﻿// SwiftShader Software Renderer
//
// Copyright(c) 2005-2013 TransGaming Inc.
//
// All rights reserved. No part of this software may be copied, distributed, transmitted,
// transcribed, stored in a retrieval system, translated into any human or computer
// language by any means, or disclosed to third parties without the explicit written
// agreement of TransGaming Inc. Without such an agreement, no rights or licenses, express
// or implied, including but not limited to any patent rights, are granted to you.
//

// Context.cpp: Implements the es2::Context class, managing all GL state and performing
// rendering operations. It is the GLES2 specific implementation of EGLContext.

#include "Context.h"

#include "main.h"
#include "mathutil.h"
#include "utilities.h"
#include "ResourceManager.h"
#include "Buffer.h"
#include "Fence.h"
#include "Framebuffer.h"
#include "Program.h"
#include "Query.h"
#include "Renderbuffer.h"
#include "Sampler.h"
#include "Shader.h"
#include "Texture.h"
#include "TransformFeedback.h"
#include "VertexArray.h"
#include "VertexDataManager.h"
#include "IndexDataManager.h"
#include "libEGL/Display.h"
#include "libEGL/Surface.h"
#include "Common/Half.hpp"

#include <EGL/eglext.h>

namespace es2
{
Context::Context(const egl::Config *config, const Context *shareContext, EGLint clientVersion)
	: clientVersion(clientVersion), mConfig(config)
{
	sw::Context *context = new sw::Context();
	device = new es2::Device(context);

    mFenceNameSpace.setBaseHandle(0);

    setClearColor(0.0f, 0.0f, 0.0f, 0.0f);

    mState.depthClearValue = 1.0f;
    mState.stencilClearValue = 0;

    mState.cullFaceEnabled = false;
    mState.cullMode = GL_BACK;
    mState.frontFace = GL_CCW;
    mState.depthTestEnabled = false;
    mState.depthFunc = GL_LESS;
    mState.blendEnabled = false;
    mState.sourceBlendRGB = GL_ONE;
    mState.sourceBlendAlpha = GL_ONE;
    mState.destBlendRGB = GL_ZERO;
    mState.destBlendAlpha = GL_ZERO;
    mState.blendEquationRGB = GL_FUNC_ADD;
    mState.blendEquationAlpha = GL_FUNC_ADD;
    mState.blendColor.red = 0;
    mState.blendColor.green = 0;
    mState.blendColor.blue = 0;
    mState.blendColor.alpha = 0;
    mState.stencilTestEnabled = false;
    mState.stencilFunc = GL_ALWAYS;
    mState.stencilRef = 0;
    mState.stencilMask = -1;
    mState.stencilWritemask = -1;
    mState.stencilBackFunc = GL_ALWAYS;
    mState.stencilBackRef = 0;
    mState.stencilBackMask = - 1;
    mState.stencilBackWritemask = -1;
    mState.stencilFail = GL_KEEP;
    mState.stencilPassDepthFail = GL_KEEP;
    mState.stencilPassDepthPass = GL_KEEP;
    mState.stencilBackFail = GL_KEEP;
    mState.stencilBackPassDepthFail = GL_KEEP;
    mState.stencilBackPassDepthPass = GL_KEEP;
    mState.polygonOffsetFillEnabled = false;
    mState.polygonOffsetFactor = 0.0f;
    mState.polygonOffsetUnits = 0.0f;
    mState.sampleAlphaToCoverageEnabled = false;
    mState.sampleCoverageEnabled = false;
    mState.sampleCoverageValue = 1.0f;
    mState.sampleCoverageInvert = false;
    mState.scissorTestEnabled = false;
    mState.ditherEnabled = true;
    mState.primitiveRestartFixedIndexEnabled = false;
    mState.rasterizerDiscardEnabled = false;
    mState.generateMipmapHint = GL_DONT_CARE;
    mState.fragmentShaderDerivativeHint = GL_DONT_CARE;

    mState.lineWidth = 1.0f;

    mState.viewportX = 0;
    mState.viewportY = 0;
    mState.viewportWidth = 0;
    mState.viewportHeight = 0;
    mState.zNear = 0.0f;
    mState.zFar = 1.0f;

    mState.scissorX = 0;
    mState.scissorY = 0;
    mState.scissorWidth = 0;
    mState.scissorHeight = 0;

    mState.colorMaskRed = true;
    mState.colorMaskGreen = true;
    mState.colorMaskBlue = true;
    mState.colorMaskAlpha = true;
    mState.depthMask = true;

    if(shareContext != NULL)
    {
        mResourceManager = shareContext->mResourceManager;
        mResourceManager->addRef();
    }
    else
    {
        mResourceManager = new ResourceManager();
    }

    // [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 = new Texture2D(0);
	mTexture3DZero = new Texture3D(0);
	mTexture2DArrayZero = new Texture2DArray(0);
    mTextureCubeMapZero = new TextureCubeMap(0);
    mTextureExternalZero = new TextureExternal(0);

    mState.activeSampler = 0;
	bindVertexArray(0);
    bindArrayBuffer(0);
    bindElementArrayBuffer(0);
    bindTextureCubeMap(0);
    bindTexture2D(0);
    bindReadFramebuffer(0);
    bindDrawFramebuffer(0);
    bindRenderbuffer(0);
    bindGenericUniformBuffer(0);
    bindTransformFeedback(0);

	mState.readFramebufferColorIndex = 0;
	for(int i = 0; i < MAX_COLOR_ATTACHMENTS; ++i)
	{
		mState.drawFramebufferColorIndices[i] = GL_NONE;
	}

    mState.currentProgram = 0;

    mState.packAlignment = 4;
	mState.unpackInfo.alignment = 4;
	mState.packRowLength = 0;
	mState.packImageHeight = 0;
	mState.packSkipPixels = 0;
	mState.packSkipRows = 0;
	mState.packSkipImages = 0;
	mState.unpackInfo.rowLength = 0;
	mState.unpackInfo.imageHeight = 0;
	mState.unpackInfo.skipPixels = 0;
	mState.unpackInfo.skipRows = 0;
	mState.unpackInfo.skipImages = 0;

    mVertexDataManager = NULL;
    mIndexDataManager = NULL;

    mInvalidEnum = false;
    mInvalidValue = false;
    mInvalidOperation = false;
    mOutOfMemory = false;
    mInvalidFramebufferOperation = false;

    mHasBeenCurrent = false;

    markAllStateDirty();
}

Context::~Context()
{
	if(mState.currentProgram != 0)
	{
		Program *programObject = mResourceManager->getProgram(mState.currentProgram);
		if(programObject)
		{
			programObject->release();
		}
		mState.currentProgram = 0;
	}

	while(!mFramebufferMap.empty())
	{
		deleteFramebuffer(mFramebufferMap.begin()->first);
	}

	while(!mFenceMap.empty())
	{
		deleteFence(mFenceMap.begin()->first);
	}

	while(!mQueryMap.empty())
	{
		deleteQuery(mQueryMap.begin()->first);
	}

	while(!mVertexArrayMap.empty())
	{
		deleteVertexArray(mVertexArrayMap.begin()->first);
	}

	while(!mTransformFeedbackMap.empty())
	{
		deleteTransformFeedback(mTransformFeedbackMap.begin()->first);
	}

	for(int type = 0; type < TEXTURE_TYPE_COUNT; type++)
	{
		for(int sampler = 0; sampler < MAX_COMBINED_TEXTURE_IMAGE_UNITS; sampler++)
		{
			mState.samplerTexture[type][sampler] = NULL;
		}
	}

	for(int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
	{
		mState.vertexAttribute[i].mBoundBuffer = NULL;
	}

	for(int i = 0; i < QUERY_TYPE_COUNT; i++)
	{
		mState.activeQuery[i] = NULL;
	}

	mState.arrayBuffer = NULL;
	mState.copyReadBuffer = NULL;
	mState.copyWriteBuffer = NULL;
	mState.pixelPackBuffer = NULL;
	mState.pixelUnpackBuffer = NULL;
	mState.genericUniformBuffer = NULL;
	mState.renderbuffer = NULL;

	for(int i = 0; i < MAX_COMBINED_TEXTURE_IMAGE_UNITS; ++i)
	{
		mState.sampler[i] = NULL;
	}

    mTexture2DZero = NULL;
	mTexture3DZero = NULL;
	mTexture2DArrayZero = NULL;
    mTextureCubeMapZero = NULL;
    mTextureExternalZero = NULL;

    delete mVertexDataManager;
    delete mIndexDataManager;

    mResourceManager->release();
	delete device;
}

void Context::makeCurrent(egl::Surface *surface)
{
    if(!mHasBeenCurrent)
    {
        mVertexDataManager = new VertexDataManager(this);
        mIndexDataManager = new IndexDataManager();

        mState.viewportX = 0;
        mState.viewportY = 0;
        mState.viewportWidth = surface->getWidth();
        mState.viewportHeight = surface->getHeight();

        mState.scissorX = 0;
        mState.scissorY = 0;
        mState.scissorWidth = surface->getWidth();
        mState.scissorHeight = surface->getHeight();

        mHasBeenCurrent = true;
    }

    // Wrap the existing resources into GL objects and assign them to the '0' names
    egl::Image *defaultRenderTarget = surface->getRenderTarget();
    egl::Image *depthStencil = surface->getDepthStencil();

    Colorbuffer *colorbufferZero = new Colorbuffer(defaultRenderTarget);
    DepthStencilbuffer *depthStencilbufferZero = new DepthStencilbuffer(depthStencil);
    Framebuffer *framebufferZero = new DefaultFramebuffer(colorbufferZero, depthStencilbufferZero);

    setFramebufferZero(framebufferZero);

    if(defaultRenderTarget)
    {
        defaultRenderTarget->release();
    }

    if(depthStencil)
    {
        depthStencil->release();
    }
    
    markAllStateDirty();
}

EGLint Context::getClientVersion() const
{
	return clientVersion;
}

// This function will set all of the state-related dirty flags, so that all state is set during next pre-draw.
void Context::markAllStateDirty()
{
    mAppliedProgramSerial = 0;

    mDepthStateDirty = true;
    mMaskStateDirty = true;
    mBlendStateDirty = true;
    mStencilStateDirty = true;
    mPolygonOffsetStateDirty = true;
    mSampleStateDirty = true;
    mDitherStateDirty = true;
    mFrontFaceDirty = true;
}

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::setCullFaceEnabled(bool enabled)
{
    mState.cullFaceEnabled = enabled;
}

bool Context::isCullFaceEnabled() const
{
    return mState.cullFaceEnabled;
}

void Context::setCullMode(GLenum mode)
{
   mState.cullMode = mode;
}

void Context::setFrontFace(GLenum front)
{
    if(mState.frontFace != front)
    {
        mState.frontFace = front;
        mFrontFaceDirty = true;
    }
}

void Context::setDepthTestEnabled(bool enabled)
{
    if(mState.depthTestEnabled != enabled)
    {
        mState.depthTestEnabled = enabled;
        mDepthStateDirty = true;
    }
}

bool Context::isDepthTestEnabled() const
{
    return mState.depthTestEnabled;
}

void Context::setDepthFunc(GLenum depthFunc)
{
    if(mState.depthFunc != depthFunc)
    {
        mState.depthFunc = depthFunc;
        mDepthStateDirty = true;
    }
}

void Context::setDepthRange(float zNear, float zFar)
{
    mState.zNear = zNear;
    mState.zFar = zFar;
}

void Context::setBlendEnabled(bool enabled)
{
    if(mState.blendEnabled != enabled)
    {
        mState.blendEnabled = enabled;
        mBlendStateDirty = true;
    }
}

bool Context::isBlendEnabled() const
{
    return mState.blendEnabled;
}

void Context::setBlendFactors(GLenum sourceRGB, GLenum destRGB, GLenum sourceAlpha, GLenum destAlpha)
{
    if(mState.sourceBlendRGB != sourceRGB ||
       mState.sourceBlendAlpha != sourceAlpha ||
       mState.destBlendRGB != destRGB ||
       mState.destBlendAlpha != destAlpha)
    {
        mState.sourceBlendRGB = sourceRGB;
        mState.destBlendRGB = destRGB;
        mState.sourceBlendAlpha = sourceAlpha;
        mState.destBlendAlpha = destAlpha;
        mBlendStateDirty = true;
    }
}

void Context::setBlendColor(float red, float green, float blue, float alpha)
{
    if(mState.blendColor.red != red ||
       mState.blendColor.green != green ||
       mState.blendColor.blue != blue ||
       mState.blendColor.alpha != alpha)
    {
        mState.blendColor.red = red;
        mState.blendColor.green = green;
        mState.blendColor.blue = blue;
        mState.blendColor.alpha = alpha;
        mBlendStateDirty = true;
    }
}

void Context::setBlendEquation(GLenum rgbEquation, GLenum alphaEquation)
{
    if(mState.blendEquationRGB != rgbEquation ||
       mState.blendEquationAlpha != alphaEquation)
    {
        mState.blendEquationRGB = rgbEquation;
        mState.blendEquationAlpha = alphaEquation;
        mBlendStateDirty = true;
    }
}

void Context::setStencilTestEnabled(bool enabled)
{
    if(mState.stencilTestEnabled != enabled)
    {
        mState.stencilTestEnabled = enabled;
        mStencilStateDirty = true;
    }
}

bool Context::isStencilTestEnabled() const
{
    return mState.stencilTestEnabled;
}

void Context::setStencilParams(GLenum stencilFunc, GLint stencilRef, GLuint stencilMask)
{
    if(mState.stencilFunc != stencilFunc ||
       mState.stencilRef != stencilRef ||
       mState.stencilMask != stencilMask)
    {
        mState.stencilFunc = stencilFunc;
        mState.stencilRef = (stencilRef > 0) ? stencilRef : 0;
        mState.stencilMask = stencilMask;
        mStencilStateDirty = true;
    }
}

void Context::setStencilBackParams(GLenum stencilBackFunc, GLint stencilBackRef, GLuint stencilBackMask)
{
    if(mState.stencilBackFunc != stencilBackFunc ||
       mState.stencilBackRef != stencilBackRef ||
       mState.stencilBackMask != stencilBackMask)
    {
        mState.stencilBackFunc = stencilBackFunc;
        mState.stencilBackRef = (stencilBackRef > 0) ? stencilBackRef : 0;
        mState.stencilBackMask = stencilBackMask;
        mStencilStateDirty = true;
    }
}

void Context::setStencilWritemask(GLuint stencilWritemask)
{
    if(mState.stencilWritemask != stencilWritemask)
    {
        mState.stencilWritemask = stencilWritemask;
        mStencilStateDirty = true;
    }
}

void Context::setStencilBackWritemask(GLuint stencilBackWritemask)
{
    if(mState.stencilBackWritemask != stencilBackWritemask)
    {
        mState.stencilBackWritemask = stencilBackWritemask;
        mStencilStateDirty = true;
    }
}

void Context::setStencilOperations(GLenum stencilFail, GLenum stencilPassDepthFail, GLenum stencilPassDepthPass)
{
    if(mState.stencilFail != stencilFail ||
       mState.stencilPassDepthFail != stencilPassDepthFail ||
       mState.stencilPassDepthPass != stencilPassDepthPass)
    {
        mState.stencilFail = stencilFail;
        mState.stencilPassDepthFail = stencilPassDepthFail;
        mState.stencilPassDepthPass = stencilPassDepthPass;
        mStencilStateDirty = true;
    }
}

void Context::setStencilBackOperations(GLenum stencilBackFail, GLenum stencilBackPassDepthFail, GLenum stencilBackPassDepthPass)
{
    if(mState.stencilBackFail != stencilBackFail ||
       mState.stencilBackPassDepthFail != stencilBackPassDepthFail ||
       mState.stencilBackPassDepthPass != stencilBackPassDepthPass)
    {
        mState.stencilBackFail = stencilBackFail;
        mState.stencilBackPassDepthFail = stencilBackPassDepthFail;
        mState.stencilBackPassDepthPass = stencilBackPassDepthPass;
        mStencilStateDirty = true;
    }
}

void Context::setPolygonOffsetFillEnabled(bool enabled)
{
    if(mState.polygonOffsetFillEnabled != enabled)
    {
        mState.polygonOffsetFillEnabled = enabled;
        mPolygonOffsetStateDirty = true;
    }
}

bool Context::isPolygonOffsetFillEnabled() const
{
    return mState.polygonOffsetFillEnabled;
}

void Context::setPolygonOffsetParams(GLfloat factor, GLfloat units)
{
    if(mState.polygonOffsetFactor != factor ||
       mState.polygonOffsetUnits != units)
    {
        mState.polygonOffsetFactor = factor;
        mState.polygonOffsetUnits = units;
        mPolygonOffsetStateDirty = true;
    }
}

void Context::setSampleAlphaToCoverageEnabled(bool enabled)
{
    if(mState.sampleAlphaToCoverageEnabled != enabled)
    {
        mState.sampleAlphaToCoverageEnabled = enabled;
        mSampleStateDirty = true;
    }
}

bool Context::isSampleAlphaToCoverageEnabled() const
{
    return mState.sampleAlphaToCoverageEnabled;
}

void Context::setSampleCoverageEnabled(bool enabled)
{
    if(mState.sampleCoverageEnabled != enabled)
    {
        mState.sampleCoverageEnabled = enabled;
        mSampleStateDirty = true;
    }
}

bool Context::isSampleCoverageEnabled() const
{
    return mState.sampleCoverageEnabled;
}

void Context::setSampleCoverageParams(GLclampf value, bool invert)
{
    if(mState.sampleCoverageValue != value ||
       mState.sampleCoverageInvert != invert)
    {
        mState.sampleCoverageValue = value;
        mState.sampleCoverageInvert = invert;
        mSampleStateDirty = true;
    }
}

void Context::setScissorTestEnabled(bool enabled)
{
    mState.scissorTestEnabled = enabled;
}

bool Context::isScissorTestEnabled() const
{
    return mState.scissorTestEnabled;
}

void Context::setDitherEnabled(bool enabled)
{
    if(mState.ditherEnabled != enabled)
    {
        mState.ditherEnabled = enabled;
        mDitherStateDirty = true;
    }
}

bool Context::isDitherEnabled() const
{
    return mState.ditherEnabled;
}

void Context::setPrimitiveRestartFixedIndexEnabled(bool enabled)
{
    UNIMPLEMENTED();
    mState.primitiveRestartFixedIndexEnabled = enabled;
}

bool Context::isPrimitiveRestartFixedIndexEnabled() const
{
    return mState.primitiveRestartFixedIndexEnabled;
}

void Context::setRasterizerDiscardEnabled(bool enabled)
{
    UNIMPLEMENTED();
    mState.rasterizerDiscardEnabled = enabled;
}

bool Context::isRasterizerDiscardEnabled() const
{
    return mState.rasterizerDiscardEnabled;
}

void Context::setLineWidth(GLfloat width)
{
    mState.lineWidth = width;
	device->setLineWidth(clamp(width, ALIASED_LINE_WIDTH_RANGE_MIN, ALIASED_LINE_WIDTH_RANGE_MAX));
}

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.viewportX = x;
    mState.viewportY = y;
    mState.viewportWidth = width;
    mState.viewportHeight = height;
}

void Context::setScissorParams(GLint x, GLint y, GLsizei width, GLsizei height)
{
    mState.scissorX = x;
    mState.scissorY = y;
    mState.scissorWidth = width;
    mState.scissorHeight = height;
}

void Context::setColorMask(bool red, bool green, bool blue, bool alpha)
{
    if(mState.colorMaskRed != red || mState.colorMaskGreen != green ||
       mState.colorMaskBlue != blue || mState.colorMaskAlpha != alpha)
    {
        mState.colorMaskRed = red;
        mState.colorMaskGreen = green;
        mState.colorMaskBlue = blue;
        mState.colorMaskAlpha = alpha;
        mMaskStateDirty = true;
    }
}

unsigned int Context::getColorMask() const
{
	return (mState.colorMaskRed ? 0x1 : 0) |
	       (mState.colorMaskGreen ? 0x2 : 0) |
	       (mState.colorMaskBlue ? 0x4 : 0) |
	       (mState.colorMaskAlpha ? 0x8 : 0);
}

void Context::setDepthMask(bool mask)
{
    if(mState.depthMask != mask)
    {
        mState.depthMask = mask;
        mMaskStateDirty = true;
    }
}

void Context::setActiveSampler(unsigned int active)
{
    mState.activeSampler = active;
}

GLuint Context::getReadFramebufferName() const
{
    return mState.readFramebuffer;
}

GLuint Context::getDrawFramebufferName() const
{
    return mState.drawFramebuffer;
}

GLuint Context::getRenderbufferName() const
{
    return mState.renderbuffer.name();
}

void Context::setReadFramebufferColorIndex(GLuint index)
{
	mState.readFramebufferColorIndex = index;
}

void Context::setDrawFramebufferColorIndices(GLsizei n, const GLenum *bufs)
{
	for(int i = 0; i < n; ++i)
	{
		mState.drawFramebufferColorIndices[i] = ((bufs[i] == GL_BACK) || (bufs[i] == GL_NONE)) ? bufs[i] : i;
	}
}

GLuint Context::getReadFramebufferColorIndex() const
{
	return mState.readFramebufferColorIndex;
}

GLuint Context::getArrayBufferName() const
{
    return mState.arrayBuffer.name();
}

GLuint Context::getElementArrayBufferName() const
{
	Buffer* elementArrayBuffer = getCurrentVertexArray()->getElementArrayBuffer();
	return elementArrayBuffer ? elementArrayBuffer->name : 0;
}

GLuint Context::getActiveQuery(GLenum target) const
{
    Query *queryObject = NULL;
    
    switch(target)
    {
    case GL_ANY_SAMPLES_PASSED_EXT:
        queryObject = mState.activeQuery[QUERY_ANY_SAMPLES_PASSED];
        break;
    case GL_ANY_SAMPLES_PASSED_CONSERVATIVE_EXT:
        queryObject = mState.activeQuery[QUERY_ANY_SAMPLES_PASSED_CONSERVATIVE];
        break;
    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
        queryObject = mState.activeQuery[QUERY_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN];
        break;
    default:
        ASSERT(false);
    }

    if(queryObject)
    {
        return queryObject->name;
    }
    
	return 0;
}

void Context::setVertexAttribArrayEnabled(unsigned int attribNum, bool enabled)
{
	getCurrentVertexArray()->enableAttribute(attribNum, enabled);
}

void Context::setVertexAttribDivisor(unsigned int attribNum, GLuint divisor)
{
	getCurrentVertexArray()->setVertexAttribDivisor(attribNum, divisor);
}

const VertexAttribute &Context::getVertexAttribState(unsigned int attribNum) const
{
	return getCurrentVertexArray()->getVertexAttribute(attribNum);
}

void Context::setVertexAttribState(unsigned int attribNum, Buffer *boundBuffer, GLint size, GLenum type, bool normalized,
                                   GLsizei stride, const void *pointer)
{
	getCurrentVertexArray()->setAttributeState(attribNum, boundBuffer, size, type, normalized, stride, pointer);
}

const void *Context::getVertexAttribPointer(unsigned int attribNum) const
{
	return getCurrentVertexArray()->getVertexAttribute(attribNum).mPointer;
}

const VertexAttributeArray &Context::getVertexArrayAttributes()
{
	return getCurrentVertexArray()->getVertexAttributes();
}

const VertexAttributeArray &Context::getCurrentVertexAttributes()
{
	return mState.vertexAttribute;
}

void Context::setPackAlignment(GLint alignment)
{
    mState.packAlignment = alignment;
}

void Context::setUnpackAlignment(GLint alignment)
{
	mState.unpackInfo.alignment = alignment;
}

const egl::Image::UnpackInfo& Context::getUnpackInfo() const
{
	return mState.unpackInfo;
}

void Context::setPackRowLength(GLint rowLength)
{
	mState.packRowLength = rowLength;
}

void Context::setPackImageHeight(GLint imageHeight)
{
	mState.packImageHeight = imageHeight;
}

void Context::setPackSkipPixels(GLint skipPixels)
{
	mState.packSkipPixels = skipPixels;
}

void Context::setPackSkipRows(GLint skipRows)
{
	mState.packSkipRows = skipRows;
}

void Context::setPackSkipImages(GLint skipImages)
{
	mState.packSkipImages = skipImages;
}

void Context::setUnpackRowLength(GLint rowLength)
{
	mState.unpackInfo.rowLength = rowLength;
}

void Context::setUnpackImageHeight(GLint imageHeight)
{
	mState.unpackInfo.imageHeight = imageHeight;
}

void Context::setUnpackSkipPixels(GLint skipPixels)
{
	mState.unpackInfo.skipPixels = skipPixels;
}

void Context::setUnpackSkipRows(GLint skipRows)
{
	mState.unpackInfo.skipRows = skipRows;
}

void Context::setUnpackSkipImages(GLint skipImages)
{
	mState.unpackInfo.skipImages = skipImages;
}

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 = mFramebufferNameSpace.allocate();

    mFramebufferMap[handle] = NULL;

    return handle;
}

GLuint Context::createFence()
{
    GLuint handle = mFenceNameSpace.allocate();

    mFenceMap[handle] = new Fence;

    return handle;
}

// Returns an unused query name
GLuint Context::createQuery()
{
    GLuint handle = mQueryNameSpace.allocate();

    mQueryMap[handle] = NULL;

    return handle;
}

// Returns an unused vertex array name
GLuint Context::createVertexArray()
{
	GLuint handle = mVertexArrayNameSpace.allocate();

	mVertexArrayMap[handle] = NULL;

	return handle;
}

GLsync Context::createFenceSync(GLenum condition, GLbitfield flags)
{
	GLuint handle = mResourceManager->createFenceSync(condition, flags);

	return reinterpret_cast<GLsync>(static_cast<uintptr_t>(handle));
}

// Returns an unused transform feedback name
GLuint Context::createTransformFeedback()
{
	GLuint handle = mTransformFeedbackNameSpace.allocate();

	mTransformFeedbackMap[handle] = NULL;

	return handle;
}

// Returns an unused sampler name
GLuint Context::createSampler()
{
	return mResourceManager->createSampler();
}

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);

        mFramebufferNameSpace.release(framebufferObject->first);
        delete framebufferObject->second;
        mFramebufferMap.erase(framebufferObject);
    }
}

void Context::deleteFence(GLuint fence)
{
    FenceMap::iterator fenceObject = mFenceMap.find(fence);

    if(fenceObject != mFenceMap.end())
    {
        mFenceNameSpace.release(fenceObject->first);
        delete fenceObject->second;
        mFenceMap.erase(fenceObject);
    }
}

void Context::deleteQuery(GLuint query)
{
    QueryMap::iterator queryObject = mQueryMap.find(query);
    
	if(queryObject != mQueryMap.end())
    {
        mQueryNameSpace.release(queryObject->first);
        
		if(queryObject->second)
        {
            queryObject->second->release();
        }
        
		mQueryMap.erase(queryObject);
    }
}

void Context::deleteVertexArray(GLuint vertexArray)
{
	VertexArrayMap::iterator vertexArrayObject = mVertexArrayMap.find(vertexArray);

	if(vertexArrayObject != mVertexArrayMap.end())
	{
		// Vertex array detachment is handled by Context, because 0 is a valid
		// VAO, and a pointer to it must be passed from Context to State at
		// binding time.

		// [OpenGL ES 3.0.2] section 2.10 page 43:
		// If a vertex array object that is currently bound is deleted, the binding
		// for that object reverts to zero and the default vertex array becomes current.
		if(getCurrentVertexArray()->name == vertexArray)
		{
			bindVertexArray(0);
		}

		mVertexArrayNameSpace.release(vertexArrayObject->first);
		delete vertexArrayObject->second;
		mVertexArrayMap.erase(vertexArrayObject);
	}
}

void Context::deleteFenceSync(GLsync fenceSync)
{
	// The spec specifies the underlying Fence object is not deleted until all current
	// wait commands finish. However, since the name becomes invalid, we cannot query the fence,
	// and since our API is currently designed for being called from a single thread, we can delete
	// the fence immediately.
	mResourceManager->deleteFenceSync(static_cast<GLuint>(reinterpret_cast<uintptr_t>(fenceSync)));
}

void Context::deleteTransformFeedback(GLuint transformFeedback)
{
	TransformFeedbackMap::iterator transformFeedbackObject = mTransformFeedbackMap.find(transformFeedback);

	if(transformFeedbackObject != mTransformFeedbackMap.end())
	{
		mTransformFeedbackNameSpace.release(transformFeedbackObject->first);
		delete transformFeedbackObject->second;
		mTransformFeedbackMap.erase(transformFeedbackObject);
	}
}

void Context::deleteSampler(GLuint sampler)
{
	if(mResourceManager->getSampler(sampler))
	{
		detachSampler(sampler);
	}

	mResourceManager->deleteSampler(sampler);
}

Buffer *Context::getBuffer(GLuint handle) const
{
    return mResourceManager->getBuffer(handle);
}

Shader *Context::getShader(GLuint handle) const
{
    return mResourceManager->getShader(handle);
}

Program *Context::getProgram(GLuint handle) const
{
    return mResourceManager->getProgram(handle);
}

Texture *Context::getTexture(GLuint handle) const
{
    return mResourceManager->getTexture(handle);
}

Renderbuffer *Context::getRenderbuffer(GLuint handle) const
{
    return mResourceManager->getRenderbuffer(handle);
}

Framebuffer *Context::getReadFramebuffer() const
{
    return getFramebuffer(mState.readFramebuffer);
}

Framebuffer *Context::getDrawFramebuffer() const
{
    return getFramebuffer(mState.drawFramebuffer);
}

void Context::bindArrayBuffer(unsigned int buffer)
{
    mResourceManager->checkBufferAllocation(buffer);

    mState.arrayBuffer = getBuffer(buffer);
}

void Context::bindElementArrayBuffer(unsigned int buffer)
{
    mResourceManager->checkBufferAllocation(buffer);

	getCurrentVertexArray()->setElementArrayBuffer(getBuffer(buffer));
}

void Context::bindCopyReadBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	mState.copyReadBuffer = getBuffer(buffer);
}

void Context::bindCopyWriteBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	mState.copyWriteBuffer = getBuffer(buffer);
}

void Context::bindPixelPackBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	mState.pixelPackBuffer = getBuffer(buffer);
}

void Context::bindPixelUnpackBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	mState.pixelUnpackBuffer = getBuffer(buffer);
}

void Context::bindTransformFeedbackBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	TransformFeedback* transformFeedback = getTransformFeedback(mState.transformFeedback);
	
	if(transformFeedback)
	{
		transformFeedback->setGenericBuffer(getBuffer(buffer));
	}
}

void Context::bindTexture2D(GLuint texture)
{
    mResourceManager->checkTextureAllocation(texture, TEXTURE_2D);

    mState.samplerTexture[TEXTURE_2D][mState.activeSampler] = getTexture(texture);
}

void Context::bindTextureCubeMap(GLuint texture)
{
    mResourceManager->checkTextureAllocation(texture, TEXTURE_CUBE);

    mState.samplerTexture[TEXTURE_CUBE][mState.activeSampler] = getTexture(texture);
}

void Context::bindTextureExternal(GLuint texture)
{
    mResourceManager->checkTextureAllocation(texture, TEXTURE_EXTERNAL);

    mState.samplerTexture[TEXTURE_EXTERNAL][mState.activeSampler] = getTexture(texture);
}

void Context::bindTexture3D(GLuint texture)
{
	mResourceManager->checkTextureAllocation(texture, TEXTURE_3D);

	mState.samplerTexture[TEXTURE_3D][mState.activeSampler] = getTexture(texture);
}

void Context::bindTexture2DArray(GLuint texture)
{
	mResourceManager->checkTextureAllocation(texture, TEXTURE_2D_ARRAY);

	mState.samplerTexture[TEXTURE_2D_ARRAY][mState.activeSampler] = getTexture(texture);
}

void Context::bindReadFramebuffer(GLuint framebuffer)
{
    if(!getFramebuffer(framebuffer))
    {
        mFramebufferMap[framebuffer] = new Framebuffer();
    }

    mState.readFramebuffer = framebuffer;
}

void Context::bindDrawFramebuffer(GLuint framebuffer)
{
    if(!getFramebuffer(framebuffer))
    {
        mFramebufferMap[framebuffer] = new Framebuffer();
    }

    mState.drawFramebuffer = framebuffer;
}

void Context::bindRenderbuffer(GLuint renderbuffer)
{
	mResourceManager->checkRenderbufferAllocation(renderbuffer);

    mState.renderbuffer = getRenderbuffer(renderbuffer);
}

bool Context::bindVertexArray(GLuint array)
{
	VertexArray* vertexArray = getVertexArray(array);

	if(!vertexArray)
	{
		vertexArray = new VertexArray(array);
		mVertexArrayMap[array] = vertexArray;
	}

	mState.vertexArray = array;

	return !!vertexArray;
}

void Context::bindGenericUniformBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	mState.genericUniformBuffer = getBuffer(buffer);
}

void Context::bindIndexedUniformBuffer(GLuint buffer, GLuint index, GLintptr offset, GLsizeiptr size)
{
	mResourceManager->checkBufferAllocation(buffer);

	Buffer* bufferObject = getBuffer(buffer);
	if(bufferObject)
	{
		bufferObject->setOffset(offset);
		bufferObject->setSize(size);
	}
	mState.uniformBuffers[index] = bufferObject;
}

void Context::bindGenericTransformFeedbackBuffer(GLuint buffer)
{
	mResourceManager->checkBufferAllocation(buffer);

	getTransformFeedback()->setGenericBuffer(getBuffer(buffer));
}

void Context::bindIndexedTransformFeedbackBuffer(GLuint buffer, GLuint index, GLintptr offset, GLsizeiptr size)
{
	mResourceManager->checkBufferAllocation(buffer);

	Buffer* bufferObject = getBuffer(buffer);
	if(bufferObject)
	{
		bufferObject->setOffset(offset);
		bufferObject->setSize(size);
	}
	getTransformFeedback()->setBuffer(index, bufferObject);
}

bool Context::bindTransformFeedback(GLuint id)
{
	if(!getTransformFeedback(id))
	{
		mTransformFeedbackMap[id] = new TransformFeedback(id);
	}

	mState.transformFeedback = id;

	return true;
}

bool Context::bindSampler(GLuint unit, GLuint sampler)
{
	mResourceManager->checkSamplerAllocation(sampler);

	Sampler* samplerObject = getSampler(sampler);

	if(sampler)
	{
		mState.sampler[unit] = samplerObject;
	}

	return !!samplerObject;
}

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);

        if(newProgram)
        {
            newProgram->addRef();
        }
        
        if(oldProgram)
        {
            oldProgram->release();
        }
    }
}

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] != NULL)
        {
            return 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;
    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN:
        qType = QUERY_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN;
        break;
    default: 
        ASSERT(false);
    }

    Query *queryObject = createQuery(query, target);

    // Check that name was obtained with glGenQueries
    if(!queryObject)
    {
        return error(GL_INVALID_OPERATION);
    }

    // Check for type mismatch
    if(queryObject->getType() != target)
    {
        return error(GL_INVALID_OPERATION);
    }

    // Set query as active for specified target
    mState.activeQuery[qType] = 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;
    case GL_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN: qType = QUERY_TRANSFORM_FEEDBACK_PRIMITIVES_WRITTEN; break;
    default: UNREACHABLE(target); return;
    }

    Query *queryObject = mState.activeQuery[qType];

    if(queryObject == NULL)
    {
        return error(GL_INVALID_OPERATION);
    }

    queryObject->end();

    mState.activeQuery[qType] = NULL;
}

void Context::setFramebufferZero(Framebuffer *buffer)
{
    delete mFramebufferMap[0];
    mFramebufferMap[0] = buffer;
}

void Context::setRenderbufferStorage(RenderbufferStorage *renderbuffer)
{
    Renderbuffer *renderbufferObject = mState.renderbuffer;
    renderbufferObject->setStorage(renderbuffer);
}

Framebuffer *Context::getFramebuffer(unsigned int handle) const
{
    FramebufferMap::const_iterator framebuffer = mFramebufferMap.find(handle);

    if(framebuffer == mFramebufferMap.end())
    {
        return NULL;
    }
    else
    {
        return framebuffer->second;
    }
}

Fence *Context::getFence(unsigned int handle) const
{
    FenceMap::const_iterator fence = mFenceMap.find(handle);

    if(fence == mFenceMap.end())
    {
        return NULL;
    }
    else
    {
        return fence->second;
    }
}

FenceSync *Context::getFenceSync(GLsync handle) const
{
	return mResourceManager->getFenceSync(static_cast<GLuint>(reinterpret_cast<uintptr_t>(handle)));
}

Query *Context::getQuery(unsigned int handle) const
{
	QueryMap::const_iterator query = mQueryMap.find(handle);

	if(query == mQueryMap.end())
	{
		return NULL;
	}
	else
	{
		return query->second;
	}
}

Query *Context::createQuery(unsigned int handle, GLenum type)
{
	QueryMap::iterator query = mQueryMap.find(handle);

	if(query == mQueryMap.end())
	{
		return NULL;
	}
	else
	{
		if(!query->second)
		{
			query->second = new Query(handle, type);
			query->second->addRef();
		}

		return query->second;
	}
}

VertexArray *Context::getVertexArray(GLuint array) const
{
	VertexArrayMap::const_iterator vertexArray = mVertexArrayMap.find(array);

	return (vertexArray == mVertexArrayMap.end()) ? NULL : vertexArray->second;
}

VertexArray *Context::getCurrentVertexArray() const
{
	return getVertexArray(mState.vertexArray);
}

bool Context::hasZeroDivisor() const
{
	// Verify there is at least one active attribute with a divisor of zero
	es2::Program *programObject = getCurrentProgram();
	for(int attributeIndex = 0; attributeIndex < MAX_VERTEX_ATTRIBS; attributeIndex++)
	{
		bool active = (programObject->getAttributeStream(attributeIndex) != -1);
		if(active && getCurrentVertexArray()->getVertexAttribute(attributeIndex).mDivisor == 0)
		{
			return true;
		}
	}

	return false;
}

TransformFeedback *Context::getTransformFeedback(GLuint transformFeedback) const
{
	TransformFeedbackMap::const_iterator transformFeedbackObject = mTransformFeedbackMap.find(transformFeedback);

	return (transformFeedbackObject == mTransformFeedbackMap.end()) ? NULL : transformFeedbackObject->second;
}

Sampler *Context::getSampler(GLuint sampler) const
{
	return mResourceManager->getSampler(sampler);
}

bool Context::isSampler(GLuint sampler) const
{
	return mResourceManager->isSampler(sampler);
}

Buffer *Context::getArrayBuffer() const
{
    return mState.arrayBuffer;
}

Buffer *Context::getElementArrayBuffer() const
{
	return getCurrentVertexArray()->getElementArrayBuffer();
}

Buffer *Context::getCopyReadBuffer() const
{
	return mState.copyReadBuffer;
}

Buffer *Context::getCopyWriteBuffer() const
{
	return mState.copyWriteBuffer;
}

Buffer *Context::getPixelPackBuffer() const
{
	return mState.pixelPackBuffer;
}

Buffer *Context::getPixelUnpackBuffer() const
{
	return mState.pixelUnpackBuffer;
}

Buffer *Context::getGenericUniformBuffer() const
{
	return mState.genericUniformBuffer;
}

bool Context::getBuffer(GLenum target, es2::Buffer **buffer) const
{
	switch(target)
	{
	case GL_ARRAY_BUFFER:
		*buffer = getArrayBuffer();
		break;
	case GL_ELEMENT_ARRAY_BUFFER:
		*buffer = getElementArrayBuffer();
		break;
	case GL_COPY_READ_BUFFER:
		if(clientVersion >= 3)
		{
			*buffer = getCopyReadBuffer();
			break;
		}
		else return false;
	case GL_COPY_WRITE_BUFFER:
		if(clientVersion >= 3)
		{
			*buffer = getCopyWriteBuffer();
			break;
		}
		else return false;
	case GL_PIXEL_PACK_BUFFER:
		if(clientVersion >= 3)
		{
			*buffer = getPixelPackBuffer();
			break;
		}
		else return false;
	case GL_PIXEL_UNPACK_BUFFER:
		if(clientVersion >= 3)
		{
			*buffer = getPixelUnpackBuffer();
			break;
		}
		else return false;
	case GL_TRANSFORM_FEEDBACK_BUFFER:
		if(clientVersion >= 3)
		{
			TransformFeedback* transformFeedback = getTransformFeedback();
			*buffer = transformFeedback ? static_cast<es2::Buffer*>(transformFeedback->getGenericBuffer()) : nullptr;
			break;
		}
		else return false;
	case GL_UNIFORM_BUFFER:
		if(clientVersion >= 3)
		{
			*buffer = getGenericUniformBuffer();
			break;
		}
		else return false;
	default:
		return false;
	}
	return true;
}

TransformFeedback *Context::getTransformFeedback() const
{
	return getTransformFeedback(mState.transformFeedback);
}

Program *Context::getCurrentProgram() const
{
    return mResourceManager->getProgram(mState.currentProgram);
}

Texture2D *Context::getTexture2D() const
{
	return static_cast<Texture2D*>(getSamplerTexture(mState.activeSampler, TEXTURE_2D));
}

Texture3D *Context::getTexture3D() const
{
	return static_cast<Texture3D*>(getSamplerTexture(mState.activeSampler, TEXTURE_3D));
}

Texture2DArray *Context::getTexture2DArray() const
{
	return static_cast<Texture2DArray*>(getSamplerTexture(mState.activeSampler, TEXTURE_2D_ARRAY));
}

TextureCubeMap *Context::getTextureCubeMap() const
{
    return static_cast<TextureCubeMap*>(getSamplerTexture(mState.activeSampler, TEXTURE_CUBE));
}

TextureExternal *Context::getTextureExternal() const
{
    return static_cast<TextureExternal*>(getSamplerTexture(mState.activeSampler, TEXTURE_EXTERNAL));
}

Texture *Context::getSamplerTexture(unsigned int sampler, TextureType type) const
{
    GLuint texid = mState.samplerTexture[type][sampler].name();

    if(texid == 0)   // Special case: 0 refers to different initial textures based on the target
    {
        switch (type)
        {
        case TEXTURE_2D: return mTexture2DZero;
		case TEXTURE_3D: return mTexture3DZero;
		case TEXTURE_2D_ARRAY: return mTexture2DArrayZero;
        case TEXTURE_CUBE: return mTextureCubeMapZero;
        case TEXTURE_EXTERNAL: return mTextureExternalZero;
        default: UNREACHABLE(type);
        }
    }

    return mState.samplerTexture[type][sampler];
}

void Context::samplerParameteri(GLuint sampler, GLenum pname, GLint param)
{
	mResourceManager->checkSamplerAllocation(sampler);

	Sampler *samplerObject = getSampler(sampler);
	ASSERT(samplerObject);

	switch(pname)
	{
	case GL_TEXTURE_MIN_FILTER:    samplerObject->setMinFilter(static_cast<GLenum>(param));       break;
	case GL_TEXTURE_MAG_FILTER:    samplerObject->setMagFilter(static_cast<GLenum>(param));       break;
	case GL_TEXTURE_WRAP_S:        samplerObject->setWrapS(static_cast<GLenum>(param));           break;
	case GL_TEXTURE_WRAP_T:        samplerObject->setWrapT(static_cast<GLenum>(param));           break;
	case GL_TEXTURE_WRAP_R:        samplerObject->setWrapR(static_cast<GLenum>(param));           break;
	case GL_TEXTURE_MIN_LOD:       samplerObject->setMinLod(static_cast<GLfloat>(param));         break;
	case GL_TEXTURE_MAX_LOD:       samplerObject->setMaxLod(static_cast<GLfloat>(param));         break;
	case GL_TEXTURE_COMPARE_MODE:  samplerObject->setComparisonMode(static_cast<GLenum>(param));  break;
	case GL_TEXTURE_COMPARE_FUNC:  samplerObject->setComparisonFunc(static_cast<GLenum>(param));  break;
	default:                       UNREACHABLE(pname); break;
	}
}

void Context::samplerParameterf(GLuint sampler, GLenum pname, GLfloat param)
{
	mResourceManager->checkSamplerAllocation(sampler);

	Sampler *samplerObject = getSampler(sampler);
	ASSERT(samplerObject);

	switch(pname)
	{
	case GL_TEXTURE_MIN_FILTER:    samplerObject->setMinFilter(static_cast<GLenum>(roundf(param)));       break;
	case GL_TEXTURE_MAG_FILTER:    samplerObject->setMagFilter(static_cast<GLenum>(roundf(param)));       break;
	case GL_TEXTURE_WRAP_S:        samplerObject->setWrapS(static_cast<GLenum>(roundf(param)));           break;
	case GL_TEXTURE_WRAP_T:        samplerObject->setWrapT(static_cast<GLenum>(roundf(param)));           break;
	case GL_TEXTURE_WRAP_R:        samplerObject->setWrapR(static_cast<GLenum>(roundf(param)));           break;
	case GL_TEXTURE_MIN_LOD:       samplerObject->setMinLod(param);                                       break;
	case GL_TEXTURE_MAX_LOD:       samplerObject->setMaxLod(param);                                       break;
	case GL_TEXTURE_COMPARE_MODE:  samplerObject->setComparisonMode(static_cast<GLenum>(roundf(param)));  break;
	case GL_TEXTURE_COMPARE_FUNC:  samplerObject->setComparisonFunc(static_cast<GLenum>(roundf(param)));  break;
	default:                       UNREACHABLE(pname); break;
	}
}

GLint Context::getSamplerParameteri(GLuint sampler, GLenum pname)
{
	mResourceManager->checkSamplerAllocation(sampler);

	Sampler *samplerObject = getSampler(sampler);
	ASSERT(samplerObject);

	switch(pname)
	{
	case GL_TEXTURE_MIN_FILTER:    return static_cast<GLint>(samplerObject->getMinFilter());
	case GL_TEXTURE_MAG_FILTER:    return static_cast<GLint>(samplerObject->getMagFilter());
	case GL_TEXTURE_WRAP_S:        return static_cast<GLint>(samplerObject->getWrapS());
	case GL_TEXTURE_WRAP_T:        return static_cast<GLint>(samplerObject->getWrapT());
	case GL_TEXTURE_WRAP_R:        return static_cast<GLint>(samplerObject->getWrapR());
	case GL_TEXTURE_MIN_LOD:       return static_cast<GLint>(roundf(samplerObject->getMinLod()));
	case GL_TEXTURE_MAX_LOD:       return static_cast<GLint>(roundf(samplerObject->getMaxLod()));
	case GL_TEXTURE_COMPARE_MODE:  return static_cast<GLint>(samplerObject->getComparisonMode());
	case GL_TEXTURE_COMPARE_FUNC:  return static_cast<GLint>(samplerObject->getComparisonFunc());
	default:                       UNREACHABLE(pname); return 0;
	}
}

GLfloat Context::getSamplerParameterf(GLuint sampler, GLenum pname)
{
	mResourceManager->checkSamplerAllocation(sampler);

	Sampler *samplerObject = getSampler(sampler);
	ASSERT(samplerObject);

	switch(pname)
	{
	case GL_TEXTURE_MIN_FILTER:    return static_cast<GLfloat>(samplerObject->getMinFilter());
	case GL_TEXTURE_MAG_FILTER:    return static_cast<GLfloat>(samplerObject->getMagFilter());
	case GL_TEXTURE_WRAP_S:        return static_cast<GLfloat>(samplerObject->getWrapS());
	case GL_TEXTURE_WRAP_T:        return static_cast<GLfloat>(samplerObject->getWrapT());
	case GL_TEXTURE_WRAP_R:        return static_cast<GLfloat>(samplerObject->getWrapR());
	case GL_TEXTURE_MIN_LOD:       return samplerObject->getMinLod();
	case GL_TEXTURE_MAX_LOD:       return samplerObject->getMaxLod();
	case GL_TEXTURE_COMPARE_MODE:  return static_cast<GLfloat>(samplerObject->getComparisonMode());
	case GL_TEXTURE_COMPARE_FUNC:  return static_cast<GLfloat>(samplerObject->getComparisonFunc());
	default:                       UNREACHABLE(pname); return 0;
	}
}

bool Context::getBooleanv(GLenum pname, GLboolean *params) const
{
    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.depthMask;                 break;
    case GL_COLOR_WRITEMASK:
        params[0] = mState.colorMaskRed;
        params[1] = mState.colorMaskGreen;
        params[2] = mState.colorMaskBlue;
        params[3] = mState.colorMaskAlpha;
        break;
    case GL_CULL_FACE:                *params = mState.cullFaceEnabled;                  break;
    case GL_POLYGON_OFFSET_FILL:      *params = mState.polygonOffsetFillEnabled;         break;
    case GL_SAMPLE_ALPHA_TO_COVERAGE: *params = mState.sampleAlphaToCoverageEnabled;     break;
    case GL_SAMPLE_COVERAGE:          *params = mState.sampleCoverageEnabled;            break;
    case GL_SCISSOR_TEST:             *params = mState.scissorTestEnabled;               break;
    case GL_STENCIL_TEST:             *params = mState.stencilTestEnabled;               break;
    case GL_DEPTH_TEST:               *params = mState.depthTestEnabled;                 break;
    case GL_BLEND:                    *params = mState.blendEnabled;                     break;
    case GL_DITHER:                   *params = mState.ditherEnabled;                    break;
    case GL_PRIMITIVE_RESTART_FIXED_INDEX: *params = mState.primitiveRestartFixedIndexEnabled; break;
    case GL_RASTERIZER_DISCARD:       *params = mState.rasterizerDiscardEnabled;         break;
	case GL_TRANSFORM_FEEDBACK_ACTIVE:
		{
			TransformFeedback* transformFeedback = getTransformFeedback(mState.transformFeedback);
			if(transformFeedback)
			{
				*params = transformFeedback->isActive();
				break;
			}
			else return false;
		}
     case GL_TRANSFORM_FEEDBACK_PAUSED:
		{
			TransformFeedback* transformFeedback = getTransformFeedback(mState.transformFeedback);
			if(transformFeedback)
			{
				*params = transformFeedback->isPaused();
				break;
			}
			else return false;
		}
    default:
        return false;
    }

    return true;
}

bool Context::getFloatv(GLenum pname, GLfloat *params) const
{
    // 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.polygonOffsetFactor;  break;
    case GL_POLYGON_OFFSET_UNITS:     *params = mState.polygonOffsetUnits;   break;
    case GL_ALIASED_LINE_WIDTH_RANGE:
        params[0] = ALIASED_LINE_WIDTH_RANGE_MIN;
        params[1] = ALIASED_LINE_WIDTH_RANGE_MAX;
        break;
    case GL_ALIASED_POINT_SIZE_RANGE:
        params[0] = ALIASED_POINT_SIZE_RANGE_MIN;
        params[1] = ALIASED_POINT_SIZE_RANGE_MAX;
        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:
        *params = MAX_TEXTURE_MAX_ANISOTROPY;
		break;
    default:
        return false;
    }

    return true;
}

template bool Context::getIntegerv<GLint>(GLenum pname, GLint *params) const;
template bool Context::getIntegerv<GLint64>(GLenum pname, GLint64 *params) const;

template<typename T> bool Context::getIntegerv(GLenum pname, T *params) const
{
    // 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 = MAX_VERTEX_ATTRIBS;               break;
    case GL_MAX_VERTEX_UNIFORM_VECTORS:       *params = MAX_VERTEX_UNIFORM_VECTORS;       break;
    case GL_MAX_VARYING_VECTORS:              *params = MAX_VARYING_VECTORS;              break;
    case GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS: *params = MAX_COMBINED_TEXTURE_IMAGE_UNITS; break;
    case GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS:   *params = MAX_VERTEX_TEXTURE_IMAGE_UNITS;   break;
    case GL_MAX_TEXTURE_IMAGE_UNITS:          *params = MAX_TEXTURE_IMAGE_UNITS;          break;
	case GL_MAX_FRAGMENT_UNIFORM_VECTORS:     *params = MAX_FRAGMENT_UNIFORM_VECTORS;     break;
	case GL_MAX_RENDERBUFFER_SIZE:            *params = IMPLEMENTATION_MAX_RENDERBUFFER_SIZE; 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 = getArrayBufferName();                 break;
    case GL_ELEMENT_ARRAY_BUFFER_BINDING:     *params = getElementArrayBufferName();          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.name();           break;
    case GL_CURRENT_PROGRAM:                  *params = mState.currentProgram;                break;
    case GL_PACK_ALIGNMENT:                   *params = mState.packAlignment;                 break;
    case GL_UNPACK_ALIGNMENT:                 *params = mState.unpackInfo.alignment;          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.stencilFunc;                   break;
    case GL_STENCIL_REF:                      *params = mState.stencilRef;                    break;
    case GL_STENCIL_VALUE_MASK:               *params = mState.stencilMask;                   break;
    case GL_STENCIL_BACK_FUNC:                *params = mState.stencilBackFunc;               break;
    case GL_STENCIL_BACK_REF:                 *params = mState.stencilBackRef;                break;
    case GL_STENCIL_BACK_VALUE_MASK:          *params = mState.stencilBackMask;               break;
    case GL_STENCIL_FAIL:                     *params = mState.stencilFail;                   break;
    case GL_STENCIL_PASS_DEPTH_FAIL:          *params = mState.stencilPassDepthFail;          break;
    case GL_STENCIL_PASS_DEPTH_PASS:          *params = mState.stencilPassDepthPass;          break;
    case GL_STENCIL_BACK_FAIL:                *params = mState.stencilBackFail;               break;
    case GL_STENCIL_BACK_PASS_DEPTH_FAIL:     *params = mState.stencilBackPassDepthFail;      break;
    case GL_STENCIL_BACK_PASS_DEPTH_PASS:     *params = mState.stencilBackPassDepthPass;      break;
    case GL_DEPTH_FUNC:                       *params = mState.depthFunc;                     break;
    case GL_BLEND_SRC_RGB:                    *params = mState.sourceBlendRGB;                break;
    case GL_BLEND_SRC_ALPHA:                  *params = mState.sourceBlendAlpha;              break;
    case GL_BLEND_DST_RGB:                    *params = mState.destBlendRGB;                  break;
    case GL_BLEND_DST_ALPHA:                  *params = mState.destBlendAlpha;                break;
    case GL_BLEND_EQUATION_RGB:               *params = mState.blendEquationRGB;              break;
    case GL_BLEND_EQUATION_ALPHA:             *params = mState.blendEquationAlpha;            break;
    case GL_STENCIL_WRITEMASK:                *params = mState.stencilWritemask;              break;
    case GL_STENCIL_BACK_WRITEMASK:           *params = mState.stencilBackWritemask;          break;
    case GL_STENCIL_CLEAR_VALUE:              *params = mState.stencilClearValue;             break;
    case GL_SUBPIXEL_BITS:                    *params = 4;                                    break;
	case GL_MAX_TEXTURE_SIZE:                 *params = IMPLEMENTATION_MAX_TEXTURE_SIZE;          break;
	case GL_MAX_CUBE_MAP_TEXTURE_SIZE:        *params = IMPLEMENTATION_MAX_CUBE_MAP_TEXTURE_SIZE; break;
    case GL_NUM_COMPRESSED_TEXTURE_FORMATS:   *params = NUM_COMPRESSED_TEXTURE_FORMATS;           break;
	case GL_MAX_SAMPLES_ANGLE:                *params = IMPLEMENTATION_MAX_SAMPLES;               break;
    case GL_SAMPLE_BUFFERS:                   
    case GL_SAMPLES:
        {
            Framebuffer *framebuffer = getDrawFramebuffer();
			int width, height, samples;

            if(framebuffer->completeness(width, height, samples) == GL_FRAMEBUFFER_COMPLETE)
            {
                switch(pname)
                {
                case GL_SAMPLE_BUFFERS:
                    if(samples > 1)
                    {
                        *params = 1;
                    }
                    else
                    {
                        *params = 0;
                    }
                    break;
                case GL_SAMPLES:
                    *params = samples;
                    break;
                }
            }
            else
            {
                *params = 0;
            }
        }
        break;
    case GL_IMPLEMENTATION_COLOR_READ_TYPE:
		{
			Framebuffer *framebuffer = getReadFramebuffer();
			*params = framebuffer->getImplementationColorReadType();
		}
		break;
    case GL_IMPLEMENTATION_COLOR_READ_FORMAT:
		{
			Framebuffer *framebuffer = getReadFramebuffer();
			*params = framebuffer->getImplementationColorReadFormat();
		}
		break;
    case GL_MAX_VIEWPORT_DIMS:
        {
			int maxDimension = IMPLEMENTATION_MAX_RENDERBUFFER_SIZE;
            params[0] = maxDimension;
            params[1] = maxDimension;
        }
        break;
    case GL_COMPRESSED_TEXTURE_FORMATS:
        {
			for(int i = 0; i < NUM_COMPRESSED_TEXTURE_FORMATS; i++)
            {
                params[i] = compressedTextureFormats[i];
            }
        }
        break;
    case GL_VIEWPORT:
        params[0] = mState.viewportX;
        params[1] = mState.viewportY;
        params[2] = mState.viewportWidth;
        params[3] = mState.viewportHeight;
        break;
    case GL_SCISSOR_BOX:
        params[0] = mState.scissorX;
        params[1] = mState.scissorY;
        params[2] = mState.scissorWidth;
        params[3] = mState.scissorHeight;
        break;
    case GL_CULL_FACE_MODE:                   *params = mState.cullMode;                 break;
    case GL_FRONT_FACE:                       *params = mState.frontFace;                break;
    case GL_RED_BITS:
    case GL_GREEN_BITS:
    case GL_BLUE_BITS:
    case GL_ALPHA_BITS:
        {
            Framebuffer *framebuffer = getDrawFramebuffer();
            Renderbuffer *colorbuffer = framebuffer->getColorbuffer(0);

            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:
        {
            Framebuffer *framebuffer = getDrawFramebuffer();
            Renderbuffer *depthbuffer = framebuffer->getDepthbuffer();

            if(depthbuffer)
            {
                *params = depthbuffer->getDepthSize();
            }
            else
            {
                *params = 0;
            }
        }
        break;
    case GL_STENCIL_BITS:
        {
            Framebuffer *framebuffer = getDrawFramebuffer();
            Renderbuffer *stencilbuffer = framebuffer->getStencilbuffer();

            if(stencilbuffer)
            {
                *params = stencilbuffer->getStencilSize();
            }
            else
            {
                *params = 0;
            }
        }
        break;
    case GL_TEXTURE_BINDING_2D:
        {
            if(mState.activeSampler > MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1)
            {
                error(GL_INVALID_OPERATION);
                return false;
            }

            *params = mState.samplerTexture[TEXTURE_2D][mState.activeSampler].name();
        }
        break;
    case GL_TEXTURE_BINDING_CUBE_MAP:
        {
            if(mState.activeSampler > MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1)
            {
                error(GL_INVALID_OPERATION);
                return false;
            }

            *params = mState.samplerTexture[TEXTURE_CUBE][mState.activeSampler].name();
        }
        break;
    case GL_TEXTURE_BINDING_EXTERNAL_OES:
        {
            if(mState.activeSampler > MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1)
            {
                error(GL_INVALID_OPERATION);
                return false;
            }

            *params = mState.samplerTexture[TEXTURE_EXTERNAL][mState.activeSampler].name();
        }
        break;
	case GL_TEXTURE_BINDING_3D_OES:
	case GL_TEXTURE_BINDING_2D_ARRAY: // GLES 3.0
	    {
			if(mState.activeSampler > MAX_COMBINED_TEXTURE_IMAGE_UNITS - 1)
			{
				error(GL_INVALID_OPERATION);
				return false;
			}

			*params = mState.samplerTexture[TEXTURE_3D][mState.activeSampler].name();
		}
		break;
	case GL_COPY_READ_BUFFER_BINDING: // name, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.copyReadBuffer.name();
		}
		else
		{
			return false;
		}
		break;
	case GL_COPY_WRITE_BUFFER_BINDING: // name, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.copyWriteBuffer.name();
		}
		else
		{
			return false;
		}
		break;
	case GL_DRAW_BUFFER0: // symbolic constant, initial value is GL_BACK​
		UNIMPLEMENTED();
		*params = GL_BACK;
		break;
	case GL_DRAW_BUFFER1: // symbolic constant, initial value is GL_NONE
	case GL_DRAW_BUFFER2:
	case GL_DRAW_BUFFER3:
	case GL_DRAW_BUFFER4:
	case GL_DRAW_BUFFER5:
	case GL_DRAW_BUFFER6:
	case GL_DRAW_BUFFER7:
	case GL_DRAW_BUFFER8:
	case GL_DRAW_BUFFER9:
	case GL_DRAW_BUFFER10:
	case GL_DRAW_BUFFER11:
	case GL_DRAW_BUFFER12:
	case GL_DRAW_BUFFER13:
	case GL_DRAW_BUFFER14:
	case GL_DRAW_BUFFER15:
		UNIMPLEMENTED();
		*params = GL_NONE;
		break;
	case GL_MAJOR_VERSION: // integer, at least 3
		UNIMPLEMENTED();
		*params = 3;
		break;
	case GL_MAX_3D_TEXTURE_SIZE: // GLint, at least 2048
		*params = IMPLEMENTATION_MAX_TEXTURE_SIZE;
		break;
	case GL_MAX_ARRAY_TEXTURE_LAYERS: // GLint, at least 2048
		*params = IMPLEMENTATION_MAX_TEXTURE_SIZE;
		break;
	case GL_MAX_COLOR_ATTACHMENTS: // integer, at least 8
		UNIMPLEMENTED();
		*params = IMPLEMENTATION_MAX_COLOR_ATTACHMENTS;
		break;
	case GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS: // integer, at least 50048
		UNIMPLEMENTED();
		*params = MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS;
		break;
	case GL_MAX_COMBINED_UNIFORM_BLOCKS: // integer, at least 70
		UNIMPLEMENTED();
		*params = 70;
		break;
	case GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS: // integer, at least 50176
		UNIMPLEMENTED();
		*params = MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS;
		break;
	case GL_MAX_DRAW_BUFFERS: // integer, at least 8
		UNIMPLEMENTED();
		*params = IMPLEMENTATION_MAX_DRAW_BUFFERS;
		break;
	case GL_MAX_ELEMENT_INDEX:
		*params = MAX_ELEMENT_INDEX;
		break;
	case GL_MAX_ELEMENTS_INDICES:
		*params = MAX_ELEMENTS_INDICES;
		break;
	case GL_MAX_ELEMENTS_VERTICES:
		*params = MAX_ELEMENTS_VERTICES;
		break;
	case GL_MAX_FRAGMENT_INPUT_COMPONENTS: // integer, at least 128
		UNIMPLEMENTED();
		*params = 128;
		break;
	case GL_MAX_FRAGMENT_UNIFORM_BLOCKS: // integer, at least 12
		UNIMPLEMENTED();
		*params = 12;
		break;
	case GL_MAX_FRAGMENT_UNIFORM_COMPONENTS: // integer, at least 1024
		UNIMPLEMENTED();
		*params = 1024;
		break;
	case GL_MAX_PROGRAM_TEXEL_OFFSET: // integer, minimum is 7
		UNIMPLEMENTED();
		*params = 7;
		break;
	case GL_MAX_SERVER_WAIT_TIMEOUT: // integer
		UNIMPLEMENTED();
		*params = 0;
		break;
	case GL_MAX_TEXTURE_LOD_BIAS: // integer,  at least 2.0
		UNIMPLEMENTED();
		*params = 2;
		break;
	case GL_MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS: // integer, at least 64
		UNIMPLEMENTED();
		*params = 64;
		break;
	case GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS: // integer, at least 4
		UNIMPLEMENTED();
		*params = IMPLEMENTATION_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS;
		break;
	case GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS: // integer, at least 4
		UNIMPLEMENTED();
		*params = 4;
		break;
	case GL_MAX_UNIFORM_BLOCK_SIZE: // integer, at least 16384
		UNIMPLEMENTED();
		*params = 16384;
		break;
	case GL_MAX_UNIFORM_BUFFER_BINDINGS: // integer, at least 36
		*params = IMPLEMENTATION_MAX_UNIFORM_BUFFER_BINDINGS;
		break;
	case GL_MAX_VARYING_COMPONENTS: // integer, at least 60
		UNIMPLEMENTED();
		*params = 60;
		break;
	case GL_MAX_VERTEX_OUTPUT_COMPONENTS: // integer,  at least 64
		UNIMPLEMENTED();
		*params = 64;
		break;
	case GL_MAX_VERTEX_UNIFORM_BLOCKS: // integer,  at least 12
		UNIMPLEMENTED();
		*params = 12;
		break;
	case GL_MAX_VERTEX_UNIFORM_COMPONENTS: // integer,  at least 1024
		UNIMPLEMENTED();
		*params = 1024;
		break;
	case GL_MIN_PROGRAM_TEXEL_OFFSET: // integer, maximum is -8
		UNIMPLEMENTED();
		*params = -8;
		break;
	case GL_MINOR_VERSION: // integer
		UNIMPLEMENTED();
		*params = 0;
		break;
	case GL_NUM_EXTENSIONS: // integer
		GLuint numExtensions;
		getExtensions(0, &numExtensions);
		*params = numExtensions;
		break;
	case GL_NUM_PROGRAM_BINARY_FORMATS: // integer, at least 0
		UNIMPLEMENTED();
		*params = 0;
		break;
	case GL_PACK_ROW_LENGTH: // integer, initially 0
		*params = mState.packRowLength;
		break;
	case GL_PACK_SKIP_PIXELS: // integer, initially 0
		*params = mState.packSkipPixels;
		break;
	case GL_PACK_SKIP_ROWS: // integer, initially 0
		*params = mState.packSkipRows;
		break;
	case GL_PIXEL_PACK_BUFFER_BINDING: // integer, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.pixelPackBuffer.name();
		}
		else
		{
			return false;
		}
		break;
	case GL_PIXEL_UNPACK_BUFFER_BINDING: // integer, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.pixelUnpackBuffer.name();
		}
		else
		{
			return false;
		}
		break;
	case GL_PROGRAM_BINARY_FORMATS: // integer[GL_NUM_PROGRAM_BINARY_FORMATS​]
		UNIMPLEMENTED();
		*params = 0;
		break;
	case GL_READ_BUFFER: // symbolic constant,  initial value is GL_BACK​
		UNIMPLEMENTED();
		*params = GL_BACK;
		break;
	case GL_SAMPLER_BINDING: // GLint, default 0
		UNIMPLEMENTED();
		*params = 0;
		break;
	case GL_UNIFORM_BUFFER_BINDING: // name, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.genericUniformBuffer.name();
		}
		else
		{
			return false;
		}
		break;
	case GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT: // integer, defaults to 1
		*params = IMPLEMENTATION_UNIFORM_BUFFER_OFFSET_ALIGNMENT;
		break;
	case GL_UNIFORM_BUFFER_SIZE: // indexed[n] 64-bit integer, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.genericUniformBuffer->size();
		}
		else
		{
			return false;
		}
		break;
	case GL_UNIFORM_BUFFER_START: // indexed[n] 64-bit integer, initially 0
		if(clientVersion >= 3)
		{
			*params = mState.genericUniformBuffer->offset();
		}
		else
		{
			return false;
		}
		*params = 0;
		break;
	case GL_UNPACK_IMAGE_HEIGHT: // integer, initially 0
		*params = mState.unpackInfo.imageHeight;
		break;
	case GL_UNPACK_ROW_LENGTH: // integer, initially 0
		*params = mState.unpackInfo.rowLength;
		break;
	case GL_UNPACK_SKIP_IMAGES: // integer, initially 0
		*params = mState.unpackInfo.skipImages;
		break;
	case GL_UNPACK_SKIP_PIXELS: // integer, initially 0
		*params = mState.unpackInfo.skipPixels;
		break;
	case GL_UNPACK_SKIP_ROWS: // integer, initially 0
		*params = mState.unpackInfo.skipRows;
		break;
	case GL_VERTEX_ARRAY_BINDING: // GLint, initially 0
		*params = getCurrentVertexArray()->name;
		break;
	default:
        return false;
    }

    return true;
}

template bool Context::getTransformFeedbackiv<GLint>(GLuint xfb, GLenum pname, GLint *param) const;
template bool Context::getTransformFeedbackiv<GLint64>(GLuint xfb, GLenum pname, GLint64 *param) const;

template<typename T> bool Context::getTransformFeedbackiv(GLuint xfb, GLenum pname, T *param) const
{
	UNIMPLEMENTED();

	TransformFeedback* transformFeedback = getTransformFeedback(mState.transformFeedback);
	if(!transformFeedback)
	{
		return false;
	}

	switch(pname)
	{
	case GL_TRANSFORM_FEEDBACK_BINDING: // GLint, initially 0
		*param = 0;
		break;
	case GL_TRANSFORM_FEEDBACK_ACTIVE: // boolean, initially GL_FALSE
		*param = transformFeedback->isActive();
		break;
	case GL_TRANSFORM_FEEDBACK_BUFFER_BINDING: // name, initially 0
		*param = transformFeedback->name;
		break;
	case GL_TRANSFORM_FEEDBACK_PAUSED: // boolean, initially GL_FALSE
		*param = transformFeedback->isPaused();
		break;
	case GL_TRANSFORM_FEEDBACK_BUFFER_SIZE: // indexed[n] 64-bit integer, initially 0
		if(transformFeedback->getGenericBuffer())
		{
			*param = transformFeedback->getGenericBuffer()->size();
			break;
		}
		else return false;
	case GL_TRANSFORM_FEEDBACK_BUFFER_START: // indexed[n] 64-bit integer, initially 0
		*param = 0;
		break;
	default:
		return false;
	}

	return true;
}

bool Context::getQueryParameterInfo(GLenum pname, GLenum *type, unsigned int *numParams) const
{
    // 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 = NUM_COMPRESSED_TEXTURE_FORMATS;
        }
		break;
    case GL_SHADER_BINARY_FORMATS:
        {
            *type = GL_INT;
            *numParams = 0;
        }
        break;
    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_NUM_SHADER_BINARY_FORMATS:
    case GL_NUM_COMPRESSED_TEXTURE_FORMATS:
    case GL_ARRAY_BUFFER_BINDING:
    case GL_FRAMEBUFFER_BINDING: // Same as GL_DRAW_FRAMEBUFFER_BINDING_ANGLE
    case GL_READ_FRAMEBUFFER_BINDING_ANGLE:
    case GL_RENDERBUFFER_BINDING:
    case GL_CURRENT_PROGRAM:
    case GL_PACK_ALIGNMENT:
    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_TEXTURE_BINDING_EXTERNAL_OES:
    case GL_TEXTURE_BINDING_3D_OES:
    case GL_COPY_READ_BUFFER_BINDING:
    case GL_COPY_WRITE_BUFFER_BINDING:
    case GL_DRAW_BUFFER0:
    case GL_DRAW_BUFFER1:
    case GL_DRAW_BUFFER2:
    case GL_DRAW_BUFFER3:
    case GL_DRAW_BUFFER4:
    case GL_DRAW_BUFFER5:
    case GL_DRAW_BUFFER6:
    case GL_DRAW_BUFFER7:
    case GL_DRAW_BUFFER8:
    case GL_DRAW_BUFFER9:
    case GL_DRAW_BUFFER10:
    case GL_DRAW_BUFFER11:
    case GL_DRAW_BUFFER12:
    case GL_DRAW_BUFFER13:
    case GL_DRAW_BUFFER14:
    case GL_DRAW_BUFFER15:
    case GL_MAJOR_VERSION:
    case GL_MAX_3D_TEXTURE_SIZE:
    case GL_MAX_ARRAY_TEXTURE_LAYERS:
    case GL_MAX_COLOR_ATTACHMENTS:
    case GL_MAX_COMBINED_FRAGMENT_UNIFORM_COMPONENTS:
    case GL_MAX_COMBINED_UNIFORM_BLOCKS:
    case GL_MAX_COMBINED_VERTEX_UNIFORM_COMPONENTS:
    case GL_MAX_DRAW_BUFFERS:
    case GL_MAX_ELEMENT_INDEX:
    case GL_MAX_ELEMENTS_INDICES:
    case GL_MAX_ELEMENTS_VERTICES:
    case GL_MAX_FRAGMENT_INPUT_COMPONENTS:
    case GL_MAX_FRAGMENT_UNIFORM_BLOCKS:
    case GL_MAX_FRAGMENT_UNIFORM_COMPONENTS:
    case GL_MAX_PROGRAM_TEXEL_OFFSET:
    case GL_MAX_SERVER_WAIT_TIMEOUT:
    case GL_MAX_TEXTURE_LOD_BIAS:
    case GL_MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS:
    case GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS:
    case GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS:
    case GL_MAX_UNIFORM_BLOCK_SIZE:
    case GL_MAX_UNIFORM_BUFFER_BINDINGS:
    case GL_MAX_VARYING_COMPONENTS:
    case GL_MAX_VERTEX_OUTPUT_COMPONENTS:
    case GL_MAX_VERTEX_UNIFORM_BLOCKS:
    case GL_MAX_VERTEX_UNIFORM_COMPONENTS:
    case GL_MIN_PROGRAM_TEXEL_OFFSET:
    case GL_MINOR_VERSION:
    case GL_NUM_EXTENSIONS:
    case GL_NUM_PROGRAM_BINARY_FORMATS:
    case GL_PACK_ROW_LENGTH:
    case GL_PACK_SKIP_PIXELS:
    case GL_PACK_SKIP_ROWS:
    case GL_PIXEL_PACK_BUFFER_BINDING:
    case GL_PIXEL_UNPACK_BUFFER_BINDING:
    case GL_PROGRAM_BINARY_FORMATS:
    case GL_READ_BUFFER:
    case GL_SAMPLER_BINDING:
    case GL_TEXTURE_BINDING_2D_ARRAY:
    case GL_UNIFORM_BUFFER_BINDING:
    case GL_UNIFORM_BUFFER_OFFSET_ALIGNMENT:
    case GL_UNIFORM_BUFFER_SIZE:
    case GL_UNIFORM_BUFFER_START:
    case GL_UNPACK_IMAGE_HEIGHT:
    case GL_UNPACK_ROW_LENGTH:
    case GL_UNPACK_SKIP_IMAGES:
    case GL_UNPACK_SKIP_PIXELS:
    case GL_UNPACK_SKIP_ROWS:
    case GL_VERTEX_ARRAY_BINDING:
        {
            *type = GL_INT;
            *numParams = 1;
        }
        break;
    case GL_MAX_SAMPLES_ANGLE:
        {
            *type = GL_INT;
            *numParams = 1;
        }
        break;
    case GL_MAX_VIEWPORT_DIMS:
        {
            *type = GL_INT;
            *numParams = 2;
        }
        break;
    case GL_VIEWPORT:
    case GL_SCISSOR_BOX:
        {
            *type = GL_INT;
            *numParams = 4;
        }
        break;
    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_PRIMITIVE_RESTART_FIXED_INDEX:
    case GL_RASTERIZER_DISCARD:
    case GL_TRANSFORM_FEEDBACK_ACTIVE:
    case GL_TRANSFORM_FEEDBACK_PAUSED:
        {
            *type = GL_BOOL;
            *numParams = 1;
        }
        break;
    case GL_COLOR_WRITEMASK:
        {
            *type = GL_BOOL;
            *numParams = 4;
        }
        break;
    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;
        }
        break;
    case GL_ALIASED_LINE_WIDTH_RANGE:
    case GL_ALIASED_POINT_SIZE_RANGE:
    case GL_DEPTH_RANGE:
        {
            *type = GL_FLOAT;
            *numParams = 2;
        }
        break;
    case GL_COLOR_CLEAR_VALUE:
    case GL_BLEND_COLOR:
        {
            *type = GL_FLOAT;
            *numParams = 4;
        }
        break;
	case GL_MAX_TEXTURE_MAX_ANISOTROPY_EXT:
        *type = GL_FLOAT;
        *numParams = 1;
        break;
    default:
        return false;
    }

    return true;
}

void Context::applyScissor(int width, int height)
{
	if(mState.scissorTestEnabled)
	{
		sw::Rect scissor = { mState.scissorX, mState.scissorY, mState.scissorX + mState.scissorWidth, mState.scissorY + mState.scissorHeight };
		scissor.clip(0, 0, width, height);

		device->setScissorRect(scissor);
		device->setScissorEnable(true);
	}
	else
	{
		device->setScissorEnable(false);
	}
}

egl::Image *Context::getScissoredImage(GLint drawbuffer, int &x0, int &y0, int &width, int &height, bool depthStencil)
{
	Framebuffer* framebuffer = getDrawFramebuffer();
	egl::Image* image = depthStencil ? framebuffer->getDepthStencil() : framebuffer->getRenderTarget(drawbuffer);

	applyScissor(image->getWidth(), image->getHeight());

	device->getScissoredRegion(image, x0, y0, width, height);

	return image;
}

// Applies the render target surface, depth stencil surface, viewport rectangle and scissor rectangle
bool Context::applyRenderTarget()
{
    Framebuffer *framebuffer = getDrawFramebuffer();
	int width, height, samples;

    if(!framebuffer || framebuffer->completeness(width, height, samples) != GL_FRAMEBUFFER_COMPLETE)
    {
        return error(GL_INVALID_FRAMEBUFFER_OPERATION, false);
    }

	for(int i = 0; i < MAX_DRAW_BUFFERS; ++i)
	{
		egl::Image *renderTarget = framebuffer->getRenderTarget(i);
		device->setRenderTarget(i, renderTarget);
		if(renderTarget) renderTarget->release();
	}

    egl::Image *depthStencil = framebuffer->getDepthStencil();
    device->setDepthStencilSurface(depthStencil);
	if(depthStencil) depthStencil->release();

    Viewport viewport;
    float zNear = clamp01(mState.zNear);
    float zFar = clamp01(mState.zFar);

    viewport.x0 = mState.viewportX;
    viewport.y0 = mState.viewportY;
    viewport.width = mState.viewportWidth;
    viewport.height = mState.viewportHeight;
    viewport.minZ = zNear;
    viewport.maxZ = zFar;

    device->setViewport(viewport);

	applyScissor(width, height);

	Program *program = getCurrentProgram();

	if(program)
	{
		GLfloat nearFarDiff[3] = {zNear, zFar, zFar - zNear};
        program->setUniform1fv(program->getUniformLocation("gl_DepthRange.near"), 1, &nearFarDiff[0]);
		program->setUniform1fv(program->getUniformLocation("gl_DepthRange.far"), 1, &nearFarDiff[1]);
		program->setUniform1fv(program->getUniformLocation("gl_DepthRange.diff"), 1, &nearFarDiff[2]);
    }

    return true;
}

// Applies the fixed-function state (culling, depth test, alpha blending, stenciling, etc)
void Context::applyState(GLenum drawMode)
{
    Framebuffer *framebuffer = getDrawFramebuffer();

    if(mState.cullFaceEnabled)
    {
        device->setCullMode(es2sw::ConvertCullMode(mState.cullMode, mState.frontFace));
    }
    else
    {
		device->setCullMode(sw::CULL_NONE);
    }

    if(mDepthStateDirty)
    {
        if(mState.depthTestEnabled)
        {
			device->setDepthBufferEnable(true);
			device->setDepthCompare(es2sw::ConvertDepthComparison(mState.depthFunc));
        }
        else
        {
            device->setDepthBufferEnable(false);
        }

        mDepthStateDirty = false;
    }

    if(mBlendStateDirty)
    {
        if(mState.blendEnabled)
        {
			device->setAlphaBlendEnable(true);
			device->setSeparateAlphaBlendEnable(true);

            device->setBlendConstant(es2sw::ConvertColor(mState.blendColor));

			device->setSourceBlendFactor(es2sw::ConvertBlendFunc(mState.sourceBlendRGB));
			device->setDestBlendFactor(es2sw::ConvertBlendFunc(mState.destBlendRGB));
			device->setBlendOperation(es2sw::ConvertBlendOp(mState.blendEquationRGB));

            device->setSourceBlendFactorAlpha(es2sw::ConvertBlendFunc(mState.sourceBlendAlpha));
			device->setDestBlendFactorAlpha(es2sw::ConvertBlendFunc(mState.destBlendAlpha));
			device->setBlendOperationAlpha(es2sw::ConvertBlendOp(mState.blendEquationAlpha));
        }
        else
        {
			device->setAlphaBlendEnable(false);
        }

        mBlendStateDirty = false;
    }

    if(mStencilStateDirty || mFrontFaceDirty)
    {
        if(mState.stencilTestEnabled && framebuffer->hasStencil())
        {
			device->setStencilEnable(true);
			device->setTwoSidedStencil(true);

            // get the maximum size of the stencil ref
            Renderbuffer *stencilbuffer = framebuffer->getStencilbuffer();
            GLuint maxStencil = (1 << stencilbuffer->getStencilSize()) - 1;

			if(mState.frontFace == GL_CCW)
			{
				device->setStencilWriteMask(mState.stencilWritemask);
				device->setStencilCompare(es2sw::ConvertStencilComparison(mState.stencilFunc));

				device->setStencilReference((mState.stencilRef < (GLint)maxStencil) ? mState.stencilRef : maxStencil);
				device->setStencilMask(mState.stencilMask);

				device->setStencilFailOperation(es2sw::ConvertStencilOp(mState.stencilFail));
				device->setStencilZFailOperation(es2sw::ConvertStencilOp(mState.stencilPassDepthFail));
				device->setStencilPassOperation(es2sw::ConvertStencilOp(mState.stencilPassDepthPass));

				device->setStencilWriteMaskCCW(mState.stencilBackWritemask);
				device->setStencilCompareCCW(es2sw::ConvertStencilComparison(mState.stencilBackFunc));

				device->setStencilReferenceCCW((mState.stencilBackRef < (GLint)maxStencil) ? mState.stencilBackRef : maxStencil);
				device->setStencilMaskCCW(mState.stencilBackMask);

				device->setStencilFailOperationCCW(es2sw::ConvertStencilOp(mState.stencilBackFail));
				device->setStencilZFailOperationCCW(es2sw::ConvertStencilOp(mState.stencilBackPassDepthFail));
				device->setStencilPassOperationCCW(es2sw::ConvertStencilOp(mState.stencilBackPassDepthPass));
			}
			else
			{
				device->setStencilWriteMaskCCW(mState.stencilWritemask);
				device->setStencilCompareCCW(es2sw::ConvertStencilComparison(mState.stencilFunc));

				device->setStencilReferenceCCW((mState.stencilRef < (GLint)maxStencil) ? mState.stencilRef : maxStencil);
				device->setStencilMaskCCW(mState.stencilMask);

				device->setStencilFailOperationCCW(es2sw::ConvertStencilOp(mState.stencilFail));
				device->setStencilZFailOperationCCW(es2sw::ConvertStencilOp(mState.stencilPassDepthFail));
				device->setStencilPassOperationCCW(es2sw::ConvertStencilOp(mState.stencilPassDepthPass));

				device->setStencilWriteMask(mState.stencilBackWritemask);
				device->setStencilCompare(es2sw::ConvertStencilComparison(mState.stencilBackFunc));

				device->setStencilReference((mState.stencilBackRef < (GLint)maxStencil) ? mState.stencilBackRef : maxStencil);
				device->setStencilMask(mState.stencilBackMask);

				device->setStencilFailOperation(es2sw::ConvertStencilOp(mState.stencilBackFail));
				device->setStencilZFailOperation(es2sw::ConvertStencilOp(mState.stencilBackPassDepthFail));
				device->setStencilPassOperation(es2sw::ConvertStencilOp(mState.stencilBackPassDepthPass));
			}
        }
        else
        {
			device->setStencilEnable(false);
        }

        mStencilStateDirty = false;
        mFrontFaceDirty = false;
    }

    if(mMaskStateDirty)
    {
		device->setColorWriteMask(0, es2sw::ConvertColorMask(mState.colorMaskRed, mState.colorMaskGreen, mState.colorMaskBlue, mState.colorMaskAlpha));
		device->setDepthWriteEnable(mState.depthMask);

        mMaskStateDirty = false;
    }

    if(mPolygonOffsetStateDirty)
    {
        if(mState.polygonOffsetFillEnabled)
        {
            Renderbuffer *depthbuffer = framebuffer->getDepthbuffer();
            if(depthbuffer)
            {
				device->setSlopeDepthBias(mState.polygonOffsetFactor);
                float depthBias = ldexp(mState.polygonOffsetUnits, -(int)(depthbuffer->getDepthSize()));
				device->setDepthBias(depthBias);
            }
        }
        else
        {
            device->setSlopeDepthBias(0);
            device->setDepthBias(0);
        }

        mPolygonOffsetStateDirty = false;
    }

    if(mSampleStateDirty)
    {
        if(mState.sampleAlphaToCoverageEnabled)
        {
            device->setTransparencyAntialiasing(sw::TRANSPARENCY_ALPHA_TO_COVERAGE);
        }
		else
		{
			device->setTransparencyAntialiasing(sw::TRANSPARENCY_NONE);
		}

        if(mState.sampleCoverageEnabled)
        {
            unsigned int mask = 0;
            if(mState.sampleCoverageValue != 0)
            {
				int width, height, samples;
				framebuffer->completeness(width, height, samples);

                float threshold = 0.5f;

                for(int i = 0; i < samples; i++)
                {
                    mask <<= 1;

                    if((i + 1) * mState.sampleCoverageValue >= threshold)
                    {
                        threshold += 1.0f;
                        mask |= 1;
                    }
                }
            }
            
            if(mState.sampleCoverageInvert)
            {
                mask = ~mask;
            }

			device->setMultiSampleMask(mask);
        }
        else
        {
			device->setMultiSampleMask(0xFFFFFFFF);
        }

        mSampleStateDirty = false;
    }

    if(mDitherStateDirty)
    {
    //	UNIMPLEMENTED();   // FIXME

        mDitherStateDirty = false;
    }
}

GLenum Context::applyVertexBuffer(GLint base, GLint first, GLsizei count, GLsizei instanceId)
{
    TranslatedAttribute attributes[MAX_VERTEX_ATTRIBS];

    GLenum err = mVertexDataManager->prepareVertexData(first, count, attributes, instanceId);
    if(err != GL_NO_ERROR)
    {
        return err;
    }

	Program *program = getCurrentProgram();

	device->resetInputStreams(false);

    for(int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
	{
		if(program->getAttributeStream(i) == -1)
		{
			continue;
		}

		sw::Resource *resource = attributes[i].vertexBuffer;
		const void *buffer = (char*)resource->data() + attributes[i].offset;
			
		int stride = attributes[i].stride;

		buffer = (char*)buffer + stride * base;

		sw::Stream attribute(resource, buffer, stride);

		attribute.type = attributes[i].type;
		attribute.count = attributes[i].count;
		attribute.normalized = attributes[i].normalized;

		int stream = program->getAttributeStream(i);
		device->setInputStream(stream, attribute);
	}

	return GL_NO_ERROR;
}

// Applies the indices and element array bindings
GLenum Context::applyIndexBuffer(const void *indices, GLuint start, GLuint end, GLsizei count, GLenum mode, GLenum type, TranslatedIndexData *indexInfo)
{
	GLenum err = mIndexDataManager->prepareIndexData(type, start, end, count, getCurrentVertexArray()->getElementArrayBuffer(), indices, indexInfo);

    if(err == GL_NO_ERROR)
    {
        device->setIndexBuffer(indexInfo->indexBuffer);
    }

    return err;
}

// Applies the shaders and shader constants
void Context::applyShaders()
{
    Program *programObject = getCurrentProgram();
    sw::VertexShader *vertexShader = programObject->getVertexShader();
	sw::PixelShader *pixelShader = programObject->getPixelShader();

    device->setVertexShader(vertexShader);
    device->setPixelShader(pixelShader);

    if(programObject->getSerial() != mAppliedProgramSerial)
    {
        programObject->dirtyAllUniforms();
        mAppliedProgramSerial = programObject->getSerial();
    }

    programObject->applyUniforms();
    programObject->applyUniformBuffers();
}

void Context::applyTextures()
{
    applyTextures(sw::SAMPLER_PIXEL);
	applyTextures(sw::SAMPLER_VERTEX);
}

void Context::applyTextures(sw::SamplerType samplerType)
{
    Program *programObject = getCurrentProgram();

    int samplerCount = (samplerType == sw::SAMPLER_PIXEL) ? MAX_TEXTURE_IMAGE_UNITS : MAX_VERTEX_TEXTURE_IMAGE_UNITS;   // Range of samplers of given sampler type

    for(int samplerIndex = 0; samplerIndex < samplerCount; samplerIndex++)
    {
        int textureUnit = programObject->getSamplerMapping(samplerType, samplerIndex);   // OpenGL texture image unit index

        if(textureUnit != -1)
        {
            TextureType textureType = programObject->getSamplerTextureType(samplerType, samplerIndex);

            Texture *texture = getSamplerTexture(textureUnit, textureType);

			if(texture->isSamplerComplete())
            {
				GLenum wrapS, wrapT, wrapR, minFilter, magFilter;

				Sampler *samplerObject = mState.sampler[textureUnit];
				if(samplerObject)
				{
					wrapS = samplerObject->getWrapS();
					wrapT = samplerObject->getWrapT();
					wrapR = samplerObject->getWrapR();
					minFilter = samplerObject->getMinFilter();
					magFilter = samplerObject->getMagFilter();
				}
				else
				{
					wrapS = texture->getWrapS();
					wrapT = texture->getWrapT();
					wrapR = texture->getWrapR();
					minFilter = texture->getMinFilter();
					magFilter = texture->getMagFilter();
				}
				GLfloat maxAnisotropy = texture->getMaxAnisotropy();

				GLenum swizzleR = texture->getSwizzleR();
				GLenum swizzleG = texture->getSwizzleG();
				GLenum swizzleB = texture->getSwizzleB();
				GLenum swizzleA = texture->getSwizzleA();

				device->setAddressingModeU(samplerType, samplerIndex, es2sw::ConvertTextureWrap(wrapS));
				device->setAddressingModeV(samplerType, samplerIndex, es2sw::ConvertTextureWrap(wrapT));
				device->setAddressingModeW(samplerType, samplerIndex, es2sw::ConvertTextureWrap(wrapR));
				device->setSwizzleR(samplerType, samplerIndex, es2sw::ConvertSwizzleType(swizzleR));
				device->setSwizzleG(samplerType, samplerIndex, es2sw::ConvertSwizzleType(swizzleG));
				device->setSwizzleB(samplerType, samplerIndex, es2sw::ConvertSwizzleType(swizzleB));
				device->setSwizzleA(samplerType, samplerIndex, es2sw::ConvertSwizzleType(swizzleA));

				device->setTextureFilter(samplerType, samplerIndex, es2sw::ConvertTextureFilter(minFilter, magFilter, maxAnisotropy));
				device->setMipmapFilter(samplerType, samplerIndex, es2sw::ConvertMipMapFilter(minFilter));
				device->setMaxAnisotropy(samplerType, samplerIndex, maxAnisotropy);

				applyTexture(samplerType, samplerIndex, texture);
            }
            else
            {
                applyTexture(samplerType, samplerIndex, nullptr);
            }
        }
        else
        {
            applyTexture(samplerType, samplerIndex, nullptr);
        }
    }
}

void Context::applyTexture(sw::SamplerType type, int index, Texture *baseTexture)
{
	Program *program = getCurrentProgram();
	int sampler = (type == sw::SAMPLER_PIXEL) ? index : 16 + index;
	bool textureUsed = false;

	if(type == sw::SAMPLER_PIXEL)
	{
		textureUsed = program->getPixelShader()->usesSampler(index);
	}
	else if(type == sw::SAMPLER_VERTEX)
	{
		textureUsed = program->getVertexShader()->usesSampler(index);
	}
	else UNREACHABLE(type);

	sw::Resource *resource = 0;

	if(baseTexture && textureUsed)
	{
		resource = baseTexture->getResource();
	}

	device->setTextureResource(sampler, resource);
			
	if(baseTexture && textureUsed)
	{
		int levelCount = baseTexture->getLevelCount();

		if(baseTexture->getTarget() == GL_TEXTURE_2D || baseTexture->getTarget() == GL_TEXTURE_EXTERNAL_OES)
		{
			Texture2D *texture = static_cast<Texture2D*>(baseTexture);

			for(int mipmapLevel = 0; mipmapLevel < MIPMAP_LEVELS; mipmapLevel++)
			{
				int surfaceLevel = mipmapLevel;

				if(surfaceLevel < 0)
				{
					surfaceLevel = 0;
				}
				else if(surfaceLevel >= levelCount)
				{
					surfaceLevel = levelCount - 1;
				}

				egl::Image *surface = texture->getImage(surfaceLevel);
				device->setTextureLevel(sampler, 0, mipmapLevel, surface, sw::TEXTURE_2D);
			}
		}
		else if(baseTexture->getTarget() == GL_TEXTURE_3D_OES)
		{
			Texture3D *texture = static_cast<Texture3D*>(baseTexture);

			for(int mipmapLevel = 0; mipmapLevel < MIPMAP_LEVELS; mipmapLevel++)
			{
				int surfaceLevel = mipmapLevel;

				if(surfaceLevel < 0)
				{
					surfaceLevel = 0;
				}
				else if(surfaceLevel >= levelCount)
				{
					surfaceLevel = levelCount - 1;
				}

				egl::Image *surface = texture->getImage(surfaceLevel);
				device->setTextureLevel(sampler, 0, mipmapLevel, surface, sw::TEXTURE_3D);
			}
		}
		else if(baseTexture->getTarget() == GL_TEXTURE_2D_ARRAY)
		{
			Texture2DArray *texture = static_cast<Texture2DArray*>(baseTexture);

			for(int mipmapLevel = 0; mipmapLevel < MIPMAP_LEVELS; mipmapLevel++)
			{
				int surfaceLevel = mipmapLevel;

				if(surfaceLevel < 0)
				{
					surfaceLevel = 0;
				}
				else if(surfaceLevel >= levelCount)
				{
					surfaceLevel = levelCount - 1;
				}

				egl::Image *surface = texture->getImage(surfaceLevel);
				device->setTextureLevel(sampler, 0, mipmapLevel, surface, sw::TEXTURE_2D_ARRAY);
			}
		}
		else if(baseTexture->getTarget() == GL_TEXTURE_CUBE_MAP)
		{
			for(int face = 0; face < 6; face++)
			{
				TextureCubeMap *cubeTexture = static_cast<TextureCubeMap*>(baseTexture);

				for(int mipmapLevel = 0; mipmapLevel < MIPMAP_LEVELS; mipmapLevel++)
				{
					int surfaceLevel = mipmapLevel;

					if(surfaceLevel < 0)
					{
						surfaceLevel = 0;
					}
					else if(surfaceLevel >= levelCount)
					{
						surfaceLevel = levelCount - 1;
					}

					egl::Image *surface = cubeTexture->getImage(face, surfaceLevel);
					device->setTextureLevel(sampler, face, mipmapLevel, surface, sw::TEXTURE_CUBE);
				}
			}
		}
		else UNIMPLEMENTED();
	}
	else
	{
		device->setTextureLevel(sampler, 0, 0, 0, sw::TEXTURE_NULL);
	}
}

void Context::readPixels(GLint x, GLint y, GLsizei width, GLsizei height,
                         GLenum format, GLenum type, GLsizei *bufSize, void* pixels)
{
    Framebuffer *framebuffer = getReadFramebuffer();
	int framebufferWidth, framebufferHeight, framebufferSamples;

    if(framebuffer->completeness(framebufferWidth, framebufferHeight, framebufferSamples) != GL_FRAMEBUFFER_COMPLETE)
    {
        return error(GL_INVALID_FRAMEBUFFER_OPERATION);
    }

    if(getReadFramebufferName() != 0 && framebufferSamples != 0)
    {
        return error(GL_INVALID_OPERATION);
    }

	GLenum readFormat = framebuffer->getImplementationColorReadFormat();
	GLenum readType = framebuffer->getImplementationColorReadType();

	if(!(readFormat == format && readType == type) && !ValidReadPixelsFormatType(readFormat, readType, format, type, clientVersion))
	{
		return error(GL_INVALID_OPERATION);
	}

	GLsizei outputPitch = egl::ComputePitch((mState.packRowLength > 0) ? mState.packRowLength : width, format, type, mState.packAlignment);
	GLsizei outputHeight = (mState.packImageHeight == 0) ? height : mState.packImageHeight;
	pixels = getPixelPackBuffer() ? (unsigned char*)getPixelPackBuffer()->data() + (ptrdiff_t)pixels : (unsigned char*)pixels;
	pixels = ((char*)pixels) + (mState.packSkipImages * outputHeight + mState.packSkipRows) * outputPitch + mState.packSkipPixels;
    
	// Sized query sanity check
    if(bufSize)
    {
        int requiredSize = outputPitch * height;
        if(requiredSize > *bufSize)
        {
            return error(GL_INVALID_OPERATION);
        }
    }

    egl::Image *renderTarget = framebuffer->getReadRenderTarget();

    if(!renderTarget)
    {
        return error(GL_OUT_OF_MEMORY);
    }

	x += mState.packSkipPixels;
	y += mState.packSkipRows;
	sw::Rect rect = {x, y, x + width, y + height};
	sw::Rect dstRect = { 0, 0, width, height };
	rect.clip(0, 0, renderTarget->getWidth(), renderTarget->getHeight());

	sw::Surface externalSurface(width, height, 1, egl::ConvertFormatType(format, type), pixels, outputPitch, outputPitch * outputHeight);
	sw::SliceRect sliceRect(rect);
	sw::SliceRect dstSliceRect(dstRect);
	device->blit(renderTarget, sliceRect, &externalSurface, dstSliceRect, false);
}

void Context::clear(GLbitfield mask)
{
    Framebuffer *framebuffer = getDrawFramebuffer();

    if(!framebuffer || framebuffer->completeness() != GL_FRAMEBUFFER_COMPLETE)
    {
        return error(GL_INVALID_FRAMEBUFFER_OPERATION);
    }

    if(!applyRenderTarget())
    {
        return;
    }
	
	if(mask & GL_COLOR_BUFFER_BIT)
	{
		unsigned int rgbaMask = getColorMask();

		if(rgbaMask != 0)
		{
			device->clearColor(mState.colorClearValue.red, mState.colorClearValue.green, mState.colorClearValue.blue, mState.colorClearValue.alpha, rgbaMask);
		}
	}

	if(mask & GL_DEPTH_BUFFER_BIT)
	{
		if(mState.depthMask != 0)
		{
			float depth = clamp01(mState.depthClearValue);
			device->clearDepth(depth);
		}
	}

	if(mask & GL_STENCIL_BUFFER_BIT)
	{
		if(mState.stencilWritemask != 0)
		{
			int stencil = mState.stencilClearValue & 0x000000FF;
			device->clearStencil(stencil, mState.stencilWritemask);
		}
	}
}

void Context::clearColorBuffer(GLint drawbuffer, void *value, sw::Format format)
{
	unsigned int rgbaMask = getColorMask();
	if(device && rgbaMask)
	{
		int x0(0), y0(0), width(0), height(0);
		egl::Image* image = getScissoredImage(drawbuffer, x0, y0, width, height, false);

		sw::SliceRect sliceRect;
		if(image->getClearRect(x0, y0, width, height, sliceRect))
		{
			device->clear(value, format, image, sliceRect, rgbaMask);
		}
	}
}

void Context::clearColorBuffer(GLint drawbuffer, const GLint *value)
{
	clearColorBuffer(drawbuffer, (void*)value, sw::FORMAT_A32B32G32R32I);
}

void Context::clearColorBuffer(GLint drawbuffer, const GLuint *value)
{
	clearColorBuffer(drawbuffer, (void*)value, sw::FORMAT_A32B32G32R32UI);
}

void Context::clearColorBuffer(GLint drawbuffer, const GLfloat *value)
{
	clearColorBuffer(drawbuffer, (void*)value, sw::FORMAT_A32B32G32R32F);
}

void Context::clearDepthBuffer(GLint drawbuffer, const GLfloat *value)
{
	if(device && mState.depthMask)
	{
		int x0(0), y0(0), width(0), height(0);
		egl::Image* image = getScissoredImage(drawbuffer, x0, y0, width, height, true);

		float depth = clamp01(value[0]);
		image->clearDepthBuffer(depth, x0, y0, width, height);
	}
}

void Context::clearStencilBuffer(GLint drawbuffer, const GLint *value)
{
	if(device && mState.stencilWritemask)
	{
		int x0(0), y0(0), width(0), height(0);
		egl::Image* image = getScissoredImage(drawbuffer, x0, y0, width, height, true);

		unsigned char stencil = value[0] < 0 ? 0 : static_cast<unsigned char>(value[0] & 0x000000FF);
		image->clearStencilBuffer(stencil, static_cast<unsigned char>(mState.stencilWritemask), x0, y0, width, height);
	}
}

void Context::clearDepthStencilBuffer(GLint drawbuffer, GLfloat depth, GLint stencil)
{
	if(device && (mState.depthMask || mState.stencilWritemask))
	{
		int x0(0), y0(0), width(0), height(0);
		egl::Image* image = getScissoredImage(drawbuffer, x0, y0, width, height, true);

		if(mState.stencilWritemask)
		{
			image->clearStencilBuffer(static_cast<unsigned char>(stencil & 0x000000FF), static_cast<unsigned char>(mState.stencilWritemask), x0, y0, width, height);
		}

		if(mState.depthMask)
		{
			image->clearDepthBuffer(clamp01(depth), x0, y0, width, height);
		}
	}
}

void Context::drawArrays(GLenum mode, GLint first, GLsizei count, GLsizei instanceCount)
{
    if(!mState.currentProgram)
    {
        return error(GL_INVALID_OPERATION);
    }

    PrimitiveType primitiveType;
    int primitiveCount;

    if(!es2sw::ConvertPrimitiveType(mode, count, primitiveType, primitiveCount))
        return error(GL_INVALID_ENUM);

    if(primitiveCount <= 0)
    {
        return;
    }

    if(!applyRenderTarget())
    {
        return;
    }

    applyState(mode);

	for(int i = 0; i < instanceCount; ++i)
	{
		device->setInstanceID(i);

		GLenum err = applyVertexBuffer(0, first, count, i);
		if(err != GL_NO_ERROR)
		{
			return error(err);
		}

		applyShaders();
		applyTextures();

		if(!getCurrentProgram()->validateSamplers(false))
		{
			return error(GL_INVALID_OPERATION);
		}

		if(!cullSkipsDraw(mode))
		{
			device->drawPrimitive(primitiveType, primitiveCount);
		}
	}
}

void Context::drawElements(GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, const void *indices, GLsizei instanceCount)
{
    if(!mState.currentProgram)
    {
        return error(GL_INVALID_OPERATION);
    }

	if(!indices && !getCurrentVertexArray()->getElementArrayBuffer())
    {
        return error(GL_INVALID_OPERATION);
    }

    PrimitiveType primitiveType;
    int primitiveCount;

    if(!es2sw::ConvertPrimitiveType(mode, count, primitiveType, primitiveCount))
        return error(GL_INVALID_ENUM);

    if(primitiveCount <= 0)
    {
        return;
    }

    if(!applyRenderTarget())
    {
        return;
    }

    applyState(mode);

	for(int i = 0; i < instanceCount; ++i)
	{
		device->setInstanceID(i);

		TranslatedIndexData indexInfo;
		GLenum err = applyIndexBuffer(indices, start, end, count, mode, type, &indexInfo);
		if(err != GL_NO_ERROR)
		{
			return error(err);
		}

		GLsizei vertexCount = indexInfo.maxIndex - indexInfo.minIndex + 1;
		err = applyVertexBuffer(-(int)indexInfo.minIndex, indexInfo.minIndex, vertexCount, i);
		if(err != GL_NO_ERROR)
		{
			return error(err);
		}

		applyShaders();
		applyTextures();

		if(!getCurrentProgram()->validateSamplers(false))
		{
			return error(GL_INVALID_OPERATION);
		}

		if(!cullSkipsDraw(mode))
		{
			device->drawIndexedPrimitive(primitiveType, indexInfo.indexOffset, primitiveCount, IndexDataManager::typeSize(type));
		}
	}
}

void Context::finish()
{
	device->finish();
}

void Context::flush()
{
    // We don't queue anything without processing it as fast as possible
}

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;
}

int Context::getSupportedMultisampleCount(int requested)
{
	int supported = 0;

	for(int i = NUM_MULTISAMPLE_COUNTS - 1; i >= 0; i--)
	{
		if(supported >= requested)
		{
			return supported;
		}

		supported = multisampleCount[i];
	}

	return supported;
}

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(getArrayBufferName() == buffer)
    {
        mState.arrayBuffer = NULL;
    }

	for(auto tfIt = mTransformFeedbackMap.begin(); tfIt != mTransformFeedbackMap.end(); tfIt++)
	{
		tfIt->second->detachBuffer(buffer);
	}

	for(auto vaoIt = mVertexArrayMap.begin(); vaoIt != mVertexArrayMap.end(); vaoIt++)
	{
		vaoIt->second->detachBuffer(buffer);
	}

    for(int attribute = 0; attribute < MAX_VERTEX_ATTRIBS; attribute++)
    {
        if(mState.vertexAttribute[attribute].mBoundBuffer.name() == buffer)
        {
            mState.vertexAttribute[attribute].mBoundBuffer = 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 < MAX_COMBINED_TEXTURE_IMAGE_UNITS; sampler++)
        {
            if(mState.samplerTexture[type][sampler].name() == texture)
            {
                mState.samplerTexture[type][sampler] = 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.name() == 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);
    }
}

void Context::detachSampler(GLuint sampler)
{
	// [OpenGL ES 3.0.2] section 3.8.2 pages 123-124:
	// If a sampler object that is currently bound to one or more texture units is
	// deleted, it is as though BindSampler is called once for each texture unit to
	// which the sampler is bound, with unit set to the texture unit and sampler set to zero.
	for(size_t textureUnit = 0; textureUnit < MAX_COMBINED_TEXTURE_IMAGE_UNITS; ++textureUnit)
	{
		gl::BindingPointer<Sampler> &samplerBinding = mState.sampler[textureUnit];
		if(samplerBinding.name() == sampler)
		{
			samplerBinding = NULL;
		}
	}
}

bool Context::cullSkipsDraw(GLenum drawMode)
{
    return mState.cullFaceEnabled && mState.cullMode == GL_FRONT_AND_BACK && isTriangleMode(drawMode);
}

bool Context::isTriangleMode(GLenum drawMode)
{
    switch (drawMode)
    {
      case GL_TRIANGLES:
      case GL_TRIANGLE_FAN:
      case GL_TRIANGLE_STRIP:
        return true;
      case GL_POINTS:
      case GL_LINES:
      case GL_LINE_LOOP:
      case GL_LINE_STRIP:
        return false;
      default: UNREACHABLE(drawMode);
    }

    return false;
}

void Context::setVertexAttrib(GLuint index, const GLfloat *values)
{
    ASSERT(index < MAX_VERTEX_ATTRIBS);

    mState.vertexAttribute[index].setCurrentValue(values);

    mVertexDataManager->dirtyCurrentValue(index);
}

void Context::setVertexAttrib(GLuint index, const GLint *values)
{
	ASSERT(index < MAX_VERTEX_ATTRIBS);

	mState.vertexAttribute[index].setCurrentValue(values);

	mVertexDataManager->dirtyCurrentValue(index);
}

void Context::setVertexAttrib(GLuint index, const GLuint *values)
{
	ASSERT(index < MAX_VERTEX_ATTRIBS);

	mState.vertexAttribute[index].setCurrentValue(values);

	mVertexDataManager->dirtyCurrentValue(index);
}

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();

	int readBufferWidth, readBufferHeight, readBufferSamples;
    int drawBufferWidth, drawBufferHeight, drawBufferSamples;

    if(!readFramebuffer || readFramebuffer->completeness(readBufferWidth, readBufferHeight, readBufferSamples) != GL_FRAMEBUFFER_COMPLETE ||
       !drawFramebuffer || drawFramebuffer->completeness(drawBufferWidth, drawBufferHeight, drawBufferSamples) != GL_FRAMEBUFFER_COMPLETE)
    {
        return error(GL_INVALID_FRAMEBUFFER_OPERATION);
    }

    if(drawBufferSamples > 1)
    {
        return error(GL_INVALID_OPERATION);
    }

    sw::SliceRect sourceRect;
    sw::SliceRect destRect;
	bool flipX = (srcX0 < srcX1) ^ (dstX0 < dstX1);
	bool flipy = (srcY0 < srcY1) ^ (dstY0 < dstY1);

    if(srcX0 < srcX1)
    {
        sourceRect.x0 = srcX0;
        sourceRect.x1 = srcX1;
    }
    else
    {
        sourceRect.x0 = srcX1;
        sourceRect.x1 = srcX0;
    }

	if(dstX0 < dstX1)
	{
		destRect.x0 = dstX0;
		destRect.x1 = dstX1;
	}
	else
	{
		destRect.x0 = dstX1;
		destRect.x1 = dstX0;
	}
	
    if(srcY0 < srcY1)
    {
        sourceRect.y0 = srcY0;
        sourceRect.y1 = srcY1;
    }
    else
    {
        sourceRect.y0 = srcY1;
        sourceRect.y1 = srcY0;
    }

	if(dstY0 < dstY1)
	{
		destRect.y0 = dstY0;
		destRect.y1 = dstY1;
	}
	else
	{
		destRect.y0 = dstY1;
		destRect.y1 = dstY0;
	}

	sw::Rect sourceScissoredRect = sourceRect;
    sw::Rect destScissoredRect = destRect;

    if(mState.scissorTestEnabled)   // Only write to parts of the destination framebuffer which pass the scissor test
    {
        if(destRect.x0 < mState.scissorX)
        {
            int xDiff = mState.scissorX - destRect.x0;
            destScissoredRect.x0 = mState.scissorX;
            sourceScissoredRect.x0 += xDiff;
        }

        if(destRect.x1 > mState.scissorX + mState.scissorWidth)
        {
            int xDiff = destRect.x1 - (mState.scissorX + mState.scissorWidth);
            destScissoredRect.x1 = mState.scissorX + mState.scissorWidth;
            sourceScissoredRect.x1 -= xDiff;
        }

        if(destRect.y0 < mState.scissorY)
        {
            int yDiff = mState.scissorY - destRect.y0;
            destScissoredRect.y0 = mState.scissorY;
            sourceScissoredRect.y0 += yDiff;
        }

        if(destRect.y1 > mState.scissorY + mState.scissorHeight)
        {
            int yDiff = destRect.y1 - (mState.scissorY + mState.scissorHeight);
            destScissoredRect.y1 = mState.scissorY + mState.scissorHeight;
            sourceScissoredRect.y1 -= yDiff;
        }
    }

    sw::Rect sourceTrimmedRect = sourceScissoredRect;
    sw::Rect 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.x0 < 0)
    {
        int xDiff = 0 - sourceTrimmedRect.x0;
        sourceTrimmedRect.x0 = 0;
        destTrimmedRect.x0 += xDiff;
    }

    if(sourceTrimmedRect.x1 > readBufferWidth)
    {
        int xDiff = sourceTrimmedRect.x1 - readBufferWidth;
        sourceTrimmedRect.x1 = readBufferWidth;
        destTrimmedRect.x1 -= xDiff;
    }

    if(sourceTrimmedRect.y0 < 0)
    {
        int yDiff = 0 - sourceTrimmedRect.y0;
        sourceTrimmedRect.y0 = 0;
        destTrimmedRect.y0 += yDiff;
    }

    if(sourceTrimmedRect.y1 > readBufferHeight)
    {
        int yDiff = sourceTrimmedRect.y1 - readBufferHeight;
        sourceTrimmedRect.y1 = readBufferHeight;
        destTrimmedRect.y1 -= yDiff;
    }

    if(destTrimmedRect.x0 < 0)
    {
        int xDiff = 0 - destTrimmedRect.x0;
        destTrimmedRect.x0 = 0;
        sourceTrimmedRect.x0 += xDiff;
    }

    if(destTrimmedRect.x1 > drawBufferWidth)
    {
        int xDiff = destTrimmedRect.x1 - drawBufferWidth;
        destTrimmedRect.x1 = drawBufferWidth;
        sourceTrimmedRect.x1 -= xDiff;
    }

    if(destTrimmedRect.y0 < 0)
    {
        int yDiff = 0 - destTrimmedRect.y0;
        destTrimmedRect.y0 = 0;
        sourceTrimmedRect.y0 += yDiff;
    }

    if(destTrimmedRect.y1 > drawBufferHeight)
    {
        int yDiff = destTrimmedRect.y1 - drawBufferHeight;
        destTrimmedRect.y1 = drawBufferHeight;
        sourceTrimmedRect.y1 -= yDiff;
    }

    bool partialBufferCopy = false;

    if(sourceTrimmedRect.y1 - sourceTrimmedRect.y0 < readBufferHeight ||
       sourceTrimmedRect.x1 - sourceTrimmedRect.x0 < readBufferWidth || 
       destTrimmedRect.y1 - destTrimmedRect.y0 < drawBufferHeight ||
       destTrimmedRect.x1 - destTrimmedRect.x0 < drawBufferWidth ||
       sourceTrimmedRect.y0 != 0 || destTrimmedRect.y0 != 0 || sourceTrimmedRect.x0 != 0 || destTrimmedRect.x0 != 0)
    {
        partialBufferCopy = true;
    }

	bool blitRenderTarget = false;
    bool blitDepthStencil = false;

    if(mask & GL_COLOR_BUFFER_BIT)
    {
        const bool validReadType = readFramebuffer->getColorbufferType(getReadFramebufferColorIndex()) == GL_TEXTURE_2D ||
                                   readFramebuffer->getColorbufferType(getReadFramebufferColorIndex()) == GL_RENDERBUFFER;
        const bool validDrawType = drawFramebuffer->getColorbufferType(0) == GL_TEXTURE_2D ||
                                   drawFramebuffer->getColorbufferType(0) == GL_RENDERBUFFER;
        if(!validReadType || !validDrawType)
        {
            return error(GL_INVALID_OPERATION);
        }
        
        if(partialBufferCopy && readBufferSamples > 1)
        {
            return 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())
                {
                    return 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())
                {
                    return 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 error(GL_INVALID_OPERATION);   // Only whole-buffer copies are permitted
        }

        if((drawDSBuffer && drawDSBuffer->getSamples() > 1) || 
           (readDSBuffer && readDSBuffer->getSamples() > 1))
        {
            return error(GL_INVALID_OPERATION);
        }
    }

    if(blitRenderTarget || blitDepthStencil)
    {
        if(blitRenderTarget)
        {
            egl::Image *readRenderTarget = readFramebuffer->getReadRenderTarget();
            egl::Image *drawRenderTarget = drawFramebuffer->getRenderTarget(0);
 
			if(flipX)
			{
				swap(destRect.x0, destRect.x1);
			}
			if(flipy)
			{
				swap(destRect.y0, destRect.y1);
			}

            bool success = device->stretchRect(readRenderTarget, &sourceRect, drawRenderTarget, &destRect, false);

            readRenderTarget->release();
            drawRenderTarget->release();

            if(!success)
            {
                ERR("BlitFramebuffer failed.");
                return;
            }
        }

        if(blitDepthStencil)
        {
            bool success = device->stretchRect(readFramebuffer->getDepthStencil(), NULL, drawFramebuffer->getDepthStencil(), NULL, false);

            if(!success)
            {
                ERR("BlitFramebuffer failed.");
                return;
            }
        }
    }
}

void Context::bindTexImage(egl::Surface *surface)
{
	es2::Texture2D *textureObject = getTexture2D();

    if(textureObject)
    {
		textureObject->bindTexImage(surface);
	}
}

EGLenum Context::validateSharedImage(EGLenum target, GLuint name, GLuint textureLevel)
{
    GLenum textureTarget = GL_NONE;

    switch(target)
    {
    case EGL_GL_TEXTURE_2D_KHR:
        textureTarget = GL_TEXTURE_2D;
        break;
    case EGL_GL_TEXTURE_CUBE_MAP_POSITIVE_X_KHR:
    case EGL_GL_TEXTURE_CUBE_MAP_NEGATIVE_X_KHR:
    case EGL_GL_TEXTURE_CUBE_MAP_POSITIVE_Y_KHR:
    case EGL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_KHR:
    case EGL_GL_TEXTURE_CUBE_MAP_POSITIVE_Z_KHR:
    case EGL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_KHR:
        textureTarget = GL_TEXTURE_CUBE_MAP;
        break;
    case EGL_GL_RENDERBUFFER_KHR:
        break;
    default:
        return EGL_BAD_PARAMETER;
    }
	
    if(textureLevel >= es2::IMPLEMENTATION_MAX_TEXTURE_LEVELS)
    {
        return EGL_BAD_MATCH;
    }

    if(textureTarget != GL_NONE)
    {
        es2::Texture *texture = getTexture(name);

        if(!texture || texture->getTarget() != textureTarget)
        {
            return EGL_BAD_PARAMETER;
        }

        if(texture->isShared(textureTarget, textureLevel))   // Bound to an EGLSurface or already an EGLImage sibling
        {
            return EGL_BAD_ACCESS;
        }

        if(textureLevel != 0 && !texture->isSamplerComplete())
        {
            return EGL_BAD_PARAMETER;
        }

        if(textureLevel == 0 && !(texture->isSamplerComplete() && texture->getLevelCount() == 1))
        {
            return EGL_BAD_PARAMETER;
        }
    }
    else if(target == EGL_GL_RENDERBUFFER_KHR)
    {
        es2::Renderbuffer *renderbuffer = getRenderbuffer(name);

        if(!renderbuffer)
        {
            return EGL_BAD_PARAMETER;
        }

        if(renderbuffer->isShared())   // Already an EGLImage sibling
        {
            return EGL_BAD_ACCESS;
        }
    }
    else UNREACHABLE(target);

	return EGL_SUCCESS;
}

egl::Image *Context::createSharedImage(EGLenum target, GLuint name, GLuint textureLevel)
{
	GLenum textureTarget = GL_NONE;

    switch(target)
    {
    case EGL_GL_TEXTURE_2D_KHR:                  textureTarget = GL_TEXTURE_2D;                  break;
    case EGL_GL_TEXTURE_CUBE_MAP_POSITIVE_X_KHR: textureTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_X; break;
    case EGL_GL_TEXTURE_CUBE_MAP_NEGATIVE_X_KHR: textureTarget = GL_TEXTURE_CUBE_MAP_NEGATIVE_X; break;
    case EGL_GL_TEXTURE_CUBE_MAP_POSITIVE_Y_KHR: textureTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_Y; break;
    case EGL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_KHR: textureTarget = GL_TEXTURE_CUBE_MAP_NEGATIVE_Y; break;
    case EGL_GL_TEXTURE_CUBE_MAP_POSITIVE_Z_KHR: textureTarget = GL_TEXTURE_CUBE_MAP_POSITIVE_Z; break;
    case EGL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_KHR: textureTarget = GL_TEXTURE_CUBE_MAP_NEGATIVE_Z; break;
    }

    if(textureTarget != GL_NONE)
    {
        es2::Texture *texture = getTexture(name);

        return texture->createSharedImage(textureTarget, textureLevel);
    }
    else if(target == EGL_GL_RENDERBUFFER_KHR)
    {
        es2::Renderbuffer *renderbuffer = getRenderbuffer(name);

        return renderbuffer->createSharedImage();
    }
    else UNREACHABLE(target);

	return 0;
}

Device *Context::getDevice()
{
	return device;
}

const GLubyte* Context::getExtensions(GLuint index, GLuint* numExt) const
{
	// Keep list sorted in following order:
	// OES extensions
	// EXT extensions
	// Vendor extensions
	static const GLubyte* extensions[] = {
		(const GLubyte*)"GL_OES_compressed_ETC1_RGB8_texture",
		(const GLubyte*)"GL_OES_depth24",
		(const GLubyte*)"GL_OES_depth32",
		(const GLubyte*)"GL_OES_depth_texture",
		(const GLubyte*)"GL_OES_depth_texture_cube_map",
		(const GLubyte*)"GL_OES_EGL_image",
		(const GLubyte*)"GL_OES_EGL_image_external",
		(const GLubyte*)"GL_OES_EGL_sync",
		(const GLubyte*)"GL_OES_element_index_uint",
		(const GLubyte*)"GL_OES_framebuffer_object",
		(const GLubyte*)"GL_OES_packed_depth_stencil",
		(const GLubyte*)"GL_OES_rgb8_rgba8",
		(const GLubyte*)"GL_OES_standard_derivatives",
		(const GLubyte*)"GL_OES_texture_float",
		(const GLubyte*)"GL_OES_texture_float_linear",
		(const GLubyte*)"GL_OES_texture_half_float",
		(const GLubyte*)"GL_OES_texture_half_float_linear",
		(const GLubyte*)"GL_OES_texture_npot",
		(const GLubyte*)"GL_OES_texture_3D",
		(const GLubyte*)"GL_EXT_blend_minmax",
		(const GLubyte*)"GL_EXT_color_buffer_half_float",
		(const GLubyte*)"GL_EXT_occlusion_query_boolean",
		(const GLubyte*)"GL_EXT_read_format_bgra",
#if (S3TC_SUPPORT)
		(const GLubyte*)"GL_EXT_texture_compression_dxt1",
#endif
		(const GLubyte*)"GL_EXT_texture_filter_anisotropic",
		(const GLubyte*)"GL_EXT_texture_format_BGRA8888",
		(const GLubyte*)"GL_ANGLE_framebuffer_blit",
		(const GLubyte*)"GL_NV_framebuffer_blit",
		(const GLubyte*)"GL_ANGLE_framebuffer_multisample",
#if (S3TC_SUPPORT)
		(const GLubyte*)"GL_ANGLE_texture_compression_dxt3",
		(const GLubyte*)"GL_ANGLE_texture_compression_dxt5",
#endif
		(const GLubyte*)"GL_NV_fence",
		(const GLubyte*)"GL_EXT_instanced_arrays",
		(const GLubyte*)"GL_ANGLE_instanced_arrays",
	};
	static const GLuint numExtensions = sizeof(extensions) / sizeof(*extensions);

	if(numExt)
	{
		*numExt = numExtensions;
		return nullptr;
	}

	if(index == GL_INVALID_INDEX)
	{
		static GLubyte* extensionsCat = nullptr;
		if((extensionsCat == nullptr) && (numExtensions > 0))
		{
			int totalLength = numExtensions; // 1 space between each extension name + terminating null
			for(int i = 0; i < numExtensions; ++i)
			{
				totalLength += strlen(reinterpret_cast<const char*>(extensions[i]));
			}
			extensionsCat = new GLubyte[totalLength];
			extensionsCat[0] = '\0';
			for(int i = 0; i < numExtensions; ++i)
			{
				if(i != 0)
				{
					strcat(reinterpret_cast<char*>(extensionsCat), " ");
				}
				strcat(reinterpret_cast<char*>(extensionsCat), reinterpret_cast<const char*>(extensions[i]));
			}
		}
		return extensionsCat;
	}

	if(index >= numExtensions)
	{
		return nullptr;
	}

	return extensions[index];
}

}

egl::Context *es2CreateContext(const egl::Config *config, const egl::Context *shareContext, int clientVersion)
{
	ASSERT(!shareContext || shareContext->getClientVersion() == clientVersion);   // Should be checked by eglCreateContext
	return new es2::Context(config, static_cast<const es2::Context*>(shareContext), clientVersion);
}