src/libGLESv2/ProgramBinary.cpp

#include "precompiled.h"
//
// Copyright (c) 2002-2013 The ANGLE Project Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//

// Program.cpp: Implements the gl::Program class. Implements GL program objects
// and related functionality. [OpenGL ES 2.0.24] section 2.10.3 page 28.

#include "libGLESv2/BinaryStream.h"
#include "libGLESv2/ProgramBinary.h"
#include "libGLESv2/renderer/ShaderExecutable.h"

#include "common/debug.h"
#include "common/version.h"
#include "utilities.h"

#include "libGLESv2/main.h"
#include "libGLESv2/Shader.h"
#include "libGLESv2/Program.h"
#include "libGLESv2/renderer/Renderer.h"
#include "libGLESv2/renderer/VertexDataManager.h"
#include "libGLESv2/Context.h"

#undef near
#undef far

namespace gl
{
std::string str(int i)
{
    char buffer[20];
    snprintf(buffer, sizeof(buffer), "%d", i);
    return buffer;
}

namespace 
{

unsigned int parseAndStripArrayIndex(std::string* name)
{
    unsigned int subscript = GL_INVALID_INDEX;

    // Strip any trailing array operator and retrieve the subscript
    size_t open = name->find_last_of('[');
    size_t close = name->find_last_of(']');
    if (open != std::string::npos && close == name->length() - 1)
    {
        subscript = atoi(name->substr(open + 1).c_str());
        name->erase(open);
    }

    return subscript;
}

}

UniformLocation::UniformLocation(const std::string &name, unsigned int element, unsigned int index) 
    : name(name), element(element), index(index)
{
}

unsigned int ProgramBinary::mCurrentSerial = 1;

ProgramBinary::ProgramBinary(rx::Renderer *renderer) : mRenderer(renderer), RefCountObject(0), mSerial(issueSerial())
{
    mPixelExecutable = NULL;
    mVertexExecutable = NULL;
    mGeometryExecutable = NULL;

    mValidated = false;

    for (int index = 0; index < MAX_VERTEX_ATTRIBS; index++)
    {
        mSemanticIndex[index] = -1;
    }

    for (int index = 0; index < MAX_TEXTURE_IMAGE_UNITS; index++)
    {
        mSamplersPS[index].active = false;
    }

    for (int index = 0; index < IMPLEMENTATION_MAX_VERTEX_TEXTURE_IMAGE_UNITS; index++)
    {
        mSamplersVS[index].active = false;
    }

    mUsedVertexSamplerRange = 0;
    mUsedPixelSamplerRange = 0;
    mUsesPointSize = false;
}

ProgramBinary::~ProgramBinary()
{
    delete mPixelExecutable;
    mPixelExecutable = NULL;

    delete mVertexExecutable;
    mVertexExecutable = NULL;

    delete mGeometryExecutable;
    mGeometryExecutable = NULL;

    while (!mUniforms.empty())
    {
        delete mUniforms.back();
        mUniforms.pop_back();
    }

    while (!mUniformBlocks.empty())
    {
        delete mUniformBlocks.back();
        mUniformBlocks.pop_back();
    }
}

unsigned int ProgramBinary::getSerial() const
{
    return mSerial;
}

unsigned int ProgramBinary::issueSerial()
{
    return mCurrentSerial++;
}

rx::ShaderExecutable *ProgramBinary::getPixelExecutable()
{
    return mPixelExecutable;
}

rx::ShaderExecutable *ProgramBinary::getVertexExecutable()
{
    return mVertexExecutable;
}

rx::ShaderExecutable *ProgramBinary::getGeometryExecutable()
{
    return mGeometryExecutable;
}

GLuint ProgramBinary::getAttributeLocation(const char *name)
{
    if (name)
    {
        for (int index = 0; index < MAX_VERTEX_ATTRIBS; index++)
        {
            if (mLinkedAttribute[index].name == std::string(name))
            {
                return index;
            }
        }
    }

    return -1;
}

int ProgramBinary::getSemanticIndex(int attributeIndex)
{
    ASSERT(attributeIndex >= 0 && attributeIndex < MAX_VERTEX_ATTRIBS);
    
    return mSemanticIndex[attributeIndex];
}

// Returns one more than the highest sampler index used.
GLint ProgramBinary::getUsedSamplerRange(SamplerType type)
{
    switch (type)
    {
      case SAMPLER_PIXEL:
        return mUsedPixelSamplerRange;
      case SAMPLER_VERTEX:
        return mUsedVertexSamplerRange;
      default:
        UNREACHABLE();
        return 0;
    }
}

bool ProgramBinary::usesPointSize() const
{
    return mUsesPointSize;
}

bool ProgramBinary::usesPointSpriteEmulation() const
{
    return mUsesPointSize && mRenderer->getMajorShaderModel() >= 4;
}

bool ProgramBinary::usesGeometryShader() const
{
    return usesPointSpriteEmulation();
}

// Returns the index of the texture image unit (0-19) corresponding to a Direct3D 9 sampler
// index (0-15 for the pixel shader and 0-3 for the vertex shader).
GLint ProgramBinary::getSamplerMapping(SamplerType type, unsigned int samplerIndex)
{
    GLint logicalTextureUnit = -1;

    switch (type)
    {
      case SAMPLER_PIXEL:
        ASSERT(samplerIndex < sizeof(mSamplersPS)/sizeof(mSamplersPS[0]));

        if (mSamplersPS[samplerIndex].active)
        {
            logicalTextureUnit = mSamplersPS[samplerIndex].logicalTextureUnit;
        }
        break;
      case SAMPLER_VERTEX:
        ASSERT(samplerIndex < sizeof(mSamplersVS)/sizeof(mSamplersVS[0]));

        if (mSamplersVS[samplerIndex].active)
        {
            logicalTextureUnit = mSamplersVS[samplerIndex].logicalTextureUnit;
        }
        break;
      default: UNREACHABLE();
    }

    if (logicalTextureUnit >= 0 && logicalTextureUnit < (GLint)mRenderer->getMaxCombinedTextureImageUnits())
    {
        return logicalTextureUnit;
    }

    return -1;
}

// Returns the texture type for a given Direct3D 9 sampler type and
// index (0-15 for the pixel shader and 0-3 for the vertex shader).
TextureType ProgramBinary::getSamplerTextureType(SamplerType type, unsigned int samplerIndex)
{
    switch (type)
    {
      case SAMPLER_PIXEL:
        ASSERT(samplerIndex < sizeof(mSamplersPS)/sizeof(mSamplersPS[0]));
        ASSERT(mSamplersPS[samplerIndex].active);
        return mSamplersPS[samplerIndex].textureType;
      case SAMPLER_VERTEX:
        ASSERT(samplerIndex < sizeof(mSamplersVS)/sizeof(mSamplersVS[0]));
        ASSERT(mSamplersVS[samplerIndex].active);
        return mSamplersVS[samplerIndex].textureType;
      default: UNREACHABLE();
    }

    return TEXTURE_2D;
}

GLint ProgramBinary::getUniformLocation(std::string name)
{
    unsigned int subscript = parseAndStripArrayIndex(&name);

    unsigned int numUniforms = mUniformIndex.size();
    for (unsigned int location = 0; location < numUniforms; location++)
    {
        if (mUniformIndex[location].name == name)
        {
            const int index = mUniformIndex[location].index;
            const bool isArray = mUniforms[index]->isArray();

            if ((isArray && mUniformIndex[location].element == subscript) || 
                (subscript == GL_INVALID_INDEX))
            {
                return location;
            }
        }
    }

    return -1;
}

GLuint ProgramBinary::getUniformIndex(std::string name)
{
    unsigned int subscript = parseAndStripArrayIndex(&name);

    // The app is not allowed to specify array indices other than 0 for arrays of basic types
    if (subscript != 0 && subscript != GL_INVALID_INDEX)
    {
        return GL_INVALID_INDEX;
    }

    unsigned int numUniforms = mUniforms.size();
    for (unsigned int index = 0; index < numUniforms; index++)
    {
        if (mUniforms[index]->name == name)
        {
            if (mUniforms[index]->isArray() || subscript == GL_INVALID_INDEX)
            {
                return index;
            }
        }
    }

    return GL_INVALID_INDEX;
}

GLuint ProgramBinary::getUniformBlockIndex(std::string name)
{
    unsigned int subscript = parseAndStripArrayIndex(&name);

    unsigned int numUniformBlocks = mUniformBlocks.size();
    for (unsigned int blockIndex = 0; blockIndex < numUniformBlocks; blockIndex++)
    {
        const UniformBlock &uniformBlock = *mUniformBlocks[blockIndex];
        if (uniformBlock.name == name)
        {
            const bool arrayElementZero = (subscript == GL_INVALID_INDEX && uniformBlock.elementIndex == 0);
            if (subscript == uniformBlock.elementIndex || arrayElementZero)
            {
                return blockIndex;
            }
        }
    }

    return GL_INVALID_INDEX;
}

template <typename T>
bool ProgramBinary::setUniform(GLint location, GLsizei count, const T* v, GLenum targetUniformType)
{
    if (location < 0 || location >= (int)mUniformIndex.size())
    {
        return false;
    }

    const int components = UniformComponentCount(targetUniformType);
    const GLenum targetBoolType = UniformBoolVectorType(targetUniformType);

    Uniform *targetUniform = mUniforms[mUniformIndex[location].index];
    targetUniform->dirty = true;

    int elementCount = targetUniform->elementCount();

    if (elementCount == 1 && count > 1)
        return false; // attempting to write an array to a non-array uniform is an INVALID_OPERATION

    count = std::min(elementCount - (int)mUniformIndex[location].element, count);

    if (targetUniform->type == targetUniformType)
    {
        T *target = (T*)targetUniform->data + mUniformIndex[location].element * 4;

        for (int i = 0; i < count; i++)
        {
            for (int c = 0; c < components; c++)
            {
                target[c] = v[c];
            }
            for (int c = components; c < 4; c++)
            {
                target[c] = 0;
            }
            target += 4;
            v += components;
        }
    }
    else if (targetUniform->type == targetBoolType)
    {
        GLint *boolParams = (GLint*)targetUniform->data + mUniformIndex[location].element * 4;

        for (int i = 0; i < count; i++)
        {
            for (int c = 0; c < components; c++)
            {
                boolParams[c] = (v[c] == static_cast<T>(0)) ? GL_FALSE : GL_TRUE;
            }
            for (int c = components; c < 4; c++)
            {
                boolParams[c] = GL_FALSE;
            }
            boolParams += 4;
            v += components;
        }
    }
    else
    {
        return false;
    }

    return true;
}

bool ProgramBinary::setUniform1fv(GLint location, GLsizei count, const GLfloat* v)
{
    return setUniform(location, count, v, GL_FLOAT);
}

bool ProgramBinary::setUniform2fv(GLint location, GLsizei count, const GLfloat *v)
{
    return setUniform(location, count, v, GL_FLOAT_VEC2);
}

bool ProgramBinary::setUniform3fv(GLint location, GLsizei count, const GLfloat *v)
{
    return setUniform(location, count, v, GL_FLOAT_VEC3);
}

bool ProgramBinary::setUniform4fv(GLint location, GLsizei count, const GLfloat *v)
{
    return setUniform(location, count, v, GL_FLOAT_VEC4);
}

template<typename T>
void transposeMatrix(T *target, const GLfloat *value, int targetWidth, int targetHeight, int srcWidth, int srcHeight)
{
    int copyWidth = std::min(targetWidth, srcWidth);
    int copyHeight = std::min(targetHeight, srcHeight);

    for (int x = 0; x < copyWidth; x++)
    {
        for (int y = 0; y < copyHeight; y++)
        {
            target[x * targetWidth + y] = static_cast<T>(value[y * srcWidth + x]);
        }
    }
    // clear unfilled right side
    for (int y = 0; y < copyWidth; y++)
    {
        for (int x = copyHeight; x < targetWidth; x++)
        {
            target[y * targetWidth + x] = static_cast<T>(0);
        }
    }
    // clear unfilled bottom.
    for (int y = copyWidth; y < targetHeight; y++)
    {
        for (int x = 0; x < targetWidth; x++)
        {
            target[y * targetWidth + x] = static_cast<T>(0);
        }
    }
}

template<typename T>
void expandMatrix(T *target, const GLfloat *value, int targetWidth, int targetHeight, int srcWidth, int srcHeight)
{
    int copyWidth = std::min(targetWidth, srcWidth);
    int copyHeight = std::min(targetHeight, srcHeight);

    for (int y = 0; y < copyHeight; y++)
    {
        for (int x = 0; x < copyWidth; x++)
        {
            target[y * targetWidth + x] = static_cast<T>(value[y * srcWidth + x]);
        }
    }
    // clear unfilled right side
    for (int y = 0; y < copyHeight; y++)
    {
        for (int x = copyWidth; x < targetWidth; x++)
        {
            target[y * targetWidth + x] = static_cast<T>(0);
        }
    }
    // clear unfilled bottom.
    for (int y = copyHeight; y < targetHeight; y++)
    {
        for (int x = 0; x < targetWidth; x++)
        {
            target[y * targetWidth + x] = static_cast<T>(0);
        }
    }
}

template <int cols, int rows>
bool ProgramBinary::setUniformMatrixfv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value, GLenum targetUniformType) 
{
    if (location < 0 || location >= (int)mUniformIndex.size())
    {
        return false;
    }

    Uniform *targetUniform = mUniforms[mUniformIndex[location].index];
    targetUniform->dirty = true;

    if (targetUniform->type != targetUniformType)
    {
        return false;
    }

    int elementCount = targetUniform->elementCount();

    if (elementCount == 1 && count > 1)
        return false; // attempting to write an array to a non-array uniform is an INVALID_OPERATION

    count = std::min(elementCount - (int)mUniformIndex[location].element, count);
    GLfloat *target = (GLfloat*)(targetUniform->data + mUniformIndex[location].element * sizeof(GLfloat) * 4 * rows);

    for (int i = 0; i < count; i++)
    {
        // Internally store matrices as transposed versions to accomodate HLSL matrix indexing
        if (transpose == GL_FALSE)
        {
            transposeMatrix<GLfloat>(target, value, 4, rows, rows, cols);
        }
        else
        {
            expandMatrix<GLfloat>(target, value, 4, rows, cols, rows);
        }
        target += 4 * rows;
        value += cols * rows;
    }

    return true;
}

bool ProgramBinary::setUniformMatrix2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<2, 2>(location, count, transpose, value, GL_FLOAT_MAT2);
}

bool ProgramBinary::setUniformMatrix3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<3, 3>(location, count, transpose, value, GL_FLOAT_MAT3);
}

bool ProgramBinary::setUniformMatrix4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<4, 4>(location, count, transpose, value, GL_FLOAT_MAT4);
}

bool ProgramBinary::setUniformMatrix2x3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<2, 3>(location, count, transpose, value, GL_FLOAT_MAT2x3);
}

bool ProgramBinary::setUniformMatrix3x2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<3, 2>(location, count, transpose, value, GL_FLOAT_MAT3x2);
}

bool ProgramBinary::setUniformMatrix2x4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<2, 4>(location, count, transpose, value, GL_FLOAT_MAT2x4);
}

bool ProgramBinary::setUniformMatrix4x2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<4, 2>(location, count, transpose, value, GL_FLOAT_MAT4x2);
}

bool ProgramBinary::setUniformMatrix3x4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<3, 4>(location, count, transpose, value, GL_FLOAT_MAT3x4);
}

bool ProgramBinary::setUniformMatrix4x3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
{
    return setUniformMatrixfv<4, 3>(location, count, transpose, value, GL_FLOAT_MAT4x3);
}

bool ProgramBinary::setUniform1iv(GLint location, GLsizei count, const GLint *v)
{
    if (location < 0 || location >= (int)mUniformIndex.size())
    {
        return false;
    }

    Uniform *targetUniform = mUniforms[mUniformIndex[location].index];
    targetUniform->dirty = true;

    int elementCount = targetUniform->elementCount();

    if (elementCount == 1 && count > 1)
        return false; // attempting to write an array to a non-array uniform is an INVALID_OPERATION

    count = std::min(elementCount - (int)mUniformIndex[location].element, count);

    if (targetUniform->type == GL_INT ||
        targetUniform->type == GL_SAMPLER_2D ||
        targetUniform->type == GL_SAMPLER_CUBE)
    {
        GLint *target = (GLint*)targetUniform->data + mUniformIndex[location].element * 4;

        for (int i = 0; i < count; i++)
        {
            target[0] = v[0];
            target[1] = 0;
            target[2] = 0;
            target[3] = 0;
            target += 4;
            v += 1;
        }
    }
    else if (targetUniform->type == GL_BOOL)
    {
        GLint *boolParams = (GLint*)targetUniform->data + mUniformIndex[location].element * 4;

        for (int i = 0; i < count; i++)
        {
            boolParams[0] = (v[0] == 0) ? GL_FALSE : GL_TRUE;
            boolParams[1] = GL_FALSE;
            boolParams[2] = GL_FALSE;
            boolParams[3] = GL_FALSE;
            boolParams += 4;
            v += 1;
        }
    }
    else
    {
        return false;
    }

    return true;
}

bool ProgramBinary::setUniform2iv(GLint location, GLsizei count, const GLint *v)
{
    return setUniform(location, count, v, GL_INT_VEC2);
}

bool ProgramBinary::setUniform3iv(GLint location, GLsizei count, const GLint *v)
{
    return setUniform(location, count, v, GL_INT_VEC3);
}

bool ProgramBinary::setUniform4iv(GLint location, GLsizei count, const GLint *v)
{
    return setUniform(location, count, v, GL_INT_VEC4);
}

bool ProgramBinary::setUniform1uiv(GLint location, GLsizei count, const GLuint *v)
{
    return setUniform(location, count, v, GL_UNSIGNED_INT);
}

bool ProgramBinary::setUniform2uiv(GLint location, GLsizei count, const GLuint *v)
{
    return setUniform(location, count, v, GL_UNSIGNED_INT_VEC2);
}

bool ProgramBinary::setUniform3uiv(GLint location, GLsizei count, const GLuint *v)
{
    return setUniform(location, count, v, GL_UNSIGNED_INT_VEC3);
}

bool ProgramBinary::setUniform4uiv(GLint location, GLsizei count, const GLuint *v)
{
    return setUniform(location, count, v, GL_UNSIGNED_INT_VEC4);
}

template <typename T>
bool ProgramBinary::getUniformv(GLint location, GLsizei *bufSize, T *params, GLenum uniformType)
{
    if (location < 0 || location >= (int)mUniformIndex.size())
    {
        return false;
    }

    Uniform *targetUniform = mUniforms[mUniformIndex[location].index];

    // sized queries -- ensure the provided buffer is large enough
    if (bufSize)
    {
        int requiredBytes = UniformExternalSize(targetUniform->type);
        if (*bufSize < requiredBytes)
        {
            return false;
        }
    }

    if (IsMatrixType(targetUniform->type))
    {
        const int rows = VariableRowCount(targetUniform->type);
        const int cols = VariableColumnCount(targetUniform->type);
        transposeMatrix(params, (GLfloat*)targetUniform->data + mUniformIndex[location].element * 4 * rows, cols, rows, 4, rows);
    }
    else if (uniformType == UniformComponentType(targetUniform->type))
    {
        unsigned int size = UniformComponentCount(targetUniform->type);
        memcpy(params, targetUniform->data + mUniformIndex[location].element * 4 * sizeof(T),
                size * sizeof(T));
    }
    else
    {
        unsigned int size = UniformComponentCount(targetUniform->type);
        switch (UniformComponentType(targetUniform->type))
        {
          case GL_BOOL:
            {
                GLint *boolParams = (GLint*)targetUniform->data + mUniformIndex[location].element * 4;

                for (unsigned int i = 0; i < size; i++)
                {
                    params[i] = (boolParams[i] == GL_FALSE) ? static_cast<T>(0) : static_cast<T>(1);
                }
            }
            break;

          case GL_FLOAT:
            {
                GLfloat *floatParams = (GLfloat*)targetUniform->data + mUniformIndex[location].element * 4;

                for (unsigned int i = 0; i < size; i++)
                {
                    params[i] = static_cast<T>(floatParams[i]);
                }
            }
            break;

          case GL_INT:
            {
                GLint *intParams = (GLint*)targetUniform->data + mUniformIndex[location].element * 4;

                for (unsigned int i = 0; i < size; i++)
                {
                    params[i] = static_cast<T>(intParams[i]);
                }
            }
            break;
       
          case GL_UNSIGNED_INT:
            {
                GLuint *uintParams = (GLuint*)targetUniform->data + mUniformIndex[location].element * 4;

                for (unsigned int i = 0; i < size; i++)
                {
                    params[i] = static_cast<T>(uintParams[i]);
                }
            }
            break;
          
          default: UNREACHABLE();
        }
    }

    return true;
}

bool ProgramBinary::getUniformfv(GLint location, GLsizei *bufSize, GLfloat *params)
{
    return getUniformv(location, bufSize, params, GL_FLOAT);
}

bool ProgramBinary::getUniformiv(GLint location, GLsizei *bufSize, GLint *params)
{
    return getUniformv(location, bufSize, params, GL_INT);
}

bool ProgramBinary::getUniformuiv(GLint location, GLsizei *bufSize, GLuint *params)
{
    return getUniformv(location, bufSize, params, GL_UNSIGNED_INT);
}

void ProgramBinary::dirtyAllUniforms()
{
    unsigned int numUniforms = mUniforms.size();
    for (unsigned int index = 0; index < numUniforms; index++)
    {
        mUniforms[index]->dirty = true;
    }
}

// Applies all the uniforms set for this program object to the renderer
void ProgramBinary::applyUniforms()
{
    // Retrieve sampler uniform values
    for (std::vector<Uniform*>::iterator ub = mUniforms.begin(), ue = mUniforms.end(); ub != ue; ++ub)
    {
        Uniform *targetUniform = *ub;

        if (targetUniform->dirty)
        {
            if (targetUniform->type == GL_SAMPLER_2D || 
                targetUniform->type == GL_SAMPLER_CUBE)
            {
                int count = targetUniform->elementCount();
                GLint (*v)[4] = (GLint(*)[4])targetUniform->data;

                if (targetUniform->isReferencedByFragmentShader())
                {
                    unsigned int firstIndex = targetUniform->psRegisterIndex;

                    for (int i = 0; i < count; i++)
                    {
                        unsigned int samplerIndex = firstIndex + i;

                        if (samplerIndex < MAX_TEXTURE_IMAGE_UNITS)
                        {
                            ASSERT(mSamplersPS[samplerIndex].active);
                            mSamplersPS[samplerIndex].logicalTextureUnit = v[i][0];
                        }
                    }
                }

                if (targetUniform->isReferencedByVertexShader())
                {
                    unsigned int firstIndex = targetUniform->vsRegisterIndex;

                    for (int i = 0; i < count; i++)
                    {
                        unsigned int samplerIndex = firstIndex + i;

                        if (samplerIndex < IMPLEMENTATION_MAX_VERTEX_TEXTURE_IMAGE_UNITS)
                        {
                            ASSERT(mSamplersVS[samplerIndex].active);
                            mSamplersVS[samplerIndex].logicalTextureUnit = v[i][0];
                        }
                    }
                }
            }
        }
    }

    mRenderer->applyUniforms(this, &mUniforms);
}

// Packs varyings into generic varying registers, using the algorithm from [OpenGL ES Shading Language 1.00 rev. 17] appendix A section 7 page 111
// Returns the number of used varying registers, or -1 if unsuccesful
int ProgramBinary::packVaryings(InfoLog &infoLog, const Varying *packing[][4], FragmentShader *fragmentShader)
{
    const int maxVaryingVectors = mRenderer->getMaxVaryingVectors();

    fragmentShader->resetVaryingsRegisterAssignment();

    for (VaryingList::iterator varying = fragmentShader->mVaryings.begin(); varying != fragmentShader->mVaryings.end(); varying++)
    {
        int n = VariableRowCount(varying->type) * varying->size;
        int m = VariableColumnCount(varying->type);
        bool success = false;

        if (m == 2 || m == 3 || m == 4)
        {
            for (int r = 0; r <= maxVaryingVectors - n && !success; r++)
            {
                bool available = true;

                for (int y = 0; y < n && available; y++)
                {
                    for (int x = 0; x < m && available; x++)
                    {
                        if (packing[r + y][x])
                        {
                            available = false;
                        }
                    }
                }

                if (available)
                {
                    varying->reg = r;
                    varying->col = 0;

                    for (int y = 0; y < n; y++)
                    {
                        for (int x = 0; x < m; x++)
                        {
                            packing[r + y][x] = &*varying;
                        }
                    }

                    success = true;
                }
            }

            if (!success && m == 2)
            {
                for (int r = maxVaryingVectors - n; r >= 0 && !success; r--)
                {
                    bool available = true;

                    for (int y = 0; y < n && available; y++)
                    {
                        for (int x = 2; x < 4 && available; x++)
                        {
                            if (packing[r + y][x])
                            {
                                available = false;
                            }
                        }
                    }

                    if (available)
                    {
                        varying->reg = r;
                        varying->col = 2;

                        for (int y = 0; y < n; y++)
                        {
                            for (int x = 2; x < 4; x++)
                            {
                                packing[r + y][x] = &*varying;
                            }
                        }

                        success = true;
                    }
                }
            }
        }
        else if (m == 1)
        {
            int space[4] = {0};

            for (int y = 0; y < maxVaryingVectors; y++)
            {
                for (int x = 0; x < 4; x++)
                {
                    space[x] += packing[y][x] ? 0 : 1;
                }
            }

            int column = 0;

            for (int x = 0; x < 4; x++)
            {
                if (space[x] >= n && space[x] < space[column])
                {
                    column = x;
                }
            }

            if (space[column] >= n)
            {
                for (int r = 0; r < maxVaryingVectors; r++)
                {
                    if (!packing[r][column])
                    {
                        varying->reg = r;

                        for (int y = r; y < r + n; y++)
                        {
                            packing[y][column] = &*varying;
                        }

                        break;
                    }
                }

                varying->col = column;

                success = true;
            }
        }
        else UNREACHABLE();

        if (!success)
        {
            infoLog.append("Could not pack varying %s", varying->name.c_str());

            return -1;
        }
    }

    // Return the number of used registers
    int registers = 0;

    for (int r = 0; r < maxVaryingVectors; r++)
    {
        if (packing[r][0] || packing[r][1] || packing[r][2] || packing[r][3])
        {
            registers++;
        }
    }

    return registers;
}

bool ProgramBinary::linkVaryings(InfoLog &infoLog, int registers, const Varying *packing[][4],
                                 std::string& pixelHLSL, std::string& vertexHLSL,
                                 FragmentShader *fragmentShader, VertexShader *vertexShader)
{
    if (pixelHLSL.empty() || vertexHLSL.empty())
    {
        return false;
    }

    bool usesMRT = fragmentShader->mUsesMultipleRenderTargets;
    bool usesFragColor = fragmentShader->mUsesFragColor;
    bool usesFragData = fragmentShader->mUsesFragData;
    if (usesFragColor && usesFragData)
    {
        infoLog.append("Cannot use both gl_FragColor and gl_FragData in the same fragment shader.");
        return false;
    }

    // Write the HLSL input/output declarations
    const int shaderModel = mRenderer->getMajorShaderModel();
    const int maxVaryingVectors = mRenderer->getMaxVaryingVectors();

    const int registersNeeded = registers + (fragmentShader->mUsesFragCoord ? 1 : 0) + (fragmentShader->mUsesPointCoord ? 1 : 0);

    // Two cases when writing to gl_FragColor and using ESSL 1.0:
    // - with a 3.0 context, the output color is copied to channel 0
    // - with a 2.0 context, the output color is broadcast to all channels
    const bool broadcast = (fragmentShader->mUsesFragColor && mRenderer->getCurrentClientVersion() < 3);
    const unsigned int numRenderTargets = (broadcast || usesMRT ? mRenderer->getMaxRenderTargets() : 1);

    if (registersNeeded > maxVaryingVectors)
    {
        infoLog.append("No varying registers left to support gl_FragCoord/gl_PointCoord");

        return false;
    }

    vertexShader->resetVaryingsRegisterAssignment();

    for (VaryingList::iterator input = fragmentShader->mVaryings.begin(); input != fragmentShader->mVaryings.end(); input++)
    {
        bool matched = false;

        for (VaryingList::iterator output = vertexShader->mVaryings.begin(); output != vertexShader->mVaryings.end(); output++)
        {
            if (output->name == input->name)
            {
                if (output->type != input->type || output->size != input->size || output->interpolation != input->interpolation)
                {
                    infoLog.append("Type of vertex varying %s does not match that of the fragment varying", output->name.c_str());

                    return false;
                }

                output->reg = input->reg;
                output->col = input->col;

                matched = true;
                break;
            }
        }

        if (!matched)
        {
            infoLog.append("Fragment varying %s does not match any vertex varying", input->name.c_str());

            return false;
        }
    }

    mUsesPointSize = vertexShader->mUsesPointSize;
    std::string varyingSemantic = (mUsesPointSize && shaderModel == 3) ? "COLOR" : "TEXCOORD";
    std::string targetSemantic = (shaderModel >= 4) ? "SV_Target" : "COLOR";
    std::string positionSemantic = (shaderModel >= 4) ? "SV_Position" : "POSITION";

    std::string varyingHLSL = generateVaryingHLSL(fragmentShader, varyingSemantic);

    // special varyings that use reserved registers
    int reservedRegisterIndex = registers;
    std::string fragCoordSemantic;
    std::string pointCoordSemantic;

    if (fragmentShader->mUsesFragCoord)
    {
        fragCoordSemantic = varyingSemantic + str(reservedRegisterIndex++);
    }

    if (fragmentShader->mUsesPointCoord)
    {
        // Shader model 3 uses a special TEXCOORD semantic for point sprite texcoords.
        // In DX11 we compute this in the GS.
        if (shaderModel == 3)
        {
            pointCoordSemantic = "TEXCOORD0";
        }
        else if (shaderModel >= 4)
        {
            pointCoordSemantic = varyingSemantic + str(reservedRegisterIndex++); 
        }
    }

    vertexHLSL += "struct VS_INPUT\n"
                  "{\n";

    int semanticIndex = 0;
    for (AttributeArray::iterator attribute = vertexShader->mAttributes.begin(); attribute != vertexShader->mAttributes.end(); attribute++)
    {
        switch (attribute->type)
        {
          case GL_FLOAT:      vertexHLSL += "    float ";    break;
          case GL_FLOAT_VEC2: vertexHLSL += "    float2 ";   break;
          case GL_FLOAT_VEC3: vertexHLSL += "    float3 ";   break;
          case GL_FLOAT_VEC4: vertexHLSL += "    float4 ";   break;
          case GL_FLOAT_MAT2: vertexHLSL += "    float2x2 "; break;
          case GL_FLOAT_MAT3: vertexHLSL += "    float3x3 "; break;
          case GL_FLOAT_MAT4: vertexHLSL += "    float4x4 "; break;
          default:  UNREACHABLE();
        }

        vertexHLSL += decorateAttribute(attribute->name) + " : TEXCOORD" + str(semanticIndex) + ";\n";

        semanticIndex += VariableRowCount(attribute->type);
    }

    vertexHLSL += "};\n"
                  "\n"
                  "struct VS_OUTPUT\n"
                  "{\n";

    if (shaderModel < 4)
    {
        vertexHLSL += "    float4 gl_Position : " + positionSemantic + ";\n";
    }

    vertexHLSL += varyingHLSL;

    if (fragmentShader->mUsesFragCoord)
    {
        vertexHLSL += "    float4 gl_FragCoord : " + fragCoordSemantic + ";\n";
    }

    if (vertexShader->mUsesPointSize && shaderModel >= 3)
    {
        vertexHLSL += "    float gl_PointSize : PSIZE;\n";
    }

    if (shaderModel >= 4)
    {
        vertexHLSL += "    float4 gl_Position : " + positionSemantic + ";\n";
    }

    vertexHLSL += "};\n"
                  "\n"
                  "VS_OUTPUT main(VS_INPUT input)\n"
                  "{\n";

    for (AttributeArray::iterator attribute = vertexShader->mAttributes.begin(); attribute != vertexShader->mAttributes.end(); attribute++)
    {
        vertexHLSL += "    " + decorateAttribute(attribute->name) + " = ";

        if (VariableRowCount(attribute->type) > 1)   // Matrix
        {
            vertexHLSL += "transpose";
        }

        vertexHLSL += "(input." + decorateAttribute(attribute->name) + ");\n";
    }

    if (shaderModel >= 4)
    {
        vertexHLSL += "\n"
                      "    gl_main();\n"
                      "\n"
                      "    VS_OUTPUT output;\n"
                      "    output.gl_Position.x = gl_Position.x;\n"
                      "    output.gl_Position.y = -gl_Position.y;\n"
                      "    output.gl_Position.z = (gl_Position.z + gl_Position.w) * 0.5;\n"
                      "    output.gl_Position.w = gl_Position.w;\n";
    }
    else
    {
        vertexHLSL += "\n"
                      "    gl_main();\n"
                      "\n"
                      "    VS_OUTPUT output;\n"
                      "    output.gl_Position.x = gl_Position.x * dx_ViewAdjust.z + dx_ViewAdjust.x * gl_Position.w;\n"
                      "    output.gl_Position.y = -(gl_Position.y * dx_ViewAdjust.w + dx_ViewAdjust.y * gl_Position.w);\n"
                      "    output.gl_Position.z = (gl_Position.z + gl_Position.w) * 0.5;\n"
                      "    output.gl_Position.w = gl_Position.w;\n";
    }

    if (vertexShader->mUsesPointSize && shaderModel >= 3)
    {
        vertexHLSL += "    output.gl_PointSize = gl_PointSize;\n";
    }

    if (fragmentShader->mUsesFragCoord)
    {
        vertexHLSL += "    output.gl_FragCoord = gl_Position;\n";
    }

    for (VaryingList::iterator varying = vertexShader->mVaryings.begin(); varying != vertexShader->mVaryings.end(); varying++)
    {
        if (varying->reg >= 0)
        {
            for (int i = 0; i < varying->size; i++)
            {
                int rows = VariableRowCount(varying->type);

                for (int j = 0; j < rows; j++)
                {
                    int r = varying->reg + i * rows + j;
                    vertexHLSL += "    output.v" + str(r);

                    bool sharedRegister = false;   // Register used by multiple varyings
                    
                    for (int x = 0; x < 4; x++)
                    {
                        if (packing[r][x] && packing[r][x] != packing[r][0])
                        {
                            sharedRegister = true;
                            break;
                        }
                    }

                    if(sharedRegister)
                    {
                        vertexHLSL += ".";

                        for (int x = 0; x < 4; x++)
                        {
                            if (packing[r][x] == &*varying)
                            {
                                switch(x)
                                {
                                  case 0: vertexHLSL += "x"; break;
                                  case 1: vertexHLSL += "y"; break;
                                  case 2: vertexHLSL += "z"; break;
                                  case 3: vertexHLSL += "w"; break;
                                }
                            }
                        }
                    }

                    vertexHLSL += " = " + varying->name;
                    
                    if (varying->array)
                    {
                        vertexHLSL += "[" + str(i) + "]";
                    }

                    if (rows > 1)
                    {
                        vertexHLSL += "[" + str(j) + "]";
                    }
                    
                    vertexHLSL += ";\n";
                }
            }
        }
    }

    vertexHLSL += "\n"
                  "    return output;\n"
                  "}\n";

    pixelHLSL += "struct PS_INPUT\n"
                 "{\n";
    
    pixelHLSL += varyingHLSL;

    if (fragmentShader->mUsesFragCoord)
    {
        pixelHLSL += "    float4 gl_FragCoord : " + fragCoordSemantic + ";\n";
    }
        
    if (fragmentShader->mUsesPointCoord && shaderModel >= 3)
    {
        pixelHLSL += "    float2 gl_PointCoord : " + pointCoordSemantic + ";\n";
    }

    // Must consume the PSIZE element if the geometry shader is not active
    // We won't know if we use a GS until we draw
    if (vertexShader->mUsesPointSize && shaderModel >= 4)
    {
        pixelHLSL += "    float gl_PointSize : PSIZE;\n";
    }

    if (fragmentShader->mUsesFragCoord)
    {
        if (shaderModel >= 4)
        {
            pixelHLSL += "    float4 dx_VPos : SV_Position;\n";
        }
        else if (shaderModel >= 3)
        {
            pixelHLSL += "    float2 dx_VPos : VPOS;\n";
        }
    }

    pixelHLSL += "};\n"
                 "\n"
                 "struct PS_OUTPUT\n"
                 "{\n";

    for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets; renderTargetIndex++)
    {
        pixelHLSL += "    float4 gl_Color" + str(renderTargetIndex) + " : " + targetSemantic + str(renderTargetIndex) + ";\n";
    }

    pixelHLSL += "};\n"
                 "\n";

    if (fragmentShader->mUsesFrontFacing)
    {
        if (shaderModel >= 4)
        {
            pixelHLSL += "PS_OUTPUT main(PS_INPUT input, bool isFrontFace : SV_IsFrontFace)\n"
                         "{\n";
        }
        else
        {
            pixelHLSL += "PS_OUTPUT main(PS_INPUT input, float vFace : VFACE)\n"
                         "{\n";
        }
    }
    else
    {
        pixelHLSL += "PS_OUTPUT main(PS_INPUT input)\n"
                     "{\n";
    }

    if (fragmentShader->mUsesFragCoord)
    {
        pixelHLSL += "    float rhw = 1.0 / input.gl_FragCoord.w;\n";
        
        if (shaderModel >= 4)
        {
            pixelHLSL += "    gl_FragCoord.x = input.dx_VPos.x;\n"
                         "    gl_FragCoord.y = input.dx_VPos.y;\n";
        }
        else if (shaderModel >= 3)
        {
            pixelHLSL += "    gl_FragCoord.x = input.dx_VPos.x + 0.5;\n"
                         "    gl_FragCoord.y = input.dx_VPos.y + 0.5;\n";
        }
        else
        {
            // dx_ViewCoords contains the viewport width/2, height/2, center.x and center.y. See Renderer::setViewport()
            pixelHLSL += "    gl_FragCoord.x = (input.gl_FragCoord.x * rhw) * dx_ViewCoords.x + dx_ViewCoords.z;\n"
                         "    gl_FragCoord.y = (input.gl_FragCoord.y * rhw) * dx_ViewCoords.y + dx_ViewCoords.w;\n";
        }
        
        pixelHLSL += "    gl_FragCoord.z = (input.gl_FragCoord.z * rhw) * dx_DepthFront.x + dx_DepthFront.y;\n"
                     "    gl_FragCoord.w = rhw;\n";
    }

    if (fragmentShader->mUsesPointCoord && shaderModel >= 3)
    {
        pixelHLSL += "    gl_PointCoord.x = input.gl_PointCoord.x;\n";
        pixelHLSL += "    gl_PointCoord.y = 1.0 - input.gl_PointCoord.y;\n";
    }

    if (fragmentShader->mUsesFrontFacing)
    {
        if (shaderModel <= 3)
        {
            pixelHLSL += "    gl_FrontFacing = (vFace * dx_DepthFront.z >= 0.0);\n";
        }
        else
        {
            pixelHLSL += "    gl_FrontFacing = isFrontFace;\n";
        }
    }

    for (VaryingList::iterator varying = fragmentShader->mVaryings.begin(); varying != fragmentShader->mVaryings.end(); varying++)
    {
        if (varying->reg >= 0)
        {
            for (int i = 0; i < varying->size; i++)
            {
                int rows = VariableRowCount(varying->type);
                for (int j = 0; j < rows; j++)
                {
                    std::string n = str(varying->reg + i * rows + j);
                    pixelHLSL += "    " + varying->name;

                    if (varying->array)
                    {
                        pixelHLSL += "[" + str(i) + "]";
                    }

                    if (rows > 1)
                    {
                        pixelHLSL += "[" + str(j) + "]";
                    }

                    switch (VariableColumnCount(varying->type))
                    {
                      case 1: pixelHLSL += " = input.v" + n + ".x;\n";   break;
                      case 2: pixelHLSL += " = input.v" + n + ".xy;\n";  break;
                      case 3: pixelHLSL += " = input.v" + n + ".xyz;\n"; break;
                      case 4: pixelHLSL += " = input.v" + n + ";\n";     break;
                      default: UNREACHABLE();
                    }
                }
            }
        }
        else UNREACHABLE();
    }

    pixelHLSL += "\n"
                 "    gl_main();\n"
                 "\n"
                 "    PS_OUTPUT output;\n";

    for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets; renderTargetIndex++)
    {
        unsigned int sourceColorIndex = broadcast ? 0 : renderTargetIndex;

        pixelHLSL += "    output.gl_Color" + str(renderTargetIndex) + " = gl_Color[" + str(sourceColorIndex) + "];\n";
    }

    pixelHLSL += "\n"
                 "    return output;\n"
                 "}\n";

    return true;
}

std::string ProgramBinary::generateVaryingHLSL(FragmentShader *fragmentShader, const std::string &varyingSemantic) const
{
    std::string varyingHLSL;

    for (VaryingList::iterator varying = fragmentShader->mVaryings.begin(); varying != fragmentShader->mVaryings.end(); varying++)
    {
        if (varying->reg >= 0)
        {
            for (int i = 0; i < varying->size; i++)
            {
                int rows = VariableRowCount(varying->type);
                for (int j = 0; j < rows; j++)
                {
                    switch (varying->interpolation)
                    {
                      case Smooth:   varyingHLSL += "    ";                 break;
                      case Flat:     varyingHLSL += "    nointerpolation "; break;
                      case Centroid: varyingHLSL += "    centroid ";        break;
                      default:  UNREACHABLE();
                    }

                    std::string n = str(varying->reg + i * rows + j);
                    varyingHLSL += "float" + str(VariableColumnCount(varying->type)) + " v" + n + " : " + varyingSemantic + n + ";\n";
                }
            }
        }
        else UNREACHABLE();
    }

    return varyingHLSL;
}

bool ProgramBinary::load(InfoLog &infoLog, const void *binary, GLsizei length)
{
    BinaryInputStream stream(binary, length);

    int format = 0;
    stream.read(&format);
    if (format != GL_PROGRAM_BINARY_ANGLE)
    {
        infoLog.append("Invalid program binary format.");
        return false;
    }

    int version = 0;
    stream.read(&version);
    if (version != VERSION_DWORD)
    {
        infoLog.append("Invalid program binary version.");
        return false;
    }

    for (int i = 0; i < MAX_VERTEX_ATTRIBS; ++i)
    {
        stream.read(&mLinkedAttribute[i].type);
        std::string name;
        stream.read(&name);
        mLinkedAttribute[i].name = name;
        stream.read(&mSemanticIndex[i]);
    }

    for (unsigned int i = 0; i < MAX_TEXTURE_IMAGE_UNITS; ++i)
    {
        stream.read(&mSamplersPS[i].active);
        stream.read(&mSamplersPS[i].logicalTextureUnit);
        
        int textureType;
        stream.read(&textureType);
        mSamplersPS[i].textureType = (TextureType) textureType;
    }

    for (unsigned int i = 0; i < IMPLEMENTATION_MAX_VERTEX_TEXTURE_IMAGE_UNITS; ++i)
    {
        stream.read(&mSamplersVS[i].active);
        stream.read(&mSamplersVS[i].logicalTextureUnit);
        
        int textureType;
        stream.read(&textureType);
        mSamplersVS[i].textureType = (TextureType) textureType;
    }

    stream.read(&mUsedVertexSamplerRange);
    stream.read(&mUsedPixelSamplerRange);
    stream.read(&mUsesPointSize);

    size_t size;
    stream.read(&size);
    if (stream.error())
    {
        infoLog.append("Invalid program binary.");
        return false;
    }

    mUniforms.resize(size);
    for (unsigned int i = 0; i < size; ++i)
    {
        GLenum type;
        GLenum precision;
        std::string name;
        unsigned int arraySize;
        int blockIndex;

        stream.read(&type);
        stream.read(&precision);
        stream.read(&name);
        stream.read(&arraySize);
        stream.read(&blockIndex);

        int offset;
        int arrayStride;
        int matrixStride;
        bool isRowMajorMatrix;

        stream.read(&offset);
        stream.read(&arrayStride);
        stream.read(&matrixStride);
        stream.read(&isRowMajorMatrix);

        const sh::BlockMemberInfo blockInfo(offset, arrayStride, matrixStride, isRowMajorMatrix);

        mUniforms[i] = new Uniform(type, precision, name, arraySize, blockIndex, blockInfo);
        
        stream.read(&mUniforms[i]->psRegisterIndex);
        stream.read(&mUniforms[i]->vsRegisterIndex);
        stream.read(&mUniforms[i]->registerCount);
    }

    stream.read(&size);
    if (stream.error())
    {
        infoLog.append("Invalid program binary.");
        return false;
    }

    mUniformBlocks.resize(size);
    for (unsigned int uniformBlockIndex = 0; uniformBlockIndex < size; ++uniformBlockIndex)
    {
        std::string name;
        unsigned int elementIndex;
        unsigned int dataSize;

        stream.read(&name);
        stream.read(&elementIndex);
        stream.read(&dataSize);

        mUniformBlocks[uniformBlockIndex] = new UniformBlock(name, elementIndex, dataSize);

        UniformBlock& uniformBlock = *mUniformBlocks[uniformBlockIndex];
        stream.read(&uniformBlock.psRegisterIndex);
        stream.read(&uniformBlock.vsRegisterIndex);

        size_t numMembers;
        stream.read(&numMembers);
        uniformBlock.memberUniformIndexes.resize(numMembers);
        for (unsigned int blockMemberIndex = 0; blockMemberIndex < numMembers; blockMemberIndex++)
        {
            stream.read(&uniformBlock.memberUniformIndexes[blockMemberIndex]);
        }
    }

    stream.read(&size);
    if (stream.error())
    {
        infoLog.append("Invalid program binary.");
        return false;
    }

    mUniformIndex.resize(size);
    for (unsigned int i = 0; i < size; ++i)
    {
        stream.read(&mUniformIndex[i].name);
        stream.read(&mUniformIndex[i].element);
        stream.read(&mUniformIndex[i].index);
    }

    unsigned int pixelShaderSize;
    stream.read(&pixelShaderSize);

    unsigned int vertexShaderSize;
    stream.read(&vertexShaderSize);

    unsigned int geometryShaderSize;
    stream.read(&geometryShaderSize);

    const char *ptr = (const char*) binary + stream.offset();

    const GUID *binaryIdentifier = (const GUID *) ptr;
    ptr += sizeof(GUID);

    GUID identifier = mRenderer->getAdapterIdentifier();
    if (memcmp(&identifier, binaryIdentifier, sizeof(GUID)) != 0)
    {
        infoLog.append("Invalid program binary.");
        return false;
    }

    const char *pixelShaderFunction = ptr;
    ptr += pixelShaderSize;

    const char *vertexShaderFunction = ptr;
    ptr += vertexShaderSize;

    const char *geometryShaderFunction = geometryShaderSize > 0 ? ptr : NULL;
    ptr += geometryShaderSize;

    mPixelExecutable = mRenderer->loadExecutable(reinterpret_cast<const DWORD*>(pixelShaderFunction),
                                                 pixelShaderSize, rx::SHADER_PIXEL);
    if (!mPixelExecutable)
    {
        infoLog.append("Could not create pixel shader.");
        return false;
    }

    mVertexExecutable = mRenderer->loadExecutable(reinterpret_cast<const DWORD*>(vertexShaderFunction),
                                                  vertexShaderSize, rx::SHADER_VERTEX);
    if (!mVertexExecutable)
    {
        infoLog.append("Could not create vertex shader.");
        delete mPixelExecutable;
        mPixelExecutable = NULL;
        return false;
    }

    if (geometryShaderFunction != NULL && geometryShaderSize > 0)
    {
        mGeometryExecutable = mRenderer->loadExecutable(reinterpret_cast<const DWORD*>(geometryShaderFunction),
                                                        geometryShaderSize, rx::SHADER_GEOMETRY);
        if (!mGeometryExecutable)
        {
            infoLog.append("Could not create geometry shader.");
            delete mPixelExecutable;
            mPixelExecutable = NULL;
            delete mVertexExecutable;
            mVertexExecutable = NULL;
            return false;
        }
    }
    else
    {
        mGeometryExecutable = NULL;
    }

    return true;
}

bool ProgramBinary::save(void* binary, GLsizei bufSize, GLsizei *length)
{
    BinaryOutputStream stream;

    stream.write(GL_PROGRAM_BINARY_ANGLE);
    stream.write(VERSION_DWORD);

    for (unsigned int i = 0; i < MAX_VERTEX_ATTRIBS; ++i)
    {
        stream.write(mLinkedAttribute[i].type);
        stream.write(mLinkedAttribute[i].name);
        stream.write(mSemanticIndex[i]);
    }

    for (unsigned int i = 0; i < MAX_TEXTURE_IMAGE_UNITS; ++i)
    {
        stream.write(mSamplersPS[i].active);
        stream.write(mSamplersPS[i].logicalTextureUnit);
        stream.write((int) mSamplersPS[i].textureType);
    }

    for (unsigned int i = 0; i < IMPLEMENTATION_MAX_VERTEX_TEXTURE_IMAGE_UNITS; ++i)
    {
        stream.write(mSamplersVS[i].active);
        stream.write(mSamplersVS[i].logicalTextureUnit);
        stream.write((int) mSamplersVS[i].textureType);
    }

    stream.write(mUsedVertexSamplerRange);
    stream.write(mUsedPixelSamplerRange);
    stream.write(mUsesPointSize);

    stream.write(mUniforms.size());
    for (unsigned int uniformIndex = 0; uniformIndex < mUniforms.size(); ++uniformIndex)
    {
        const Uniform &uniform = *mUniforms[uniformIndex];

        stream.write(uniform.type);
        stream.write(uniform.precision);
        stream.write(uniform.name);
        stream.write(uniform.arraySize);
        stream.write(uniform.blockIndex);

        stream.write(uniform.blockInfo.offset);
        stream.write(uniform.blockInfo.arrayStride);
        stream.write(uniform.blockInfo.matrixStride);
        stream.write(uniform.blockInfo.isRowMajorMatrix);

        stream.write(uniform.psRegisterIndex);
        stream.write(uniform.vsRegisterIndex);
        stream.write(uniform.registerCount);
    }

    stream.write(mUniformBlocks.size());
    for (unsigned int uniformBlockIndex = 0; uniformBlockIndex < mUniformBlocks.size(); ++uniformBlockIndex)
    {
        const UniformBlock& uniformBlock = *mUniformBlocks[uniformBlockIndex];

        stream.write(uniformBlock.name);
        stream.write(uniformBlock.elementIndex);
        stream.write(uniformBlock.dataSize);

        stream.write(uniformBlock.memberUniformIndexes.size());
        for (unsigned int blockMemberIndex = 0; blockMemberIndex < uniformBlock.memberUniformIndexes.size(); blockMemberIndex++)
        {
            stream.write(uniformBlock.memberUniformIndexes[blockMemberIndex]);
        }

        stream.write(uniformBlock.psRegisterIndex);
        stream.write(uniformBlock.vsRegisterIndex);
    }

    stream.write(mUniformIndex.size());
    for (unsigned int i = 0; i < mUniformIndex.size(); ++i)
    {
        stream.write(mUniformIndex[i].name);
        stream.write(mUniformIndex[i].element);
        stream.write(mUniformIndex[i].index);
    }

    UINT pixelShaderSize = mPixelExecutable->getLength();
    stream.write(pixelShaderSize);

    UINT vertexShaderSize = mVertexExecutable->getLength();
    stream.write(vertexShaderSize);

    UINT geometryShaderSize = (mGeometryExecutable != NULL) ? mGeometryExecutable->getLength() : 0;
    stream.write(geometryShaderSize);

    GUID identifier = mRenderer->getAdapterIdentifier();

    GLsizei streamLength = stream.length();
    const void *streamData = stream.data();

    GLsizei totalLength = streamLength + sizeof(GUID) + pixelShaderSize + vertexShaderSize + geometryShaderSize;
    if (totalLength > bufSize)
    {
        if (length)
        {
            *length = 0;
        }

        return false;
    }

    if (binary)
    {
        char *ptr = (char*) binary;

        memcpy(ptr, streamData, streamLength);
        ptr += streamLength;

        memcpy(ptr, &identifier, sizeof(GUID));
        ptr += sizeof(GUID);

        memcpy(ptr, mPixelExecutable->getFunction(), pixelShaderSize);
        ptr += pixelShaderSize;

        memcpy(ptr, mVertexExecutable->getFunction(), vertexShaderSize);
        ptr += vertexShaderSize;

        if (mGeometryExecutable != NULL && geometryShaderSize > 0)
        {
            memcpy(ptr, mGeometryExecutable->getFunction(), geometryShaderSize);
            ptr += geometryShaderSize;
        }

        ASSERT(ptr - totalLength == binary);
    }

    if (length)
    {
        *length = totalLength;
    }

    return true;
}

GLint ProgramBinary::getLength()
{
    GLint length;
    if (save(NULL, INT_MAX, &length))
    {
        return length;
    }
    else
    {
        return 0;
    }
}

bool ProgramBinary::link(InfoLog &infoLog, const AttributeBindings &attributeBindings, FragmentShader *fragmentShader, VertexShader *vertexShader)
{
    if (!fragmentShader || !fragmentShader->isCompiled())
    {
        return false;
    }

    if (!vertexShader || !vertexShader->isCompiled())
    {
        return false;
    }

    std::string pixelHLSL = fragmentShader->getHLSL();
    std::string vertexHLSL = vertexShader->getHLSL();

    // Map the varyings to the register file
    const Varying *packing[IMPLEMENTATION_MAX_VARYING_VECTORS][4] = {NULL};
    int registers = packVaryings(infoLog, packing, fragmentShader);

    if (registers < 0)
    {
        return false;
    }

    if (!linkVaryings(infoLog, registers, packing, pixelHLSL, vertexHLSL, fragmentShader, vertexShader))
    {
        return false;
    }

    bool success = true;
    mVertexExecutable = mRenderer->compileToExecutable(infoLog, vertexHLSL.c_str(), rx::SHADER_VERTEX);
    mPixelExecutable = mRenderer->compileToExecutable(infoLog, pixelHLSL.c_str(), rx::SHADER_PIXEL);

    if (usesGeometryShader())
    {
        std::string geometryHLSL = generateGeometryShaderHLSL(registers, packing, fragmentShader, vertexShader);
        mGeometryExecutable = mRenderer->compileToExecutable(infoLog, geometryHLSL.c_str(), rx::SHADER_GEOMETRY);
    }

    if (!mVertexExecutable || !mPixelExecutable || (usesGeometryShader() && !mGeometryExecutable))
    {
        infoLog.append("Failed to create D3D shaders.");
        success = false;

        delete mVertexExecutable;
        mVertexExecutable = NULL;
        delete mPixelExecutable;
        mPixelExecutable = NULL;
        delete mGeometryExecutable;
        mGeometryExecutable = NULL;
    }

    if (!linkAttributes(infoLog, attributeBindings, fragmentShader, vertexShader))
    {
        success = false;
    }

    if (!linkUniforms(infoLog, vertexShader->getUniforms(), fragmentShader->getUniforms()))
    {
        success = false;
    }

    // special case for gl_DepthRange, the only built-in uniform (also a struct)
    if (vertexShader->mUsesDepthRange || fragmentShader->mUsesDepthRange)
    {
        mUniforms.push_back(new Uniform(GL_FLOAT, GL_HIGH_FLOAT, "gl_DepthRange.near", 0, -1, sh::BlockMemberInfo::defaultBlockInfo));
        mUniforms.push_back(new Uniform(GL_FLOAT, GL_HIGH_FLOAT, "gl_DepthRange.far", 0, -1, sh::BlockMemberInfo::defaultBlockInfo));
        mUniforms.push_back(new Uniform(GL_FLOAT, GL_HIGH_FLOAT, "gl_DepthRange.diff", 0, -1, sh::BlockMemberInfo::defaultBlockInfo));
    }

    return success;
}

// Determines the mapping between GL attributes and Direct3D 9 vertex stream usage indices
bool ProgramBinary::linkAttributes(InfoLog &infoLog, const AttributeBindings &attributeBindings, FragmentShader *fragmentShader, VertexShader *vertexShader)
{
    unsigned int usedLocations = 0;

    // Link attributes that have a binding location
    for (AttributeArray::iterator attribute = vertexShader->mAttributes.begin(); attribute != vertexShader->mAttributes.end(); attribute++)
    {
        int location = attributeBindings.getAttributeBinding(attribute->name);

        if (location != -1)   // Set by glBindAttribLocation
        {
            if (!mLinkedAttribute[location].name.empty())
            {
                // Multiple active attributes bound to the same location; not an error
            }

            mLinkedAttribute[location] = *attribute;

            int rows = VariableRowCount(attribute->type);

            if (rows + location > MAX_VERTEX_ATTRIBS)
            {
                infoLog.append("Active attribute (%s) at location %d is too big to fit", attribute->name.c_str(), location);

                return false;
            }

            for (int i = 0; i < rows; i++)
            {
                usedLocations |= 1 << (location + i);
            }
        }
    }

    // Link attributes that don't have a binding location
    for (AttributeArray::iterator attribute = vertexShader->mAttributes.begin(); attribute != vertexShader->mAttributes.end(); attribute++)
    {
        int location = attributeBindings.getAttributeBinding(attribute->name);

        if (location == -1)   // Not set by glBindAttribLocation
        {
            int rows = VariableRowCount(attribute->type);
            int availableIndex = AllocateFirstFreeBits(&usedLocations, rows, MAX_VERTEX_ATTRIBS);

            if (availableIndex == -1 || availableIndex + rows > MAX_VERTEX_ATTRIBS)
            {
                infoLog.append("Too many active attributes (%s)", attribute->name.c_str());

                return false;   // Fail to link
            }

            mLinkedAttribute[availableIndex] = *attribute;
        }
    }

    for (int attributeIndex = 0; attributeIndex < MAX_VERTEX_ATTRIBS; )
    {
        int index = vertexShader->getSemanticIndex(mLinkedAttribute[attributeIndex].name);
        int rows = std::max(VariableRowCount(mLinkedAttribute[attributeIndex].type), 1);

        for (int r = 0; r < rows; r++)
        {
            mSemanticIndex[attributeIndex++] = index++;
        }
    }

    return true;
}

bool ProgramBinary::linkUniforms(InfoLog &infoLog, const sh::ActiveUniforms &vertexUniforms, const sh::ActiveUniforms &fragmentUniforms)
{
    for (sh::ActiveUniforms::const_iterator uniform = vertexUniforms.begin(); uniform != vertexUniforms.end(); uniform++)
    {
        if (!defineUniform(GL_VERTEX_SHADER, *uniform, infoLog))
        {
            return false;
        }
    }

    for (sh::ActiveUniforms::const_iterator uniform = fragmentUniforms.begin(); uniform != fragmentUniforms.end(); uniform++)
    {
        if (!defineUniform(GL_FRAGMENT_SHADER, *uniform, infoLog))
        {
            return false;
        }
    }

    return true;
}

bool ProgramBinary::defineUniform(GLenum shader, const sh::Uniform &constant, InfoLog &infoLog)
{
    if (constant.type == GL_SAMPLER_2D ||
        constant.type == GL_SAMPLER_CUBE)
    {
        unsigned int samplerIndex = constant.registerIndex;
            
        do
        {
            if (shader == GL_VERTEX_SHADER)
            {
                if (samplerIndex < mRenderer->getMaxVertexTextureImageUnits())
                {
                    mSamplersVS[samplerIndex].active = true;
                    mSamplersVS[samplerIndex].textureType = (constant.type == GL_SAMPLER_CUBE) ? TEXTURE_CUBE : TEXTURE_2D;
                    mSamplersVS[samplerIndex].logicalTextureUnit = 0;
                    mUsedVertexSamplerRange = std::max(samplerIndex + 1, mUsedVertexSamplerRange);
                }
                else
                {
                    infoLog.append("Vertex shader sampler count exceeds the maximum vertex texture units (%d).", mRenderer->getMaxVertexTextureImageUnits());
                    return false;
                }
            }
            else if (shader == GL_FRAGMENT_SHADER)
            {
                if (samplerIndex < MAX_TEXTURE_IMAGE_UNITS)
                {
                    mSamplersPS[samplerIndex].active = true;
                    mSamplersPS[samplerIndex].textureType = (constant.type == GL_SAMPLER_CUBE) ? TEXTURE_CUBE : TEXTURE_2D;
                    mSamplersPS[samplerIndex].logicalTextureUnit = 0;
                    mUsedPixelSamplerRange = std::max(samplerIndex + 1, mUsedPixelSamplerRange);
                }
                else
                {
                    infoLog.append("Pixel shader sampler count exceeds MAX_TEXTURE_IMAGE_UNITS (%d).", MAX_TEXTURE_IMAGE_UNITS);
                    return false;
                }
            }
            else UNREACHABLE();

            samplerIndex++;
        }
        while (samplerIndex < constant.registerIndex + constant.arraySize);
    }

    Uniform *uniform = NULL;
    GLint location = getUniformLocation(constant.name);

    if (location >= 0)   // Previously defined, type and precision must match
    {
        uniform = mUniforms[mUniformIndex[location].index];

        if (uniform->type != constant.type)
        {
            infoLog.append("Types for uniform %s do not match between the vertex and fragment shader", uniform->name.c_str());
            return false;
        }

        if (uniform->precision != constant.precision)
        {
            infoLog.append("Precisions for uniform %s do not match between the vertex and fragment shader", uniform->name.c_str());
            return false;
        }
    }
    else
    {
        uniform = new Uniform(constant.type, constant.precision, constant.name, constant.arraySize, -1, sh::BlockMemberInfo::defaultBlockInfo);
    }

    if (!uniform)
    {
        return false;
    }

    if (shader == GL_FRAGMENT_SHADER)
    {
        uniform->psRegisterIndex = constant.registerIndex;
    }
    else if (shader == GL_VERTEX_SHADER)
    {
        uniform->vsRegisterIndex = constant.registerIndex;
    }
    else UNREACHABLE();

    if (location >= 0)
    {
        return uniform->type == constant.type;
    }

    mUniforms.push_back(uniform);
    unsigned int uniformIndex = mUniforms.size() - 1;

    for (unsigned int i = 0; i < uniform->elementCount(); i++)
    {
        mUniformIndex.push_back(UniformLocation(constant.name, i, uniformIndex));
    }

    if (shader == GL_VERTEX_SHADER)
    {
        if (constant.registerIndex + uniform->registerCount > mRenderer->getReservedVertexUniformVectors() + mRenderer->getMaxVertexUniformVectors())
        {
            infoLog.append("Vertex shader active uniforms exceed GL_MAX_VERTEX_UNIFORM_VECTORS (%u)", mRenderer->getMaxVertexUniformVectors());
            return false;
        }
    }
    else if (shader == GL_FRAGMENT_SHADER)
    {
        if (constant.registerIndex + uniform->registerCount > mRenderer->getReservedFragmentUniformVectors() + mRenderer->getMaxFragmentUniformVectors())
        {
            infoLog.append("Fragment shader active uniforms exceed GL_MAX_FRAGMENT_UNIFORM_VECTORS (%u)", mRenderer->getMaxFragmentUniformVectors());
            return false;
        }
    }
    else UNREACHABLE();

    return true;
}

std::string ProgramBinary::generateGeometryShaderHLSL(int registers, const Varying *packing[][4], FragmentShader *fragmentShader, VertexShader *vertexShader) const
{
    // for now we only handle point sprite emulation
    ASSERT(usesPointSpriteEmulation());
    return generatePointSpriteHLSL(registers, packing, fragmentShader, vertexShader);
}

std::string ProgramBinary::generatePointSpriteHLSL(int registers, const Varying *packing[][4], FragmentShader *fragmentShader, VertexShader *vertexShader) const
{
    ASSERT(registers >= 0);
    ASSERT(vertexShader->mUsesPointSize);
    ASSERT(mRenderer->getMajorShaderModel() >= 4);

    std::string geomHLSL;

    std::string varyingSemantic = "TEXCOORD";

    std::string fragCoordSemantic;
    std::string pointCoordSemantic;

    int reservedRegisterIndex = registers;

    if (fragmentShader->mUsesFragCoord)
    {
        fragCoordSemantic = varyingSemantic + str(reservedRegisterIndex++);
    }

    if (fragmentShader->mUsesPointCoord)
    {
        pointCoordSemantic = varyingSemantic + str(reservedRegisterIndex++);
    }

    geomHLSL += "uniform float4 dx_ViewCoords : register(c1);\n"
                "\n"
                "struct GS_INPUT\n"
                "{\n";

    std::string varyingHLSL = generateVaryingHLSL(fragmentShader, varyingSemantic);

    geomHLSL += varyingHLSL;

    if (fragmentShader->mUsesFragCoord)
    {
        geomHLSL += "    float4 gl_FragCoord : " + fragCoordSemantic + ";\n";
    }

    geomHLSL += "    float gl_PointSize : PSIZE;\n"
                "    float4 gl_Position : SV_Position;\n"
                "};\n"
                "\n"
                "struct GS_OUTPUT\n"
                "{\n";

    geomHLSL += varyingHLSL;

    if (fragmentShader->mUsesFragCoord)
    {
        geomHLSL += "    float4 gl_FragCoord : " + fragCoordSemantic + ";\n";
    }

    if (fragmentShader->mUsesPointCoord)
    {
        geomHLSL += "    float2 gl_PointCoord : " + pointCoordSemantic + ";\n";
    }

    geomHLSL +=   "    float gl_PointSize : PSIZE;\n"
                  "    float4 gl_Position : SV_Position;\n"
                  "};\n"
                  "\n"
                  "static float2 pointSpriteCorners[] = \n"
                  "{\n"
                  "    float2( 0.5f, -0.5f),\n"
                  "    float2( 0.5f,  0.5f),\n"
                  "    float2(-0.5f, -0.5f),\n"
                  "    float2(-0.5f,  0.5f)\n"
                  "};\n"
                  "\n"
                  "static float2 pointSpriteTexcoords[] = \n"
                  "{\n"
                  "    float2(1.0f, 1.0f),\n"
                  "    float2(1.0f, 0.0f),\n"
                  "    float2(0.0f, 1.0f),\n"
                  "    float2(0.0f, 0.0f)\n"
                  "};\n"
                  "\n"
                  "static float minPointSize = " + str(ALIASED_POINT_SIZE_RANGE_MIN) + ".0f;\n"
                  "static float maxPointSize = " + str(mRenderer->getMaxPointSize()) + ".0f;\n"
                  "\n"
                  "[maxvertexcount(4)]\n"
                  "void main(point GS_INPUT input[1], inout TriangleStream<GS_OUTPUT> outStream)\n"
                  "{\n"
                  "    GS_OUTPUT output = (GS_OUTPUT)0;\n"
                  "    output.gl_PointSize = input[0].gl_PointSize;\n";

    for (int r = 0; r < registers; r++)
    {
        geomHLSL += "    output.v" + str(r) + " = input[0].v" + str(r) + ";\n";
    }

    if (fragmentShader->mUsesFragCoord)
    {
        geomHLSL += "    output.gl_FragCoord = input[0].gl_FragCoord;\n";
    }

    geomHLSL += "    \n"
                "    float gl_PointSize = clamp(input[0].gl_PointSize, minPointSize, maxPointSize);\n"
                "    float4 gl_Position = input[0].gl_Position;\n"
                "    float2 viewportScale = float2(1.0f / dx_ViewCoords.x, 1.0f / dx_ViewCoords.y) * gl_Position.w;\n";

    for (int corner = 0; corner < 4; corner++)
    {
        geomHLSL += "    \n"
                    "    output.gl_Position = gl_Position + float4(pointSpriteCorners[" + str(corner) + "] * viewportScale * gl_PointSize, 0.0f, 0.0f);\n";

        if (fragmentShader->mUsesPointCoord)
        {
            geomHLSL += "    output.gl_PointCoord = pointSpriteTexcoords[" + str(corner) + "];\n";
        }

        geomHLSL += "    outStream.Append(output);\n";
    }

    geomHLSL += "    \n"
                "    outStream.RestartStrip();\n"
                "}\n";

    return geomHLSL;
}

// This method needs to match OutputHLSL::decorate
std::string ProgramBinary::decorateAttribute(const std::string &name)
{
    if (name.compare(0, 3, "gl_") != 0 && name.compare(0, 3, "dx_") != 0)
    {
        return "_" + name;
    }
    
    return name;
}

bool ProgramBinary::isValidated() const 
{
    return mValidated;
}

void ProgramBinary::getActiveAttribute(GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, GLchar *name) const
{
    // Skip over inactive attributes
    unsigned int activeAttribute = 0;
    unsigned int attribute;
    for (attribute = 0; attribute < MAX_VERTEX_ATTRIBS; attribute++)
    {
        if (mLinkedAttribute[attribute].name.empty())
        {
            continue;
        }

        if (activeAttribute == index)
        {
            break;
        }

        activeAttribute++;
    }

    if (bufsize > 0)
    {
        const char *string = mLinkedAttribute[attribute].name.c_str();

        strncpy(name, string, bufsize);
        name[bufsize - 1] = '\0';

        if (length)
        {
            *length = strlen(name);
        }
    }

    *size = 1;   // Always a single 'type' instance

    *type = mLinkedAttribute[attribute].type;
}

GLint ProgramBinary::getActiveAttributeCount() const
{
    int count = 0;

    for (int attributeIndex = 0; attributeIndex < MAX_VERTEX_ATTRIBS; attributeIndex++)
    {
        if (!mLinkedAttribute[attributeIndex].name.empty())
        {
            count++;
        }
    }

    return count;
}

GLint ProgramBinary::getActiveAttributeMaxLength() const
{
    int maxLength = 0;

    for (int attributeIndex = 0; attributeIndex < MAX_VERTEX_ATTRIBS; attributeIndex++)
    {
        if (!mLinkedAttribute[attributeIndex].name.empty())
        {
            maxLength = std::max((int)(mLinkedAttribute[attributeIndex].name.length() + 1), maxLength);
        }
    }

    return maxLength;
}

void ProgramBinary::getActiveUniform(GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, GLchar *name) const
{
    ASSERT(index < mUniforms.size());   // index must be smaller than getActiveUniformCount()

    if (bufsize > 0)
    {
        std::string string = mUniforms[index]->name;

        if (mUniforms[index]->isArray())
        {
            string += "[0]";
        }

        strncpy(name, string.c_str(), bufsize);
        name[bufsize - 1] = '\0';

        if (length)
        {
            *length = strlen(name);
        }
    }

    *size = mUniforms[index]->elementCount();

    *type = mUniforms[index]->type;
}

GLint ProgramBinary::getActiveUniformCount() const
{
    return mUniforms.size();
}

GLint ProgramBinary::getActiveUniformMaxLength() const
{
    int maxLength = 0;

    unsigned int numUniforms = mUniforms.size();
    for (unsigned int uniformIndex = 0; uniformIndex < numUniforms; uniformIndex++)
    {
        if (!mUniforms[uniformIndex]->name.empty())
        {
            int length = (int)(mUniforms[uniformIndex]->name.length() + 1);
            if (mUniforms[uniformIndex]->isArray())
            {
                length += 3;  // Counting in "[0]".
            }
            maxLength = std::max(length, maxLength);
        }
    }

    return maxLength;
}

GLint ProgramBinary::getActiveUniformi(GLuint index, GLenum pname) const
{
    const gl::Uniform& uniform = *mUniforms[index];

    switch (pname)
    {
      case GL_UNIFORM_TYPE:         return static_cast<GLint>(uniform.type);
      case GL_UNIFORM_SIZE:         return static_cast<GLint>(uniform.elementCount());
      case GL_UNIFORM_NAME_LENGTH:  return static_cast<GLint>(uniform.name.size() + 1);
      case GL_UNIFORM_BLOCK_INDEX:  return uniform.blockIndex;

      case GL_UNIFORM_OFFSET:       return uniform.blockInfo.offset;
      case GL_UNIFORM_ARRAY_STRIDE: return uniform.blockInfo.arrayStride;
      case GL_UNIFORM_MATRIX_STRIDE: return uniform.blockInfo.matrixStride;
      case GL_UNIFORM_IS_ROW_MAJOR: return static_cast<GLint>(uniform.blockInfo.isRowMajorMatrix);

      default:
        UNREACHABLE();
        break;
    }
    return 0;
}

GLuint ProgramBinary::getActiveUniformBlockCount() const
{
    return mUniformBlocks.size();
}

void ProgramBinary::validate(InfoLog &infoLog)
{
    applyUniforms();
    if (!validateSamplers(&infoLog))
    {
        mValidated = false;
    }
    else
    {
        mValidated = true;
    }
}

bool ProgramBinary::validateSamplers(InfoLog *infoLog)
{
    // if any two active samplers in a program are of different types, but refer to the same
    // texture image unit, and this is the current program, then ValidateProgram will fail, and
    // DrawArrays and DrawElements will issue the INVALID_OPERATION error.

    const unsigned int maxCombinedTextureImageUnits = mRenderer->getMaxCombinedTextureImageUnits();
    TextureType textureUnitType[IMPLEMENTATION_MAX_COMBINED_TEXTURE_IMAGE_UNITS];

    for (unsigned int i = 0; i < IMPLEMENTATION_MAX_COMBINED_TEXTURE_IMAGE_UNITS; ++i)
    {
        textureUnitType[i] = TEXTURE_UNKNOWN;
    }

    for (unsigned int i = 0; i < mUsedPixelSamplerRange; ++i)
    {
        if (mSamplersPS[i].active)
        {
            unsigned int unit = mSamplersPS[i].logicalTextureUnit;
            
            if (unit >= maxCombinedTextureImageUnits)
            {
                if (infoLog)
                {
                    infoLog->append("Sampler uniform (%d) exceeds IMPLEMENTATION_MAX_COMBINED_TEXTURE_IMAGE_UNITS (%d)", unit, maxCombinedTextureImageUnits);
                }

                return false;
            }

            if (textureUnitType[unit] != TEXTURE_UNKNOWN)
            {
                if (mSamplersPS[i].textureType != textureUnitType[unit])
                {
                    if (infoLog)
                    {
                        infoLog->append("Samplers of conflicting types refer to the same texture image unit (%d).", unit);
                    }

                    return false;
                }
            }
            else
            {
                textureUnitType[unit] = mSamplersPS[i].textureType;
            }
        }
    }

    for (unsigned int i = 0; i < mUsedVertexSamplerRange; ++i)
    {
        if (mSamplersVS[i].active)
        {
            unsigned int unit = mSamplersVS[i].logicalTextureUnit;
            
            if (unit >= maxCombinedTextureImageUnits)
            {
                if (infoLog)
                {
                    infoLog->append("Sampler uniform (%d) exceeds IMPLEMENTATION_MAX_COMBINED_TEXTURE_IMAGE_UNITS (%d)", unit, maxCombinedTextureImageUnits);
                }

                return false;
            }

            if (textureUnitType[unit] != TEXTURE_UNKNOWN)
            {
                if (mSamplersVS[i].textureType != textureUnitType[unit])
                {
                    if (infoLog)
                    {
                        infoLog->append("Samplers of conflicting types refer to the same texture image unit (%d).", unit);
                    }

                    return false;
                }
            }
            else
            {
                textureUnitType[unit] = mSamplersVS[i].textureType;
            }
        }
    }

    return true;
}

ProgramBinary::Sampler::Sampler() : active(false), logicalTextureUnit(0), textureType(TEXTURE_2D)
{
}

struct AttributeSorter
{
    AttributeSorter(const int (&semanticIndices)[MAX_VERTEX_ATTRIBS])
        : originalIndices(semanticIndices)
    {
        for (int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
        {
            indices[i] = i;
        }

        std::sort(&indices[0], &indices[MAX_VERTEX_ATTRIBS], *this);
    }

    bool operator()(int a, int b)
    {
        return originalIndices[a] == -1 ? false : originalIndices[a] < originalIndices[b];
    }

    int indices[MAX_VERTEX_ATTRIBS];
    const int (&originalIndices)[MAX_VERTEX_ATTRIBS];
};

void ProgramBinary::sortAttributesByLayout(rx::TranslatedAttribute attributes[MAX_VERTEX_ATTRIBS], int sortedSemanticIndices[MAX_VERTEX_ATTRIBS]) const
{
    AttributeSorter sorter(mSemanticIndex);

    int oldIndices[MAX_VERTEX_ATTRIBS];
    rx::TranslatedAttribute oldTranslatedAttributes[MAX_VERTEX_ATTRIBS];

    for (int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
    {
        oldIndices[i] = mSemanticIndex[i];
        oldTranslatedAttributes[i] = attributes[i];
    }

    for (int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
    {
        int oldIndex = sorter.indices[i];
        sortedSemanticIndices[i] = oldIndices[oldIndex];
        attributes[i] = oldTranslatedAttributes[oldIndex];
    }
}

}