C++ GrDrawState::getCoverage方法代码示例

GrOptDrawState::GrOptDrawState(const GrDrawState& drawState,
                               BlendOptFlags blendOptFlags,
                               GrBlendCoeff optSrcCoeff,
                               GrBlendCoeff optDstCoeff,
                               const GrDrawTargetCaps& caps) : INHERITED(drawState) {
    fColor = drawState.getColor();
    fCoverage = drawState.getCoverage();
    fViewMatrix = drawState.getViewMatrix();
    fBlendConstant = drawState.getBlendConstant();
    fFlagBits = drawState.getFlagBits();
    fVAPtr = drawState.getVertexAttribs();
    fVACount = drawState.getVertexAttribCount();
    fVAStride = drawState.getVertexStride();
    fStencilSettings = drawState.getStencil();
    fDrawFace = drawState.getDrawFace();
    fBlendOptFlags = blendOptFlags;
    fSrcBlend = optSrcCoeff;
    fDstBlend = optDstCoeff;

    memcpy(fFixedFunctionVertexAttribIndices,
            drawState.getFixedFunctionVertexAttribIndices(),
            sizeof(fFixedFunctionVertexAttribIndices));


    fInputColorIsUsed = true;
    fInputCoverageIsUsed = true;

    if (drawState.hasGeometryProcessor()) {
        fGeometryProcessor.reset(SkNEW_ARGS(GrGeometryStage, (*drawState.getGeometryProcessor())));
    } else {
        fGeometryProcessor.reset(NULL);
    }

    this->copyEffectiveColorStages(drawState);
    this->copyEffectiveCoverageStages(drawState);
    this->adjustFromBlendOpts();
    this->getStageStats();
    this->setOutputStateInfo(caps);
};

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>() = 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.........

void GrGLProgramDesc::Build(const GrDrawState& drawState,
                            bool isPoints,
                            GrDrawState::BlendOptFlags blendOpts,
                            GrBlendCoeff srcCoeff,
                            GrBlendCoeff dstCoeff,
                            const GrGpuGL* gpu,
                            const GrDeviceCoordTexture* dstCopy,
                            GrGLProgramDesc* desc) {

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

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

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

    // 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.


    desc->fEmitsPointSize = isPoints;

    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();

    // fColorInput/fCoverageInput records how colors are specified for the program so we strip the
    // bits from the bindings to avoid false negatives when searching for an existing program in the
    // cache.

    desc->fColorFilterXfermode = skipColor ? SkXfermode::kDst_Mode : drawState.getColorFilterMode();


    bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
    bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
                             (!requiresColorAttrib && 0xffffffff == drawState.getColor());
    if (colorIsTransBlack) {
        desc->fColorInput = kTransBlack_ColorInput;
    } else if (colorIsSolidWhite) {
        desc->fColorInput = kSolidWhite_ColorInput;
    } else if (GR_GL_NO_CONSTANT_ATTRIBUTES && !requiresColorAttrib) {
        desc->fColorInput = kUniform_ColorInput;
    } else {
        desc->fColorInput = kAttribute_ColorInput;
    }

    bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverage();

    if (skipCoverage) {
        desc->fCoverageInput = kTransBlack_ColorInput;
    } else if (covIsSolidWhite) {
        desc->fCoverageInput = kSolidWhite_ColorInput;
    } else if (GR_GL_NO_CONSTANT_ATTRIBUTES && !requiresCoverageAttrib) {
        desc->fCoverageInput = kUniform_ColorInput;
    } else {
        desc->fCoverageInput = kAttribute_ColorInput;
    }

    bool readsDst = false;
    int lastEnabledStage = -1;

    for (int s = 0; s < GrDrawState::kNumStages; ++s) {

        bool skip = s < drawState.getFirstCoverageStage() ? skipColor : skipCoverage;
        if (!skip && drawState.isStageEnabled(s)) {
            lastEnabledStage = s;
            const GrEffectRef& effect = *drawState.getStage(s).getEffect();
            const GrBackendEffectFactory& factory = effect->getFactory();
            GrDrawEffect drawEffect(drawState.getStage(s), requiresLocalCoordAttrib);
            desc->fEffectKeys[s] = factory.glEffectKey(drawEffect, gpu->glCaps());
            if (effect->willReadDst()) {
                readsDst = true;
            }
        } else {
            desc->fEffectKeys[s] = 0;
        }
    }

    if (readsDst) {
        GrAssert(NULL != dstCopy);
        desc->fDstRead = GrGLShaderBuilder::KeyForDstRead(dstCopy->texture(), gpu->glCaps());
        GrAssert(0 != desc->fDstRead);
    } else {
        desc->fDstRead = 0;
    }

    desc->fCoverageOutput = kModulate_CoverageOutput;

    // 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).
#if GR_GL_EXPERIMENTAL_GS
#if 0
    desc->fExperimentalGS = gpu->caps().geometryShaderSupport();
#else
    desc->fExperimentalGS = false;
//.........这里部分代码省略.........