        for (int i = 0; i < IMPLEMENTATION_MAX_COMBINED_SHADER_UNIFORM_BUFFERS; i++)
        {
            bindIndexedUniformBuffer(0, i, 0, -1);
        }
    
        bindGenericTransformFeedbackBuffer(0);
        for (int i = 0; i < IMPLEMENTATION_MAX_TRANSFORM_FEEDBACK_BUFFERS; i++)
        {
            bindIndexedTransformFeedbackBuffer(0, i, 0, -1);
        }
    
        bindCopyReadBuffer(0);
        bindCopyWriteBuffer(0);
        bindPixelPackBuffer(0);
        bindPixelUnpackBuffer(0);
    
        mState.currentProgram = 0;
        mCurrentProgramBinary.set(NULL);
    
        mState.packAlignment = 4;
        mState.unpackAlignment = 4;
        mState.packReverseRowOrder = false;
    
        mExtensionString = NULL;
        mRendererString = NULL;
    
        mInvalidEnum = false;
        mInvalidValue = false;
        mInvalidOperation = false;
        mOutOfMemory = false;
        mInvalidFramebufferOperation = false;
    
        mHasBeenCurrent = false;
        mContextLost = false;
        mResetStatus = GL_NO_ERROR;
        mResetStrategy = (notifyResets ? GL_LOSE_CONTEXT_ON_RESET_EXT : GL_NO_RESET_NOTIFICATION_EXT);
        mRobustAccess = robustAccess;
    
        mSupportsBGRATextures = false;
        mSupportsDXT1Textures = false;
        mSupportsDXT3Textures = false;
        mSupportsDXT5Textures = false;
        mSupportsEventQueries = false;
        mSupportsOcclusionQueries = false;
        mNumCompressedTextureFormats = 0;
    }
    
    Context::~Context()
    {
        if (mState.currentProgram != 0)
        {
            Program *programObject = mResourceManager->getProgram(mState.currentProgram);
            if (programObject)
            {
                programObject->release();
            }
            mState.currentProgram = 0;
        }
        mCurrentProgramBinary.set(NULL);
    
        while (!mFramebufferMap.empty())
        {
            deleteFramebuffer(mFramebufferMap.begin()->first);
        }
    
        while (!mFenceMap.empty())
        {
            deleteFence(mFenceMap.begin()->first);
        }
    
        while (!mQueryMap.empty())
        {
            deleteQuery(mQueryMap.begin()->first);
        }
    
        for (int type = 0; type < TEXTURE_TYPE_COUNT; type++)
        {
            for (int sampler = 0; sampler < IMPLEMENTATION_MAX_COMBINED_TEXTURE_IMAGE_UNITS; sampler++)
            {
                mState.samplerTexture[type][sampler].set(NULL);
            }
        }
    
        for (int type = 0; type < TEXTURE_TYPE_COUNT; type++)
        {
            mIncompleteTextures[type].set(NULL);
        }
    
        for (int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
        {
            mState.vertexAttribute[i].mBoundBuffer.set(NULL);
        }
    
        for (int i = 0; i < QUERY_TYPE_COUNT; i++)
        {
            mState.activeQuery[i].set(NULL);
        }
    
        mState.arrayBuffer.set(NULL);
        mState.elementArrayBuffer.set(NULL);
        mState.renderbuffer.set(NULL);
    
        mTexture2DZero.set(NULL);
        mTextureCubeMapZero.set(NULL);
    
        mState.genericUniformBuffer.set(NULL);
        for (int i = 0; i < IMPLEMENTATION_MAX_COMBINED_SHADER_UNIFORM_BUFFERS; i++)
        {
            mState.uniformBuffers[i].set(NULL);
        }
    
        mState.genericTransformFeedbackBuffer.set(NULL);
        for (int i = 0; i < IMPLEMENTATION_MAX_TRANSFORM_FEEDBACK_BUFFERS; i++)
        {
            mState.transformFeedbackBuffers[i].set(NULL);
        }
    
        mState.copyReadBuffer.set(NULL);
        mState.copyWriteBuffer.set(NULL);
    
        mState.pixelPackBuffer.set(NULL);
        mState.pixelUnpackBuffer.set(NULL);
    
        mResourceManager->release();
    }
    
    void Context::makeCurrent(egl::Surface *surface)
    {
        if (!mHasBeenCurrent)
        {
            mMajorShaderModel = mRenderer->getMajorShaderModel();
            mMaximumPointSize = mRenderer->getMaxPointSize();
            mSupportsVertexTexture = mRenderer->getVertexTextureSupport();
            mSupportsNonPower2Texture = mRenderer->getNonPower2TextureSupport();
            mSupportsInstancing = mRenderer->getInstancingSupport();
    
            mMaxViewportDimension = mRenderer->getMaxViewportDimension();
            mMaxTextureDimension = std::min(std::min(mRenderer->getMaxTextureWidth(), mRenderer->getMaxTextureHeight()),
                                            (int)gl::IMPLEMENTATION_MAX_TEXTURE_SIZE);
            mMaxCubeTextureDimension = std::min(mMaxTextureDimension, (int)gl::IMPLEMENTATION_MAX_CUBE_MAP_TEXTURE_SIZE);
            mMaxRenderbufferDimension = mMaxTextureDimension;
            mMaxTextureLevel = log2(mMaxTextureDimension) + 1;
            mMaxTextureAnisotropy = mRenderer->getTextureMaxAnisotropy();
            TRACE("MaxTextureDimension=%d, MaxCubeTextureDimension=%d, MaxRenderbufferDimension=%d, MaxTextureLevel=%d, MaxTextureAnisotropy=%f",
                  mMaxTextureDimension, mMaxCubeTextureDimension, mMaxRenderbufferDimension, mMaxTextureLevel, mMaxTextureAnisotropy);
    
            mSupportsEventQueries = mRenderer->getEventQuerySupport();
            mSupportsOcclusionQueries = mRenderer->getOcclusionQuerySupport();
            mSupportsBGRATextures = mRenderer->getBGRATextureSupport();
            mSupportsDXT1Textures = mRenderer->getDXT1TextureSupport();
            mSupportsDXT3Textures = mRenderer->getDXT3TextureSupport();
            mSupportsDXT5Textures = mRenderer->getDXT5TextureSupport();
            mSupportsFloat32Textures = mRenderer->getFloat32TextureSupport(&mSupportsFloat32LinearFilter, &mSupportsFloat32RenderableTextures);
            mSupportsFloat16Textures = mRenderer->getFloat16TextureSupport(&mSupportsFloat16LinearFilter, &mSupportsFloat16RenderableTextures);
            mSupportsLuminanceTextures = mRenderer->getLuminanceTextureSupport();
            mSupportsLuminanceAlphaTextures = mRenderer->getLuminanceAlphaTextureSupport();
            mSupportsDepthTextures = mRenderer->getDepthTextureSupport();
            mSupportsTextureFilterAnisotropy = mRenderer->getTextureFilterAnisotropySupport();
            mSupports32bitIndices = mRenderer->get32BitIndexSupport();
    
            mNumCompressedTextureFormats = 0;
            if (supportsDXT1Textures())
            {
                mNumCompressedTextureFormats += 2;
            }
            if (supportsDXT3Textures())
            {
                mNumCompressedTextureFormats += 1;
            }
            if (supportsDXT5Textures())
            {
                mNumCompressedTextureFormats += 1;
            }
    
            initExtensionString();
            initRendererString();
    
            mState.viewport.x = 0;
            mState.viewport.y = 0;
            mState.viewport.width = surface->getWidth();
            mState.viewport.height = surface->getHeight();
    
            mState.scissor.x = 0;
            mState.scissor.y = 0;
            mState.scissor.width = surface->getWidth();
            mState.scissor.height = surface->getHeight();
    
            mHasBeenCurrent = true;
        }
    
        // Wrap the existing swapchain resources into GL objects and assign them to the '0' names
        rx::SwapChain *swapchain = surface->getSwapChain();
    
        Colorbuffer *colorbufferZero = new Colorbuffer(mRenderer, swapchain);
        DepthStencilbuffer *depthStencilbufferZero = new DepthStencilbuffer(mRenderer, swapchain);
        Framebuffer *framebufferZero = new DefaultFramebuffer(mRenderer, colorbufferZero, depthStencilbufferZero);
    
        setFramebufferZero(framebufferZero);
    
        // Store the current client version in the renderer
        mRenderer->setCurrentClientVersion(mClientVersion);
    }
    
    // NOTE: this function should not assume that this context is current!
    void Context::markContextLost()
    {
        if (mResetStrategy == GL_LOSE_CONTEXT_ON_RESET_EXT)
            mResetStatus = GL_UNKNOWN_CONTEXT_RESET_EXT;
        mContextLost = true;
    }
    
    bool Context::isContextLost()
    {
        return mContextLost;
    }
    
    void Context::setClearColor(float red, float green, float blue, float alpha)
    {
        mState.colorClearValue.red = red;
        mState.colorClearValue.green = green;
        mState.colorClearValue.blue = blue;
        mState.colorClearValue.alpha = alpha;
    }
    
    void Context::setClearDepth(float depth)
    {
        mState.depthClearValue = depth;
    }
    
    void Context::setClearStencil(int stencil)
    {
        mState.stencilClearValue = stencil;
    }
    
    void Context::setCullFace(bool enabled)
    {
        mState.rasterizer.cullFace = enabled;
    }
    
    bool Context::isCullFaceEnabled() const
    {
        return mState.rasterizer.cullFace;
    }
    
    void Context::setCullMode(GLenum mode)
    {
        mState.rasterizer.cullMode = mode;
    }
    
    void Context::setFrontFace(GLenum front)
    {
        mState.rasterizer.frontFace = front;
    }
    
    void Context::setDepthTest(bool enabled)
    {
        mState.depthStencil.depthTest = enabled;
    }
    
    bool Context::isDepthTestEnabled() const
    {
        return mState.depthStencil.depthTest;
    }
    
    void Context::setDepthFunc(GLenum depthFunc)
    {
         mState.depthStencil.depthFunc = depthFunc;
    }
    
    void Context::setDepthRange(float zNear, float zFar)
    {
        mState.zNear = zNear;
        mState.zFar = zFar;
    }
    
    void Context::setBlend(bool enabled)
    {
        mState.blend.blend = enabled;
    }
    
    bool Context::isBlendEnabled() const
    {
        return mState.blend.blend;
    }
    
    void Context::setBlendFactors(GLenum sourceRGB, GLenum destRGB, GLenum sourceAlpha, GLenum destAlpha)
    {
        mState.blend.sourceBlendRGB = sourceRGB;
        mState.blend.destBlendRGB = destRGB;
        mState.blend.sourceBlendAlpha = sourceAlpha;
        mState.blend.destBlendAlpha = destAlpha;
    }
    
    void Context::setBlendColor(float red, float green, float blue, float alpha)
    {
        mState.blendColor.red = red;
        mState.blendColor.green = green;
        mState.blendColor.blue = blue;
        mState.blendColor.alpha = alpha;
    }
    
    void Context::setBlendEquation(GLenum rgbEquation, GLenum alphaEquation)
    {
        mState.blend.blendEquationRGB = rgbEquation;
        mState.blend.blendEquationAlpha = alphaEquation;
    }
    
    void Context::setStencilTest(bool enabled)
    {
        mState.depthStencil.stencilTest = enabled;
    }
    
    bool Context::isStencilTestEnabled() const
    {
        return mState.depthStencil.stencilTest;
    }
    
    void Context::setStencilParams(GLenum stencilFunc, GLint stencilRef, GLuint stencilMask)
    {
        mState.depthStencil.stencilFunc = stencilFunc;
        mState.stencilRef = (stencilRef > 0) ? stencilRef : 0;
        mState.depthStencil.stencilMask = stencilMask;
    }
    
    void Context::setStencilBackParams(GLenum stencilBackFunc, GLint stencilBackRef, GLuint stencilBackMask)
    {
        mState.depthStencil.stencilBackFunc = stencilBackFunc;
        mState.stencilBackRef = (stencilBackRef > 0) ? stencilBackRef : 0;
        mState.depthStencil.stencilBackMask = stencilBackMask;
    }
    
    void Context::setStencilWritemask(GLuint stencilWritemask)
    {
        mState.depthStencil.stencilWritemask = stencilWritemask;
    }
    
    void Context::setStencilBackWritemask(GLuint stencilBackWritemask)
    {
        mState.depthStencil.stencilBackWritemask = stencilBackWritemask;
    }
    
    void Context::setStencilOperations(GLenum stencilFail, GLenum stencilPassDepthFail, GLenum stencilPassDepthPass)
    {
        mState.depthStencil.stencilFail = stencilFail;
        mState.depthStencil.stencilPassDepthFail = stencilPassDepthFail;
        mState.depthStencil.stencilPassDepthPass = stencilPassDepthPass;
    }
    
    void Context::setStencilBackOperations(GLenum stencilBackFail, GLenum stencilBackPassDepthFail, GLenum stencilBackPassDepthPass)
    {
        mState.depthStencil.stencilBackFail = stencilBackFail;
        mState.depthStencil.stencilBackPassDepthFail = stencilBackPassDepthFail;
        mState.depthStencil.stencilBackPassDepthPass = stencilBackPassDepthPass;
    }
    
    void Context::setPolygonOffsetFill(bool enabled)
    {
         mState.rasterizer.polygonOffsetFill = enabled;
    }
    
    bool Context::isPolygonOffsetFillEnabled() const
    {
        return mState.rasterizer.polygonOffsetFill;
    }
    
    void Context::setPolygonOffsetParams(GLfloat factor, GLfloat units)
    {
        // An application can pass NaN values here, so handle this gracefully
        mState.rasterizer.polygonOffsetFactor = factor != factor ? 0.0f : factor;
        mState.rasterizer.polygonOffsetUnits = units != units ? 0.0f : units;
    }
    
    void Context::setSampleAlphaToCoverage(bool enabled)
    {
        mState.blend.sampleAlphaToCoverage = enabled;
    }
    
    bool Context::isSampleAlphaToCoverageEnabled() const
    {
        return mState.blend.sampleAlphaToCoverage;
    }
    
    void Context::setSampleCoverage(bool enabled)
    {
        mState.sampleCoverage = enabled;
    }
    
    bool Context::isSampleCoverageEnabled() const
    {
        return mState.sampleCoverage;
    }
    
    void Context::setSampleCoverageParams(GLclampf value, bool invert)
    {
        mState.sampleCoverageValue = value;
        mState.sampleCoverageInvert = invert;
    }
    
    void Context::setScissorTest(bool enabled)
    {
        mState.scissorTest = enabled;
    }
    
    bool Context::isScissorTestEnabled() const
    {
        return mState.scissorTest;
    }
    
    void Context::setDither(bool enabled)
    {
        mState.blend.dither = enabled;
    }
    
    bool Context::isDitherEnabled() const
    {
        return mState.blend.dither;
    }
    
    void Context::setLineWidth(GLfloat width)
    {
        mState.lineWidth = width;
    }
    
    void Context::setGenerateMipmapHint(GLenum hint)
    {
        mState.generateMipmapHint = hint;
    }
    
    void Context::setFragmentShaderDerivativeHint(GLenum hint)
    {
        mState.fragmentShaderDerivativeHint = hint;
        // TODO: Propagate the hint to shader translator so we can write
        // ddx, ddx_coarse, or ddx_fine depending on the hint.
        // Ignore for now. It is valid for implementations to ignore hint.
    }
    
    void Context::setViewportParams(GLint x, GLint y, GLsizei width, GLsizei height)
    {
        mState.viewport.x = x;
        mState.viewport.y = y;
        mState.viewport.width = width;
        mState.viewport.height = height;
    }
    
    void Context::setScissorParams(GLint x, GLint y, GLsizei width, GLsizei height)
    {
        mState.scissor.x = x;
        mState.scissor.y = y;
        mState.scissor.width = width;
        mState.scissor.height = height;
    }
    
    void Context::setColorMask(bool red, bool green, bool blue, bool alpha)
    {
        mState.blend.colorMaskRed = red;
        mState.blend.colorMaskGreen = green;
        mState.blend.colorMaskBlue = blue;
        mState.blend.colorMaskAlpha = alpha;
    }
    
    void Context::setDepthMask(bool mask)
    {
        mState.depthStencil.depthMask = mask;
    }
    
    void Context::setActiveSampler(unsigned int active)
    {
        mState.activeSampler = active;
    }
    
    GLuint Context::getReadFramebufferHandle() const
    {
        return mState.readFramebuffer;
    }
    
    GLuint Context::getDrawFramebufferHandle() const
    {
        return mState.drawFramebuffer;
    }
    
    GLuint Context::getRenderbufferHandle() const
    {
        return mState.renderbuffer.id();
    }
    
    GLuint Context::getArrayBufferHandle() const
    {
        return mState.arrayBuffer.id();
    }
    
    GLuint Context::getActiveQuery(GLenum target) const
    {
        Query *queryObject = NULL;
        
        switch (target)
        {
          case GL_ANY_SAMPLES_PASSED_EXT:
            queryObject = mState.activeQuery[QUERY_ANY_SAMPLES_PASSED].get();
            break;
          case GL_ANY_SAMPLES_PASSED_CONSERVATIVE_EXT:
            queryObject = mState.activeQuery[QUERY_ANY_SAMPLES_PASSED_CONSERVATIVE].get();
            break;
          default:
            ASSERT(false);
        }
    
        if (queryObject)
        {
            return queryObject->id();
        }
        else
        {
            return 0;
        }
    }
    
    void Context::setEnableVertexAttribArray(unsigned int attribNum, bool enabled)
    {
        mState.vertexAttribute[attribNum].mArrayEnabled = enabled;
    }
    
    const VertexAttribute &Context::getVertexAttribState(unsigned int attribNum)
    {
        return mState.vertexAttribute[attribNum];
    }
    
    void Context::setVertexAttribState(unsigned int attribNum, Buffer *boundBuffer, GLint size, GLenum type, bool normalized,
                                       bool pureInteger, GLsizei stride, const void *pointer)
    {
        mState.vertexAttribute[attribNum].mBoundBuffer.set(boundBuffer);
        mState.vertexAttribute[attribNum].mSize = size;
        mState.vertexAttribute[attribNum].mType = type;
        mState.vertexAttribute[attribNum].mNormalized = normalized;
        mState.vertexAttribute[attribNum].mPureInteger = pureInteger;
        mState.vertexAttribute[attribNum].mStride = stride;
        mState.vertexAttribute[attribNum].mPointer = pointer;
    }
    
    const void *Context::getVertexAttribPointer(unsigned int attribNum) const
    {
        return mState.vertexAttribute[attribNum].mPointer;
    }
    
    void Context::setPackAlignment(GLint alignment)
    {
        mState.packAlignment = alignment;
    }
    
    GLint Context::getPackAlignment() const
    {
        return mState.packAlignment;
    }
    
    void Context::setUnpackAlignment(GLint alignment)
    {
        mState.unpackAlignment = alignment;
    }
    
    GLint Context::getUnpackAlignment() const
    {
        return mState.unpackAlignment;
    }
    
    void Context::setPackReverseRowOrder(bool reverseRowOrder)
    {
        mState.packReverseRowOrder = reverseRowOrder;
    }
    
    bool Context::getPackReverseRowOrder() const
    {
        return mState.packReverseRowOrder;
    }
    
    GLuint Context::createBuffer()
    {
        return mResourceManager->createBuffer();
    }
    
    GLuint Context::createProgram()
    {
        return mResourceManager->createProgram();
    }
    
    GLuint Context::createShader(GLenum type)
    {
        return mResourceManager->createShader(type);
    }
    
    GLuint Context::createTexture()
    {
        return mResourceManager->createTexture();
    }
    
    GLuint Context::createRenderbuffer()
    {
        return mResourceManager->createRenderbuffer();
    }
    
    // Returns an unused framebuffer name
    GLuint Context::createFramebuffer()
    {
        GLuint handle = mFramebufferHandleAllocator.allocate();
    
        mFramebufferMap[handle] = NULL;
    
        return handle;
    }
    
    GLuint Context::createFence()
    {
        GLuint handle = mFenceHandleAllocator.allocate();
    
        mFenceMap[handle] = new Fence(mRenderer);
    
        return handle;
    }
    
    // Returns an unused query name
    GLuint Context::createQuery()
    {
        GLuint handle = mQueryHandleAllocator.allocate();
    
        mQueryMap[handle] = NULL;
    
        return handle;
    }
    
    void Context::deleteBuffer(GLuint buffer)
    {
        if (mResourceManager->getBuffer(buffer))
        {
            detachBuffer(buffer);
        }
        
        mResourceManager->deleteBuffer(buffer);
    }
    
    void Context::deleteShader(GLuint shader)
    {
        mResourceManager->deleteShader(shader);
    }
    
    void Context::deleteProgram(GLuint program)
    {
        mResourceManager->deleteProgram(program);
    }
    
    void Context::deleteTexture(GLuint texture)
    {
        if (mResourceManager->getTexture(texture))
        {
            detachTexture(texture);
        }
    
        mResourceManager->deleteTexture(texture);
    }
    
    void Context::deleteRenderbuffer(GLuint renderbuffer)
    {
        if (mResourceManager->getRenderbuffer(renderbuffer))
        {
            detachRenderbuffer(renderbuffer);
        }
        
        mResourceManager->deleteRenderbuffer(renderbuffer);
    }
    
    void Context::deleteFramebuffer(GLuint framebuffer)
    {
        FramebufferMap::iterator framebufferObject = mFramebufferMap.find(framebuffer);
    
        if (framebufferObject != mFramebufferMap.end())
        {
            detachFramebuffer(framebuffer);
    
            mFramebufferHandleAllocator.release(framebufferObject->first);
            delete framebufferObject->second;
            mFramebufferMap.erase(framebufferObject);
        }
    }
    
    void Context::deleteFence(GLuint fence)
    {
        FenceMap::iterator fenceObject = mFenceMap.find(fence);
    
        if (fenceObject != mFenceMap.end())
        {
            mFenceHandleAllocator.release(fenceObject->first);
            delete fenceObject->second;
            mFenceMap.erase(fenceObject);
        }
    }
    
    void Context::deleteQuery(GLuint query)
    {
        QueryMap::iterator queryObject = mQueryMap.find(query);
        if (queryObject != mQueryMap.end())
        {
            mQueryHandleAllocator.release(queryObject->first);
            if (queryObject->second)
            {
                queryObject->second->release();
            }
            mQueryMap.erase(queryObject);
        }
    }
    
    Buffer *Context::getBuffer(GLuint handle)
    {
        return mResourceManager->getBuffer(handle);
    }
    
    Shader *Context::getShader(GLuint handle)
    {
        return mResourceManager->getShader(handle);
    }
    
    Program *Context::getProgram(GLuint handle)
    {
        return mResourceManager->getProgram(handle);
    }
    
    Texture *Context::getTexture(GLuint handle)
    {
        return mResourceManager->getTexture(handle);
    }
    
    Renderbuffer *Context::getRenderbuffer(GLuint handle)
    {
        return mResourceManager->getRenderbuffer(handle);
    }
    
    Framebuffer *Context::getReadFramebuffer()
    {
        return getFramebuffer(mState.readFramebuffer);
    }
    
    Framebuffer *Context::getDrawFramebuffer()
    {
        return mBoundDrawFramebuffer;
    }
    
    void Context::bindArrayBuffer(unsigned int buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.arrayBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindElementArrayBuffer(unsigned int buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.elementArrayBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindTexture2D(GLuint texture)
    {
        mResourceManager->checkTextureAllocation(texture, TEXTURE_2D);
    
        mState.samplerTexture[TEXTURE_2D][mState.activeSampler].set(getTexture(texture));
    }
    
    void Context::bindTextureCubeMap(GLuint texture)
    {
        mResourceManager->checkTextureAllocation(texture, TEXTURE_CUBE);
    
        mState.samplerTexture[TEXTURE_CUBE][mState.activeSampler].set(getTexture(texture));
    }
    
    void Context::bindReadFramebuffer(GLuint framebuffer)
    {
        if (!getFramebuffer(framebuffer))
        {
            mFramebufferMap[framebuffer] = new Framebuffer(mRenderer);
        }
    
        mState.readFramebuffer = framebuffer;
    }
    
    void Context::bindDrawFramebuffer(GLuint framebuffer)
    {
        if (!getFramebuffer(framebuffer))
        {
            mFramebufferMap[framebuffer] = new Framebuffer(mRenderer);
        }
    
        mState.drawFramebuffer = framebuffer;
    
        mBoundDrawFramebuffer = getFramebuffer(framebuffer);
    }
    
    void Context::bindRenderbuffer(GLuint renderbuffer)
    {
        mResourceManager->checkRenderbufferAllocation(renderbuffer);
    
        mState.renderbuffer.set(getRenderbuffer(renderbuffer));
    }
    
    void Context::bindGenericUniformBuffer(GLuint buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.genericUniformBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindIndexedUniformBuffer(GLuint buffer, GLuint index, GLintptr offset, GLsizeiptr size)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.uniformBuffers[index].set(getBuffer(buffer), offset, size);
    }
    
    void Context::bindGenericTransformFeedbackBuffer(GLuint buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.genericTransformFeedbackBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindIndexedTransformFeedbackBuffer(GLuint buffer, GLuint index, GLintptr offset, GLsizeiptr size)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.transformFeedbackBuffers[index].set(getBuffer(buffer), offset, size);
    }
    
    void Context::bindCopyReadBuffer(GLuint buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.copyReadBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindCopyWriteBuffer(GLuint buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.copyWriteBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindPixelPackBuffer(GLuint buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.pixelPackBuffer.set(getBuffer(buffer));
    }
    
    void Context::bindPixelUnpackBuffer(GLuint buffer)
    {
        mResourceManager->checkBufferAllocation(buffer);
    
        mState.pixelUnpackBuffer.set(getBuffer(buffer));
    }
    
    void Context::useProgram(GLuint program)
    {
        GLuint priorProgram = mState.currentProgram;
        mState.currentProgram = program;               // Must switch before trying to delete, otherwise it only gets flagged.
    
        if (priorProgram != program)
        {
            Program *newProgram = mResourceManager->getProgram(program);
            Program *oldProgram = mResourceManager->getProgram(priorProgram);
            mCurrentProgramBinary.set(NULL);
    
            if (newProgram)
            {
                newProgram->addRef();
                mCurrentProgramBinary.set(newProgram->getProgramBinary());
            }
            
            if (oldProgram)
            {
                oldProgram->release();
            }
        }
    }
    
    void Context::linkProgram(GLuint program)
    {
        Program *programObject = mResourceManager->getProgram(program);
    
        bool linked = programObject->link();
    
        // if the current program was relinked successfully we
        // need to install the new executables
        if (linked && program == mState.currentProgram)
        {
            mCurrentProgramBinary.set(programObject->getProgramBinary());
        }
    }
    
    void Context::setProgramBinary(GLuint program, const void *binary, GLint length)
    {
        Program *programObject = mResourceManager->getProgram(program);
    
        bool loaded = programObject->setProgramBinary(binary, length);
    
        // if the current program was reloaded successfully we
        // need to install the new executables
        if (loaded && program == mState.currentProgram)
        {
            mCurrentProgramBinary.set(programObject->getProgramBinary());
        }
    
    }
    
    void Context::beginQuery(GLenum target, GLuint query)
    {
        // From EXT_occlusion_query_boolean: If BeginQueryEXT is called with an <id>  
        // of zero, if the active query object name for <target> is non-zero (for the  
        // targets ANY_SAMPLES_PASSED_EXT and ANY_SAMPLES_PASSED_CONSERVATIVE_EXT, if  
        // the active query for either target is non-zero), if <id> is the name of an 
        // existing query object whose type does not match <target>, or if <id> is the
        // active query object name for any query type, the error INVALID_OPERATION is
        // generated.
    
        // Ensure no other queries are active
        // NOTE: If other queries than occlusion are supported, we will need to check
        // separately that:
        //    a) The query ID passed is not the current active query for any target/type
        //    b) There are no active queries for the requested target (and in the case
        //       of GL_ANY_SAMPLES_PASSED_EXT and GL_ANY_SAMPLES_PASSED_CONSERVATIVE_EXT,
        //       no query may be active for either if glBeginQuery targets either.
        for (int i = 0; i < QUERY_TYPE_COUNT; i++)
        {
            if (mState.activeQuery[i].get() != NULL)
            {
                return gl::error(GL_INVALID_OPERATION);
            }
        }
    
        QueryType qType;
        switch (target)
        {
          case GL_ANY_SAMPLES_PASSED_EXT: 
            qType = QUERY_ANY_SAMPLES_PASSED; 
            break;
          case GL_ANY_SAMPLES_PASSED_CONSERVATIVE_EXT: 
            qType = QUERY_ANY_SAMPLES_PASSED_CONSERVATIVE; 
            break;
          default: 
            ASSERT(false);
            return;
        }
    
        Query *queryObject = getQuery(query, true, target);
    
        // check that name was obtained with glGenQueries
        if (!queryObject)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        // check for type mismatch
        if (queryObject->getType() != target)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        // set query as active for specified target
        mState.activeQuery[qType].set(queryObject);
    
        // begin query
        queryObject->begin();
    }
    
    void Context::endQuery(GLenum target)
    {
        QueryType qType;
    
        switch (target)
        {
          case GL_ANY_SAMPLES_PASSED_EXT: 
            qType = QUERY_ANY_SAMPLES_PASSED; 
            break;
          case GL_ANY_SAMPLES_PASSED_CONSERVATIVE_EXT: 
            qType = QUERY_ANY_SAMPLES_PASSED_CONSERVATIVE; 
            break;
          default: 
            ASSERT(false);
            return;
        }
    
        Query *queryObject = mState.activeQuery[qType].get();
    
        if (queryObject == NULL)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        queryObject->end();
    
        mState.activeQuery[qType].set(NULL);
    }
    
    void Context::setFramebufferZero(Framebuffer *buffer)
    {
        delete mFramebufferMap[0];
        mFramebufferMap[0] = buffer;
        if (mState.drawFramebuffer == 0)
        {
            mBoundDrawFramebuffer = buffer;
        }
    }
    
    void Context::setRenderbufferStorage(GLsizei width, GLsizei height, GLenum internalformat, GLsizei samples)
    {
        RenderbufferStorage *renderbuffer = NULL;
        switch (internalformat)
        {
          case GL_DEPTH_COMPONENT16:
            renderbuffer = new gl::Depthbuffer(mRenderer, width, height, samples);
            break;
          case GL_RGBA4:
          case GL_RGB5_A1:
          case GL_RGB565:
          case GL_RGB8_OES:
          case GL_RGBA8_OES:
          case GL_SRGB8_ALPHA8:
          case GL_RGB10_A2:
          case GL_RG8:
          case GL_R8:
            renderbuffer = new gl::Colorbuffer(mRenderer,width, height, internalformat, samples);
            break;
          case GL_STENCIL_INDEX8:
            renderbuffer = new gl::Stencilbuffer(mRenderer, width, height, samples);
            break;
          case GL_DEPTH24_STENCIL8_OES:
            renderbuffer = new gl::DepthStencilbuffer(mRenderer, width, height, samples);
            break;
          default:
            UNIMPLEMENTED();   // TODO: Remaining ES3 formats
            UNREACHABLE(); return;
        }
    
        Renderbuffer *renderbufferObject = mState.renderbuffer.get();
        renderbufferObject->setStorage(renderbuffer);
    }
    
    Framebuffer *Context::getFramebuffer(unsigned int handle)
    {
        FramebufferMap::iterator framebuffer = mFramebufferMap.find(handle);
    
        if (framebuffer == mFramebufferMap.end())
        {
            return NULL;
        }
        else
        {
            return framebuffer->second;
        }
    }
    
    Fence *Context::getFence(unsigned int handle)
    {
        FenceMap::iterator fence = mFenceMap.find(handle);
    
        if (fence == mFenceMap.end())
        {
            return NULL;
        }
        else
        {
            return fence->second;
        }
    }
    
    Query *Context::getQuery(unsigned int handle, bool create, GLenum type)
    {
        QueryMap::iterator query = mQueryMap.find(handle);
    
        if (query == mQueryMap.end())
        {
            return NULL;
        }
        else
        {
            if (!query->second && create)
            {
                query->second = new Query(mRenderer, type, handle);
                query->second->addRef();
            }
            return query->second;
        }
    }
    
    Buffer *Context::getArrayBuffer()
    {
        return mState.arrayBuffer.get();
    }
    
    Buffer *Context::getElementArrayBuffer()
    {
        return mState.elementArrayBuffer.get();
    }
    
    ProgramBinary *Context::getCurrentProgramBinary()
    {
        return mCurrentProgramBinary.get();
    }
    
    Texture2D *Context::getTexture2D()
    {
        return static_cast<Texture2D*>(getSamplerTexture(mState.activeSampler, TEXTURE_2D));
    }
    
    TextureCubeMap *Context::getTextureCubeMap()
    {
        return static_cast<TextureCubeMap*>(getSamplerTexture(mState.activeSampler, TEXTURE_CUBE));
    }
    
    Buffer *Context::getGenericUniformBuffer()
    {
        return mState.genericUniformBuffer.get();
    }
    
    Buffer *Context::getGenericTransformFeedbackBuffer()
    {
        return mState.genericTransformFeedbackBuffer.get();
    }
    
    Buffer *Context::getCopyReadBuffer()
    {
        return mState.copyReadBuffer.get();
    }
    
    Buffer *Context::getCopyWriteBuffer()
    {
        return mState.copyWriteBuffer.get();
    }
    
    Buffer *Context::getPixelPackBuffer()
    {
        return mState.pixelPackBuffer.get();
    }
    
    Buffer *Context::getPixelUnpackBuffer()
    {
        return mState.pixelUnpackBuffer.get();
    }
    
    Texture *Context::getSamplerTexture(unsigned int sampler, TextureType type)
    {
        GLuint texid = mState.samplerTexture[type][sampler].id();
    
        if (texid == 0)   // Special case: 0 refers to different initial textures based on the target
        {
            switch (type)
            {
              default: UNREACHABLE();
              case TEXTURE_2D: return mTexture2DZero.get();
              case TEXTURE_CUBE: return mTextureCubeMapZero.get();
            }
        }
    
        return mState.samplerTexture[type][sampler].get();
    }
    
    bool Context::getBooleanv(GLenum pname, GLboolean *params)
    {
        switch (pname)
        {
          case GL_SHADER_COMPILER:           *params = GL_TRUE;                             break;
          case GL_SAMPLE_COVERAGE_INVERT:    *params = mState.sampleCoverageInvert;         break;
          case GL_DEPTH_WRITEMASK:           *params = mState.depthStencil.depthMask;       break;
          case GL_COLOR_WRITEMASK:
            params[0] = mState.blend.colorMaskRed;
            params[1] = mState.blend.colorMaskGreen;
            params[2] = mState.blend.colorMaskBlue;
            params[3] = mState.blend.colorMaskAlpha;
            break;
          case GL_CULL_FACE:                 *params = mState.rasterizer.cullFace;          break;
          case GL_POLYGON_OFFSET_FILL:       *params = mState.rasterizer.polygonOffsetFill; break;
          case GL_SAMPLE_ALPHA_TO_COVERAGE:  *params = mState.blend.sampleAlphaToCoverage;  break;
          case GL_SAMPLE_COVERAGE:           *params = mState.sampleCoverage;               break;
          case GL_SCISSOR_TEST:              *params = mState.scissorTest;                  break;
          case GL_STENCIL_TEST:              *params = mState.depthStencil.stencilTest;     break;
          case GL_DEPTH_TEST:                *params = mState.depthStencil.depthTest;       break;
          case GL_BLEND:                     *params = mState.blend.blend;                  break;
          case GL_DITHER:                    *params = mState.blend.dither;                 break;
          case GL_CONTEXT_ROBUST_ACCESS_EXT: *params = mRobustAccess ? GL_TRUE : GL_FALSE;  break;
          default:
            return false;
        }
    
        return true;
    }
    
    bool Context::getFloatv(GLenum pname, GLfloat *params)
    {
        // Please note: DEPTH_CLEAR_VALUE is included in our internal getFloatv implementation
        // because it is stored as a float, despite the fact that the GL ES 2.0 spec names
        // GetIntegerv as its native query function. As it would require conversion in any
        // case, this should make no difference to the calling application.
        switch (pname)
        {
          case GL_LINE_WIDTH:               *params = mState.lineWidth;                         break;
          case GL_SAMPLE_COVERAGE_VALUE:    *params = mState.sampleCoverageValue;               break;
          case GL_DEPTH_CLEAR_VALUE:        *params = mState.depthClearValue;                   break;
          case GL_POLYGON_OFFSET_FACTOR:    *params = mState.rasterizer.polygonOffsetFactor;    break;
          case GL_POLYGON_OFFSET_UNITS:     *params = mState.rasterizer.polygonOffsetUnits;     break;
          case GL_ALIASED_LINE_WIDTH_RANGE:
            params[0] = gl::ALIASED_LINE_WIDTH_RANGE_MIN;
            params[1] = gl::ALIASED_LINE_WIDTH_RANGE_MAX;
            break;
          case GL_ALIASED_POINT_SIZE_RANGE:
            params[0] = gl::ALIASED_POINT_SIZE_RANGE_MIN;
            params[1] = getMaximumPointSize();
            break;
          case GL_DEPTH_RANGE:
            params[0] = mState.zNear;
            params[1] = mState.zFar;
            break;
          case GL_COLOR_CLEAR_VALUE:
            params[0] = mState.colorClearValue.red;
            params[1] = mState.colorClearValue.green;
            params[2] = mState.colorClearValue.blue;
            params[3] = mState.colorClearValue.alpha;
            break;
          case GL_BLEND_COLOR:
            params[0] = mState.blendColor.red;
            params[1] = mState.blendColor.green;
            params[2] = mState.blendColor.blue;
            params[3] = mState.blendColor.alpha;
            break;
          case GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT:
            if (!supportsTextureFilterAnisotropy())
            {
                return false;
            }
            *params = mMaxTextureAnisotropy;
            break;
          default:
            return false;
        }
    
        return true;
    }
    
    bool Context::getIntegerv(GLenum pname, GLint *params)
    {
        if (pname >= GL_DRAW_BUFFER0_EXT && pname <= GL_DRAW_BUFFER15_EXT)
        {
            unsigned int colorAttachment = (pname - GL_DRAW_BUFFER0_EXT);
    
            if (colorAttachment >= mRenderer->getMaxRenderTargets())
            {
                // return true to stop further operation in the parent call
                return gl::error(GL_INVALID_OPERATION, true);
            }
    
            Framebuffer *framebuffer = getDrawFramebuffer();
    
            *params = framebuffer->getDrawBufferState(colorAttachment);
            return true;
        }
    
        // Please note: DEPTH_CLEAR_VALUE is not included in our internal getIntegerv implementation
        // because it is stored as a float, despite the fact that the GL ES 2.0 spec names
        // GetIntegerv as its native query function. As it would require conversion in any
        // case, this should make no difference to the calling application. You may find it in 
        // Context::getFloatv.
        switch (pname)
        {
          case GL_MAX_VERTEX_ATTRIBS:               *params = gl::MAX_VERTEX_ATTRIBS;               break;
          case GL_MAX_VERTEX_UNIFORM_VECTORS:       *params = mRenderer->getMaxVertexUniformVectors(); break;
          case GL_MAX_VARYING_VECTORS:              *params = mRenderer->getMaxVaryingVectors();    break;
          case GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS: *params = mRenderer->getMaxCombinedTextureImageUnits(); break;
          case GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS:   *params = mRenderer->getMaxVertexTextureImageUnits(); break;
          case GL_MAX_TEXTURE_IMAGE_UNITS:          *params = gl::MAX_TEXTURE_IMAGE_UNITS;          break;
          case GL_MAX_FRAGMENT_UNIFORM_VECTORS:     *params = mRenderer->getMaxFragmentUniformVectors(); break;
          case GL_MAX_RENDERBUFFER_SIZE:            *params = getMaximumRenderbufferDimension();    break;
          case GL_MAX_COLOR_ATTACHMENTS_EXT:        *params = mRenderer->getMaxRenderTargets();     break;
          case GL_MAX_DRAW_BUFFERS_EXT:             *params = mRenderer->getMaxRenderTargets();     break;
          case GL_NUM_SHADER_BINARY_FORMATS:        *params = 0;                                    break;
          case GL_SHADER_BINARY_FORMATS:      /* no shader binary formats are supported */          break;
          case GL_ARRAY_BUFFER_BINDING:             *params = mState.arrayBuffer.id();              break;
          case GL_ELEMENT_ARRAY_BUFFER_BINDING:     *params = mState.elementArrayBuffer.id();       break;
          //case GL_FRAMEBUFFER_BINDING:            // now equivalent to GL_DRAW_FRAMEBUFFER_BINDING_ANGLE
          case GL_DRAW_FRAMEBUFFER_BINDING_ANGLE:   *params = mState.drawFramebuffer;               break;
          case GL_READ_FRAMEBUFFER_BINDING_ANGLE:   *params = mState.readFramebuffer;               break;
          case GL_RENDERBUFFER_BINDING:             *params = mState.renderbuffer.id();             break;
          case GL_CURRENT_PROGRAM:                  *params = mState.currentProgram;                break;
          case GL_PACK_ALIGNMENT:                   *params = mState.packAlignment;                 break;
          case GL_PACK_REVERSE_ROW_ORDER_ANGLE:     *params = mState.packReverseRowOrder;           break;
          case GL_UNPACK_ALIGNMENT:                 *params = mState.unpackAlignment;               break;
          case GL_GENERATE_MIPMAP_HINT:             *params = mState.generateMipmapHint;            break;
          case GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES: *params = mState.fragmentShaderDerivativeHint; break;
          case GL_ACTIVE_TEXTURE:                   *params = (mState.activeSampler + GL_TEXTURE0); break;
          case GL_STENCIL_FUNC:                     *params = mState.depthStencil.stencilFunc;             break;
          case GL_STENCIL_REF:                      *params = mState.stencilRef;                           break;
          case GL_STENCIL_VALUE_MASK:               *params = mState.depthStencil.stencilMask;             break;
          case GL_STENCIL_BACK_FUNC:                *params = mState.depthStencil.stencilBackFunc;         break;
          case GL_STENCIL_BACK_REF:                 *params = mState.stencilBackRef;                       break;
          case GL_STENCIL_BACK_VALUE_MASK:          *params = mState.depthStencil.stencilBackMask;         break;
          case GL_STENCIL_FAIL:                     *params = mState.depthStencil.stencilFail;             break;
          case GL_STENCIL_PASS_DEPTH_FAIL:          *params = mState.depthStencil.stencilPassDepthFail;    break;
          case GL_STENCIL_PASS_DEPTH_PASS:          *params = mState.depthStencil.stencilPassDepthPass;    break;
          case GL_STENCIL_BACK_FAIL:                *params = mState.depthStencil.stencilBackFail;         break;
          case GL_STENCIL_BACK_PASS_DEPTH_FAIL:     *params = mState.depthStencil.stencilBackPassDepthFail; break;
          case GL_STENCIL_BACK_PASS_DEPTH_PASS:     *params = mState.depthStencil.stencilBackPassDepthPass; break;
          case GL_DEPTH_FUNC:                       *params = mState.depthStencil.depthFunc;               break;
          case GL_BLEND_SRC_RGB:                    *params = mState.blend.sourceBlendRGB;                 break;
          case GL_BLEND_SRC_ALPHA:                  *params = mState.blend.sourceBlendAlpha;               break;
          case GL_BLEND_DST_RGB:                    *params = mState.blend.destBlendRGB;                   break;
          case GL_BLEND_DST_ALPHA:                  *params = mState.blend.destBlendAlpha;                 break;
          case GL_BLEND_EQUATION_RGB:               *params = mState.blend.blendEquationRGB;               break;
          case GL_BLEND_EQUATION_ALPHA:             *params = mState.blend.blendEquationAlpha;             break;
          case GL_STENCIL_WRITEMASK:                *params = mState.depthStencil.stencilWritemask;        break;
          case GL_STENCIL_BACK_WRITEMASK:           *params = mState.depthStencil.stencilBackWritemask;    break;
          case GL_STENCIL_CLEAR_VALUE:              *params = mState.stencilClearValue;             break;
          case GL_SUBPIXEL_BITS:                    *params = 4;                                    break;
          case GL_MAX_TEXTURE_SIZE:                 *params = getMaximumTextureDimension();         break;
          case GL_MAX_CUBE_MAP_TEXTURE_SIZE:        *params = getMaximumCubeTextureDimension();     break;
          case GL_NUM_COMPRESSED_TEXTURE_FORMATS:   
            params[0] = mNumCompressedTextureFormats;
            break;
          case GL_MAX_SAMPLES_ANGLE:
            {
                GLsizei maxSamples = getMaxSupportedSamples();
                if (maxSamples != 0)
                {
                    *params = maxSamples;
                }
                else
                {
                    return false;
                }
    
                break;
            }
          case GL_SAMPLE_BUFFERS:                   
          case GL_SAMPLES:
            {
                gl::Framebuffer *framebuffer = getDrawFramebuffer();
                if (framebuffer->completeness() == GL_FRAMEBUFFER_COMPLETE)
                {
                    switch (pname)
                    {
                      case GL_SAMPLE_BUFFERS:
                        if (framebuffer->getSamples() != 0)
                        {
                            *params = 1;
                        }
                        else
                        {
                            *params = 0;
                        }
                        break;
                      case GL_SAMPLES:
                        *params = framebuffer->getSamples();
                        break;
                    }
                }
                else 
                {
                    *params = 0;
                }
            }
            break;
          case GL_IMPLEMENTATION_COLOR_READ_TYPE:
          case GL_IMPLEMENTATION_COLOR_READ_FORMAT:
            {
                GLenum format, type;
                if (getCurrentReadFormatType(&format, &type))
                {
                    if (pname == GL_IMPLEMENTATION_COLOR_READ_FORMAT)
                        *params = format;
                    else
                        *params = type;
                }
            }
            break;
          case GL_MAX_VIEWPORT_DIMS:
            {
                params[0] = mMaxViewportDimension;
                params[1] = mMaxViewportDimension;
            }
            break;
          case GL_COMPRESSED_TEXTURE_FORMATS:
            {
                if (supportsDXT1Textures())
                {
                    *params++ = GL_COMPRESSED_RGB_S3TC_DXT1_EXT;
                    *params++ = GL_COMPRESSED_RGBA_S3TC_DXT1_EXT;
                }
                if (supportsDXT3Textures())
                {
                    *params++ = GL_COMPRESSED_RGBA_S3TC_DXT3_ANGLE;
                }
                if (supportsDXT5Textures())
                {
                    *params++ = GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE;
                }
            }
            break;
          case GL_VIEWPORT:
            params[0] = mState.viewport.x;
            params[1] = mState.viewport.y;
            params[2] = mState.viewport.width;
            params[3] = mState.viewport.height;
            break;
          case GL_SCISSOR_BOX:
            params[0] = mState.scissor.x;
            params[1] = mState.scissor.y;
            params[2] = mState.scissor.width;
            params[3] = mState.scissor.height;
            break;
          case GL_CULL_FACE_MODE:                   *params = mState.rasterizer.cullMode;   break;
          case GL_FRONT_FACE:                       *params = mState.rasterizer.frontFace;  break;
          case GL_RED_BITS:
          case GL_GREEN_BITS:
          case GL_BLUE_BITS:
          case GL_ALPHA_BITS:
            {
                gl::Framebuffer *framebuffer = getDrawFramebuffer();
                gl::Renderbuffer *colorbuffer = framebuffer->getFirstColorbuffer();
    
                if (colorbuffer)
                {
                    switch (pname)
                    {
                      case GL_RED_BITS:   *params = colorbuffer->getRedSize();      break;
                      case GL_GREEN_BITS: *params = colorbuffer->getGreenSize();    break;
                      case GL_BLUE_BITS:  *params = colorbuffer->getBlueSize();     break;
                      case GL_ALPHA_BITS: *params = colorbuffer->getAlphaSize();    break;
                    }
                }
                else
                {
                    *params = 0;
                }
            }
            break;
          case GL_DEPTH_BITS:
            {
                gl::Framebuffer *framebuffer = getDrawFramebuffer();
                gl::Renderbuffer *depthbuffer = framebuffer->getDepthbuffer();
    
                if (depthbuffer)
                {
                    *params = depthbuffer->getDepthSize();
                }
                else
                {
                    *params = 0;
                }
            }
            break;
          case GL_STENCIL_BITS:
            {
                gl::Framebuffer *framebuffer = getDrawFramebuffer();
                gl::Renderbuffer *stencilbuffer = framebuffer->getStencilbuffer();
    
                if (stencilbuffer)
                {
                    *params = stencilbuffer->getStencilSize();
                }
                else
                {
                    *params = 0;
                }
            }
            break;
          case GL_TEXTURE_BINDING_2D:
            {
                if (mState.activeSampler > mRenderer->getMaxCombinedTextureImageUnits() - 1)
                {
                    gl::error(GL_INVALID_OPERATION);
                    return false;
                }
    
                *params = mState.samplerTexture[TEXTURE_2D][mState.activeSampler].id();
            }
            break;
          case GL_TEXTURE_BINDING_CUBE_MAP:
            {
                if (mState.activeSampler > mRenderer->getMaxCombinedTextureImageUnits() - 1)
                {
                    gl::error(GL_INVALID_OPERATION);
                    return false;
                }
    
                *params = mState.samplerTexture[TEXTURE_CUBE][mState.activeSampler].id();
            }
            break;
          case GL_RESET_NOTIFICATION_STRATEGY_EXT:
            *params = mResetStrategy;
            break;
          case GL_NUM_PROGRAM_BINARY_FORMATS_OES:
            *params = 1;
            break;
          case GL_PROGRAM_BINARY_FORMATS_OES:
            *params = GL_PROGRAM_BINARY_ANGLE;
            break;
          case GL_UNIFORM_BUFFER_BINDING:
            *params = mState.genericUniformBuffer.id();
            break;
          case GL_TRANSFORM_FEEDBACK_BUFFER_BINDING:
            *params = mState.genericTransformFeedbackBuffer.id();
            break;
          case GL_COPY_READ_BUFFER_BINDING:
            *params = mState.copyReadBuffer.id();
            break;
          case GL_COPY_WRITE_BUFFER_BINDING:
            *params = mState.copyWriteBuffer.id();
            break;
          case GL_PIXEL_PACK_BUFFER_BINDING:
            *params = mState.pixelPackBuffer.id();
            break;
          case GL_PIXEL_UNPACK_BUFFER_BINDING:
            *params = mState.pixelUnpackBuffer.id();
            break;
          default:
            return false;
        }
    
        return true;
    }
    
    bool Context::getQueryParameterInfo(GLenum pname, GLenum *type, unsigned int *numParams)
    {
        if (pname >= GL_DRAW_BUFFER0_EXT && pname <= GL_DRAW_BUFFER15_EXT)
        {
            *type = GL_INT;
            *numParams = 1;
            return true;
        }
    
        // Please note: the query type returned for DEPTH_CLEAR_VALUE in this implementation
        // is FLOAT rather than INT, as would be suggested by the GL ES 2.0 spec. This is due
        // to the fact that it is stored internally as a float, and so would require conversion
        // if returned from Context::getIntegerv. Since this conversion is already implemented 
        // in the case that one calls glGetIntegerv to retrieve a float-typed state variable, we
        // place DEPTH_CLEAR_VALUE with the floats. This should make no difference to the calling
        // application.
        switch (pname)
        {
          case GL_COMPRESSED_TEXTURE_FORMATS:
            {
                *type = GL_INT;
                *numParams = mNumCompressedTextureFormats;
            }
            return true;
          case GL_SHADER_BINARY_FORMATS:
            {
                *type = GL_INT;
                *numParams = 0;
            }
            return true;
          case GL_MAX_VERTEX_ATTRIBS:
          case GL_MAX_VERTEX_UNIFORM_VECTORS:
          case GL_MAX_VARYING_VECTORS:
          case GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS:
          case GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS:
          case GL_MAX_TEXTURE_IMAGE_UNITS:
          case GL_MAX_FRAGMENT_UNIFORM_VECTORS:
          case GL_MAX_RENDERBUFFER_SIZE:
          case GL_MAX_COLOR_ATTACHMENTS_EXT:
          case GL_MAX_DRAW_BUFFERS_EXT:
          case GL_NUM_SHADER_BINARY_FORMATS:
          case GL_NUM_COMPRESSED_TEXTURE_FORMATS:
          case GL_ARRAY_BUFFER_BINDING:
          case GL_FRAMEBUFFER_BINDING:
          case GL_RENDERBUFFER_BINDING:
          case GL_CURRENT_PROGRAM:
          case GL_PACK_ALIGNMENT:
          case GL_PACK_REVERSE_ROW_ORDER_ANGLE:
          case GL_UNPACK_ALIGNMENT:
          case GL_GENERATE_MIPMAP_HINT:
          case GL_FRAGMENT_SHADER_DERIVATIVE_HINT_OES:
          case GL_RED_BITS:
          case GL_GREEN_BITS:
          case GL_BLUE_BITS:
          case GL_ALPHA_BITS:
          case GL_DEPTH_BITS:
          case GL_STENCIL_BITS:
          case GL_ELEMENT_ARRAY_BUFFER_BINDING:
          case GL_CULL_FACE_MODE:
          case GL_FRONT_FACE:
          case GL_ACTIVE_TEXTURE:
          case GL_STENCIL_FUNC:
          case GL_STENCIL_VALUE_MASK:
          case GL_STENCIL_REF:
          case GL_STENCIL_FAIL:
          case GL_STENCIL_PASS_DEPTH_FAIL:
          case GL_STENCIL_PASS_DEPTH_PASS:
          case GL_STENCIL_BACK_FUNC:
          case GL_STENCIL_BACK_VALUE_MASK:
          case GL_STENCIL_BACK_REF:
          case GL_STENCIL_BACK_FAIL:
          case GL_STENCIL_BACK_PASS_DEPTH_FAIL:
          case GL_STENCIL_BACK_PASS_DEPTH_PASS:
          case GL_DEPTH_FUNC:
          case GL_BLEND_SRC_RGB:
          case GL_BLEND_SRC_ALPHA:
          case GL_BLEND_DST_RGB:
          case GL_BLEND_DST_ALPHA:
          case GL_BLEND_EQUATION_RGB:
          case GL_BLEND_EQUATION_ALPHA:
          case GL_STENCIL_WRITEMASK:
          case GL_STENCIL_BACK_WRITEMASK:
          case GL_STENCIL_CLEAR_VALUE:
          case GL_SUBPIXEL_BITS:
          case GL_MAX_TEXTURE_SIZE:
          case GL_MAX_CUBE_MAP_TEXTURE_SIZE:
          case GL_SAMPLE_BUFFERS:
          case GL_SAMPLES:
          case GL_IMPLEMENTATION_COLOR_READ_TYPE:
          case GL_IMPLEMENTATION_COLOR_READ_FORMAT:
          case GL_TEXTURE_BINDING_2D:
          case GL_TEXTURE_BINDING_CUBE_MAP:
          case GL_RESET_NOTIFICATION_STRATEGY_EXT:
          case GL_NUM_PROGRAM_BINARY_FORMATS_OES:
          case GL_PROGRAM_BINARY_FORMATS_OES:
            {
                *type = GL_INT;
                *numParams = 1;
            }
            return true;
          case GL_MAX_SAMPLES_ANGLE:
            {
                if (getMaxSupportedSamples() != 0)
                {
                    *type = GL_INT;
                    *numParams = 1;
                }
                else
                {
                    return false;
                }
            }
            return true;
          case GL_MAX_VIEWPORT_DIMS:
            {
                *type = GL_INT;
                *numParams = 2;
            }
            return true;
          case GL_VIEWPORT:
          case GL_SCISSOR_BOX:
            {
                *type = GL_INT;
                *numParams = 4;
            }
            return true;
          case GL_SHADER_COMPILER:
          case GL_SAMPLE_COVERAGE_INVERT:
          case GL_DEPTH_WRITEMASK:
          case GL_CULL_FACE:                // CULL_FACE through DITHER are natural to IsEnabled,
          case GL_POLYGON_OFFSET_FILL:      // but can be retrieved through the Get{Type}v queries.
          case GL_SAMPLE_ALPHA_TO_COVERAGE: // For this purpose, they are treated here as bool-natural
          case GL_SAMPLE_COVERAGE:
          case GL_SCISSOR_TEST:
          case GL_STENCIL_TEST:
          case GL_DEPTH_TEST:
          case GL_BLEND:
          case GL_DITHER:
          case GL_CONTEXT_ROBUST_ACCESS_EXT:
            {
                *type = GL_BOOL;
                *numParams = 1;
            }
            return true;
          case GL_COLOR_WRITEMASK:
            {
                *type = GL_BOOL;
                *numParams = 4;
            }
            return true;
          case GL_POLYGON_OFFSET_FACTOR:
          case GL_POLYGON_OFFSET_UNITS:
          case GL_SAMPLE_COVERAGE_VALUE:
          case GL_DEPTH_CLEAR_VALUE:
          case GL_LINE_WIDTH:
            {
                *type = GL_FLOAT;
                *numParams = 1;
            }
            return true;
          case GL_ALIASED_LINE_WIDTH_RANGE:
          case GL_ALIASED_POINT_SIZE_RANGE:
          case GL_DEPTH_RANGE:
            {
                *type = GL_FLOAT;
                *numParams = 2;
            }
            return true;
          case GL_COLOR_CLEAR_VALUE:
          case GL_BLEND_COLOR:
            {
                *type = GL_FLOAT;
                *numParams = 4;
            }
            return true;
          case GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT:
            if (!supportsTextureFilterAnisotropy())
            {
                return false;
            }
            *type = GL_FLOAT;
            *numParams = 1;
            return true;
        }
    
        if (mClientVersion < 3)
        {
            return false;
        }
    
        // Check for ES3.0+ parameter names
        switch (pname)
        {
          case GL_UNIFORM_BUFFER_BINDING:
          case GL_TRANSFORM_FEEDBACK_BINDING:
          case GL_COPY_READ_BUFFER_BINDING:
          case GL_COPY_WRITE_BUFFER_BINDING:
          case GL_PIXEL_PACK_BUFFER_BINDING:
          case GL_PIXEL_UNPACK_BUFFER_BINDING:
            {
                *type = GL_INT;
                *numParams = 1;
            }
            return true;
        }
    
        return false;
    }
    
    // Applies the render target surface, depth stencil surface, viewport rectangle and
    // scissor rectangle to the renderer
    bool Context::applyRenderTarget(GLenum drawMode, bool ignoreViewport)
    {
        Framebuffer *framebufferObject = getDrawFramebuffer();
    
        if (!framebufferObject || framebufferObject->completeness() != GL_FRAMEBUFFER_COMPLETE)
        {
            return gl::error(GL_INVALID_FRAMEBUFFER_OPERATION, false);
        }
    
        mRenderer->applyRenderTarget(framebufferObject);
    
        if (!mRenderer->setViewport(mState.viewport, mState.zNear, mState.zFar, drawMode, mState.rasterizer.frontFace,
                                    ignoreViewport))
        {
            return false;
        }
    
        mRenderer->setScissorRectangle(mState.scissor, mState.scissorTest);
    
        return true;
    }
    
    // Applies the fixed-function state (culling, depth test, alpha blending, stenciling, etc) to the Direct3D 9 device
    void Context::applyState(GLenum drawMode)
    {
        mState.rasterizer.pointDrawMode = (drawMode == GL_POINTS);
        mRenderer->setRasterizerState(mState.rasterizer);
    
        unsigned int mask = 0;
        if (mState.sampleCoverage)
        {
            if (mState.sampleCoverageValue != 0)
            {
                Framebuffer *framebufferObject = getDrawFramebuffer();
                float threshold = 0.5f;
    
                for (int i = 0; i < framebufferObject->getSamples(); ++i)
                {
                    mask <<= 1;
    
                    if ((i + 1) * mState.sampleCoverageValue >= threshold)
                    {
                        threshold += 1.0f;
                        mask |= 1;
                    }
                }
            }
    
            if (mState.sampleCoverageInvert)
            {
                mask = ~mask;
            }
        }
        else
        {
            mask = 0xFFFFFFFF;
        }
        mRenderer->setBlendState(mState.blend, mState.blendColor, mask);
    
        mRenderer->setDepthStencilState(mState.depthStencil, mState.stencilRef, mState.stencilBackRef,
                                        mState.rasterizer.frontFace == GL_CCW);
    }
    
    // Applies the shaders and shader constants to the Direct3D 9 device
    void Context::applyShaders()
    {
        ProgramBinary *programBinary = getCurrentProgramBinary();
    
        mRenderer->applyShaders(programBinary);
        
        programBinary->applyUniforms();
    }
    
    // Applies the textures and sampler states to the Direct3D 9 device
    void Context::applyTextures()
    {
        applyTextures(SAMPLER_PIXEL);
    
        if (mSupportsVertexTexture)
        {
            applyTextures(SAMPLER_VERTEX);
        }
    }
    
    // For each Direct3D 9 sampler of either the pixel or vertex stage,
    // looks up the corresponding OpenGL texture image unit and texture type,
    // and sets the texture and its addressing/filtering state (or NULL when inactive).
    void Context::applyTextures(SamplerType type)
    {
        ProgramBinary *programBinary = getCurrentProgramBinary();
    
        // Range of Direct3D samplers of given sampler type
        int samplerCount = (type == SAMPLER_PIXEL) ? MAX_TEXTURE_IMAGE_UNITS : mRenderer->getMaxVertexTextureImageUnits();
        int samplerRange = programBinary->getUsedSamplerRange(type);
    
        for (int samplerIndex = 0; samplerIndex < samplerRange; samplerIndex++)
        {
            int textureUnit = programBinary->getSamplerMapping(type, samplerIndex);   // OpenGL texture image unit index
    
            if (textureUnit != -1)
            {
                TextureType textureType = programBinary->getSamplerTextureType(type, samplerIndex);
                Texture *texture = getSamplerTexture(textureUnit, textureType);
    
                if (texture->isSamplerComplete())
                {
                    SamplerState samplerState;
                    texture->getSamplerState(&samplerState);
                    mRenderer->setSamplerState(type, samplerIndex, samplerState);
    
                    mRenderer->setTexture(type, samplerIndex, texture);
    
                    texture->resetDirty();
                }
                else
                {
                    mRenderer->setTexture(type, samplerIndex, getIncompleteTexture(textureType));
                }
            }
            else
            {
                mRenderer->setTexture(type, samplerIndex, NULL);
            }
        }
    
        for (int samplerIndex = samplerRange; samplerIndex < samplerCount; samplerIndex++)
        {
            mRenderer->setTexture(type, samplerIndex, NULL);
        }
    }
    
    void Context::readPixels(GLint x, GLint y, GLsizei width, GLsizei height,
                             GLenum format, GLenum type, GLsizei *bufSize, void* pixels)
    {
        Framebuffer *framebuffer = getReadFramebuffer();
    
        if (framebuffer->completeness() != GL_FRAMEBUFFER_COMPLETE)
        {
            return gl::error(GL_INVALID_FRAMEBUFFER_OPERATION);
        }
    
        if (getReadFramebufferHandle() != 0 && framebuffer->getSamples() != 0)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        GLsizei outputPitch = ComputeRowPitch(width, ConvertSizedInternalFormat(format, type), getPackAlignment());
        // sized query sanity check
        if (bufSize)
        {
            int requiredSize = outputPitch * height;
            if (requiredSize > *bufSize)
            {
                return gl::error(GL_INVALID_OPERATION);
            }
        }
    
        mRenderer->readPixels(framebuffer, x, y, width, height, format, type, outputPitch, getPackReverseRowOrder(), getPackAlignment(), pixels);
    }
    
    void Context::clear(GLbitfield mask)
    {
        Framebuffer *framebufferObject = getDrawFramebuffer();
    
        if (!framebufferObject || framebufferObject->completeness() != GL_FRAMEBUFFER_COMPLETE)
        {
            return gl::error(GL_INVALID_FRAMEBUFFER_OPERATION);
        }
    
        DWORD flags = 0;
        GLbitfield finalMask = 0;
    
        if (mask & GL_COLOR_BUFFER_BIT)
        {
            mask &= ~GL_COLOR_BUFFER_BIT;
    
            if (framebufferObject->hasEnabledColorAttachment())
            {
                finalMask |= GL_COLOR_BUFFER_BIT;
            }
        }
    
        if (mask & GL_DEPTH_BUFFER_BIT)
        {
            mask &= ~GL_DEPTH_BUFFER_BIT;
            if (mState.depthStencil.depthMask && framebufferObject->getDepthbufferType() != GL_NONE)
            {
                finalMask |= GL_DEPTH_BUFFER_BIT;
            }
        }
    
        if (mask & GL_STENCIL_BUFFER_BIT)
        {
            mask &= ~GL_STENCIL_BUFFER_BIT;
            if (framebufferObject->getStencilbufferType() != GL_NONE)
            {
                rx::RenderTarget *depthStencil = framebufferObject->getStencilbuffer()->getDepthStencil();
                if (!depthStencil)
                {
                    ERR("Depth stencil pointer unexpectedly null.");
                    return;
                }
    
                if (GetStencilSize(depthStencil->getActualFormat()) > 0)
                {
                    finalMask |= GL_STENCIL_BUFFER_BIT;
                }
            }
        }
    
        if (mask != 0)
        {
            return gl::error(GL_INVALID_VALUE);
        }
    
        if (!applyRenderTarget(GL_TRIANGLES, true))   // Clips the clear to the scissor rectangle but not the viewport
        {
            return;
        }
    
        ClearParameters clearParams;
        clearParams.mask = finalMask;
        clearParams.colorClearValue = mState.colorClearValue;
        clearParams.colorMaskRed = mState.blend.colorMaskRed;
        clearParams.colorMaskGreen = mState.blend.colorMaskGreen;
        clearParams.colorMaskBlue = mState.blend.colorMaskBlue;
        clearParams.colorMaskAlpha = mState.blend.colorMaskAlpha;
        clearParams.depthClearValue = mState.depthClearValue;
        clearParams.stencilClearValue = mState.stencilClearValue;
        clearParams.stencilWriteMask = mState.depthStencil.stencilWritemask;
    
        mRenderer->clear(clearParams, framebufferObject);
    }
    
    void Context::drawArrays(GLenum mode, GLint first, GLsizei count, GLsizei instances)
    {
        if (!mState.currentProgram)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        if (!mRenderer->applyPrimitiveType(mode, count))
        {
            return;
        }
    
        if (!applyRenderTarget(mode, false))
        {
            return;
        }
    
        applyState(mode);
    
        ProgramBinary *programBinary = getCurrentProgramBinary();
    
        GLenum err = mRenderer->applyVertexBuffer(programBinary, mState.vertexAttribute, first, count, instances);
        if (err != GL_NO_ERROR)
        {
            return gl::error(err);
        }
    
        applyShaders();
        applyTextures();
    
        if (!programBinary->validateSamplers(NULL))
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        if (!skipDraw(mode))
        {
            mRenderer->drawArrays(mode, count, instances);
        }
    }
    
    void Context::drawElements(GLenum mode, GLsizei count, GLenum type, const GLvoid *indices, GLsizei instances)
    {
        if (!mState.currentProgram)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        if (!indices && !mState.elementArrayBuffer)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
        
        if (!mRenderer->applyPrimitiveType(mode, count))
        {
            return;
        }
    
        if (!applyRenderTarget(mode, false))
        {
            return;
        }
    
        applyState(mode);
    
        rx::TranslatedIndexData indexInfo;
        GLenum err = mRenderer->applyIndexBuffer(indices, mState.elementArrayBuffer.get(), count, mode, type, &indexInfo);
        if (err != GL_NO_ERROR)
        {
            return gl::error(err);
        }
    
        ProgramBinary *programBinary = getCurrentProgramBinary();
    
        GLsizei vertexCount = indexInfo.maxIndex - indexInfo.minIndex + 1;
        err = mRenderer->applyVertexBuffer(programBinary, mState.vertexAttribute, indexInfo.minIndex, vertexCount, instances);
        if (err != GL_NO_ERROR)
        {
            return gl::error(err);
        }
    
        applyShaders();
        applyTextures();
    
        if (!programBinary->validateSamplers(NULL))
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        if (!skipDraw(mode))
        {
            mRenderer->drawElements(mode, count, type, indices, mState.elementArrayBuffer.get(), indexInfo, instances);
        }
    }
    
    // Implements glFlush when block is false, glFinish when block is true
    void Context::sync(bool block)
    {
        mRenderer->sync(block);
    }
    
    void Context::recordInvalidEnum()
    {
        mInvalidEnum = true;
    }
    
    void Context::recordInvalidValue()
    {
        mInvalidValue = true;
    }
    
    void Context::recordInvalidOperation()
    {
        mInvalidOperation = true;
    }
    
    void Context::recordOutOfMemory()
    {
        mOutOfMemory = true;
    }
    
    void Context::recordInvalidFramebufferOperation()
    {
        mInvalidFramebufferOperation = true;
    }
    
    // Get one of the recorded errors and clear its flag, if any.
    // [OpenGL ES 2.0.24] section 2.5 page 13.
    GLenum Context::getError()
    {
        if (mInvalidEnum)
        {
            mInvalidEnum = false;
    
            return GL_INVALID_ENUM;
        }
    
        if (mInvalidValue)
        {
            mInvalidValue = false;
    
            return GL_INVALID_VALUE;
        }
    
        if (mInvalidOperation)
        {
            mInvalidOperation = false;
    
            return GL_INVALID_OPERATION;
        }
    
        if (mOutOfMemory)
        {
            mOutOfMemory = false;
    
            return GL_OUT_OF_MEMORY;
        }
    
        if (mInvalidFramebufferOperation)
        {
            mInvalidFramebufferOperation = false;
    
            return GL_INVALID_FRAMEBUFFER_OPERATION;
        }
    
        return GL_NO_ERROR;
    }
    
    GLenum Context::getResetStatus()
    {
        if (mResetStatus == GL_NO_ERROR && !mContextLost)
        {
            // mResetStatus will be set by the markContextLost callback
            // in the case a notification is sent
            mRenderer->testDeviceLost(true);
        }
    
        GLenum status = mResetStatus;
    
        if (mResetStatus != GL_NO_ERROR)
        {
            ASSERT(mContextLost);
    
            if (mRenderer->testDeviceResettable())
            {
                mResetStatus = GL_NO_ERROR;
            }
        }
        
        return status;
    }
    
    bool Context::isResetNotificationEnabled()
    {
        return (mResetStrategy == GL_LOSE_CONTEXT_ON_RESET_EXT);
    }
    
    int Context::getClientVersion() const
    {
        return mClientVersion;
    }
    
    int Context::getMajorShaderModel() const
    {
        return mMajorShaderModel;
    }
    
    float Context::getMaximumPointSize() const
    {
        return mMaximumPointSize;
    }
    
    unsigned int Context::getMaximumCombinedTextureImageUnits() const
    {
        return mRenderer->getMaxCombinedTextureImageUnits();
    }
    
    unsigned int Context::getMaximumCombinedUniformBufferBindings() const
    {
        return mRenderer->getMaxVertexShaderUniformBuffers() +
               mRenderer->getMaxFragmentShaderUniformBuffers();
    }
    
    int Context::getMaxSupportedSamples() const
    {
        return mRenderer->getMaxSupportedSamples();
    }
    
    unsigned int Context::getMaxTransformFeedbackBufferBindings() const
    {
        return mRenderer->getMaxTransformFeedbackBuffers();
    }
    
    unsigned int Context::getMaximumRenderTargets() const
    {
        return mRenderer->getMaxRenderTargets();
    }
    
    bool Context::supportsEventQueries() const
    {
        return mSupportsEventQueries;
    }
    
    bool Context::supportsOcclusionQueries() const
    {
        return mSupportsOcclusionQueries;
    }
    
    bool Context::supportsBGRATextures() const
    {
        return mSupportsBGRATextures;
    }
    
    bool Context::supportsDXT1Textures() const
    {
        return mSupportsDXT1Textures;
    }
    
    bool Context::supportsDXT3Textures() const
    {
        return mSupportsDXT3Textures;
    }
    
    bool Context::supportsDXT5Textures() const
    {
        return mSupportsDXT5Textures;
    }
    
    bool Context::supportsFloat32Textures() const
    {
        return mSupportsFloat32Textures;
    }
    
    bool Context::supportsFloat32LinearFilter() const
    {
        return mSupportsFloat32LinearFilter;
    }
    
    bool Context::supportsFloat32RenderableTextures() const
    {
        return mSupportsFloat32RenderableTextures;
    }
    
    bool Context::supportsFloat16Textures() const
    {
        return mSupportsFloat16Textures;
    }
    
    bool Context::supportsFloat16LinearFilter() const
    {
        return mSupportsFloat16LinearFilter;
    }
    
    bool Context::supportsFloat16RenderableTextures() const
    {
        return mSupportsFloat16RenderableTextures;
    }
    
    int Context::getMaximumRenderbufferDimension() const
    {
        return mMaxRenderbufferDimension;
    }
    
    int Context::getMaximumTextureDimension() const
    {
        return mMaxTextureDimension;
    }
    
    int Context::getMaximumCubeTextureDimension() const
    {
        return mMaxCubeTextureDimension;
    }
    
    int Context::getMaximumTextureLevel() const
    {
        return mMaxTextureLevel;
    }
    
    bool Context::supportsLuminanceTextures() const
    {
        return mSupportsLuminanceTextures;
    }
    
    bool Context::supportsLuminanceAlphaTextures() const
    {
        return mSupportsLuminanceAlphaTextures;
    }
    
    bool Context::supportsDepthTextures() const
    {
        return mSupportsDepthTextures;
    }
    
    bool Context::supports32bitIndices() const
    {
        return mSupports32bitIndices;
    }
    
    bool Context::supportsNonPower2Texture() const
    {
        return mSupportsNonPower2Texture;
    }
    
    bool Context::supportsInstancing() const
    {
        return mSupportsInstancing;
    }
    
    bool Context::supportsTextureFilterAnisotropy() const
    {
        return mSupportsTextureFilterAnisotropy;
    }
    
    float Context::getTextureMaxAnisotropy() const
    {
        return mMaxTextureAnisotropy;
    }
    
    bool Context::getCurrentReadFormatType(GLenum *format, GLenum *type)
    {
        Framebuffer *framebuffer = getReadFramebuffer();
        if (!framebuffer || framebuffer->completeness() != GL_FRAMEBUFFER_COMPLETE)
        {
            return gl::error(GL_INVALID_OPERATION, false);
        }
    
        Renderbuffer *renderbuffer = framebuffer->getReadColorbuffer();
        if (!renderbuffer)
        {
            return gl::error(GL_INVALID_OPERATION, false);
        }
    
        *format = gl::ExtractFormat(renderbuffer->getActualFormat()); 
        *type = gl::ExtractType(renderbuffer->getActualFormat());
    
        return true;
    }
    
    void Context::detachBuffer(GLuint buffer)
    {
        // [OpenGL ES 2.0.24] section 2.9 page 22:
        // If a buffer object is deleted while it is bound, all bindings to that object in the current context
        // (i.e. in the thread that called Delete-Buffers) are reset to zero.
    
        if (mState.arrayBuffer.id() == buffer)
        {
            mState.arrayBuffer.set(NULL);
        }
    
        if (mState.elementArrayBuffer.id() == buffer)
        {
            mState.elementArrayBuffer.set(NULL);
        }
    
        for (int attribute = 0; attribute < MAX_VERTEX_ATTRIBS; attribute++)
        {
            if (mState.vertexAttribute[attribute].mBoundBuffer.id() == buffer)
            {
                mState.vertexAttribute[attribute].mBoundBuffer.set(NULL);
            }
        }
    }
    
    void Context::detachTexture(GLuint texture)
    {
        // [OpenGL ES 2.0.24] section 3.8 page 84:
        // If a texture object is deleted, it is as if all texture units which are bound to that texture object are
        // rebound to texture object zero
    
        for (int type = 0; type < TEXTURE_TYPE_COUNT; type++)
        {
            for (int sampler = 0; sampler < IMPLEMENTATION_MAX_COMBINED_TEXTURE_IMAGE_UNITS; sampler++)
            {
                if (mState.samplerTexture[type][sampler].id() == texture)
                {
                    mState.samplerTexture[type][sampler].set(NULL);
                }
            }
        }
    
        // [OpenGL ES 2.0.24] section 4.4 page 112:
        // If a texture object is deleted while its image is attached to the currently bound framebuffer, then it is
        // as if FramebufferTexture2D had been called, with a texture of 0, for each attachment point to which this
        // image was attached in the currently bound framebuffer.
    
        Framebuffer *readFramebuffer = getReadFramebuffer();
        Framebuffer *drawFramebuffer = getDrawFramebuffer();
    
        if (readFramebuffer)
        {
            readFramebuffer->detachTexture(texture);
        }
    
        if (drawFramebuffer && drawFramebuffer != readFramebuffer)
        {
            drawFramebuffer->detachTexture(texture);
        }
    }
    
    void Context::detachFramebuffer(GLuint framebuffer)
    {
        // [OpenGL ES 2.0.24] section 4.4 page 107:
        // If a framebuffer that is currently bound to the target FRAMEBUFFER is deleted, it is as though
        // BindFramebuffer had been executed with the target of FRAMEBUFFER and framebuffer of zero.
    
        if (mState.readFramebuffer == framebuffer)
        {
            bindReadFramebuffer(0);
        }
    
        if (mState.drawFramebuffer == framebuffer)
        {
            bindDrawFramebuffer(0);
        }
    }
    
    void Context::detachRenderbuffer(GLuint renderbuffer)
    {
        // [OpenGL ES 2.0.24] section 4.4 page 109:
        // If a renderbuffer that is currently bound to RENDERBUFFER is deleted, it is as though BindRenderbuffer
        // had been executed with the target RENDERBUFFER and name of zero.
    
        if (mState.renderbuffer.id() == renderbuffer)
        {
            bindRenderbuffer(0);
        }
    
        // [OpenGL ES 2.0.24] section 4.4 page 111:
        // If a renderbuffer object is deleted while its image is attached to the currently bound framebuffer,
        // then it is as if FramebufferRenderbuffer had been called, with a renderbuffer of 0, for each attachment
        // point to which this image was attached in the currently bound framebuffer.
    
        Framebuffer *readFramebuffer = getReadFramebuffer();
        Framebuffer *drawFramebuffer = getDrawFramebuffer();
    
        if (readFramebuffer)
        {
            readFramebuffer->detachRenderbuffer(renderbuffer);
        }
    
        if (drawFramebuffer && drawFramebuffer != readFramebuffer)
        {
            drawFramebuffer->detachRenderbuffer(renderbuffer);
        }
    }
    
    Texture *Context::getIncompleteTexture(TextureType type)
    {
        Texture *t = mIncompleteTextures[type].get();
    
        if (t == NULL)
        {
            static const GLubyte color[] = { 0, 0, 0, 255 };
    
            switch (type)
            {
              default:
                UNREACHABLE();
                // default falls through to TEXTURE_2D
    
              case TEXTURE_2D:
                {
                    Texture2D *incomplete2d = new Texture2D(mRenderer, Texture::INCOMPLETE_TEXTURE_ID);
                    incomplete2d->setImage(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
                    t = incomplete2d;
                }
                break;
    
              case TEXTURE_CUBE:
                {
                  TextureCubeMap *incompleteCube = new TextureCubeMap(mRenderer, Texture::INCOMPLETE_TEXTURE_ID);
    
                  incompleteCube->setImagePosX(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
                  incompleteCube->setImageNegX(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
                  incompleteCube->setImagePosY(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
                  incompleteCube->setImageNegY(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
                  incompleteCube->setImagePosZ(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
                  incompleteCube->setImageNegZ(0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, 1, color);
    
                  t = incompleteCube;
                }
                break;
            }
    
            mIncompleteTextures[type].set(t);
        }
    
        return t;
    }
    
    bool Context::skipDraw(GLenum drawMode)
    {
        if (drawMode == GL_POINTS)
        {
            // ProgramBinary assumes non-point rendering if gl_PointSize isn't written,
            // which affects varying interpolation. Since the value of gl_PointSize is
            // undefined when not written, just skip drawing to avoid unexpected results.
            if (!getCurrentProgramBinary()->usesPointSize())
            {
                // This is stictly speaking not an error, but developers should be 
                // notified of risking undefined behavior.
                ERR("Point rendering without writing to gl_PointSize.");
    
                return true;
            }
        }
        else if (IsTriangleMode(drawMode))
        {
            if (mState.rasterizer.cullFace && mState.rasterizer.cullMode == GL_FRONT_AND_BACK)
            {
                return true;
            }
        }
    
        return false;
    }
    
    void Context::setVertexAttribf(GLuint index, const GLfloat values[4])
    {
        ASSERT(index < gl::MAX_VERTEX_ATTRIBS);
    
        mState.vertexAttribute[index].mCurrentValue.FloatValues[0] = values[0];
        mState.vertexAttribute[index].mCurrentValue.FloatValues[1] = values[1];
        mState.vertexAttribute[index].mCurrentValue.FloatValues[2] = values[2];
        mState.vertexAttribute[index].mCurrentValue.FloatValues[3] = values[3];
        mState.vertexAttribute[index].mCurrentValue.Type = GL_FLOAT;
        mState.vertexAttribute[index].mPureInteger = false;
    }
    
    void Context::setVertexAttribu(GLuint index, const GLuint values[4])
    {
        ASSERT(index < gl::MAX_VERTEX_ATTRIBS);
    
        mState.vertexAttribute[index].mCurrentValue.UnsignedIntValues[0] = values[0];
        mState.vertexAttribute[index].mCurrentValue.UnsignedIntValues[1] = values[1];
        mState.vertexAttribute[index].mCurrentValue.UnsignedIntValues[2] = values[2];
        mState.vertexAttribute[index].mCurrentValue.UnsignedIntValues[3] = values[3];
        mState.vertexAttribute[index].mCurrentValue.Type = GL_UNSIGNED_INT;
        mState.vertexAttribute[index].mPureInteger = true;
    }
    
    void Context::setVertexAttribi(GLuint index, const GLint values[4])
    {
        ASSERT(index < gl::MAX_VERTEX_ATTRIBS);
    
        mState.vertexAttribute[index].mCurrentValue.IntValues[0] = values[0];
        mState.vertexAttribute[index].mCurrentValue.IntValues[1] = values[1];
        mState.vertexAttribute[index].mCurrentValue.IntValues[2] = values[2];
        mState.vertexAttribute[index].mCurrentValue.IntValues[3] = values[3];
        mState.vertexAttribute[index].mCurrentValue.Type = GL_INT;
        mState.vertexAttribute[index].mPureInteger = true;
    }
    
    void Context::setVertexAttribDivisor(GLuint index, GLuint divisor)
    {
        ASSERT(index < gl::MAX_VERTEX_ATTRIBS);
    
        mState.vertexAttribute[index].mDivisor = divisor;
    }
    
    // keep list sorted in following order
    // OES extensions
    // EXT extensions
    // Vendor extensions
    void Context::initExtensionString()
    {
        std::string extensionString = "";
    
        // OES extensions
        if (supports32bitIndices())
        {
            extensionString += "GL_OES_element_index_uint ";
        }
    
        extensionString += "GL_OES_packed_depth_stencil ";
        extensionString += "GL_OES_get_program_binary ";
        extensionString += "GL_OES_rgb8_rgba8 ";
        if (mRenderer->getDerivativeInstructionSupport())
        {
            extensionString += "GL_OES_standard_derivatives ";
        }
    
        if (supportsFloat16Textures())
        {
            extensionString += "GL_OES_texture_half_float ";
        }
        if (supportsFloat16LinearFilter())
        {
            extensionString += "GL_OES_texture_half_float_linear ";
        }
        if (supportsFloat32Textures())
        {
            extensionString += "GL_OES_texture_float ";
        }
        if (supportsFloat32LinearFilter())
        {
            extensionString += "GL_OES_texture_float_linear ";
        }
    
        if (supportsNonPower2Texture())
        {
            extensionString += "GL_OES_texture_npot ";
        }
    
        // Multi-vendor (EXT) extensions
        if (supportsOcclusionQueries())
        {
            extensionString += "GL_EXT_occlusion_query_boolean ";
        }
    
        extensionString += "GL_EXT_read_format_bgra ";
        extensionString += "GL_EXT_robustness ";
    
        if (supportsDXT1Textures())
        {
            extensionString += "GL_EXT_texture_compression_dxt1 ";
        }
    
        if (supportsTextureFilterAnisotropy())
        {
            extensionString += "GL_EXT_texture_filter_anisotropic ";
        }
    
        if (supportsBGRATextures())
        {
            extensionString += "GL_EXT_texture_format_BGRA8888 ";
        }
    
        if (mRenderer->getMaxRenderTargets() > 1)
        {
            extensionString += "GL_EXT_draw_buffers ";
        }
    
        extensionString += "GL_EXT_texture_storage ";
    
        // ANGLE-specific extensions
        if (supportsDepthTextures())
        {
            extensionString += "GL_ANGLE_depth_texture ";
        }
    
        extensionString += "GL_ANGLE_framebuffer_blit ";
        if (getMaxSupportedSamples() != 0)
        {
            extensionString += "GL_ANGLE_framebuffer_multisample ";
        }
    
        if (supportsInstancing())
        {
            extensionString += "GL_ANGLE_instanced_arrays ";
        }
    
        extensionString += "GL_ANGLE_pack_reverse_row_order ";
    
        if (supportsDXT3Textures())
        {
            extensionString += "GL_ANGLE_texture_compression_dxt3 ";
        }
        if (supportsDXT5Textures())
        {
            extensionString += "GL_ANGLE_texture_compression_dxt5 ";
        }
    
        extensionString += "GL_ANGLE_texture_usage ";
        extensionString += "GL_ANGLE_translated_shader_source ";
    
        // Other vendor-specific extensions
        if (supportsEventQueries())
        {
            extensionString += "GL_NV_fence ";
        }
    
        std::string::size_type end = extensionString.find_last_not_of(' ');
        if (end != std::string::npos)
        {
            extensionString.resize(end+1);
        }
    
        mExtensionString = makeStaticString(extensionString);
    }
    
    const char *Context::getExtensionString() const
    {
        return mExtensionString;
    }
    
    void Context::initRendererString()
    {
        std::ostringstream rendererString;
        rendererString << "ANGLE (";
        rendererString << mRenderer->getRendererDescription();
        rendererString << ")";
    
        mRendererString = makeStaticString(rendererString.str());
    }
    
    const char *Context::getRendererString() const
    {
        return mRendererString;
    }
    
    void Context::blitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1, 
                                  GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
                                  GLbitfield mask)
    {
        Framebuffer *readFramebuffer = getReadFramebuffer();
        Framebuffer *drawFramebuffer = getDrawFramebuffer();
    
        if (!readFramebuffer || readFramebuffer->completeness() != GL_FRAMEBUFFER_COMPLETE ||
            !drawFramebuffer || drawFramebuffer->completeness() != GL_FRAMEBUFFER_COMPLETE)
        {
            return gl::error(GL_INVALID_FRAMEBUFFER_OPERATION);
        }
    
        if (drawFramebuffer->getSamples() != 0)
        {
            return gl::error(GL_INVALID_OPERATION);
        }
    
        Renderbuffer *readColorBuffer = readFramebuffer->getReadColorbuffer();
        Renderbuffer *drawColorBuffer = drawFramebuffer->getFirstColorbuffer();
    
        if (drawColorBuffer == NULL)
        {
            ERR("Draw buffers formats don't match, which is not supported in this implementation of BlitFramebufferANGLE");
            return gl::error(GL_INVALID_OPERATION);
        }
    
        int readBufferWidth = readColorBuffer->getWidth();
        int readBufferHeight = readColorBuffer->getHeight();
        int drawBufferWidth = drawColorBuffer->getWidth();
        int drawBufferHeight = drawColorBuffer->getHeight();
    
        Rectangle sourceRect;
        Rectangle destRect;
    
        if (srcX0 < srcX1)
        {
            sourceRect.x = srcX0;
            destRect.x = dstX0;
            sourceRect.width = srcX1 - srcX0;
            destRect.width = dstX1 - dstX0;
        }
        else
        {
            sourceRect.x = srcX1;
            destRect.x = dstX1;
            sourceRect.width = srcX0 - srcX1;
            destRect.width = dstX0 - dstX1;
        }
    
        if (srcY0 < srcY1)
        {
            sourceRect.height = srcY1 - srcY0;
            destRect.height = dstY1 - dstY0;
            sourceRect.y = srcY0;
            destRect.y = dstY0;
        }
        else
        {
            sourceRect.height = srcY0 - srcY1;
            destRect.height = dstY0 - srcY1;
            sourceRect.y = srcY1;
            destRect.y = dstY1;
        }
    
        Rectangle sourceScissoredRect = sourceRect;
        Rectangle destScissoredRect = destRect;
    
        if (mState.scissorTest)
        {
            // Only write to parts of the destination framebuffer which pass the scissor test.
            if (destRect.x < mState.scissor.x)
            {
                int xDiff = mState.scissor.x - destRect.x;
                destScissoredRect.x = mState.scissor.x;
                destScissoredRect.width -= xDiff;
                sourceScissoredRect.x += xDiff;
                sourceScissoredRect.width -= xDiff;
    
            }
    
            if (destRect.x + destRect.width > mState.scissor.x + mState.scissor.width)
            {
                int xDiff = (destRect.x + destRect.width) - (mState.scissor.x + mState.scissor.width);
                destScissoredRect.width -= xDiff;
                sourceScissoredRect.width -= xDiff;
            }
    
            if (destRect.y < mState.scissor.y)
            {
                int yDiff = mState.scissor.y - destRect.y;
                destScissoredRect.y = mState.scissor.y;
                destScissoredRect.height -= yDiff;
                sourceScissoredRect.y += yDiff;
                sourceScissoredRect.height -= yDiff;
            }
    
            if (destRect.y + destRect.height > mState.scissor.y + mState.scissor.height)
            {
                int yDiff = (destRect.y + destRect.height) - (mState.scissor.y + mState.scissor.height);
                destScissoredRect.height  -= yDiff;
                sourceScissoredRect.height -= yDiff;
            }
        }
    
        bool blitRenderTarget = false;
        bool blitDepthStencil = false;
    
        Rectangle sourceTrimmedRect = sourceScissoredRect;
        Rectangle destTrimmedRect = destScissoredRect;
    
        // The source & destination rectangles also may need to be trimmed if they fall out of the bounds of 
        // the actual draw and read surfaces.
        if (sourceTrimmedRect.x < 0)
        {
            int xDiff = 0 - sourceTrimmedRect.x;
            sourceTrimmedRect.x = 0;
            sourceTrimmedRect.width -= xDiff;
            destTrimmedRect.x += xDiff;
            destTrimmedRect.width -= xDiff;
        }
    
        if (sourceTrimmedRect.x + sourceTrimmedRect.width > readBufferWidth)
        {
            int xDiff = (sourceTrimmedRect.x + sourceTrimmedRect.width) - readBufferWidth;
            sourceTrimmedRect.width -= xDiff;
            destTrimmedRect.width -= xDiff;
        }
    
        if (sourceTrimmedRect.y < 0)
        {
            int yDiff = 0 - sourceTrimmedRect.y;
            sourceTrimmedRect.y = 0;
            sourceTrimmedRect.height -= yDiff;
            destTrimmedRect.y += yDiff;
            destTrimmedRect.height -= yDiff;
        }
    
        if (sourceTrimmedRect.y + sourceTrimmedRect.height > readBufferHeight)
        {
            int yDiff = (sourceTrimmedRect.y + sourceTrimmedRect.height) - readBufferHeight;
            sourceTrimmedRect.height -= yDiff;
            destTrimmedRect.height -= yDiff;
        }
    
        if (destTrimmedRect.x < 0)
        {
            int xDiff = 0 - destTrimmedRect.x;
            destTrimmedRect.x = 0;
            destTrimmedRect.width -= xDiff;
            sourceTrimmedRect.x += xDiff;
            sourceTrimmedRect.width -= xDiff;
        }
    
        if (destTrimmedRect.x + destTrimmedRect.width > drawBufferWidth)
        {
            int xDiff = (destTrimmedRect.x + destTrimmedRect.width) - drawBufferWidth;
            destTrimmedRect.width -= xDiff;
            sourceTrimmedRect.width -= xDiff;
        }
    
        if (destTrimmedRect.y < 0)
        {
            int yDiff = 0 - destTrimmedRect.y;
            destTrimmedRect.y = 0;
            destTrimmedRect.height -= yDiff;
            sourceTrimmedRect.y += yDiff;
            sourceTrimmedRect.height -= yDiff;
        }
    
        if (destTrimmedRect.y + destTrimmedRect.height > drawBufferHeight)
        {
            int yDiff = (destTrimmedRect.y + destTrimmedRect.height) - drawBufferHeight;
            destTrimmedRect.height -= yDiff;
            sourceTrimmedRect.height -= yDiff;
        }
    
        bool partialBufferCopy = false;
        if (sourceTrimmedRect.height < readBufferHeight ||
            sourceTrimmedRect.width < readBufferWidth || 
            destTrimmedRect.height < drawBufferHeight ||
            destTrimmedRect.width < drawBufferWidth ||
            sourceTrimmedRect.y != 0 || destTrimmedRect.y != 0 || sourceTrimmedRect.x != 0 || destTrimmedRect.x != 0)
        {
            partialBufferCopy = true;
        }
    
        if (mask & GL_COLOR_BUFFER_BIT)
        {
            const GLenum readColorbufferType = readFramebuffer->getReadColorbufferType();
            const bool validReadType = (readColorbufferType == GL_TEXTURE_2D) || (readColorbufferType == GL_RENDERBUFFER);
            bool validDrawType = true;
            bool validDrawFormat = true;
    
            for (unsigned int colorAttachment = 0; colorAttachment < gl::IMPLEMENTATION_MAX_DRAW_BUFFERS; colorAttachment++)
            {
                if (drawFramebuffer->isEnabledColorAttachment(colorAttachment))
                {
                    if (drawFramebuffer->getColorbufferType(colorAttachment) != GL_TEXTURE_2D &&
                        drawFramebuffer->getColorbufferType(colorAttachment) != GL_RENDERBUFFER)
                    {
                        validDrawType = false;
                    }
    
                    if (drawFramebuffer->getColorbuffer(colorAttachment)->getActualFormat() != readColorBuffer->getActualFormat())
                    {
                        validDrawFormat = false;
                    }
                }
            }
    
            if (!validReadType || !validDrawType || !validDrawFormat)
            {
                ERR("Color buffer format conversion in BlitFramebufferANGLE not supported by this implementation");
                return gl::error(GL_INVALID_OPERATION);
            }
            
            if (partialBufferCopy && readFramebuffer->getSamples() != 0)
            {
                return gl::error(GL_INVALID_OPERATION);
            }
    
            blitRenderTarget = true;
    
        }
    
        if (mask & (GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT))
        {
            Renderbuffer *readDSBuffer = NULL;
            Renderbuffer *drawDSBuffer = NULL;
    
            // We support OES_packed_depth_stencil, and do not support a separately attached depth and stencil buffer, so if we have
            // both a depth and stencil buffer, it will be the same buffer.
    
            if (mask & GL_DEPTH_BUFFER_BIT)
            {
                if (readFramebuffer->getDepthbuffer() && drawFramebuffer->getDepthbuffer())
                {
                    if (readFramebuffer->getDepthbufferType() != drawFramebuffer->getDepthbufferType() ||
                        readFramebuffer->getDepthbuffer()->getActualFormat() != drawFramebuffer->getDepthbuffer()->getActualFormat())
                    {
                        return gl::error(GL_INVALID_OPERATION);
                    }
    
                    blitDepthStencil = true;
                    readDSBuffer = readFramebuffer->getDepthbuffer();
                    drawDSBuffer = drawFramebuffer->getDepthbuffer();
                }
            }
    
            if (mask & GL_STENCIL_BUFFER_BIT)
            {
                if (readFramebuffer->getStencilbuffer() && drawFramebuffer->getStencilbuffer())
                {
                    if (readFramebuffer->getStencilbufferType() != drawFramebuffer->getStencilbufferType() ||
                        readFramebuffer->getStencilbuffer()->getActualFormat() != drawFramebuffer->getStencilbuffer()->getActualFormat())
                    {
                        return gl::error(GL_INVALID_OPERATION);
                    }
    
                    blitDepthStencil = true;
                    readDSBuffer = readFramebuffer->getStencilbuffer();
                    drawDSBuffer = drawFramebuffer->getStencilbuffer();
                }
            }
    
            if (partialBufferCopy)
            {
                ERR("Only whole-buffer depth and stencil blits are supported by this implementation.");
                return gl::error(GL_INVALID_OPERATION); // only whole-buffer copies are permitted
            }
    
            if ((drawDSBuffer && drawDSBuffer->getSamples() != 0) || 
                (readDSBuffer && readDSBuffer->getSamples() != 0))
            {
                return gl::error(GL_INVALID_OPERATION);
            }
        }
    
        if (blitRenderTarget || blitDepthStencil)
        {
            mRenderer->blitRect(readFramebuffer, sourceTrimmedRect, drawFramebuffer, destTrimmedRect, blitRenderTarget, blitDepthStencil);
        }
    }
    
    }
    
    extern "C"
    {
    gl::Context *glCreateContext(int clientVersion, const gl::Context *shareContext, rx::Renderer *renderer, bool notifyResets, bool robustAccess)
    {
        return new gl::Context(clientVersion, shareContext, renderer, notifyResets, robustAccess);
    }
    
    void glDestroyContext(gl::Context *context)
    {
        delete context;
    
        if (context == gl::getContext())
        {
            gl::makeCurrent(NULL, NULL, NULL);
        }
    }
    
    void glMakeCurrent(gl::Context *context, egl::Display *display, egl::Surface *surface)
    {
        gl::makeCurrent(context, display, surface);
    }
    
    gl::Context *glGetCurrentContext()
    {
        return gl::getContext();
    }
    
    }