C++ GrProcOptInfo::validFlags方法代码示例

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;
    }
}

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;
    }
    
    // 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();
}

void GrPorterDuffXPFactory::getInvariantOutput(const GrProcOptInfo& colorPOI,
                                               const GrProcOptInfo& coveragePOI,
                                               GrXPFactory::InvariantOutput* output) const {
    if (!coveragePOI.isSolidWhite()) {
        output->fWillBlendWithDst = true;
        output->fBlendedColorFlags = 0;
        return;
    }

    GrBlendCoeff srcCoeff = fSrcCoeff;
    GrBlendCoeff dstCoeff = fDstCoeff;

    // TODO: figure out to merge this simplify with other current optimization code paths and
    // eventually remove from GrBlend
    GrSimplifyBlend(&srcCoeff, &dstCoeff, colorPOI.color(), colorPOI.validFlags(),
                    0, 0, 0);

    if (GrBlendCoeffRefsDst(srcCoeff)) {
        output->fWillBlendWithDst = true;
        output->fBlendedColorFlags = 0;
        return;
    }

    if (kZero_GrBlendCoeff != dstCoeff) {
        bool srcAIsOne = colorPOI.isOpaque();
        if (kISA_GrBlendCoeff != dstCoeff || !srcAIsOne) {
            output->fWillBlendWithDst = true;
        }
        output->fBlendedColorFlags = 0;
        return;
    }

    switch (srcCoeff) {
        case kZero_GrBlendCoeff:
            output->fBlendedColor = 0;
            output->fBlendedColorFlags = kRGBA_GrColorComponentFlags;
            break;

        case kOne_GrBlendCoeff:
            output->fBlendedColor = colorPOI.color();
            output->fBlendedColorFlags = colorPOI.validFlags();
            break;

            // The src coeff should never refer to the src and if it refers to dst then opaque
            // should have been false.
        case kSC_GrBlendCoeff:
        case kISC_GrBlendCoeff:
        case kDC_GrBlendCoeff:
        case kIDC_GrBlendCoeff:
        case kSA_GrBlendCoeff:
        case kISA_GrBlendCoeff:
        case kDA_GrBlendCoeff:
        case kIDA_GrBlendCoeff:
        default:
            SkFAIL("srcCoeff should not refer to src or dst.");
            break;

            // TODO: update this once GrPaint actually has a const color.
        case kConstC_GrBlendCoeff:
        case kIConstC_GrBlendCoeff:
        case kConstA_GrBlendCoeff:
        case kIConstA_GrBlendCoeff:
            output->fBlendedColorFlags = 0;
            break;
    }

    output->fWillBlendWithDst = false;
}