C++ GrDrawState::getColorStage方法代码示例

void GrOptDrawState::copyEffectiveColorStages(const GrDrawState& ds) {
    int firstColorStage = 0;

    // Set up color and flags for ConstantColorComponent checks
    GrColor color;
    uint32_t validComponentFlags;
    if (!this->hasColorVertexAttribute()) {
        color = ds.getColor();
        validComponentFlags = kRGBA_GrColorComponentFlags;
    } else {
        if (ds.vertexColorsAreOpaque()) {
            color = 0xFF << GrColor_SHIFT_A;
            validComponentFlags = kA_GrColorComponentFlag;
        } else {
            validComponentFlags = 0;
            color = 0; // not strictly necessary but we get false alarms from tools about uninit.
        }
    }

    for (int i = 0; i < ds.numColorStages(); ++i) {
        const GrFragmentProcessor* fp = ds.getColorStage(i).getFragmentProcessor();
        if (!fp->willUseInputColor()) {
            firstColorStage = i;
            fInputColorIsUsed = false;
        }
        fp->getConstantColorComponents(&color, &validComponentFlags);
        if (kRGBA_GrColorComponentFlags == validComponentFlags) {
            firstColorStage = i + 1;
            fColor = color;
            fInputColorIsUsed = true;
            this->removeFixedFunctionVertexAttribs(0x1 << kColor_GrVertexAttribBinding);
        }
    }
    if (firstColorStage < ds.numColorStages()) {
        fColorStages.reset(&ds.getColorStage(firstColorStage),
                           ds.numColorStages() - firstColorStage);
    } else {
        fColorStages.reset();
    }
}

void GrGLProgramDesc::Build(const GrDrawState& drawState,
                            bool isPoints,
                            GrDrawState::BlendOptFlags blendOpts,
                            GrBlendCoeff srcCoeff,
                            GrBlendCoeff dstCoeff,
                            const GrGpuGL* gpu,
                            const GrDeviceCoordTexture* dstCopy,
                            SkTArray<const GrEffectStage*, true>* colorStages,
                            SkTArray<const GrEffectStage*, true>* coverageStages,
                            GrGLProgramDesc* desc) {
    colorStages->reset();
    coverageStages->reset();

    // This should already have been caught
    SkASSERT(!(GrDrawState::kSkipDraw_BlendOptFlag & blendOpts));

    bool skipCoverage = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);

    bool skipColor = SkToBool(blendOpts & (GrDrawState::kEmitTransBlack_BlendOptFlag |
                                           GrDrawState::kEmitCoverage_BlendOptFlag));
    int firstEffectiveColorStage = 0;
    bool inputColorIsUsed = true;
    if (!skipColor) {
        firstEffectiveColorStage = drawState.numColorStages();
        while (firstEffectiveColorStage > 0 && inputColorIsUsed) {
            --firstEffectiveColorStage;
            const GrEffect* effect = drawState.getColorStage(firstEffectiveColorStage).getEffect()->get();
            inputColorIsUsed = effect->willUseInputColor();
        }
    }

    int firstEffectiveCoverageStage = 0;
    bool inputCoverageIsUsed = true;
    if (!skipCoverage) {
        firstEffectiveCoverageStage = drawState.numCoverageStages();
        while (firstEffectiveCoverageStage > 0 && inputCoverageIsUsed) {
            --firstEffectiveCoverageStage;
            const GrEffect* effect = drawState.getCoverageStage(firstEffectiveCoverageStage).getEffect()->get();
            inputCoverageIsUsed = effect->willUseInputColor();
        }
    }

    // The descriptor is used as a cache key. Thus when a field of the
    // descriptor will not affect program generation (because of the attribute
    // bindings in use or other descriptor field settings) it should be set
    // to a canonical value to avoid duplicate programs with different keys.

    bool requiresColorAttrib = !skipColor && drawState.hasColorVertexAttribute();
    bool requiresCoverageAttrib = !skipCoverage && drawState.hasCoverageVertexAttribute();
    // we only need the local coords if we're actually going to generate effect code
    bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                    drawState.hasLocalCoordAttribute();

    bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
    bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
                             (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
                             (!inputColorIsUsed);

    int numEffects = (skipColor ? 0 : (drawState.numColorStages() - firstEffectiveColorStage)) +
                     (skipCoverage ? 0 : (drawState.numCoverageStages() - firstEffectiveCoverageStage));

    size_t newKeyLength = KeyLength(numEffects);
    bool allocChanged;
    desc->fKey.reset(newKeyLength, SkAutoMalloc::kAlloc_OnShrink, &allocChanged);
    if (allocChanged || !desc->fInitialized) {
        // make sure any padding in the header is zero if we we haven't used this allocation before.
        memset(desc->header(), 0, kHeaderSize);
    }
    // write the key length
    *desc->atOffset<uint32_t, kLengthOffset>() = SkToU32(newKeyLength);

    KeyHeader* header = desc->header();
    EffectKey* effectKeys = desc->effectKeys();

    int currEffectKey = 0;
    bool readsDst = false;
    bool readFragPosition = false;
    bool hasVertexCode = false;
    if (!skipColor) {
        for (int s = firstEffectiveColorStage; s < drawState.numColorStages(); ++s) {
            effectKeys[currEffectKey++] =
                get_key_and_update_stats(drawState.getColorStage(s), gpu->glCaps(),
                                         requiresLocalCoordAttrib, &readsDst, &readFragPosition,
                                         &hasVertexCode);
        }
    }
    if (!skipCoverage) {
        for (int s = firstEffectiveCoverageStage; s < drawState.numCoverageStages(); ++s) {
            effectKeys[currEffectKey++] =
                get_key_and_update_stats(drawState.getCoverageStage(s), gpu->glCaps(),
                                         requiresLocalCoordAttrib, &readsDst, &readFragPosition,
                                         &hasVertexCode);
        }
    }

    header->fHasVertexCode = hasVertexCode || requiresLocalCoordAttrib;
    header->fEmitsPointSize = isPoints;

    // Currently the experimental GS will only work with triangle prims (and it doesn't do anything
    // other than pass through values from the VS to the FS anyway).
//.........这里部分代码省略.........

bool GrGLProgramDesc::Build(const GrDrawState& drawState,
                            GrGpu::DrawType drawType,
                            GrDrawState::BlendOptFlags blendOpts,
                            GrBlendCoeff srcCoeff,
                            GrBlendCoeff dstCoeff,
                            const GrGpuGL* gpu,
                            const GrDeviceCoordTexture* dstCopy,
                            const GrEffectStage** geometryProcessor,
                            SkTArray<const GrEffectStage*, true>* colorStages,
                            SkTArray<const GrEffectStage*, true>* coverageStages,
                            GrGLProgramDesc* desc) {
    colorStages->reset();
    coverageStages->reset();

    // This should already have been caught
    SkASSERT(!(GrDrawState::kSkipDraw_BlendOptFlag & blendOpts));

    bool skipCoverage = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);

    bool skipColor = SkToBool(blendOpts & (GrDrawState::kEmitTransBlack_BlendOptFlag |
                                           GrDrawState::kEmitCoverage_BlendOptFlag));

    int firstEffectiveColorStage = 0;
    bool inputColorIsUsed = true;

    if (!skipColor) {
        firstEffectiveColorStage = drawState.numColorStages();
        while (firstEffectiveColorStage > 0 && inputColorIsUsed) {
            --firstEffectiveColorStage;
            const GrEffect* effect = drawState.getColorStage(firstEffectiveColorStage).getEffect();
            inputColorIsUsed = effect->willUseInputColor();
        }
    }

    int firstEffectiveCoverageStage = 0;
    bool inputCoverageIsUsed = true;
    if (!skipCoverage) {
        firstEffectiveCoverageStage = drawState.numCoverageStages();
        while (firstEffectiveCoverageStage > 0 && inputCoverageIsUsed) {
            --firstEffectiveCoverageStage;
            const GrEffect* effect = drawState.getCoverageStage(firstEffectiveCoverageStage).getEffect();
            inputCoverageIsUsed = effect->willUseInputColor();
        }
    }

    // The descriptor is used as a cache key. Thus when a field of the
    // descriptor will not affect program generation (because of the attribute
    // bindings in use or other descriptor field settings) it should be set
    // to a canonical value to avoid duplicate programs with different keys.

    bool requiresColorAttrib = !skipColor && drawState.hasColorVertexAttribute();
    bool requiresCoverageAttrib = !skipCoverage && drawState.hasCoverageVertexAttribute();
    // we only need the local coords if we're actually going to generate effect code
    bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                    drawState.hasLocalCoordAttribute();

    bool readsDst = false;
    bool readFragPosition = false;

    // Provide option for shader programs without vertex shader only when drawing paths.
    bool requiresVertexShader = !GrGpu::IsPathRenderingDrawType(drawType);

    int numStages = 0;
    if (drawState.hasGeometryProcessor()) {
        numStages++;
    }
    if (!skipColor) {
        numStages += drawState.numColorStages() - firstEffectiveColorStage;
    }
    if (!skipCoverage) {
        numStages += drawState.numCoverageStages() - firstEffectiveCoverageStage;
    }
    GR_STATIC_ASSERT(0 == kEffectKeyOffsetsAndLengthOffset % sizeof(uint32_t));
    // Make room for everything up to and including the array of offsets to effect keys.
    desc->fKey.reset();
    desc->fKey.push_back_n(kEffectKeyOffsetsAndLengthOffset + 2 * sizeof(uint16_t) * numStages);

    int offsetAndSizeIndex = 0;
    bool effectKeySuccess = true;

    KeyHeader* header = desc->header();
    // make sure any padding in the header is zeroed.
    memset(desc->header(), 0, kHeaderSize);

    // We can only have one effect which touches the vertex shader
    if (drawState.hasGeometryProcessor()) {
        uint16_t* offsetAndSize =
                reinterpret_cast<uint16_t*>(desc->fKey.begin() + kEffectKeyOffsetsAndLengthOffset +
                                            offsetAndSizeIndex * 2 * sizeof(uint16_t));

            GrEffectKeyBuilder b(&desc->fKey);
            uint16_t effectKeySize;
            uint32_t effectOffset = desc->fKey.count();
            effectKeySuccess |= GetEffectKeyAndUpdateStats(
                                    *drawState.getGeometryProcessor(), gpu->glCaps(),
                                    requiresLocalCoordAttrib, &b,
                                    &effectKeySize, &readsDst,
                                    &readFragPosition, &requiresVertexShader);
            effectKeySuccess |= (effectOffset <= SK_MaxU16);

//.........这里部分代码省略.........