C++ GrProcOptInfo类代码示例

bool GrPorterDuffXPFactory::willReadDstColor(const GrDrawTargetCaps& caps,
                                             const GrProcOptInfo& colorPOI,
                                             const GrProcOptInfo& coveragePOI) const {
    // We can always blend correctly if we have dual source blending.
    if (caps.shaderCaps()->dualSourceBlendingSupport()) {
        return false;
    }

    if (can_tweak_alpha_for_coverage(fDstCoeff)) {
        return false;
    }

    bool srcAIsOne = colorPOI.isOpaque();

    if (kZero_GrBlendCoeff == fDstCoeff) {
        if (kZero_GrBlendCoeff == fSrcCoeff || srcAIsOne) {
            return false;
        }
    }

    // Reduces to: coeffS * (Cov*S) + D
    if (kSA_GrBlendCoeff == fDstCoeff && srcAIsOne) {
        return false;
    }

    // We can always blend correctly if we have solid coverage.
    if (coveragePOI.isSolidWhite()) {
        return false;
    }

    return true;
}

void GrPorterDuffXPFactory::getInvariantBlendedColor(const GrProcOptInfo& colorPOI,
                                                     InvariantBlendedColor* blendedColor) const {
    // Find the blended color info based on the formula that does not have coverage.
    BlendFormula colorFormula = gBlendTable[colorPOI.isOpaque()][0][fXfermode];
    if (colorFormula.usesDstColor()) {
        blendedColor->fWillBlendWithDst = true;
        blendedColor->fKnownColorFlags = kNone_GrColorComponentFlags;
        return;
    }

    blendedColor->fWillBlendWithDst = false;

    SkASSERT(kAdd_GrBlendEquation == colorFormula.fBlendEquation);

    switch (colorFormula.fSrcCoeff) {
        case kZero_GrBlendCoeff:
            blendedColor->fKnownColor = 0;
            blendedColor->fKnownColorFlags = kRGBA_GrColorComponentFlags;
            return;

        case kOne_GrBlendCoeff:
            blendedColor->fKnownColor = colorPOI.color();
            blendedColor->fKnownColorFlags = colorPOI.validFlags();
            return;

        default:
            blendedColor->fKnownColorFlags = kNone_GrColorComponentFlags;
            return;
    }
}

GrXferProcessor::OptFlags
PorterDuffXferProcessor::onGetOptimizations(const GrProcOptInfo& colorPOI,
                                            const GrProcOptInfo& coveragePOI,
                                            bool doesStencilWrite,
                                            GrColor* overrideColor,
                                            const GrCaps& caps) {
    GrXferProcessor::OptFlags optFlags = GrXferProcessor::kNone_OptFlags;
    if (!fBlendFormula.modifiesDst()) {
        if (!doesStencilWrite) {
            optFlags |= GrXferProcessor::kSkipDraw_OptFlag;
        }
        optFlags |= (GrXferProcessor::kIgnoreColor_OptFlag |
                     GrXferProcessor::kIgnoreCoverage_OptFlag |
                     GrXferProcessor::kCanTweakAlphaForCoverage_OptFlag);
    } else {
        if (!fBlendFormula.usesInputColor()) {
            optFlags |= GrXferProcessor::kIgnoreColor_OptFlag;
        }
        if (coveragePOI.isSolidWhite()) {
            optFlags |= GrXferProcessor::kIgnoreCoverage_OptFlag;
        }
        if (colorPOI.allStagesMultiplyInput() && fBlendFormula.canTweakAlphaForCoverage()) {
            optFlags |= GrXferProcessor::kCanTweakAlphaForCoverage_OptFlag;
        }
    }
    return optFlags;
}

void GrPipeline::adjustProgramFromOptimizations(const GrPipelineBuilder& pipelineBuilder,
                                                GrXferProcessor::OptFlags flags,
                                                const GrProcOptInfo& colorPOI,
                                                const GrProcOptInfo& coveragePOI,
                                                int* firstColorStageIdx,
                                                int* firstCoverageStageIdx) {
    fReadsFragPosition = fXferProcessor->willReadFragmentPosition();

    if ((flags & GrXferProcessor::kIgnoreColor_OptFlag) ||
        (flags & GrXferProcessor::kOverrideColor_OptFlag)) {
        *firstColorStageIdx = pipelineBuilder.numColorFragmentStages();
    } else {
        if (coveragePOI.readsFragPosition()) {
            fReadsFragPosition = true;
        }
    }

    if (flags & GrXferProcessor::kIgnoreCoverage_OptFlag) {
        *firstCoverageStageIdx = pipelineBuilder.numCoverageFragmentStages();
    } else {
        if (coveragePOI.readsFragPosition()) {
            fReadsFragPosition = true;
        }
    }
}

static BlendFormula get_blend_formula(SkXfermode::Mode xfermode,
                                      const GrProcOptInfo& colorPOI,
                                      const GrProcOptInfo& coveragePOI) {
    SkASSERT(xfermode >= 0 && xfermode <= SkXfermode::kLastCoeffMode);
    SkASSERT(!coveragePOI.isFourChannelOutput());

    return gBlendTable[colorPOI.isOpaque()][!coveragePOI.isSolidWhite()][xfermode];
}

static BlendFormula get_blend_formula(const GrProcOptInfo& colorPOI,
                                      const GrProcOptInfo& coveragePOI,
                                      bool hasMixedSamples,
                                      SkXfermode::Mode xfermode) {
    SkASSERT(xfermode >= 0 && xfermode <= SkXfermode::kLastCoeffMode);
    SkASSERT(!coveragePOI.isFourChannelOutput());

    bool conflatesCoverage = !coveragePOI.isSolidWhite() || hasMixedSamples;
    return gBlendTable[colorPOI.isOpaque()][conflatesCoverage][xfermode];
}

bool GrPaint::isConstantBlendedColor(GrColor* color) const {
    GrProcOptInfo colorProcInfo;
    colorProcInfo.calcWithInitialValues(fColorStages.begin(), this->numColorStages(), fColor,
                                        kRGBA_GrColorComponentFlags, false);

    GrXPFactory::InvariantBlendedColor blendedColor;
    fXPFactory->getInvariantBlendedColor(colorProcInfo, &blendedColor);

    if (kRGBA_GrColorComponentFlags == blendedColor.fKnownColorFlags) {
        *color = blendedColor.fKnownColor;
        return true;
    }
    return false;
}

static BlendFormula get_lcd_blend_formula(const GrProcOptInfo& coveragePOI,
                                          SkBlendMode xfermode) {
    SkASSERT((unsigned)xfermode <= (unsigned)SkBlendMode::kLastCoeffMode);
    SkASSERT(coveragePOI.isFourChannelOutput());

    return gLCDBlendTable[(int)xfermode];
}

bool GrPorterDuffXPFactory::willReadDstColor(const GrCaps& caps,
                                             const GrProcOptInfo& colorPOI,
                                             const GrProcOptInfo& coveragePOI) const {
    if (coveragePOI.isFourChannelOutput()) {
        return false; // The LCD XP never does a dst read.
    }

    // We fallback on the shader XP when the blend formula would use dual source blending but we
    // don't have support for it.
    return !caps.shaderCaps()->dualSourceBlendingSupport() &&
           get_blend_formula(fXfermode, colorPOI, coveragePOI).hasSecondaryOutput();
}

bool GrPorterDuffXPFactory::willReadDstColor(const GrCaps& caps,
                                             const GrProcOptInfo& colorPOI,
                                             const GrProcOptInfo& covPOI,
                                             bool hasMixedSamples) const {
    if (caps.shaderCaps()->dualSourceBlendingSupport()) {
        return false;
    }
    
    // When we have four channel coverage we always need to read the dst in order to correctly
    // blend. The one exception is when we are using srcover mode and we know the input color into
    // the XP.
    if (covPOI.isFourChannelOutput()) {
        if (SkXfermode::kSrcOver_Mode == fXfermode &&
            kRGBA_GrColorComponentFlags == colorPOI.validFlags()) {
            return false;
        }
        return get_lcd_blend_formula(covPOI, fXfermode).hasSecondaryOutput();
    }
    // We fallback on the shader XP when the blend formula would use dual source blending but we
    // don't have support for it.
    return get_blend_formula(colorPOI, covPOI, hasMixedSamples, fXfermode).hasSecondaryOutput();
}

bool GrPaint::isConstantBlendedColor(GrColor* color) const {
    GrProcOptInfo colorProcInfo;
    colorProcInfo.calcWithInitialValues(fColorFragmentProcessors.begin(),
                                        this->numColorFragmentProcessors(), fColor,
                                        kRGBA_GrColorComponentFlags, false);

    GrXPFactory::InvariantBlendedColor blendedColor;
    if (fXPFactory) {
        fXPFactory->getInvariantBlendedColor(colorProcInfo, &blendedColor);
    } else {
        GrPorterDuffXPFactory::SrcOverInvariantBlendedColor(colorProcInfo.color(),
                                                            colorProcInfo.validFlags(),
                                                            colorProcInfo.isOpaque(),
                                                            &blendedColor); 
    }

    if (kRGBA_GrColorComponentFlags == blendedColor.fKnownColorFlags) {
        *color = blendedColor.fKnownColor;
        return true;
    }
    return false;
}

bool GrPorterDuffXPFactory::willReadDstColor(const GrCaps& caps,
                                             const GrProcOptInfo& colorPOI,
                                             const GrProcOptInfo& covPOI,
                                             bool hasMixedSamples) const {
    if (caps.shaderCaps()->dualSourceBlendingSupport()) {
        return false;
    }
    if (covPOI.isFourChannelOutput()) {
        return false; // The LCD XP will abort rather than doing a dst read.
    }
    // We fallback on the shader XP when the blend formula would use dual source blending but we
    // don't have support for it.
    return get_blend_formula(colorPOI, covPOI, hasMixedSamples, fXfermode).hasSecondaryOutput();
}

GrXferProcessor::OptFlags
PorterDuffXferProcessor::getOptimizations(const GrProcOptInfo& colorPOI,
                                          const GrProcOptInfo& coveragePOI,
                                          bool doesStencilWrite,
                                          GrColor* overrideColor,
                                          const GrDrawTargetCaps& caps) {
    GrXferProcessor::OptFlags optFlags;
    // Optimizations when doing RGB Coverage
    if (coveragePOI.isFourChannelOutput()) {
        // We want to force our primary output to be alpha * Coverage, where alpha is the alpha
        // value of the blend the constant. We should already have valid blend coeff's if we are at
        // a point where we have RGB coverage. We don't need any color stages since the known color
        // output is already baked into the blendConstant.
        uint8_t alpha = GrColorUnpackA(fBlendConstant);
        *overrideColor = GrColorPackRGBA(alpha, alpha, alpha, alpha);
        optFlags = GrXferProcessor::kOverrideColor_OptFlag;
    } else {
        optFlags = this->internalGetOptimizations(colorPOI,
                                                  coveragePOI,
                                                  doesStencilWrite);
    }
    this->calcOutputTypes(optFlags, caps, coveragePOI.isSolidWhite());
    return optFlags;
}

void GrCoverageSetOpXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
                                                  const GrProcOptInfo& coveragePOI,
                                                  GrXPFactory::InvariantOutput* output) const {
    if (SkRegion::kReplace_Op == fRegionOp) {
        if (coveragePOI.isSolidWhite()) {
            output->fBlendedColor = GrColor_WHITE;
            output->fBlendedColorFlags = kRGBA_GrColorComponentFlags;
        } else {
            output->fBlendedColorFlags = 0;
        }

        output->fWillBlendWithDst = false;
    } else {
        output->fBlendedColorFlags = 0;
        output->fWillBlendWithDst = true;
    }
}

GrXferProcessor::OptFlags GrXferProcessor::getOptimizations(const GrProcOptInfo& colorPOI,
                                                            const GrProcOptInfo& coveragePOI,
                                                            bool doesStencilWrite,
                                                            GrColor* overrideColor,
                                                            const GrCaps& caps) {
    GrXferProcessor::OptFlags flags = this->onGetOptimizations(colorPOI,
                                                               coveragePOI,
                                                               doesStencilWrite,
                                                               overrideColor,
                                                               caps);

    if (this->willReadDstColor()) {
        // When performing a dst read we handle coverage in the base class.
        SkASSERT(!(flags & GrXferProcessor::kIgnoreCoverage_OptFlag));
        if (coveragePOI.isSolidWhite()) {
            flags |= GrXferProcessor::kIgnoreCoverage_OptFlag;
        }
    }
    if (flags & GrXferProcessor::kIgnoreCoverage_OptFlag) {
        fReadsCoverage = false;
    }
    return flags;
}