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kc3-lang/angle/src/libANGLE/Program.cpp

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  • Author : Jamie Madill
    Date : 2015-08-18 10:46:20
    Hash : 36cfd6a3
    Message : Clean up Program::validate. This method should really be an Impl method, since it corresponds to a specific OpenGL call. Making it an Impl method also allows us to remove applyUniforms, which doesn't correspond to a GL call. BUG=angleproject:1123 Change-Id: I2abee3cfaa7393cad44566782d51ed701e84846b Reviewed-on: https://chromium-review.googlesource.com/293825 Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>

  • src/libANGLE/Program.cpp
  • //
    // Copyright (c) 2002-2014 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 "libANGLE/Program.h"
    
    #include <algorithm>
    
    #include "common/debug.h"
    #include "common/platform.h"
    #include "common/utilities.h"
    #include "common/version.h"
    #include "compiler/translator/blocklayout.h"
    #include "libANGLE/Data.h"
    #include "libANGLE/ResourceManager.h"
    #include "libANGLE/features.h"
    #include "libANGLE/renderer/Renderer.h"
    #include "libANGLE/renderer/ProgramImpl.h"
    
    namespace gl
    {
    const char * const g_fakepath = "C:\\fakepath";
    
    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;
    }
    
    }
    
    AttributeBindings::AttributeBindings()
    {
    }
    
    AttributeBindings::~AttributeBindings()
    {
    }
    
    InfoLog::InfoLog()
    {
    }
    
    InfoLog::~InfoLog()
    {
    }
    
    size_t InfoLog::getLength() const
    {
        const std::string &logString = mStream.str();
        return logString.empty() ? 0 : logString.length() + 1;
    }
    
    void InfoLog::getLog(GLsizei bufSize, GLsizei *length, char *infoLog)
    {
        size_t index = 0;
    
        if (bufSize > 0)
        {
            const std::string str(mStream.str());
    
            if (!str.empty())
            {
                index = std::min(static_cast<size_t>(bufSize) - 1, str.length());
                memcpy(infoLog, str.c_str(), index);
            }
    
            infoLog[index] = '\0';
        }
    
        if (length)
        {
            *length = static_cast<GLsizei>(index);
        }
    }
    
    // append a santized message to the program info log.
    // The D3D compiler includes a fake file path in some of the warning or error 
    // messages, so lets remove all occurrences of this fake file path from the log.
    void InfoLog::appendSanitized(const char *message)
    {
        std::string msg(message);
    
        size_t found;
        do
        {
            found = msg.find(g_fakepath);
            if (found != std::string::npos)
            {
                msg.erase(found, strlen(g_fakepath));
            }
        }
        while (found != std::string::npos);
    
        mStream << message << std::endl;
    }
    
    void InfoLog::reset()
    {
    }
    
    VariableLocation::VariableLocation()
        : name(),
          element(0),
          index(0)
    {
    }
    
    VariableLocation::VariableLocation(const std::string &name, unsigned int element, unsigned int index)
        : name(name),
          element(element),
          index(index)
    {
    }
    
    LinkedVarying::LinkedVarying()
    {
    }
    
    LinkedVarying::LinkedVarying(const std::string &name, GLenum type, GLsizei size, const std::string &semanticName,
                                 unsigned int semanticIndex, unsigned int semanticIndexCount)
        : name(name), type(type), size(size), semanticName(semanticName), semanticIndex(semanticIndex), semanticIndexCount(semanticIndexCount)
    {
    }
    
    Program::Data::Data()
        : mAttachedFragmentShader(nullptr),
          mAttachedVertexShader(nullptr),
          mTransformFeedbackBufferMode(GL_NONE)
    {
    }
    
    Program::Data::~Data()
    {
        if (mAttachedVertexShader != nullptr)
        {
            mAttachedVertexShader->release();
        }
    
        if (mAttachedFragmentShader != nullptr)
        {
            mAttachedFragmentShader->release();
        }
    }
    
    Program::Program(rx::ImplFactory *factory, ResourceManager *manager, GLuint handle)
        : mProgram(factory->createProgram(mData)),
          mLinkedAttributes(gl::MAX_VERTEX_ATTRIBS),
          mValidated(false),
          mLinked(false),
          mDeleteStatus(false),
          mRefCount(0),
          mResourceManager(manager),
          mHandle(handle)
    {
        ASSERT(mProgram);
    
        resetUniformBlockBindings();
        unlink();
    }
    
    Program::~Program()
    {
        unlink(true);
    
        SafeDelete(mProgram);
    }
    
    bool Program::attachShader(Shader *shader)
    {
        if (shader->getType() == GL_VERTEX_SHADER)
        {
            if (mData.mAttachedVertexShader)
            {
                return false;
            }
    
            mData.mAttachedVertexShader = shader;
            mData.mAttachedVertexShader->addRef();
        }
        else if (shader->getType() == GL_FRAGMENT_SHADER)
        {
            if (mData.mAttachedFragmentShader)
            {
                return false;
            }
    
            mData.mAttachedFragmentShader = shader;
            mData.mAttachedFragmentShader->addRef();
        }
        else UNREACHABLE();
    
        return true;
    }
    
    bool Program::detachShader(Shader *shader)
    {
        if (shader->getType() == GL_VERTEX_SHADER)
        {
            if (mData.mAttachedVertexShader != shader)
            {
                return false;
            }
    
            shader->release();
            mData.mAttachedVertexShader = nullptr;
        }
        else if (shader->getType() == GL_FRAGMENT_SHADER)
        {
            if (mData.mAttachedFragmentShader != shader)
            {
                return false;
            }
    
            shader->release();
            mData.mAttachedFragmentShader = nullptr;
        }
        else UNREACHABLE();
    
        return true;
    }
    
    int Program::getAttachedShadersCount() const
    {
        return (mData.mAttachedVertexShader ? 1 : 0) + (mData.mAttachedFragmentShader ? 1 : 0);
    }
    
    void AttributeBindings::bindAttributeLocation(GLuint index, const char *name)
    {
        if (index < MAX_VERTEX_ATTRIBS)
        {
            for (int i = 0; i < MAX_VERTEX_ATTRIBS; i++)
            {
                mAttributeBinding[i].erase(name);
            }
    
            mAttributeBinding[index].insert(name);
        }
    }
    
    void Program::bindAttributeLocation(GLuint index, const char *name)
    {
        mAttributeBindings.bindAttributeLocation(index, name);
        mProgram->bindAttributeLocation(index, name);
    }
    
    // Links the HLSL code of the vertex and pixel shader by matching up their varyings,
    // compiling them into binaries, determining the attribute mappings, and collecting
    // a list of uniforms
    Error Program::link(const gl::Data &data)
    {
        unlink(false);
    
        mInfoLog.reset();
        resetUniformBlockBindings();
    
        if (!mData.mAttachedFragmentShader || !mData.mAttachedFragmentShader->isCompiled())
        {
            return Error(GL_NO_ERROR);
        }
        ASSERT(mData.mAttachedFragmentShader->getType() == GL_FRAGMENT_SHADER);
    
        if (!mData.mAttachedVertexShader || !mData.mAttachedVertexShader->isCompiled())
        {
            return Error(GL_NO_ERROR);
        }
        ASSERT(mData.mAttachedVertexShader->getType() == GL_VERTEX_SHADER);
    
        if (!linkAttributes(data, mInfoLog, mAttributeBindings, mData.mAttachedVertexShader))
        {
            return Error(GL_NO_ERROR);
        }
    
        if (!linkVaryings(mInfoLog, mData.mAttachedVertexShader, mData.mAttachedFragmentShader))
        {
            return Error(GL_NO_ERROR);
        }
    
        if (!linkUniforms(mInfoLog, *data.caps))
        {
            return Error(GL_NO_ERROR);
        }
    
        if (!linkUniformBlocks(mInfoLog, *data.caps))
        {
            return Error(GL_NO_ERROR);
        }
    
        const auto &mergedVaryings = getMergedVaryings();
    
        if (!linkValidateTransformFeedback(mInfoLog, mergedVaryings, *data.caps))
        {
            return Error(GL_NO_ERROR);
        }
    
        rx::LinkResult result = mProgram->link(data, mInfoLog, mData.mAttachedFragmentShader,
                                               mData.mAttachedVertexShader, &mOutputVariables);
    
        if (result.error.isError() || !result.linkSuccess)
        {
            return result.error;
        }
    
        gatherTransformFeedbackVaryings(mergedVaryings);
    
        mLinked = true;
        return gl::Error(GL_NO_ERROR);
    }
    
    int AttributeBindings::getAttributeBinding(const std::string &name) const
    {
        for (int location = 0; location < MAX_VERTEX_ATTRIBS; location++)
        {
            if (mAttributeBinding[location].find(name) != mAttributeBinding[location].end())
            {
                return location;
            }
        }
    
        return -1;
    }
    
    // Returns the program object to an unlinked state, before re-linking, or at destruction
    void Program::unlink(bool destroy)
    {
        if (destroy)   // Object being destructed
        {
            if (mData.mAttachedFragmentShader)
            {
                mData.mAttachedFragmentShader->release();
                mData.mAttachedFragmentShader = nullptr;
            }
    
            if (mData.mAttachedVertexShader)
            {
                mData.mAttachedVertexShader->release();
                mData.mAttachedVertexShader = nullptr;
            }
        }
    
        mLinkedAttributes.assign(mLinkedAttributes.size(), sh::Attribute());
        mData.mTransformFeedbackVaryingVars.clear();
    
        mProgram->reset();
    
        mValidated = false;
    
        mLinked = false;
    }
    
    bool Program::isLinked()
    {
        return mLinked;
    }
    
    Error Program::loadBinary(GLenum binaryFormat, const void *binary, GLsizei length)
    {
        unlink(false);
    
    #if ANGLE_PROGRAM_BINARY_LOAD != ANGLE_ENABLED
        return Error(GL_NO_ERROR);
    #else
        ASSERT(binaryFormat == mProgram->getBinaryFormat());
    
        BinaryInputStream stream(binary, length);
    
        GLenum format = stream.readInt<GLenum>();
        if (format != mProgram->getBinaryFormat())
        {
            mInfoLog << "Invalid program binary format.";
            return Error(GL_NO_ERROR);
        }
    
        int majorVersion = stream.readInt<int>();
        int minorVersion = stream.readInt<int>();
        if (majorVersion != ANGLE_MAJOR_VERSION || minorVersion != ANGLE_MINOR_VERSION)
        {
            mInfoLog << "Invalid program binary version.";
            return Error(GL_NO_ERROR);
        }
    
        unsigned char commitString[ANGLE_COMMIT_HASH_SIZE];
        stream.readBytes(commitString, ANGLE_COMMIT_HASH_SIZE);
        if (memcmp(commitString, ANGLE_COMMIT_HASH, sizeof(unsigned char) * ANGLE_COMMIT_HASH_SIZE) != 0)
        {
            mInfoLog << "Invalid program binary version.";
            return Error(GL_NO_ERROR);
        }
    
        // TODO(jmadill): replace MAX_VERTEX_ATTRIBS
        for (int i = 0; i < MAX_VERTEX_ATTRIBS; ++i)
        {
            stream.readInt(&mLinkedAttributes[i].type);
            stream.readString(&mLinkedAttributes[i].name);
            stream.readInt(&mProgram->getSemanticIndexes()[i]);
        }
    
        unsigned int attribCount = stream.readInt<unsigned int>();
        for (unsigned int attribIndex = 0; attribIndex < attribCount; ++attribIndex)
        {
            GLenum type = stream.readInt<GLenum>();
            GLenum precision = stream.readInt<GLenum>();
            std::string name = stream.readString();
            GLint arraySize = stream.readInt<GLint>();
            int location = stream.readInt<int>();
            mProgram->setShaderAttribute(attribIndex, type, precision, name, arraySize, location);
        }
    
        stream.readInt(&mData.mTransformFeedbackBufferMode);
    
        rx::LinkResult result = mProgram->load(mInfoLog, &stream);
        if (result.error.isError() || !result.linkSuccess)
        {
            return result.error;
        }
    
        mLinked = true;
        return Error(GL_NO_ERROR);
    #endif // #if ANGLE_PROGRAM_BINARY_LOAD == ANGLE_ENABLED
    }
    
    Error Program::saveBinary(GLenum *binaryFormat, void *binary, GLsizei bufSize, GLsizei *length) const
    {
        if (binaryFormat)
        {
            *binaryFormat = mProgram->getBinaryFormat();
        }
    
        BinaryOutputStream stream;
    
        stream.writeInt(mProgram->getBinaryFormat());
        stream.writeInt(ANGLE_MAJOR_VERSION);
        stream.writeInt(ANGLE_MINOR_VERSION);
        stream.writeBytes(reinterpret_cast<const unsigned char*>(ANGLE_COMMIT_HASH), ANGLE_COMMIT_HASH_SIZE);
    
        // TODO(jmadill): replace MAX_VERTEX_ATTRIBS
        for (unsigned int i = 0; i < MAX_VERTEX_ATTRIBS; ++i)
        {
            stream.writeInt(mLinkedAttributes[i].type);
            stream.writeString(mLinkedAttributes[i].name);
            stream.writeInt(mProgram->getSemanticIndexes()[i]);
        }
    
        const auto &shaderAttributes = mProgram->getShaderAttributes();
        stream.writeInt(shaderAttributes.size());
        for (const auto &attrib : shaderAttributes)
        {
            stream.writeInt(attrib.type);
            stream.writeInt(attrib.precision);
            stream.writeString(attrib.name);
            stream.writeInt(attrib.arraySize);
            stream.writeInt(attrib.location);
        }
    
        stream.writeInt(mData.mTransformFeedbackBufferMode);
    
        gl::Error error = mProgram->save(&stream);
        if (error.isError())
        {
            return error;
        }
    
        GLsizei streamLength   = static_cast<GLsizei>(stream.length());
        const void *streamData = stream.data();
    
        if (streamLength > bufSize)
        {
            if (length)
            {
                *length = 0;
            }
    
            // TODO: This should be moved to the validation layer but computing the size of the binary before saving
            // it causes the save to happen twice.  It may be possible to write the binary to a separate buffer, validate
            // sizes and then copy it.
            return Error(GL_INVALID_OPERATION);
        }
    
        if (binary)
        {
            char *ptr = reinterpret_cast<char*>(binary);
    
            memcpy(ptr, streamData, streamLength);
            ptr += streamLength;
    
            ASSERT(ptr - streamLength == binary);
        }
    
        if (length)
        {
            *length = streamLength;
        }
    
        return Error(GL_NO_ERROR);
    }
    
    GLint Program::getBinaryLength() const
    {
        GLint length;
        Error error = saveBinary(nullptr, nullptr, std::numeric_limits<GLint>::max(), &length);
        if (error.isError())
        {
            return 0;
        }
    
        return length;
    }
    
    void Program::release()
    {
        mRefCount--;
    
        if (mRefCount == 0 && mDeleteStatus)
        {
            mResourceManager->deleteProgram(mHandle);
        }
    }
    
    void Program::addRef()
    {
        mRefCount++;
    }
    
    unsigned int Program::getRefCount() const
    {
        return mRefCount;
    }
    
    int Program::getInfoLogLength() const
    {
        return static_cast<int>(mInfoLog.getLength());
    }
    
    void Program::getInfoLog(GLsizei bufSize, GLsizei *length, char *infoLog)
    {
        return mInfoLog.getLog(bufSize, length, infoLog);
    }
    
    void Program::getAttachedShaders(GLsizei maxCount, GLsizei *count, GLuint *shaders)
    {
        int total = 0;
    
        if (mData.mAttachedVertexShader)
        {
            if (total < maxCount)
            {
                shaders[total] = mData.mAttachedVertexShader->getHandle();
            }
    
            total++;
        }
    
        if (mData.mAttachedFragmentShader)
        {
            if (total < maxCount)
            {
                shaders[total] = mData.mAttachedFragmentShader->getHandle();
            }
    
            total++;
        }
    
        if (count)
        {
            *count = total;
        }
    }
    
    GLuint Program::getAttributeLocation(const std::string &name)
    {
        for (size_t index = 0; index < mLinkedAttributes.size(); index++)
        {
            if (mLinkedAttributes[index].name == name)
            {
                return static_cast<GLuint>(index);
            }
        }
    
        return static_cast<GLuint>(-1);
    }
    
    const int *Program::getSemanticIndexes() const
    {
        return mProgram->getSemanticIndexes();
    }
    
    int Program::getSemanticIndex(int attributeIndex) const
    {
        ASSERT(attributeIndex >= 0 && attributeIndex < MAX_VERTEX_ATTRIBS);
    
        return mProgram->getSemanticIndexes()[attributeIndex];
    }
    
    void Program::getActiveAttribute(GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, GLchar *name)
    {
        if (mLinked)
        {
            // Skip over inactive attributes
            unsigned int activeAttribute = 0;
            unsigned int attribute;
            for (attribute = 0; attribute < static_cast<unsigned int>(mLinkedAttributes.size());
                 attribute++)
            {
                if (mLinkedAttributes[attribute].name.empty())
                {
                    continue;
                }
    
                if (activeAttribute == index)
                {
                    break;
                }
    
                activeAttribute++;
            }
    
            if (bufsize > 0)
            {
                const char *string = mLinkedAttributes[attribute].name.c_str();
    
                strncpy(name, string, bufsize);
                name[bufsize - 1] = '\0';
    
                if (length)
                {
                    *length = static_cast<GLsizei>(strlen(name));
                }
            }
    
            *size = 1;   // Always a single 'type' instance
    
            *type = mLinkedAttributes[attribute].type;
        }
        else
        {
            if (bufsize > 0)
            {
                name[0] = '\0';
            }
    
            if (length)
            {
                *length = 0;
            }
    
            *type = GL_NONE;
            *size = 1;
        }
    }
    
    GLint Program::getActiveAttributeCount()
    {
        int count = 0;
    
        if (mLinked)
        {
            for (int attributeIndex = 0; attributeIndex < MAX_VERTEX_ATTRIBS; attributeIndex++)
            {
                if (!mLinkedAttributes[attributeIndex].name.empty())
                {
                    count++;
                }
            }
        }
    
        return count;
    }
    
    GLint Program::getActiveAttributeMaxLength()
    {
        GLint maxLength = 0;
    
        if (mLinked)
        {
            for (int attributeIndex = 0; attributeIndex < MAX_VERTEX_ATTRIBS; attributeIndex++)
            {
                if (!mLinkedAttributes[attributeIndex].name.empty())
                {
                    maxLength = std::max(
                        static_cast<GLint>(mLinkedAttributes[attributeIndex].name.length() + 1),
                        maxLength);
                }
            }
        }
    
        return maxLength;
    }
    
    GLint Program::getFragDataLocation(const std::string &name) const
    {
        std::string baseName(name);
        unsigned int arrayIndex = ParseAndStripArrayIndex(&baseName);
        for (auto outputPair : mOutputVariables)
        {
            const VariableLocation &outputVariable = outputPair.second;
            if (outputVariable.name == baseName && (arrayIndex == GL_INVALID_INDEX || arrayIndex == outputVariable.element))
            {
                return static_cast<GLint>(outputPair.first);
            }
        }
        return -1;
    }
    
    void Program::getActiveUniform(GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, GLchar *name)
    {
        if (mLinked)
        {
            ASSERT(index < mProgram->getUniforms().size());   // index must be smaller than getActiveUniformCount()
            LinkedUniform *uniform = mProgram->getUniforms()[index];
    
            if (bufsize > 0)
            {
                std::string string = uniform->name;
                if (uniform->isArray())
                {
                    string += "[0]";
                }
    
                strncpy(name, string.c_str(), bufsize);
                name[bufsize - 1] = '\0';
    
                if (length)
                {
                    *length = static_cast<GLsizei>(strlen(name));
                }
            }
    
            *size = uniform->elementCount();
            *type = uniform->type;
        }
        else
        {
            if (bufsize > 0)
            {
                name[0] = '\0';
            }
    
            if (length)
            {
                *length = 0;
            }
    
            *size = 0;
            *type = GL_NONE;
        }
    }
    
    GLint Program::getActiveUniformCount()
    {
        if (mLinked)
        {
            return static_cast<GLint>(mProgram->getUniforms().size());
        }
        else
        {
            return 0;
        }
    }
    
    GLint Program::getActiveUniformMaxLength()
    {
        int maxLength = 0;
    
        if (mLinked)
        {
            unsigned int numUniforms = static_cast<unsigned int>(mProgram->getUniforms().size());
            for (unsigned int uniformIndex = 0; uniformIndex < numUniforms; uniformIndex++)
            {
                if (!mProgram->getUniforms()[uniformIndex]->name.empty())
                {
                    int length = (int)(mProgram->getUniforms()[uniformIndex]->name.length() + 1);
                    if (mProgram->getUniforms()[uniformIndex]->isArray())
                    {
                        length += 3;  // Counting in "[0]".
                    }
                    maxLength = std::max(length, maxLength);
                }
            }
        }
    
        return maxLength;
    }
    
    GLint Program::getActiveUniformi(GLuint index, GLenum pname) const
    {
        const gl::LinkedUniform& uniform = *mProgram->getUniforms()[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 + (uniform.isArray() ? 3 : 0));
          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;
    }
    
    bool Program::isValidUniformLocation(GLint location) const
    {
        const auto &uniformIndices = mProgram->getUniformIndices();
        ASSERT(rx::IsIntegerCastSafe<GLint>(uniformIndices.size()));
        return (location >= 0 && uniformIndices.find(location) != uniformIndices.end());
    }
    
    LinkedUniform *Program::getUniformByLocation(GLint location) const
    {
        return mProgram->getUniformByLocation(location);
    }
    
    LinkedUniform *Program::getUniformByName(const std::string &name) const
    {
        return mProgram->getUniformByName(name);
    }
    
    GLint Program::getUniformLocation(const std::string &name)
    {
        return mProgram->getUniformLocation(name);
    }
    
    GLuint Program::getUniformIndex(const std::string &name)
    {
        return mProgram->getUniformIndex(name);
    }
    
    void Program::setUniform1fv(GLint location, GLsizei count, const GLfloat *v)
    {
        mProgram->setUniform1fv(location, count, v);
    }
    
    void Program::setUniform2fv(GLint location, GLsizei count, const GLfloat *v)
    {
        mProgram->setUniform2fv(location, count, v);
    }
    
    void Program::setUniform3fv(GLint location, GLsizei count, const GLfloat *v)
    {
        mProgram->setUniform3fv(location, count, v);
    }
    
    void Program::setUniform4fv(GLint location, GLsizei count, const GLfloat *v)
    {
        mProgram->setUniform4fv(location, count, v);
    }
    
    void Program::setUniform1iv(GLint location, GLsizei count, const GLint *v)
    {
        mProgram->setUniform1iv(location, count, v);
    }
    
    void Program::setUniform2iv(GLint location, GLsizei count, const GLint *v)
    {
        mProgram->setUniform2iv(location, count, v);
    }
    
    void Program::setUniform3iv(GLint location, GLsizei count, const GLint *v)
    {
        mProgram->setUniform3iv(location, count, v);
    }
    
    void Program::setUniform4iv(GLint location, GLsizei count, const GLint *v)
    {
        mProgram->setUniform4iv(location, count, v);
    }
    
    void Program::setUniform1uiv(GLint location, GLsizei count, const GLuint *v)
    {
        mProgram->setUniform1uiv(location, count, v);
    }
    
    void Program::setUniform2uiv(GLint location, GLsizei count, const GLuint *v)
    {
        mProgram->setUniform2uiv(location, count, v);
    }
    
    void Program::setUniform3uiv(GLint location, GLsizei count, const GLuint *v)
    {
        mProgram->setUniform3uiv(location, count, v);
    }
    
    void Program::setUniform4uiv(GLint location, GLsizei count, const GLuint *v)
    {
        mProgram->setUniform4uiv(location, count, v);
    }
    
    void Program::setUniformMatrix2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix2fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix3fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix4fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix2x3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix2x3fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix2x4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix2x4fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix3x2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix3x2fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix3x4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix3x4fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix4x2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix4x2fv(location, count, transpose, v);
    }
    
    void Program::setUniformMatrix4x3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *v)
    {
        mProgram->setUniformMatrix4x3fv(location, count, transpose, v);
    }
    
    void Program::getUniformfv(GLint location, GLfloat *v)
    {
        mProgram->getUniformfv(location, v);
    }
    
    void Program::getUniformiv(GLint location, GLint *v)
    {
        mProgram->getUniformiv(location, v);
    }
    
    void Program::getUniformuiv(GLint location, GLuint *v)
    {
        mProgram->getUniformuiv(location, v);
    }
    
    void Program::flagForDeletion()
    {
        mDeleteStatus = true;
    }
    
    bool Program::isFlaggedForDeletion() const
    {
        return mDeleteStatus;
    }
    
    void Program::validate(const Caps &caps)
    {
        mInfoLog.reset();
    
        if (mLinked)
        {
            mValidated = (mProgram->validate(caps, &mInfoLog) == GL_TRUE);
        }
        else
        {
            mInfoLog << "Program has not been successfully linked.";
        }
    }
    
    bool Program::validateSamplers(InfoLog *infoLog, const Caps &caps)
    {
        return mProgram->validateSamplers(infoLog, caps);
    }
    
    bool Program::isValidated() const
    {
        return mValidated;
    }
    
    GLuint Program::getActiveUniformBlockCount()
    {
        return static_cast<GLuint>(mProgram->getUniformBlocks().size());
    }
    
    void Program::getActiveUniformBlockName(GLuint uniformBlockIndex, GLsizei bufSize, GLsizei *length, GLchar *uniformBlockName) const
    {
        ASSERT(uniformBlockIndex < mProgram->getUniformBlocks().size());   // index must be smaller than getActiveUniformBlockCount()
    
        const UniformBlock &uniformBlock = *mProgram->getUniformBlocks()[uniformBlockIndex];
    
        if (bufSize > 0)
        {
            std::string string = uniformBlock.name;
    
            if (uniformBlock.isArrayElement())
            {
                string += ArrayString(uniformBlock.elementIndex);
            }
    
            strncpy(uniformBlockName, string.c_str(), bufSize);
            uniformBlockName[bufSize - 1] = '\0';
    
            if (length)
            {
                *length = static_cast<GLsizei>(strlen(uniformBlockName));
            }
        }
    }
    
    void Program::getActiveUniformBlockiv(GLuint uniformBlockIndex, GLenum pname, GLint *params) const
    {
        ASSERT(uniformBlockIndex < mProgram->getUniformBlocks().size());   // index must be smaller than getActiveUniformBlockCount()
    
        const UniformBlock &uniformBlock = *mProgram->getUniformBlocks()[uniformBlockIndex];
    
        switch (pname)
        {
          case GL_UNIFORM_BLOCK_DATA_SIZE:
            *params = static_cast<GLint>(uniformBlock.dataSize);
            break;
          case GL_UNIFORM_BLOCK_NAME_LENGTH:
            *params = static_cast<GLint>(uniformBlock.name.size() + 1 + (uniformBlock.isArrayElement() ? 3 : 0));
            break;
          case GL_UNIFORM_BLOCK_ACTIVE_UNIFORMS:
            *params = static_cast<GLint>(uniformBlock.memberUniformIndexes.size());
            break;
          case GL_UNIFORM_BLOCK_ACTIVE_UNIFORM_INDICES:
            {
                for (unsigned int blockMemberIndex = 0; blockMemberIndex < uniformBlock.memberUniformIndexes.size(); blockMemberIndex++)
                {
                    params[blockMemberIndex] = static_cast<GLint>(uniformBlock.memberUniformIndexes[blockMemberIndex]);
                }
            }
            break;
          case GL_UNIFORM_BLOCK_REFERENCED_BY_VERTEX_SHADER:
            *params = static_cast<GLint>(uniformBlock.isReferencedByVertexShader());
            break;
          case GL_UNIFORM_BLOCK_REFERENCED_BY_FRAGMENT_SHADER:
            *params = static_cast<GLint>(uniformBlock.isReferencedByFragmentShader());
            break;
          default: UNREACHABLE();
        }
    }
    
    GLint Program::getActiveUniformBlockMaxLength()
    {
        int maxLength = 0;
    
        if (mLinked)
        {
            unsigned int numUniformBlocks =
                static_cast<unsigned int>(mProgram->getUniformBlocks().size());
            for (unsigned int uniformBlockIndex = 0; uniformBlockIndex < numUniformBlocks; uniformBlockIndex++)
            {
                const UniformBlock &uniformBlock = *mProgram->getUniformBlocks()[uniformBlockIndex];
                if (!uniformBlock.name.empty())
                {
                    const int length = static_cast<int>(uniformBlock.name.length()) + 1;
    
                    // Counting in "[0]".
                    const int arrayLength = (uniformBlock.isArrayElement() ? 3 : 0);
    
                    maxLength = std::max(length + arrayLength, maxLength);
                }
            }
        }
    
        return maxLength;
    }
    
    GLuint Program::getUniformBlockIndex(const std::string &name)
    {
        return mProgram->getUniformBlockIndex(name);
    }
    
    const UniformBlock *Program::getUniformBlockByIndex(GLuint index) const
    {
        return mProgram->getUniformBlockByIndex(index);
    }
    
    void Program::bindUniformBlock(GLuint uniformBlockIndex, GLuint uniformBlockBinding)
    {
        mData.mUniformBlockBindings[uniformBlockIndex] = uniformBlockBinding;
    }
    
    GLuint Program::getUniformBlockBinding(GLuint uniformBlockIndex) const
    {
        return mData.getUniformBlockBinding(uniformBlockIndex);
    }
    
    void Program::resetUniformBlockBindings()
    {
        for (unsigned int blockId = 0; blockId < IMPLEMENTATION_MAX_COMBINED_SHADER_UNIFORM_BUFFERS; blockId++)
        {
            mData.mUniformBlockBindings[blockId] = 0;
        }
    }
    
    void Program::setTransformFeedbackVaryings(GLsizei count, const GLchar *const *varyings, GLenum bufferMode)
    {
        mData.mTransformFeedbackVaryingNames.resize(count);
        for (GLsizei i = 0; i < count; i++)
        {
            mData.mTransformFeedbackVaryingNames[i] = varyings[i];
        }
    
        mData.mTransformFeedbackBufferMode = bufferMode;
    }
    
    void Program::getTransformFeedbackVarying(GLuint index, GLsizei bufSize, GLsizei *length, GLsizei *size, GLenum *type, GLchar *name) const
    {
        if (mLinked)
        {
            ASSERT(index < mData.mTransformFeedbackVaryingVars.size());
            const sh::Varying &varying = mData.mTransformFeedbackVaryingVars[index];
            GLsizei lastNameIdx = std::min(bufSize - 1, static_cast<GLsizei>(varying.name.length()));
            if (length)
            {
                *length = lastNameIdx;
            }
            if (size)
            {
                *size = varying.elementCount();
            }
            if (type)
            {
                *type = varying.type;
            }
            if (name)
            {
                memcpy(name, varying.name.c_str(), lastNameIdx);
                name[lastNameIdx] = '\0';
            }
        }
    }
    
    GLsizei Program::getTransformFeedbackVaryingCount() const
    {
        if (mLinked)
        {
            return static_cast<GLsizei>(mData.mTransformFeedbackVaryingVars.size());
        }
        else
        {
            return 0;
        }
    }
    
    GLsizei Program::getTransformFeedbackVaryingMaxLength() const
    {
        if (mLinked)
        {
            GLsizei maxSize = 0;
            for (const sh::Varying &varying : mData.mTransformFeedbackVaryingVars)
            {
                maxSize = std::max(maxSize, static_cast<GLsizei>(varying.name.length() + 1));
            }
    
            return maxSize;
        }
        else
        {
            return 0;
        }
    }
    
    GLenum Program::getTransformFeedbackBufferMode() const
    {
        return mData.mTransformFeedbackBufferMode;
    }
    
    // static
    bool Program::linkVaryings(InfoLog &infoLog,
                               const Shader *vertexShader,
                               const Shader *fragmentShader)
    {
        const std::vector<PackedVarying> &vertexVaryings   = vertexShader->getVaryings();
        const std::vector<PackedVarying> &fragmentVaryings = fragmentShader->getVaryings();
    
        for (const PackedVarying &output : fragmentVaryings)
        {
            bool matched = false;
    
            // Built-in varyings obey special rules
            if (output.isBuiltIn())
            {
                continue;
            }
    
            for (const PackedVarying &input : vertexVaryings)
            {
                if (output.name == input.name)
                {
                    ASSERT(!input.isBuiltIn());
                    if (!linkValidateVaryings(infoLog, output.name, input, output))
                    {
                        return false;
                    }
    
                    matched = true;
                    break;
                }
            }
    
            // We permit unmatched, unreferenced varyings
            if (!matched && output.staticUse)
            {
                infoLog << "Fragment varying " << output.name << " does not match any vertex varying";
                return false;
            }
        }
    
        // TODO(jmadill): verify no unmatched vertex varyings?
    
        return true;
    }
    
    bool Program::linkUniforms(gl::InfoLog &infoLog, const gl::Caps & /*caps*/) const
    {
        const std::vector<sh::Uniform> &vertexUniforms   = mData.mAttachedVertexShader->getUniforms();
        const std::vector<sh::Uniform> &fragmentUniforms = mData.mAttachedFragmentShader->getUniforms();
    
        // Check that uniforms defined in the vertex and fragment shaders are identical
        std::map<std::string, const sh::Uniform *> linkedUniforms;
    
        for (const sh::Uniform &vertexUniform : vertexUniforms)
        {
            linkedUniforms[vertexUniform.name] = &vertexUniform;
        }
    
        for (const sh::Uniform &fragmentUniform : fragmentUniforms)
        {
            auto entry = linkedUniforms.find(fragmentUniform.name);
            if (entry != linkedUniforms.end())
            {
                const sh::Uniform &vertexUniform = *entry->second;
                const std::string &uniformName = "uniform '" + vertexUniform.name + "'";
                if (!linkValidateUniforms(infoLog, uniformName, vertexUniform, fragmentUniform))
                {
                    return false;
                }
            }
        }
    
        // TODO(jmadill): check sampler uniforms with caps
        return true;
    }
    
    bool Program::linkValidateInterfaceBlockFields(InfoLog &infoLog, const std::string &uniformName, const sh::InterfaceBlockField &vertexUniform, const sh::InterfaceBlockField &fragmentUniform)
    {
        if (!linkValidateVariablesBase(infoLog, uniformName, vertexUniform, fragmentUniform, true))
        {
            return false;
        }
    
        if (vertexUniform.isRowMajorLayout != fragmentUniform.isRowMajorLayout)
        {
            infoLog << "Matrix packings for " << uniformName << " differ between vertex and fragment shaders";
            return false;
        }
    
        return true;
    }
    
    // Determines the mapping between GL attributes and Direct3D 9 vertex stream usage indices
    bool Program::linkAttributes(const gl::Data &data,
                                 InfoLog &infoLog,
                                 const AttributeBindings &attributeBindings,
                                 const Shader *vertexShader)
    {
        unsigned int usedLocations = 0;
        const std::vector<sh::Attribute> &shaderAttributes = vertexShader->getActiveAttributes();
        GLuint maxAttribs = data.caps->maxVertexAttributes;
    
        // TODO(jmadill): handle aliasing robustly
        if (shaderAttributes.size() > maxAttribs)
        {
            infoLog << "Too many vertex attributes.";
            return false;
        }
    
        // Link attributes that have a binding location
        for (unsigned int attributeIndex = 0; attributeIndex < shaderAttributes.size(); attributeIndex++)
        {
            const sh::Attribute &attribute = shaderAttributes[attributeIndex];
    
            ASSERT(attribute.staticUse);
    
            const int location = attribute.location == -1 ? attributeBindings.getAttributeBinding(attribute.name) : attribute.location;
    
            mProgram->setShaderAttribute(attributeIndex, attribute);
    
            if (location != -1)   // Set by glBindAttribLocation or by location layout qualifier
            {
                const int rows = VariableRegisterCount(attribute.type);
    
                if (static_cast<GLuint>(rows + location) > maxAttribs)
                {
                    infoLog << "Active attribute (" << attribute.name << ") at location "
                            << location << " is too big to fit";
    
                    return false;
                }
    
                for (int row = 0; row < rows; row++)
                {
                    const int rowLocation = location + row;
                    sh::ShaderVariable *linkedAttribute = &mLinkedAttributes[rowLocation];
    
                    // In GLSL 3.00, attribute aliasing produces a link error
                    // In GLSL 1.00, attribute aliasing is allowed, but ANGLE currently has a bug
                    // TODO(jmadill): fix aliasing on ES2
                    // if (mProgram->getShaderVersion() >= 300)
                    {
                        if (!linkedAttribute->name.empty())
                        {
                            infoLog << "Attribute '" << attribute.name << "' aliases attribute '"
                                    << linkedAttribute->name << "' at location " << rowLocation;
                            return false;
                        }
                    }
    
                    *linkedAttribute = attribute;
                    usedLocations |= 1 << rowLocation;
                }
            }
        }
    
        // Link attributes that don't have a binding location
        for (unsigned int attributeIndex = 0; attributeIndex < shaderAttributes.size(); attributeIndex++)
        {
            const sh::Attribute &attribute = shaderAttributes[attributeIndex];
    
            ASSERT(attribute.staticUse);
    
            const int location = attribute.location == -1 ? attributeBindings.getAttributeBinding(attribute.name) : attribute.location;
    
            if (location == -1)   // Not set by glBindAttribLocation or by location layout qualifier
            {
                int rows = VariableRegisterCount(attribute.type);
                int availableIndex = AllocateFirstFreeBits(&usedLocations, rows, maxAttribs);
    
                if (availableIndex == -1 || static_cast<GLuint>(availableIndex + rows) > maxAttribs)
                {
                    infoLog << "Too many active attributes (" << attribute.name << ")";
                    return false;   // Fail to link
                }
    
                mLinkedAttributes[availableIndex] = attribute;
            }
        }
    
        for (GLuint attributeIndex = 0; attributeIndex < maxAttribs;)
        {
            int index = vertexShader->getSemanticIndex(mLinkedAttributes[attributeIndex].name);
            int rows  = VariableRegisterCount(mLinkedAttributes[attributeIndex].type);
    
            for (int r = 0; r < rows; r++)
            {
                mProgram->getSemanticIndexes()[attributeIndex++] = index++;
            }
        }
    
        return true;
    }
    
    bool Program::linkUniformBlocks(InfoLog &infoLog, const Caps &caps)
    {
        const Shader &vertexShader   = *mData.mAttachedVertexShader;
        const Shader &fragmentShader = *mData.mAttachedFragmentShader;
    
        const std::vector<sh::InterfaceBlock> &vertexInterfaceBlocks = vertexShader.getInterfaceBlocks();
        const std::vector<sh::InterfaceBlock> &fragmentInterfaceBlocks = fragmentShader.getInterfaceBlocks();
    
        // Check that interface blocks defined in the vertex and fragment shaders are identical
        typedef std::map<std::string, const sh::InterfaceBlock*> UniformBlockMap;
        UniformBlockMap linkedUniformBlocks;
    
        GLuint vertexBlockCount = 0;
        for (const sh::InterfaceBlock &vertexInterfaceBlock : vertexInterfaceBlocks)
        {
            linkedUniformBlocks[vertexInterfaceBlock.name] = &vertexInterfaceBlock;
    
            // Note: shared and std140 layouts are always considered active
            if (vertexInterfaceBlock.staticUse || vertexInterfaceBlock.layout != sh::BLOCKLAYOUT_PACKED)
            {
                if (++vertexBlockCount > caps.maxVertexUniformBlocks)
                {
                    infoLog << "Vertex shader uniform block count exceed GL_MAX_VERTEX_UNIFORM_BLOCKS ("
                            << caps.maxVertexUniformBlocks << ")";
                    return false;
                }
            }
        }
    
        GLuint fragmentBlockCount = 0;
        for (const sh::InterfaceBlock &fragmentInterfaceBlock : fragmentInterfaceBlocks)
        {
            auto entry = linkedUniformBlocks.find(fragmentInterfaceBlock.name);
            if (entry != linkedUniformBlocks.end())
            {
                const sh::InterfaceBlock &vertexInterfaceBlock = *entry->second;
                if (!areMatchingInterfaceBlocks(infoLog, vertexInterfaceBlock, fragmentInterfaceBlock))
                {
                    return false;
                }
            }
    
            // Note: shared and std140 layouts are always considered active
            if (fragmentInterfaceBlock.staticUse ||
                fragmentInterfaceBlock.layout != sh::BLOCKLAYOUT_PACKED)
            {
                if (++fragmentBlockCount > caps.maxFragmentUniformBlocks)
                {
                    infoLog
                        << "Fragment shader uniform block count exceed GL_MAX_FRAGMENT_UNIFORM_BLOCKS ("
                        << caps.maxFragmentUniformBlocks << ")";
                    return false;
                }
            }
        }
    
        return true;
    }
    
    bool Program::areMatchingInterfaceBlocks(gl::InfoLog &infoLog, const sh::InterfaceBlock &vertexInterfaceBlock,
                                             const sh::InterfaceBlock &fragmentInterfaceBlock)
    {
        const char* blockName = vertexInterfaceBlock.name.c_str();
        // validate blocks for the same member types
        if (vertexInterfaceBlock.fields.size() != fragmentInterfaceBlock.fields.size())
        {
            infoLog << "Types for interface block '" << blockName
                    << "' differ between vertex and fragment shaders";
            return false;
        }
        if (vertexInterfaceBlock.arraySize != fragmentInterfaceBlock.arraySize)
        {
            infoLog << "Array sizes differ for interface block '" << blockName
                    << "' between vertex and fragment shaders";
            return false;
        }
        if (vertexInterfaceBlock.layout != fragmentInterfaceBlock.layout || vertexInterfaceBlock.isRowMajorLayout != fragmentInterfaceBlock.isRowMajorLayout)
        {
            infoLog << "Layout qualifiers differ for interface block '" << blockName
                    << "' between vertex and fragment shaders";
            return false;
        }
        const unsigned int numBlockMembers =
            static_cast<unsigned int>(vertexInterfaceBlock.fields.size());
        for (unsigned int blockMemberIndex = 0; blockMemberIndex < numBlockMembers; blockMemberIndex++)
        {
            const sh::InterfaceBlockField &vertexMember = vertexInterfaceBlock.fields[blockMemberIndex];
            const sh::InterfaceBlockField &fragmentMember = fragmentInterfaceBlock.fields[blockMemberIndex];
            if (vertexMember.name != fragmentMember.name)
            {
                infoLog << "Name mismatch for field " << blockMemberIndex
                        << " of interface block '" << blockName
                        << "': (in vertex: '" << vertexMember.name
                        << "', in fragment: '" << fragmentMember.name << "')";
                return false;
            }
            std::string memberName = "interface block '" + vertexInterfaceBlock.name + "' member '" + vertexMember.name + "'";
            if (!linkValidateInterfaceBlockFields(infoLog, memberName, vertexMember, fragmentMember))
            {
                return false;
            }
        }
        return true;
    }
    
    bool Program::linkValidateVariablesBase(InfoLog &infoLog, const std::string &variableName, const sh::ShaderVariable &vertexVariable,
                                                  const sh::ShaderVariable &fragmentVariable, bool validatePrecision)
    {
        if (vertexVariable.type != fragmentVariable.type)
        {
            infoLog << "Types for " << variableName << " differ between vertex and fragment shaders";
            return false;
        }
        if (vertexVariable.arraySize != fragmentVariable.arraySize)
        {
            infoLog << "Array sizes for " << variableName << " differ between vertex and fragment shaders";
            return false;
        }
        if (validatePrecision && vertexVariable.precision != fragmentVariable.precision)
        {
            infoLog << "Precisions for " << variableName << " differ between vertex and fragment shaders";
            return false;
        }
    
        if (vertexVariable.fields.size() != fragmentVariable.fields.size())
        {
            infoLog << "Structure lengths for " << variableName << " differ between vertex and fragment shaders";
            return false;
        }
        const unsigned int numMembers = static_cast<unsigned int>(vertexVariable.fields.size());
        for (unsigned int memberIndex = 0; memberIndex < numMembers; memberIndex++)
        {
            const sh::ShaderVariable &vertexMember = vertexVariable.fields[memberIndex];
            const sh::ShaderVariable &fragmentMember = fragmentVariable.fields[memberIndex];
    
            if (vertexMember.name != fragmentMember.name)
            {
                infoLog << "Name mismatch for field '" << memberIndex
                        << "' of " << variableName
                        << ": (in vertex: '" << vertexMember.name
                        << "', in fragment: '" << fragmentMember.name << "')";
                return false;
            }
    
            const std::string memberName = variableName.substr(0, variableName.length() - 1) + "." +
                                           vertexMember.name + "'";
    
            if (!linkValidateVariablesBase(infoLog, vertexMember.name, vertexMember, fragmentMember, validatePrecision))
            {
                return false;
            }
        }
    
        return true;
    }
    
    bool Program::linkValidateUniforms(InfoLog &infoLog, const std::string &uniformName, const sh::Uniform &vertexUniform, const sh::Uniform &fragmentUniform)
    {
    #if ANGLE_PROGRAM_LINK_VALIDATE_UNIFORM_PRECISION == ANGLE_ENABLED
        const bool validatePrecision = true;
    #else
        const bool validatePrecision = false;
    #endif
    
        if (!linkValidateVariablesBase(infoLog, uniformName, vertexUniform, fragmentUniform, validatePrecision))
        {
            return false;
        }
    
        return true;
    }
    
    bool Program::linkValidateVaryings(InfoLog &infoLog, const std::string &varyingName, const sh::Varying &vertexVarying, const sh::Varying &fragmentVarying)
    {
        if (!linkValidateVariablesBase(infoLog, varyingName, vertexVarying, fragmentVarying, false))
        {
            return false;
        }
    
        if (!sh::InterpolationTypesMatch(vertexVarying.interpolation, fragmentVarying.interpolation))
        {
            infoLog << "Interpolation types for " << varyingName << " differ between vertex and fragment shaders";
            return false;
        }
    
        return true;
    }
    
    bool Program::linkValidateTransformFeedback(InfoLog &infoLog,
                                                const std::vector<const sh::Varying *> &varyings,
                                                const Caps &caps) const
    {
        size_t totalComponents = 0;
    
        std::set<std::string> uniqueNames;
    
        for (const std::string &tfVaryingName : mData.mTransformFeedbackVaryingNames)
        {
            bool found = false;
            for (const sh::Varying *varying : varyings)
            {
                if (tfVaryingName == varying->name)
                {
                    if (uniqueNames.count(tfVaryingName) > 0)
                    {
                        infoLog << "Two transform feedback varyings specify the same output variable ("
                                << tfVaryingName << ").";
                        return false;
                    }
                    uniqueNames.insert(tfVaryingName);
    
                    // TODO(jmadill): Investigate implementation limits on D3D11
                    size_t componentCount = gl::VariableComponentCount(varying->type);
                    if (mData.mTransformFeedbackBufferMode == GL_SEPARATE_ATTRIBS &&
                        componentCount > caps.maxTransformFeedbackSeparateComponents)
                    {
                        infoLog << "Transform feedback varying's " << varying->name << " components ("
                                << componentCount << ") exceed the maximum separate components ("
                                << caps.maxTransformFeedbackSeparateComponents << ").";
                        return false;
                    }
    
                    totalComponents += componentCount;
                    found = true;
                    break;
                }
            }
    
            // All transform feedback varyings are expected to exist since packVaryings checks for them.
            ASSERT(found);
            UNUSED_ASSERTION_VARIABLE(found);
        }
    
        if (mData.mTransformFeedbackBufferMode == GL_INTERLEAVED_ATTRIBS &&
            totalComponents > caps.maxTransformFeedbackInterleavedComponents)
        {
            infoLog << "Transform feedback varying total components (" << totalComponents
                    << ") exceed the maximum interleaved components ("
                    << caps.maxTransformFeedbackInterleavedComponents << ").";
            return false;
        }
    
        return true;
    }
    
    void Program::gatherTransformFeedbackVaryings(const std::vector<const sh::Varying *> &varyings)
    {
        // Gather the linked varyings that are used for transform feedback, they should all exist.
        mData.mTransformFeedbackVaryingVars.clear();
        for (const std::string &tfVaryingName : mData.mTransformFeedbackVaryingNames)
        {
            for (const sh::Varying *varying : varyings)
            {
                if (tfVaryingName == varying->name)
                {
                    mData.mTransformFeedbackVaryingVars.push_back(*varying);
                    break;
                }
            }
        }
    }
    
    std::vector<const sh::Varying *> Program::getMergedVaryings() const
    {
        std::set<std::string> uniqueNames;
        std::vector<const sh::Varying *> varyings;
    
        for (const sh::Varying &varying : mData.mAttachedVertexShader->getVaryings())
        {
            if (uniqueNames.count(varying.name) == 0)
            {
                uniqueNames.insert(varying.name);
                varyings.push_back(&varying);
            }
        }
    
        for (const sh::Varying &varying : mData.mAttachedFragmentShader->getVaryings())
        {
            if (uniqueNames.count(varying.name) == 0)
            {
                uniqueNames.insert(varying.name);
                varyings.push_back(&varying);
            }
        }
    
        return varyings;
    }
    }