Edit

kc3-lang/angle/src/libANGLE/renderer/d3d/DynamicHLSL.cpp

Branch :

  • Show log

    Commit

  • Author : Tim Van Patten
    Date : 2019-09-04 15:39:58
    Hash : 90a58622
    Message : Refactor ShaderVariable to Remove Specializations The following structs are being refactored and moved into the parent struct ShaderVariable: VariableWithLocation Uniform Attribute OutputVariable InterfaceBlockField Varying Bug: angleproject:3899 Test: CQ Change-Id: I389eb3ab4ed44a360e09fca75ecc78d64a277f83 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1785877 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com> Commit-Queue: Tim Van Patten <timvp@google.com>

  • src/libANGLE/renderer/d3d/DynamicHLSL.cpp
  • //
    // Copyright 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.
    //
    // DynamicHLSL.cpp: Implementation for link and run-time HLSL generation
    //
    
    #include "libANGLE/renderer/d3d/DynamicHLSL.h"
    
    #include "common/string_utils.h"
    #include "common/utilities.h"
    #include "compiler/translator/blocklayoutHLSL.h"
    #include "libANGLE/Context.h"
    #include "libANGLE/Program.h"
    #include "libANGLE/Shader.h"
    #include "libANGLE/VaryingPacking.h"
    #include "libANGLE/formatutils.h"
    #include "libANGLE/renderer/d3d/ProgramD3D.h"
    #include "libANGLE/renderer/d3d/RendererD3D.h"
    #include "libANGLE/renderer/d3d/ShaderD3D.h"
    
    using namespace gl;
    
    namespace rx
    {
    
    namespace
    {
    
    const char *HLSLComponentTypeString(GLenum componentType)
    {
        switch (componentType)
        {
            case GL_UNSIGNED_INT:
                return "uint";
            case GL_INT:
                return "int";
            case GL_UNSIGNED_NORMALIZED:
            case GL_SIGNED_NORMALIZED:
            case GL_FLOAT:
                return "float";
            default:
                UNREACHABLE();
                return "not-component-type";
        }
    }
    
    void HLSLComponentTypeString(std::ostringstream &ostream, GLenum componentType, int componentCount)
    {
        ostream << HLSLComponentTypeString(componentType);
        if (componentCount > 1)
        {
            ostream << componentCount;
        }
    }
    
    const char *HLSLMatrixTypeString(GLenum type)
    {
        switch (type)
        {
            case GL_FLOAT_MAT2:
                return "float2x2";
            case GL_FLOAT_MAT3:
                return "float3x3";
            case GL_FLOAT_MAT4:
                return "float4x4";
            case GL_FLOAT_MAT2x3:
                return "float2x3";
            case GL_FLOAT_MAT3x2:
                return "float3x2";
            case GL_FLOAT_MAT2x4:
                return "float2x4";
            case GL_FLOAT_MAT4x2:
                return "float4x2";
            case GL_FLOAT_MAT3x4:
                return "float3x4";
            case GL_FLOAT_MAT4x3:
                return "float4x3";
            default:
                UNREACHABLE();
                return "not-matrix-type";
        }
    }
    
    void HLSLTypeString(std::ostringstream &ostream, GLenum type)
    {
        if (gl::IsMatrixType(type))
        {
            ostream << HLSLMatrixTypeString(type);
            return;
        }
    
        HLSLComponentTypeString(ostream, gl::VariableComponentType(type),
                                gl::VariableComponentCount(type));
    }
    
    const PixelShaderOutputVariable *FindOutputAtLocation(
        const std::vector<PixelShaderOutputVariable> &outputVariables,
        unsigned int location,
        size_t index = 0)
    {
        for (auto &outputVar : outputVariables)
        {
            if (outputVar.outputLocation == location && outputVar.outputIndex == index)
            {
                return &outputVar;
            }
        }
    
        return nullptr;
    }
    
    void WriteArrayString(std::ostringstream &strstr, unsigned int i)
    {
        static_assert(GL_INVALID_INDEX == UINT_MAX,
                      "GL_INVALID_INDEX must be equal to the max unsigned int.");
        if (i == UINT_MAX)
        {
            return;
        }
    
        strstr << "[";
        strstr << i;
        strstr << "]";
    }
    
    constexpr const char *VERTEX_ATTRIBUTE_STUB_STRING      = "@@ VERTEX ATTRIBUTES @@";
    constexpr const char *VERTEX_OUTPUT_STUB_STRING         = "@@ VERTEX OUTPUT @@";
    constexpr const char *PIXEL_OUTPUT_STUB_STRING          = "@@ PIXEL OUTPUT @@";
    constexpr const char *PIXEL_MAIN_PARAMETERS_STUB_STRING = "@@ PIXEL MAIN PARAMETERS @@";
    constexpr const char *MAIN_PROLOGUE_STUB_STRING         = "@@ MAIN PROLOGUE @@";
    }  // anonymous namespace
    
    // BuiltinInfo implementation
    
    BuiltinInfo::BuiltinInfo()  = default;
    BuiltinInfo::~BuiltinInfo() = default;
    
    // DynamicHLSL implementation
    
    DynamicHLSL::DynamicHLSL(RendererD3D *const renderer) : mRenderer(renderer) {}
    
    std::string DynamicHLSL::generateVertexShaderForInputLayout(
        const std::string &sourceShader,
        const InputLayout &inputLayout,
        const std::vector<sh::ShaderVariable> &shaderAttributes) const
    {
        std::ostringstream structStream;
        std::ostringstream initStream;
    
        structStream << "struct VS_INPUT\n"
                     << "{\n";
    
        int semanticIndex       = 0;
        unsigned int inputIndex = 0;
    
        // If gl_PointSize is used in the shader then pointsprites rendering is expected.
        // If the renderer does not support Geometry shaders then Instanced PointSprite emulation
        // must be used.
        bool usesPointSize = sourceShader.find("GL_USES_POINT_SIZE") != std::string::npos;
        bool useInstancedPointSpriteEmulation =
            usesPointSize && mRenderer->getFeatures().useInstancedPointSpriteEmulation.enabled;
    
        // Instanced PointSprite emulation requires additional entries in the
        // VS_INPUT structure to support the vertices that make up the quad vertices.
        // These values must be in sync with the cooresponding values added during inputlayout creation
        // in InputLayoutCache::applyVertexBuffers().
        //
        // The additional entries must appear first in the VS_INPUT layout because
        // Windows Phone 8 era devices require per vertex data to physically come
        // before per instance data in the shader.
        if (useInstancedPointSpriteEmulation)
        {
            structStream << "    float3 spriteVertexPos : SPRITEPOSITION0;\n"
                         << "    float2 spriteTexCoord : SPRITETEXCOORD0;\n";
        }
    
        for (size_t attributeIndex = 0; attributeIndex < shaderAttributes.size(); ++attributeIndex)
        {
            const sh::ShaderVariable &shaderAttribute = shaderAttributes[attributeIndex];
            if (!shaderAttribute.name.empty())
            {
                ASSERT(inputIndex < MAX_VERTEX_ATTRIBS);
                angle::FormatID vertexFormatID =
                    inputIndex < inputLayout.size() ? inputLayout[inputIndex] : angle::FormatID::NONE;
    
                // HLSL code for input structure
                if (IsMatrixType(shaderAttribute.type))
                {
                    // Matrix types are always transposed
                    structStream << "    "
                                 << HLSLMatrixTypeString(TransposeMatrixType(shaderAttribute.type));
                }
                else
                {
                    GLenum componentType = mRenderer->getVertexComponentType(vertexFormatID);
    
                    if (shaderAttribute.name == "gl_InstanceID" ||
                        shaderAttribute.name == "gl_VertexID")
                    {
                        // The input types of the instance ID and vertex ID in HLSL (uint) differs from
                        // the ones in ESSL (int).
                        structStream << " uint";
                    }
                    else
                    {
                        structStream << "    ";
                        HLSLComponentTypeString(structStream, componentType,
                                                VariableComponentCount(shaderAttribute.type));
                    }
                }
    
                structStream << " " << DecorateVariable(shaderAttribute.name) << " : ";
    
                if (shaderAttribute.name == "gl_InstanceID")
                {
                    structStream << "SV_InstanceID";
                }
                else if (shaderAttribute.name == "gl_VertexID")
                {
                    structStream << "SV_VertexID";
                }
                else
                {
                    structStream << "TEXCOORD" << semanticIndex;
                    semanticIndex += VariableRegisterCount(shaderAttribute.type);
                }
    
                structStream << ";\n";
    
                // HLSL code for initialization
                initStream << "    " << DecorateVariable(shaderAttribute.name) << " = ";
    
                // Mismatched vertex attribute to vertex input may result in an undefined
                // data reinterpretation (eg for pure integer->float, float->pure integer)
                // TODO: issue warning with gl debug info extension, when supported
                if (IsMatrixType(shaderAttribute.type) ||
                    (mRenderer->getVertexConversionType(vertexFormatID) & VERTEX_CONVERT_GPU) != 0)
                {
                    GenerateAttributeConversionHLSL(vertexFormatID, shaderAttribute, initStream);
                }
                else
                {
                    initStream << "input." << DecorateVariable(shaderAttribute.name);
                }
    
                if (shaderAttribute.name == "gl_VertexID")
                {
                    // dx_VertexID contains the firstVertex offset
                    initStream << " + dx_VertexID";
                }
    
                initStream << ";\n";
    
                inputIndex += VariableRowCount(TransposeMatrixType(shaderAttribute.type));
            }
        }
    
        structStream << "};\n"
                        "\n"
                        "void initAttributes(VS_INPUT input)\n"
                        "{\n"
                     << initStream.str() << "}\n";
    
        std::string vertexHLSL(sourceShader);
    
        bool success =
            angle::ReplaceSubstring(&vertexHLSL, VERTEX_ATTRIBUTE_STUB_STRING, structStream.str());
        ASSERT(success);
    
        return vertexHLSL;
    }
    
    std::string DynamicHLSL::generatePixelShaderForOutputSignature(
        const std::string &sourceShader,
        const std::vector<PixelShaderOutputVariable> &outputVariables,
        bool usesFragDepth,
        const std::vector<GLenum> &outputLayout) const
    {
        const int shaderModel      = mRenderer->getMajorShaderModel();
        std::string targetSemantic = (shaderModel >= 4) ? "SV_TARGET" : "COLOR";
        std::string depthSemantic  = (shaderModel >= 4) ? "SV_Depth" : "DEPTH";
    
        std::ostringstream declarationStream;
        std::ostringstream copyStream;
    
        declarationStream << "struct PS_OUTPUT\n"
                             "{\n";
    
        size_t numOutputs = outputLayout.size();
    
        // Workaround for HLSL 3.x: We can't do a depth/stencil only render, the runtime will complain.
        if (numOutputs == 0 && (shaderModel == 3 || !mRenderer->getShaderModelSuffix().empty()))
        {
            numOutputs = 1u;
        }
        const PixelShaderOutputVariable defaultOutput(GL_FLOAT_VEC4, "dummy", "float4(0, 0, 0, 1)", 0,
                                                      0);
        size_t outputIndex = 0;
    
        for (size_t layoutIndex = 0; layoutIndex < numOutputs; ++layoutIndex)
        {
            GLenum binding = outputLayout.empty() ? GL_COLOR_ATTACHMENT0 : outputLayout[layoutIndex];
    
            if (binding != GL_NONE)
            {
                unsigned int location = (binding - GL_COLOR_ATTACHMENT0);
                outputIndex =
                    layoutIndex > 0 && binding == outputLayout[layoutIndex - 1] ? outputIndex + 1 : 0;
    
                const PixelShaderOutputVariable *outputVariable =
                    outputLayout.empty() ? &defaultOutput
                                         : FindOutputAtLocation(outputVariables, location, outputIndex);
    
                // OpenGL ES 3.0 spec $4.2.1
                // If [...] not all user-defined output variables are written, the values of fragment
                // colors corresponding to unwritten variables are similarly undefined.
                if (outputVariable)
                {
                    declarationStream << "    ";
                    HLSLTypeString(declarationStream, outputVariable->type);
                    declarationStream << " " << outputVariable->name << " : " << targetSemantic
                                      << static_cast<int>(layoutIndex) << ";\n";
    
                    copyStream << "    output." << outputVariable->name << " = "
                               << outputVariable->source << ";\n";
                }
            }
        }
    
        if (usesFragDepth)
        {
            declarationStream << "    float gl_Depth : " << depthSemantic << ";\n";
            copyStream << "    output.gl_Depth = gl_Depth; \n";
        }
    
        declarationStream << "};\n"
                             "\n"
                             "PS_OUTPUT generateOutput()\n"
                             "{\n"
                             "    PS_OUTPUT output;\n"
                          << copyStream.str()
                          << "    return output;\n"
                             "}\n";
    
        std::string pixelHLSL(sourceShader);
    
        bool success =
            angle::ReplaceSubstring(&pixelHLSL, PIXEL_OUTPUT_STUB_STRING, declarationStream.str());
        ASSERT(success);
    
        return pixelHLSL;
    }
    
    std::string DynamicHLSL::generateComputeShaderForImage2DBindSignature(
        const d3d::Context *context,
        ProgramD3D &programD3D,
        const gl::ProgramState &programData,
        std::vector<sh::ShaderVariable> &image2DUniforms,
        const gl::ImageUnitTextureTypeMap &image2DBindLayout) const
    {
        std::string computeHLSL(
            programData.getAttachedShader(ShaderType::Compute)->getTranslatedSource());
    
        if (image2DUniforms.empty())
        {
            return computeHLSL;
        }
    
        return GenerateComputeShaderForImage2DBindSignature(context, programD3D, programData,
                                                            image2DUniforms, image2DBindLayout);
    }
    
    void DynamicHLSL::generateVaryingLinkHLSL(const VaryingPacking &varyingPacking,
                                              const BuiltinInfo &builtins,
                                              bool programUsesPointSize,
                                              std::ostringstream &hlslStream) const
    {
        ASSERT(builtins.dxPosition.enabled);
        hlslStream << "{\n"
                   << "    float4 dx_Position : " << builtins.dxPosition.str() << ";\n";
    
        if (builtins.glPosition.enabled)
        {
            hlslStream << "    float4 gl_Position : " << builtins.glPosition.str() << ";\n";
        }
    
        if (builtins.glFragCoord.enabled)
        {
            hlslStream << "    float4 gl_FragCoord : " << builtins.glFragCoord.str() << ";\n";
        }
    
        if (builtins.glPointCoord.enabled)
        {
            hlslStream << "    float2 gl_PointCoord : " << builtins.glPointCoord.str() << ";\n";
        }
    
        if (builtins.glPointSize.enabled)
        {
            hlslStream << "    float gl_PointSize : " << builtins.glPointSize.str() << ";\n";
        }
    
        if (builtins.glViewIDOVR.enabled)
        {
            hlslStream << "    nointerpolation uint gl_ViewID_OVR : " << builtins.glViewIDOVR.str()
                       << ";\n";
        }
    
        std::string varyingSemantic =
            GetVaryingSemantic(mRenderer->getMajorShaderModel(), programUsesPointSize);
    
        const auto &registerInfos = varyingPacking.getRegisterList();
        for (GLuint registerIndex = 0u; registerIndex < registerInfos.size(); ++registerIndex)
        {
            const PackedVaryingRegister &registerInfo = registerInfos[registerIndex];
            const auto &varying                       = *registerInfo.packedVarying->varying;
            ASSERT(!varying.isStruct());
    
            // TODO: Add checks to ensure D3D interpolation modifiers don't result in too many
            // registers being used.
            // For example, if there are N registers, and we have N vec3 varyings and 1 float
            // varying, then D3D will pack them into N registers.
            // If the float varying has the 'nointerpolation' modifier on it then we would need
            // N + 1 registers, and D3D compilation will fail.
    
            switch (registerInfo.packedVarying->interpolation)
            {
                case sh::INTERPOLATION_SMOOTH:
                    hlslStream << "    ";
                    break;
                case sh::INTERPOLATION_FLAT:
                    hlslStream << "    nointerpolation ";
                    break;
                case sh::INTERPOLATION_CENTROID:
                    hlslStream << "    centroid ";
                    break;
                default:
                    UNREACHABLE();
            }
    
            GLenum transposedType = gl::TransposeMatrixType(varying.type);
            GLenum componentType  = gl::VariableComponentType(transposedType);
            int columnCount       = gl::VariableColumnCount(transposedType);
            HLSLComponentTypeString(hlslStream, componentType, columnCount);
            hlslStream << " v" << registerIndex << " : " << varyingSemantic << registerIndex << ";\n";
        }
    
        // Note that the following outputs need to be declared after the others. They are not included
        // in pixel shader inputs even when they are in vertex/geometry shader outputs, and the pixel
        // shader input struct must be a prefix of the vertex/geometry shader output struct.
    
        if (builtins.glViewportIndex.enabled)
        {
            hlslStream << "    nointerpolation uint gl_ViewportIndex : "
                       << builtins.glViewportIndex.str() << ";\n";
        }
    
        if (builtins.glLayer.enabled)
        {
            hlslStream << "    nointerpolation uint gl_Layer : " << builtins.glLayer.str() << ";\n";
        }
    
        hlslStream << "};\n";
    }
    
    void DynamicHLSL::generateShaderLinkHLSL(const gl::Caps &caps,
                                             const gl::ProgramState &programData,
                                             const ProgramD3DMetadata &programMetadata,
                                             const VaryingPacking &varyingPacking,
                                             const BuiltinVaryingsD3D &builtinsD3D,
                                             gl::ShaderMap<std::string> *shaderHLSL) const
    {
        ASSERT(shaderHLSL);
        ASSERT((*shaderHLSL)[gl::ShaderType::Vertex].empty() &&
               (*shaderHLSL)[gl::ShaderType::Fragment].empty());
    
        gl::Shader *vertexShaderGL   = programData.getAttachedShader(ShaderType::Vertex);
        gl::Shader *fragmentShaderGL = programData.getAttachedShader(ShaderType::Fragment);
        const int shaderModel        = mRenderer->getMajorShaderModel();
    
        const ShaderD3D *fragmentShader = nullptr;
        if (fragmentShaderGL)
        {
            fragmentShader = GetImplAs<ShaderD3D>(fragmentShaderGL);
        }
    
        // usesViewScale() isn't supported in the D3D9 renderer
        ASSERT(shaderModel >= 4 || !programMetadata.usesViewScale());
    
        bool useInstancedPointSpriteEmulation =
            programMetadata.usesPointSize() &&
            mRenderer->getFeatures().useInstancedPointSpriteEmulation.enabled;
    
        // Validation done in the compiler
        ASSERT(!fragmentShader || !fragmentShader->usesFragColor() || !fragmentShader->usesFragData());
    
        std::ostringstream vertexStream;
        vertexStream << "struct VS_OUTPUT\n";
        const auto &vertexBuiltins = builtinsD3D[gl::ShaderType::Vertex];
        generateVaryingLinkHLSL(varyingPacking, vertexBuiltins, builtinsD3D.usesPointSize(),
                                vertexStream);
    
        // Instanced PointSprite emulation requires additional entries originally generated in the
        // GeometryShader HLSL. These include pointsize clamp values.
        if (useInstancedPointSpriteEmulation)
        {
            vertexStream << "static float minPointSize = " << static_cast<int>(caps.minAliasedPointSize)
                         << ".0f;\n"
                         << "static float maxPointSize = " << static_cast<int>(caps.maxAliasedPointSize)
                         << ".0f;\n";
        }
    
        std::ostringstream vertexGenerateOutput;
        vertexGenerateOutput << "VS_OUTPUT generateOutput(VS_INPUT input)\n"
                             << "{\n"
                             << "    VS_OUTPUT output;\n";
    
        if (vertexBuiltins.glPosition.enabled)
        {
            vertexGenerateOutput << "    output.gl_Position = gl_Position;\n";
        }
    
        if (vertexBuiltins.glViewIDOVR.enabled)
        {
            vertexGenerateOutput << "    output.gl_ViewID_OVR = ViewID_OVR;\n";
        }
        if (programMetadata.hasANGLEMultiviewEnabled() && programMetadata.canSelectViewInVertexShader())
        {
            ASSERT(vertexBuiltins.glViewportIndex.enabled && vertexBuiltins.glLayer.enabled);
            vertexGenerateOutput << "    if (multiviewSelectViewportIndex)\n"
                                 << "    {\n"
                                 << "         output.gl_ViewportIndex = ViewID_OVR;\n"
                                 << "    } else {\n"
                                 << "         output.gl_ViewportIndex = 0;\n"
                                 << "         output.gl_Layer = ViewID_OVR;\n"
                                 << "    }\n";
        }
    
        // On D3D9 or D3D11 Feature Level 9, we need to emulate large viewports using dx_ViewAdjust.
        if (shaderModel >= 4 && mRenderer->getShaderModelSuffix() == "")
        {
            vertexGenerateOutput << "    output.dx_Position.x = gl_Position.x;\n";
    
            if (programMetadata.usesViewScale())
            {
                // This code assumes that dx_ViewScale.y = -1.0f when rendering to texture, and +1.0f
                // when rendering to the default framebuffer. No other values are valid.
                vertexGenerateOutput << "    output.dx_Position.y = dx_ViewScale.y * gl_Position.y;\n";
            }
            else
            {
                vertexGenerateOutput << "    output.dx_Position.y = - gl_Position.y;\n";
            }
    
            vertexGenerateOutput
                << "    output.dx_Position.z = (gl_Position.z + gl_Position.w) * 0.5;\n"
                << "    output.dx_Position.w = gl_Position.w;\n";
        }
        else
        {
            vertexGenerateOutput << "    output.dx_Position.x = gl_Position.x * dx_ViewAdjust.z + "
                                    "dx_ViewAdjust.x * gl_Position.w;\n";
    
            // If usesViewScale() is true and we're using the D3D11 renderer via Feature Level 9_*,
            // then we need to multiply the gl_Position.y by the viewScale.
            // usesViewScale() isn't supported when using the D3D9 renderer.
            if (programMetadata.usesViewScale() &&
                (shaderModel >= 4 && mRenderer->getShaderModelSuffix() != ""))
            {
                vertexGenerateOutput << "    output.dx_Position.y = dx_ViewScale.y * (gl_Position.y * "
                                        "dx_ViewAdjust.w + dx_ViewAdjust.y * gl_Position.w);\n";
            }
            else
            {
                vertexGenerateOutput
                    << "    output.dx_Position.y = -(gl_Position.y * dx_ViewAdjust.w + "
                       "dx_ViewAdjust.y * gl_Position.w);\n";
            }
    
            vertexGenerateOutput
                << "    output.dx_Position.z = (gl_Position.z + gl_Position.w) * 0.5;\n"
                << "    output.dx_Position.w = gl_Position.w;\n";
        }
    
        // We don't need to output gl_PointSize if we use are emulating point sprites via instancing.
        if (vertexBuiltins.glPointSize.enabled)
        {
            vertexGenerateOutput << "    output.gl_PointSize = gl_PointSize;\n";
        }
    
        if (vertexBuiltins.glFragCoord.enabled)
        {
            vertexGenerateOutput << "    output.gl_FragCoord = gl_Position;\n";
        }
    
        const auto &registerInfos = varyingPacking.getRegisterList();
        for (GLuint registerIndex = 0u; registerIndex < registerInfos.size(); ++registerIndex)
        {
            const PackedVaryingRegister &registerInfo = registerInfos[registerIndex];
            const auto &packedVarying                 = *registerInfo.packedVarying;
            const auto &varying                       = *packedVarying.varying;
            ASSERT(!varying.isStruct());
    
            vertexGenerateOutput << "    output.v" << registerIndex << " = ";
    
            if (packedVarying.isStructField())
            {
                vertexGenerateOutput << DecorateVariable(packedVarying.parentStructName) << ".";
            }
    
            vertexGenerateOutput << DecorateVariable(varying.name);
    
            if (varying.isArray())
            {
                WriteArrayString(vertexGenerateOutput, registerInfo.varyingArrayIndex);
            }
    
            if (VariableRowCount(varying.type) > 1)
            {
                WriteArrayString(vertexGenerateOutput, registerInfo.varyingRowIndex);
            }
    
            vertexGenerateOutput << ";\n";
        }
    
        // Instanced PointSprite emulation requires additional entries to calculate
        // the final output vertex positions of the quad that represents each sprite.
        if (useInstancedPointSpriteEmulation)
        {
            vertexGenerateOutput
                << "\n"
                << "    gl_PointSize = clamp(gl_PointSize, minPointSize, maxPointSize);\n";
    
            vertexGenerateOutput
                << "    output.dx_Position.x += (input.spriteVertexPos.x * gl_PointSize / "
                   "(dx_ViewCoords.x*2)) * output.dx_Position.w;";
    
            if (programMetadata.usesViewScale())
            {
                // Multiply by ViewScale to invert the rendering when appropriate
                vertexGenerateOutput
                    << "    output.dx_Position.y += (-dx_ViewScale.y * "
                       "input.spriteVertexPos.y * gl_PointSize / (dx_ViewCoords.y*2)) * "
                       "output.dx_Position.w;";
            }
            else
            {
                vertexGenerateOutput
                    << "    output.dx_Position.y += (input.spriteVertexPos.y * gl_PointSize / "
                       "(dx_ViewCoords.y*2)) * output.dx_Position.w;";
            }
    
            vertexGenerateOutput
                << "    output.dx_Position.z += input.spriteVertexPos.z * output.dx_Position.w;\n";
    
            if (programMetadata.usesPointCoord())
            {
                vertexGenerateOutput << "\n"
                                     << "    output.gl_PointCoord = input.spriteTexCoord;\n";
            }
        }
    
        // Renderers that enable instanced pointsprite emulation require the vertex shader output member
        // gl_PointCoord to be set to a default value if used without gl_PointSize. 0.5,0.5 is the same
        // default value used in the generated pixel shader.
        if (programMetadata.usesInsertedPointCoordValue())
        {
            ASSERT(!useInstancedPointSpriteEmulation);
            vertexGenerateOutput << "\n"
                                 << "    output.gl_PointCoord = float2(0.5, 0.5);\n";
        }
    
        vertexGenerateOutput << "\n"
                             << "    return output;\n"
                             << "}";
    
        if (vertexShaderGL)
        {
            std::string vertexSource = vertexShaderGL->getTranslatedSource();
            angle::ReplaceSubstring(&vertexSource, std::string(MAIN_PROLOGUE_STUB_STRING),
                                    "    initAttributes(input);\n");
            angle::ReplaceSubstring(&vertexSource, std::string(VERTEX_OUTPUT_STUB_STRING),
                                    vertexGenerateOutput.str());
            vertexStream << vertexSource;
        }
    
        const auto &pixelBuiltins = builtinsD3D[gl::ShaderType::Fragment];
    
        std::ostringstream pixelStream;
        pixelStream << "struct PS_INPUT\n";
        generateVaryingLinkHLSL(varyingPacking, pixelBuiltins, builtinsD3D.usesPointSize(),
                                pixelStream);
        pixelStream << "\n";
    
        std::ostringstream pixelPrologue;
        if (fragmentShader && fragmentShader->usesViewID())
        {
            ASSERT(pixelBuiltins.glViewIDOVR.enabled);
            pixelPrologue << "    ViewID_OVR = input.gl_ViewID_OVR;\n";
        }
    
        if (pixelBuiltins.glFragCoord.enabled)
        {
            pixelPrologue << "    float rhw = 1.0 / input.gl_FragCoord.w;\n";
    
            // Certain Shader Models (4_0+ and 3_0) allow reading from dx_Position in the pixel shader.
            // Other Shader Models (4_0_level_9_3 and 2_x) don't support this, so we emulate it using
            // dx_ViewCoords.
            if (shaderModel >= 4 && mRenderer->getShaderModelSuffix() == "")
            {
                pixelPrologue << "    gl_FragCoord.x = input.dx_Position.x;\n"
                              << "    gl_FragCoord.y = input.dx_Position.y;\n";
            }
            else if (shaderModel == 3)
            {
                pixelPrologue << "    gl_FragCoord.x = input.dx_Position.x + 0.5;\n"
                              << "    gl_FragCoord.y = input.dx_Position.y + 0.5;\n";
            }
            else
            {
                // dx_ViewCoords contains the viewport width/2, height/2, center.x and center.y. See
                // Renderer::setViewport()
                pixelPrologue
                    << "    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";
            }
    
            if (programMetadata.usesViewScale())
            {
                // For Feature Level 9_3 and below, we need to correct gl_FragCoord.y to account
                // for dx_ViewScale. On Feature Level 10_0+, gl_FragCoord.y is calculated above using
                // dx_ViewCoords and is always correct irrespective of dx_ViewScale's value.
                // NOTE: usesViewScale() can only be true on D3D11 (i.e. Shader Model 4.0+).
                if (shaderModel >= 4 && mRenderer->getShaderModelSuffix() == "")
                {
                    // Some assumptions:
                    //  - dx_ViewScale.y = -1.0f when rendering to texture
                    //  - dx_ViewScale.y = +1.0f when rendering to the default framebuffer
                    //  - gl_FragCoord.y has been set correctly above.
                    //
                    // When rendering to the backbuffer, the code inverts gl_FragCoord's y coordinate.
                    // This involves subtracting the y coordinate from the height of the area being
                    // rendered to.
                    //
                    // First we calculate the height of the area being rendered to:
                    //    render_area_height = (2.0f / (1.0f - input.gl_FragCoord.y * rhw)) *
                    //    gl_FragCoord.y
                    //
                    // Note that when we're rendering to default FB, we want our output to be
                    // equivalent to:
                    //    "gl_FragCoord.y = render_area_height - gl_FragCoord.y"
                    //
                    // When we're rendering to a texture, we want our output to be equivalent to:
                    //    "gl_FragCoord.y = gl_FragCoord.y;"
                    //
                    // If we set scale_factor = ((1.0f + dx_ViewScale.y) / 2.0f), then notice that
                    //  - When rendering to default FB: scale_factor = 1.0f
                    //  - When rendering to texture:    scale_factor = 0.0f
                    //
                    // Therefore, we can get our desired output by setting:
                    //    "gl_FragCoord.y = scale_factor * render_area_height - dx_ViewScale.y *
                    //    gl_FragCoord.y"
                    //
                    // Simplifying, this becomes:
                    pixelPrologue
                        << "    gl_FragCoord.y = (1.0f + dx_ViewScale.y) * gl_FragCoord.y /"
                           "(1.0f - input.gl_FragCoord.y * rhw)  - dx_ViewScale.y * gl_FragCoord.y;\n";
                }
            }
    
            pixelPrologue << "    gl_FragCoord.z = (input.gl_FragCoord.z * rhw) * dx_DepthFront.x + "
                             "dx_DepthFront.y;\n"
                          << "    gl_FragCoord.w = rhw;\n";
        }
    
        if (pixelBuiltins.glPointCoord.enabled && shaderModel >= 3)
        {
            pixelPrologue << "    gl_PointCoord.x = input.gl_PointCoord.x;\n"
                          << "    gl_PointCoord.y = 1.0 - input.gl_PointCoord.y;\n";
        }
    
        if (fragmentShader && fragmentShader->usesFrontFacing())
        {
            if (shaderModel <= 3)
            {
                pixelPrologue << "    gl_FrontFacing = (vFace * dx_DepthFront.z >= 0.0);\n";
            }
            else
            {
                pixelPrologue << "    gl_FrontFacing = isFrontFace;\n";
            }
        }
    
        for (GLuint registerIndex = 0u; registerIndex < registerInfos.size(); ++registerIndex)
        {
            const PackedVaryingRegister &registerInfo = registerInfos[registerIndex];
            const auto &packedVarying                 = *registerInfo.packedVarying;
            const auto &varying                       = *packedVarying.varying;
            ASSERT(!varying.isBuiltIn() && !varying.isStruct());
    
            // Don't reference VS-only transform feedback varyings in the PS. Note that we're relying on
            // that the active flag is set according to usage in the fragment shader.
            if (packedVarying.vertexOnly || !varying.active)
                continue;
    
            pixelPrologue << "    ";
    
            if (packedVarying.isStructField())
            {
                pixelPrologue << DecorateVariable(packedVarying.parentStructName) << ".";
            }
    
            pixelPrologue << DecorateVariable(varying.name);
    
            if (varying.isArray())
            {
                WriteArrayString(pixelPrologue, registerInfo.varyingArrayIndex);
            }
    
            GLenum transposedType = TransposeMatrixType(varying.type);
            if (VariableRowCount(transposedType) > 1)
            {
                WriteArrayString(pixelPrologue, registerInfo.varyingRowIndex);
            }
    
            pixelPrologue << " = input.v" << registerIndex;
    
            switch (VariableColumnCount(transposedType))
            {
                case 1:
                    pixelPrologue << ".x";
                    break;
                case 2:
                    pixelPrologue << ".xy";
                    break;
                case 3:
                    pixelPrologue << ".xyz";
                    break;
                case 4:
                    break;
                default:
                    UNREACHABLE();
            }
            pixelPrologue << ";\n";
        }
    
        if (fragmentShaderGL)
        {
            std::string pixelSource = fragmentShaderGL->getTranslatedSource();
    
            if (fragmentShader->usesFrontFacing())
            {
                if (shaderModel >= 4)
                {
                    angle::ReplaceSubstring(&pixelSource,
                                            std::string(PIXEL_MAIN_PARAMETERS_STUB_STRING),
                                            "PS_INPUT input, bool isFrontFace : SV_IsFrontFace");
                }
                else
                {
                    angle::ReplaceSubstring(&pixelSource,
                                            std::string(PIXEL_MAIN_PARAMETERS_STUB_STRING),
                                            "PS_INPUT input, float vFace : VFACE");
                }
            }
            else
            {
                angle::ReplaceSubstring(&pixelSource, std::string(PIXEL_MAIN_PARAMETERS_STUB_STRING),
                                        "PS_INPUT input");
            }
    
            angle::ReplaceSubstring(&pixelSource, std::string(MAIN_PROLOGUE_STUB_STRING),
                                    pixelPrologue.str());
            pixelStream << pixelSource;
        }
    
        (*shaderHLSL)[gl::ShaderType::Vertex]   = vertexStream.str();
        (*shaderHLSL)[gl::ShaderType::Fragment] = pixelStream.str();
    }
    
    std::string DynamicHLSL::generateGeometryShaderPreamble(const VaryingPacking &varyingPacking,
                                                            const BuiltinVaryingsD3D &builtinsD3D,
                                                            const bool hasANGLEMultiviewEnabled,
                                                            const bool selectViewInVS) const
    {
        ASSERT(mRenderer->getMajorShaderModel() >= 4);
    
        std::ostringstream preambleStream;
    
        const auto &vertexBuiltins = builtinsD3D[gl::ShaderType::Vertex];
    
        preambleStream << "struct GS_INPUT\n";
        generateVaryingLinkHLSL(varyingPacking, vertexBuiltins, builtinsD3D.usesPointSize(),
                                preambleStream);
        preambleStream << "\n"
                       << "struct GS_OUTPUT\n";
        generateVaryingLinkHLSL(varyingPacking, builtinsD3D[gl::ShaderType::Geometry],
                                builtinsD3D.usesPointSize(), preambleStream);
        preambleStream
            << "\n"
            << "void copyVertex(inout GS_OUTPUT output, GS_INPUT input, GS_INPUT flatinput)\n"
            << "{\n"
            << "    output.gl_Position = input.gl_Position;\n";
    
        if (vertexBuiltins.glPointSize.enabled)
        {
            preambleStream << "    output.gl_PointSize = input.gl_PointSize;\n";
        }
    
        if (hasANGLEMultiviewEnabled)
        {
            preambleStream << "    output.gl_ViewID_OVR = input.gl_ViewID_OVR;\n";
            if (selectViewInVS)
            {
                ASSERT(builtinsD3D[gl::ShaderType::Geometry].glViewportIndex.enabled &&
                       builtinsD3D[gl::ShaderType::Geometry].glLayer.enabled);
    
                // If the view is already selected in the VS, then we just pass the gl_ViewportIndex and
                // gl_Layer to the output.
                preambleStream << "    output.gl_ViewportIndex = input.gl_ViewportIndex;\n"
                               << "    output.gl_Layer = input.gl_Layer;\n";
            }
        }
    
        const auto &registerInfos = varyingPacking.getRegisterList();
        for (GLuint registerIndex = 0u; registerIndex < registerInfos.size(); ++registerIndex)
        {
            const PackedVaryingRegister &varyingRegister = registerInfos[registerIndex];
            preambleStream << "    output.v" << registerIndex << " = ";
            if (varyingRegister.packedVarying->interpolation == sh::INTERPOLATION_FLAT)
            {
                preambleStream << "flat";
            }
            preambleStream << "input.v" << registerIndex << "; \n";
        }
    
        if (vertexBuiltins.glFragCoord.enabled)
        {
            preambleStream << "    output.gl_FragCoord = input.gl_FragCoord;\n";
        }
    
        // Only write the dx_Position if we aren't using point sprites
        preambleStream << "#ifndef ANGLE_POINT_SPRITE_SHADER\n"
                       << "    output.dx_Position = input.dx_Position;\n"
                       << "#endif  // ANGLE_POINT_SPRITE_SHADER\n"
                       << "}\n";
    
        if (hasANGLEMultiviewEnabled && !selectViewInVS)
        {
            ASSERT(builtinsD3D[gl::ShaderType::Geometry].glViewportIndex.enabled &&
                   builtinsD3D[gl::ShaderType::Geometry].glLayer.enabled);
    
            // According to the HLSL reference, using SV_RenderTargetArrayIndex is only valid if the
            // render target is an array resource. Because of this we do not write to gl_Layer if we are
            // taking the side-by-side code path. We still select the viewport index in the layered code
            // path as that is always valid. See:
            // https://msdn.microsoft.com/en-us/library/windows/desktop/bb509647(v=vs.85).aspx
            preambleStream << "\n"
                           << "void selectView(inout GS_OUTPUT output, GS_INPUT input)\n"
                           << "{\n"
                           << "    if (multiviewSelectViewportIndex)\n"
                           << "    {\n"
                           << "        output.gl_ViewportIndex = input.gl_ViewID_OVR;\n"
                           << "    } else {\n"
                           << "        output.gl_ViewportIndex = 0;\n"
                           << "        output.gl_Layer = input.gl_ViewID_OVR;\n"
                           << "    }\n"
                           << "}\n";
        }
    
        return preambleStream.str();
    }
    
    std::string DynamicHLSL::generateGeometryShaderHLSL(const gl::Caps &caps,
                                                        gl::PrimitiveMode primitiveType,
                                                        const gl::ProgramState &programData,
                                                        const bool useViewScale,
                                                        const bool hasANGLEMultiviewEnabled,
                                                        const bool selectViewInVS,
                                                        const bool pointSpriteEmulation,
                                                        const std::string &preambleString) const
    {
        ASSERT(mRenderer->getMajorShaderModel() >= 4);
    
        std::stringstream shaderStream;
    
        const bool pointSprites = (primitiveType == gl::PrimitiveMode::Points) && pointSpriteEmulation;
        const bool usesPointCoord = preambleString.find("gl_PointCoord") != std::string::npos;
    
        const char *inputPT  = nullptr;
        const char *outputPT = nullptr;
        int inputSize        = 0;
        int maxVertexOutput  = 0;
    
        switch (primitiveType)
        {
            case gl::PrimitiveMode::Points:
                inputPT   = "point";
                inputSize = 1;
    
                if (pointSprites)
                {
                    outputPT        = "Triangle";
                    maxVertexOutput = 4;
                }
                else
                {
                    outputPT        = "Point";
                    maxVertexOutput = 1;
                }
    
                break;
    
            case gl::PrimitiveMode::Lines:
            case gl::PrimitiveMode::LineStrip:
            case gl::PrimitiveMode::LineLoop:
                inputPT         = "line";
                outputPT        = "Line";
                inputSize       = 2;
                maxVertexOutput = 2;
                break;
    
            case gl::PrimitiveMode::Triangles:
            case gl::PrimitiveMode::TriangleStrip:
            case gl::PrimitiveMode::TriangleFan:
                inputPT         = "triangle";
                outputPT        = "Triangle";
                inputSize       = 3;
                maxVertexOutput = 3;
                break;
    
            default:
                UNREACHABLE();
                break;
        }
    
        if (pointSprites || hasANGLEMultiviewEnabled)
        {
            shaderStream << "cbuffer DriverConstants : register(b0)\n"
                            "{\n";
    
            if (pointSprites)
            {
                shaderStream << "    float4 dx_ViewCoords : packoffset(c1);\n";
                if (useViewScale)
                {
                    shaderStream << "    float2 dx_ViewScale : packoffset(c3);\n";
                }
            }
    
            if (hasANGLEMultiviewEnabled)
            {
                // We have to add a value which we can use to keep track of which multi-view code path
                // is to be selected in the GS.
                shaderStream << "    float multiviewSelectViewportIndex : packoffset(c3.z);\n";
            }
    
            shaderStream << "};\n\n";
        }
    
        if (pointSprites)
        {
            shaderStream << "#define ANGLE_POINT_SPRITE_SHADER\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 = "
                         << static_cast<int>(caps.minAliasedPointSize)
                         << ".0f;\n"
                            "static float maxPointSize = "
                         << static_cast<int>(caps.maxAliasedPointSize) << ".0f;\n"
                         << "\n";
        }
    
        shaderStream << preambleString << "\n"
                     << "[maxvertexcount(" << maxVertexOutput << ")]\n"
                     << "void main(" << inputPT << " GS_INPUT input[" << inputSize << "], ";
    
        if (primitiveType == gl::PrimitiveMode::TriangleStrip)
        {
            shaderStream << "uint primitiveID : SV_PrimitiveID, ";
        }
    
        shaderStream << " inout " << outputPT << "Stream<GS_OUTPUT> outStream)\n"
                     << "{\n"
                     << "    GS_OUTPUT output = (GS_OUTPUT)0;\n";
    
        if (primitiveType == gl::PrimitiveMode::TriangleStrip)
        {
            shaderStream << "    uint lastVertexIndex = (primitiveID % 2 == 0 ? 2 : 1);\n";
        }
        else
        {
            shaderStream << "    uint lastVertexIndex = " << (inputSize - 1) << ";\n";
        }
    
        for (int vertexIndex = 0; vertexIndex < inputSize; ++vertexIndex)
        {
            shaderStream << "    copyVertex(output, input[" << vertexIndex
                         << "], input[lastVertexIndex]);\n";
            if (hasANGLEMultiviewEnabled && !selectViewInVS)
            {
                shaderStream << "   selectView(output, input[" << vertexIndex << "]);\n";
            }
            if (!pointSprites)
            {
                ASSERT(inputSize == maxVertexOutput);
                shaderStream << "    outStream.Append(output);\n";
            }
        }
    
        if (pointSprites)
        {
            shaderStream << "\n"
                            "    float4 dx_Position = input[0].dx_Position;\n"
                            "    float gl_PointSize = clamp(input[0].gl_PointSize, minPointSize, "
                            "maxPointSize);\n"
                            "    float2 viewportScale = float2(1.0f / dx_ViewCoords.x, 1.0f / "
                            "dx_ViewCoords.y) * dx_Position.w;\n";
    
            for (int corner = 0; corner < 4; corner++)
            {
                if (useViewScale)
                {
                    shaderStream << "    \n"
                                    "    output.dx_Position = dx_Position + float4(1.0f, "
                                    "-dx_ViewScale.y, 1.0f, 1.0f)"
                                    "        * float4(pointSpriteCorners["
                                 << corner << "] * viewportScale * gl_PointSize, 0.0f, 0.0f);\n";
                }
                else
                {
                    shaderStream << "\n"
                                    "    output.dx_Position = dx_Position + float4(pointSpriteCorners["
                                 << corner << "] * viewportScale * gl_PointSize, 0.0f, 0.0f);\n";
                }
    
                if (usesPointCoord)
                {
                    shaderStream << "    output.gl_PointCoord = pointSpriteTexcoords[" << corner
                                 << "];\n";
                }
    
                shaderStream << "    outStream.Append(output);\n";
            }
        }
    
        shaderStream << "    \n"
                        "    outStream.RestartStrip();\n"
                        "}\n";
    
        return shaderStream.str();
    }
    
    // static
    void DynamicHLSL::GenerateAttributeConversionHLSL(angle::FormatID vertexFormatID,
                                                      const sh::ShaderVariable &shaderAttrib,
                                                      std::ostringstream &outStream)
    {
        // Matrix
        if (IsMatrixType(shaderAttrib.type))
        {
            outStream << "transpose(input." << DecorateVariable(shaderAttrib.name) << ")";
            return;
        }
    
        GLenum shaderComponentType           = VariableComponentType(shaderAttrib.type);
        int shaderComponentCount             = VariableComponentCount(shaderAttrib.type);
        const gl::VertexFormat &vertexFormat = gl::GetVertexFormatFromID(vertexFormatID);
    
        // Perform integer to float conversion (if necessary)
        if (shaderComponentType == GL_FLOAT && vertexFormat.type != GL_FLOAT)
        {
            // TODO: normalization for 32-bit integer formats
            ASSERT(!vertexFormat.normalized && !vertexFormat.pureInteger);
            outStream << "float" << shaderComponentCount << "(input."
                      << DecorateVariable(shaderAttrib.name) << ")";
            return;
        }
    
        // No conversion necessary
        outStream << "input." << DecorateVariable(shaderAttrib.name);
    }
    
    void DynamicHLSL::getPixelShaderOutputKey(const gl::State &data,
                                              const gl::ProgramState &programData,
                                              const ProgramD3DMetadata &metadata,
                                              std::vector<PixelShaderOutputVariable> *outPixelShaderKey)
    {
        // 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
        bool broadcast = metadata.usesBroadcast(data);
        const unsigned int numRenderTargets =
            (broadcast || metadata.usesMultipleFragmentOuts() ? data.getCaps().maxDrawBuffers : 1);
    
        if (!metadata.usesCustomOutVars())
        {
            for (unsigned int renderTargetIndex = 0; renderTargetIndex < numRenderTargets;
                 renderTargetIndex++)
            {
                PixelShaderOutputVariable outputKeyVariable;
                outputKeyVariable.type = GL_FLOAT_VEC4;
                outputKeyVariable.name = "gl_Color" + Str(renderTargetIndex);
                outputKeyVariable.source =
                    broadcast ? "gl_Color[0]" : "gl_Color[" + Str(renderTargetIndex) + "]";
                outputKeyVariable.outputLocation = renderTargetIndex;
    
                outPixelShaderKey->push_back(outputKeyVariable);
            }
    
            if (metadata.usesSecondaryColor())
            {
                for (unsigned int secondaryIndex = 0;
                     secondaryIndex < data.getExtensions().maxDualSourceDrawBuffers; secondaryIndex++)
                {
                    PixelShaderOutputVariable outputKeyVariable;
                    outputKeyVariable.type           = GL_FLOAT_VEC4;
                    outputKeyVariable.name           = "gl_SecondaryColor" + Str(secondaryIndex);
                    outputKeyVariable.source         = "gl_SecondaryColor[" + Str(secondaryIndex) + "]";
                    outputKeyVariable.outputLocation = secondaryIndex;
                    outputKeyVariable.outputIndex    = 1;
    
                    outPixelShaderKey->push_back(outputKeyVariable);
                }
            }
        }
        else
        {
            const ShaderD3D *fragmentShader = metadata.getFragmentShader();
    
            if (!fragmentShader)
            {
                return;
            }
    
            const auto &shaderOutputVars = fragmentShader->getData().getActiveOutputVariables();
    
            for (size_t outputLocationIndex = 0u;
                 outputLocationIndex < programData.getOutputLocations().size(); ++outputLocationIndex)
            {
                const VariableLocation &outputLocation =
                    programData.getOutputLocations().at(outputLocationIndex);
                if (!outputLocation.used())
                {
                    continue;
                }
                const sh::ShaderVariable &outputVariable = shaderOutputVars[outputLocation.index];
                const std::string &variableName          = "out_" + outputVariable.name;
    
                // Fragment outputs can't be arrays of arrays. ESSL 3.10 section 4.3.6.
                const std::string &elementString =
                    (outputVariable.isArray() ? Str(outputLocation.arrayIndex) : "");
    
                ASSERT(outputVariable.active);
    
                PixelShaderOutputVariable outputKeyVariable;
                outputKeyVariable.type = outputVariable.type;
                outputKeyVariable.name = variableName + elementString;
                outputKeyVariable.source =
                    variableName +
                    (outputVariable.isArray() ? ArrayString(outputLocation.arrayIndex) : "");
                outputKeyVariable.outputLocation = outputLocationIndex;
    
                outPixelShaderKey->push_back(outputKeyVariable);
            }
    
            // Now generate any secondary outputs...
            for (size_t outputLocationIndex = 0u;
                 outputLocationIndex < programData.getSecondaryOutputLocations().size();
                 ++outputLocationIndex)
            {
                const VariableLocation &outputLocation =
                    programData.getSecondaryOutputLocations().at(outputLocationIndex);
                if (!outputLocation.used())
                {
                    continue;
                }
                const sh::ShaderVariable &outputVariable = shaderOutputVars[outputLocation.index];
                const std::string &variableName          = "out_" + outputVariable.name;
    
                // Fragment outputs can't be arrays of arrays. ESSL 3.10 section 4.3.6.
                const std::string &elementString =
                    (outputVariable.isArray() ? Str(outputLocation.arrayIndex) : "");
    
                ASSERT(outputVariable.active);
    
                PixelShaderOutputVariable outputKeyVariable;
                outputKeyVariable.type = outputVariable.type;
                outputKeyVariable.name = variableName + elementString;
                outputKeyVariable.source =
                    variableName +
                    (outputVariable.isArray() ? ArrayString(outputLocation.arrayIndex) : "");
                outputKeyVariable.outputLocation = outputLocationIndex;
                outputKeyVariable.outputIndex    = 1;
    
                outPixelShaderKey->push_back(outputKeyVariable);
            }
        }
    }
    
    // BuiltinVarying Implementation.
    BuiltinVarying::BuiltinVarying() : enabled(false), index(0), systemValue(false) {}
    
    std::string BuiltinVarying::str() const
    {
        return (systemValue ? semantic : (semantic + Str(index)));
    }
    
    void BuiltinVarying::enableSystem(const std::string &systemValueSemantic)
    {
        enabled     = true;
        semantic    = systemValueSemantic;
        systemValue = true;
    }
    
    void BuiltinVarying::enable(const std::string &semanticVal, unsigned int indexVal)
    {
        enabled  = true;
        semantic = semanticVal;
        index    = indexVal;
    }
    
    // BuiltinVaryingsD3D Implementation.
    BuiltinVaryingsD3D::BuiltinVaryingsD3D(const ProgramD3DMetadata &metadata,
                                           const VaryingPacking &packing)
    {
        updateBuiltins(gl::ShaderType::Vertex, metadata, packing);
        updateBuiltins(gl::ShaderType::Fragment, metadata, packing);
        int shaderModel = metadata.getRendererMajorShaderModel();
        if (shaderModel >= 4)
        {
            updateBuiltins(gl::ShaderType::Geometry, metadata, packing);
        }
        // In shader model >= 4, some builtins need to be the same in vertex and pixel shaders - input
        // struct needs to be a prefix of output struct.
        ASSERT(shaderModel < 4 || mBuiltinInfo[gl::ShaderType::Vertex].glPosition.enabled ==
                                      mBuiltinInfo[gl::ShaderType::Fragment].glPosition.enabled);
        ASSERT(shaderModel < 4 || mBuiltinInfo[gl::ShaderType::Vertex].glFragCoord.enabled ==
                                      mBuiltinInfo[gl::ShaderType::Fragment].glFragCoord.enabled);
        ASSERT(shaderModel < 4 || mBuiltinInfo[gl::ShaderType::Vertex].glPointCoord.enabled ==
                                      mBuiltinInfo[gl::ShaderType::Fragment].glPointCoord.enabled);
        ASSERT(shaderModel < 4 || mBuiltinInfo[gl::ShaderType::Vertex].glPointSize.enabled ==
                                      mBuiltinInfo[gl::ShaderType::Fragment].glPointSize.enabled);
        ASSERT(shaderModel < 4 || mBuiltinInfo[gl::ShaderType::Vertex].glViewIDOVR.enabled ==
                                      mBuiltinInfo[gl::ShaderType::Fragment].glViewIDOVR.enabled);
    }
    
    BuiltinVaryingsD3D::~BuiltinVaryingsD3D() = default;
    
    void BuiltinVaryingsD3D::updateBuiltins(gl::ShaderType shaderType,
                                            const ProgramD3DMetadata &metadata,
                                            const VaryingPacking &packing)
    {
        const std::string &userSemantic = GetVaryingSemantic(metadata.getRendererMajorShaderModel(),
                                                             metadata.usesSystemValuePointSize());
    
        // Note that when enabling builtins only for specific shader stages in shader model >= 4, the
        // code needs to ensure that the input struct of the shader stage is a prefix of the output
        // struct of the previous stage.
    
        unsigned int reservedSemanticIndex = packing.getMaxSemanticIndex();
    
        BuiltinInfo *builtins = &mBuiltinInfo[shaderType];
    
        if (metadata.getRendererMajorShaderModel() >= 4)
        {
            builtins->dxPosition.enableSystem("SV_Position");
        }
        else if (shaderType == gl::ShaderType::Fragment)
        {
            builtins->dxPosition.enableSystem("VPOS");
        }
        else
        {
            builtins->dxPosition.enableSystem("POSITION");
        }
    
        if (metadata.usesTransformFeedbackGLPosition())
        {
            builtins->glPosition.enable(userSemantic, reservedSemanticIndex++);
        }
    
        if (metadata.usesFragCoord())
        {
            builtins->glFragCoord.enable(userSemantic, reservedSemanticIndex++);
        }
    
        if (shaderType == gl::ShaderType::Vertex ? metadata.addsPointCoordToVertexShader()
                                                 : metadata.usesPointCoord())
        {
            // SM3 reserves the TEXCOORD semantic for point sprite texcoords (gl_PointCoord)
            // In D3D11 we manually compute gl_PointCoord in the GS.
            if (metadata.getRendererMajorShaderModel() >= 4)
            {
                builtins->glPointCoord.enable(userSemantic, reservedSemanticIndex++);
            }
            else
            {
                builtins->glPointCoord.enable("TEXCOORD", 0);
            }
        }
    
        if (metadata.hasANGLEMultiviewEnabled())
        {
            // Although it is possible to compute gl_ViewID_OVR from the value of
            // SV_ViewportArrayIndex or SV_RenderTargetArrayIndex and the multi-view state in the
            // driver constant buffer, it is easier and cleaner to always pass it as a varying.
            builtins->glViewIDOVR.enable(userSemantic, reservedSemanticIndex++);
    
            if (shaderType == gl::ShaderType::Vertex)
            {
                if (metadata.canSelectViewInVertexShader())
                {
                    builtins->glViewportIndex.enableSystem("SV_ViewportArrayIndex");
                    builtins->glLayer.enableSystem("SV_RenderTargetArrayIndex");
                }
            }
    
            if (shaderType == gl::ShaderType::Geometry)
            {
                // gl_Layer and gl_ViewportIndex are necessary so that we can write to either based on
                // the multiview state in the driver constant buffer.
                builtins->glViewportIndex.enableSystem("SV_ViewportArrayIndex");
                builtins->glLayer.enableSystem("SV_RenderTargetArrayIndex");
            }
        }
    
        // Special case: do not include PSIZE semantic in HLSL 3 pixel shaders
        if (metadata.usesSystemValuePointSize() &&
            (shaderType != gl::ShaderType::Fragment || metadata.getRendererMajorShaderModel() >= 4))
        {
            builtins->glPointSize.enableSystem("PSIZE");
        }
    }
    
    }  // namespace rx