void DynamicHLSL::getPixelShaderOutputKey(const gl::Data &data,
                                          const gl::Program::Data &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.caps->maxDrawBuffers : 1);

    if (metadata.getMajorShaderVersion() < 300)
    {
        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.outputIndex = renderTargetIndex;

            outPixelShaderKey->push_back(outputKeyVariable);
        }
    }
    else
    {
        const auto &shaderOutputVars =
            metadata.getFragmentShader()->getData().getActiveOutputVariables();

        for (auto outputPair : programData.getOutputVariables())
        {
            const VariableLocation &outputLocation   = outputPair.second;
            const sh::ShaderVariable &outputVariable = shaderOutputVars[outputLocation.index];
            const std::string &variableName = "out_" + outputLocation.name;
            const std::string &elementString =
                (outputLocation.element == GL_INVALID_INDEX ? "" : Str(outputLocation.element));

            ASSERT(outputVariable.staticUse);

            PixelShaderOutputVariable outputKeyVariable;
            outputKeyVariable.type        = outputVariable.type;
            outputKeyVariable.name        = variableName + elementString;
            outputKeyVariable.source      = variableName + ArrayString(outputLocation.element);
            outputKeyVariable.outputIndex = outputPair.first;

            outPixelShaderKey->push_back(outputKeyVariable);
        }
    }
}
Beispiel #2
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void VaryingPacking::enableBuiltins(ShaderType shaderType,
                                    const ProgramD3DMetadata &programMetadata)
{
    int majorShaderModel = programMetadata.getRendererMajorShaderModel();
    bool position        = programMetadata.usesTransformFeedbackGLPosition();
    bool fragCoord       = programMetadata.usesFragCoord();
    bool pointCoord = shaderType == SHADER_VERTEX ? programMetadata.addsPointCoordToVertexShader()
                                                  : programMetadata.usesPointCoord();
    bool pointSize                  = programMetadata.usesSystemValuePointSize();
    bool hlsl4                      = (majorShaderModel >= 4);
    const std::string &userSemantic = GetVaryingSemantic(majorShaderModel, pointSize);

    unsigned int reservedSemanticIndex = getMaxSemanticIndex();

    BuiltinInfo *builtins = &mBuiltinInfo[shaderType];

    if (hlsl4)
    {
        builtins->dxPosition.enableSystem("SV_Position");
    }
    else if (shaderType == SHADER_PIXEL)
    {
        builtins->dxPosition.enableSystem("VPOS");
    }
    else
    {
        builtins->dxPosition.enableSystem("POSITION");
    }

    if (position)
    {
        builtins->glPosition.enable(userSemantic, reservedSemanticIndex++);
    }

    if (fragCoord)
    {
        builtins->glFragCoord.enable(userSemantic, reservedSemanticIndex++);
    }

    if (pointCoord)
    {
        // SM3 reserves the TEXCOORD semantic for point sprite texcoords (gl_PointCoord)
        // In D3D11 we manually compute gl_PointCoord in the GS.
        if (hlsl4)
        {
            builtins->glPointCoord.enable(userSemantic, reservedSemanticIndex++);
        }
        else
        {
            builtins->glPointCoord.enable("TEXCOORD", 0);
        }
    }

    // Special case: do not include PSIZE semantic in HLSL 3 pixel shaders
    if (pointSize && (shaderType != SHADER_PIXEL || hlsl4))
    {
        builtins->glPointSize.enableSystem("PSIZE");
    }
}
bool DynamicHLSL::generateShaderLinkHLSL(const gl::Data &data,
                                         const gl::Program::Data &programData,
                                         const ProgramD3DMetadata &programMetadata,
                                         const VaryingPacking &varyingPacking,
                                         std::string *pixelHLSL,
                                         std::string *vertexHLSL) const
{
    ASSERT(pixelHLSL->empty() && vertexHLSL->empty());

    const gl::Shader *vertexShaderGL   = programData.getAttachedVertexShader();
    const gl::Shader *fragmentShaderGL = programData.getAttachedFragmentShader();
    const ShaderD3D *fragmentShader    = GetImplAs<ShaderD3D>(fragmentShaderGL);
    const int shaderModel              = mRenderer->getMajorShaderModel();

    // usesViewScale() isn't supported in the D3D9 renderer
    ASSERT(shaderModel >= 4 || !programMetadata.usesViewScale());

    bool useInstancedPointSpriteEmulation =
        programMetadata.usesPointSize() &&
        mRenderer->getWorkarounds().useInstancedPointSpriteEmulation;

    // Validation done in the compiler
    ASSERT(!fragmentShader->usesFragColor() || !fragmentShader->usesFragData());

    std::stringstream vertexStream;
    vertexStream << vertexShaderGL->getTranslatedSource();

    // 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>(data.caps->minAliasedPointSize) << ".0f;\n"
                     << "static float maxPointSize = "
                     << static_cast<int>(data.caps->maxAliasedPointSize) << ".0f;\n";
    }

    // Add stub string to be replaced when shader is dynamically defined by its layout
    vertexStream << "\n" << VERTEX_ATTRIBUTE_STUB_STRING + "\n";

    // Write the HLSL input/output declarations
    vertexStream << "struct VS_OUTPUT\n";
    generateVaryingLinkHLSL(SHADER_VERTEX, varyingPacking, vertexStream);
    vertexStream << "\n"
                 << "VS_OUTPUT main(VS_INPUT input)\n"
                 << "{\n"
                 << "    initAttributes(input);\n";

    vertexStream << "\n"
                 << "    gl_main();\n"
                 << "\n"
                 << "    VS_OUTPUT output;\n";

    const auto &vertexBuiltins = varyingPacking.builtins(SHADER_VERTEX);

    if (vertexBuiltins.glPosition.enabled)
    {
        vertexStream << "    output.gl_Position = gl_Position;\n";
    }

    // On D3D9 or D3D11 Feature Level 9, we need to emulate large viewports using dx_ViewAdjust.
    if (shaderModel >= 4 && mRenderer->getShaderModelSuffix() == "")
    {
        vertexStream << "    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.
            vertexStream << "    output.dx_Position.y = dx_ViewScale.y * gl_Position.y;\n";
        }
        else
        {
            vertexStream << "    output.dx_Position.y = - gl_Position.y;\n";
        }

        vertexStream << "    output.dx_Position.z = (gl_Position.z + gl_Position.w) * 0.5;\n"
                     << "    output.dx_Position.w = gl_Position.w;\n";
    }
    else
    {
        vertexStream << "    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() != ""))
        {
            vertexStream << "    output.dx_Position.y = dx_ViewScale.y * (gl_Position.y * "
                            "dx_ViewAdjust.w + dx_ViewAdjust.y * gl_Position.w);\n";
        }
        else
        {
            vertexStream << "    output.dx_Position.y = -(gl_Position.y * dx_ViewAdjust.w + "
                            "dx_ViewAdjust.y * gl_Position.w);\n";
        }

        vertexStream << "    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)
    {
        vertexStream << "    output.gl_PointSize = gl_PointSize;\n";
    }

    if (vertexBuiltins.glFragCoord.enabled)
    {
        vertexStream << "    output.gl_FragCoord = gl_Position;\n";
    }

    for (const PackedVaryingRegister &registerInfo : varyingPacking.getRegisterList())
    {
        const auto &packedVarying = *registerInfo.packedVarying;
        const auto &varying = *packedVarying.varying;
        ASSERT(!varying.isStruct());

        vertexStream << "    output.v" << registerInfo.semanticIndex << " = ";

        if (packedVarying.isStructField())
        {
            vertexStream << decorateVariable(packedVarying.parentStructName) << ".";
        }

        vertexStream << decorateVariable(varying.name);

        if (varying.isArray())
        {
            WriteArrayString(vertexStream, registerInfo.varyingArrayIndex);
        }

        if (VariableRowCount(varying.type) > 1)
        {
            WriteArrayString(vertexStream, registerInfo.varyingRowIndex);
        }

        vertexStream << ";\n";
    }

    // Instanced PointSprite emulation requires additional entries to calculate
    // the final output vertex positions of the quad that represents each sprite.
    if (useInstancedPointSpriteEmulation)
    {
        vertexStream << "\n"
                     << "    gl_PointSize = clamp(gl_PointSize, minPointSize, maxPointSize);\n";

        vertexStream << "    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
            vertexStream << "    output.dx_Position.y += (-dx_ViewScale.y * "
                            "input.spriteVertexPos.y * gl_PointSize / (dx_ViewCoords.y*2)) * "
                            "output.dx_Position.w;";
        }
        else
        {
            vertexStream << "    output.dx_Position.y += (input.spriteVertexPos.y * gl_PointSize / "
                            "(dx_ViewCoords.y*2)) * output.dx_Position.w;";
        }

        vertexStream
            << "    output.dx_Position.z += input.spriteVertexPos.z * output.dx_Position.w;\n";

        if (programMetadata.usesPointCoord())
        {
            vertexStream << "\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);
        vertexStream << "\n"
                     << "    output.gl_PointCoord = float2(0.5, 0.5);\n";
    }

    vertexStream << "\n"
                 << "    return output;\n"
                 << "}\n";

    std::stringstream pixelStream;
    pixelStream << fragmentShaderGL->getTranslatedSource();
    pixelStream << "struct PS_INPUT\n";
    generateVaryingLinkHLSL(SHADER_PIXEL, varyingPacking, pixelStream);
    pixelStream << "\n";

    pixelStream << PIXEL_OUTPUT_STUB_STRING + "\n";

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

    const auto &pixelBuiltins = varyingPacking.builtins(SHADER_PIXEL);

    if (pixelBuiltins.glFragCoord.enabled)
    {
        pixelStream << "    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() == "")
        {
            pixelStream << "    gl_FragCoord.x = input.dx_Position.x;\n"
                        << "    gl_FragCoord.y = input.dx_Position.y;\n";
        }
        else if (shaderModel == 3)
        {
            pixelStream << "    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()
            pixelStream << "    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:
                pixelStream
                    << "    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";
            }
        }

        pixelStream << "    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)
    {
        pixelStream << "    gl_PointCoord.x = input.gl_PointCoord.x;\n"
                    << "    gl_PointCoord.y = 1.0 - input.gl_PointCoord.y;\n";
    }

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

    for (const PackedVaryingRegister &registerInfo : varyingPacking.getRegisterList())
    {
        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.
        if (registerInfo.packedVarying->vertexOnly)
            continue;

        pixelStream << "    ";

        if (packedVarying.isStructField())
        {
            pixelStream << decorateVariable(packedVarying.parentStructName) << ".";
        }

        pixelStream << decorateVariable(varying.name);

        if (varying.isArray())
        {
            WriteArrayString(pixelStream, registerInfo.varyingArrayIndex);
        }

        GLenum transposedType = TransposeMatrixType(varying.type);
        if (VariableRowCount(transposedType) > 1)
        {
            WriteArrayString(pixelStream, registerInfo.varyingRowIndex);
        }

        pixelStream << " = input.v" << registerInfo.semanticIndex;

        switch (VariableColumnCount(transposedType))
        {
            case 1:
                pixelStream << ".x";
                break;
            case 2:
                pixelStream << ".xy";
                break;
            case 3:
                pixelStream << ".xyz";
                break;
            case 4:
                break;
            default:
                UNREACHABLE();
        }
        pixelStream << ";\n";
    }

    pixelStream << "\n"
                << "    gl_main();\n"
                << "\n"
                << "    return generateOutput();\n"
                << "}\n";

    *vertexHLSL = vertexStream.str();
    *pixelHLSL  = pixelStream.str();

    return true;
}