C++ GrPipelineBuilder::getStencil方法代码示例

/*
 * This method traverses the clip stack to see if the GrSoftwarePathRenderer
 * will be used on any element. If so, it returns true to indicate that the
 * entire clip should be rendered in SW and then uploaded en masse to the gpu.
 */
bool GrClipMaskManager::UseSWOnlyPath(GrContext* context,
                                      const GrPipelineBuilder& pipelineBuilder,
                                      const GrRenderTarget* rt,
                                      const SkVector& clipToMaskOffset,
                                      const GrReducedClip::ElementList& elements) {
    // TODO: generalize this function so that when
    // a clip gets complex enough it can just be done in SW regardless
    // of whether it would invoke the GrSoftwarePathRenderer.

    // Set the matrix so that rendered clip elements are transformed to mask space from clip
    // space.
    const SkMatrix translate = SkMatrix::MakeTrans(clipToMaskOffset.fX, clipToMaskOffset.fY);

    for (GrReducedClip::ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
        const Element* element = iter.get();

        SkRegion::Op op = element->getOp();
        bool invert = element->isInverseFilled();
        bool needsStencil = invert ||
                            SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op;

        if (PathNeedsSWRenderer(context, pipelineBuilder.getStencil().isDisabled(),
                                rt, translate, element, nullptr, needsStencil)) {
            return true;
        }
    }
    return false;
}

void GrClipMaskManager::setPipelineBuilderStencil(const GrPipelineBuilder& pipelineBuilder,
                                                  GrPipelineBuilder::AutoRestoreStencil* ars) {
    // We make two copies of the StencilSettings here (except in the early
    // exit scenario. One copy from draw state to the stack var. Then another
    // from the stack var to the gpu. We could make this class hold a ptr to
    // GrGpu's fStencilSettings and eliminate the stack copy here.

    // use stencil for clipping if clipping is enabled and the clip
    // has been written into the stencil.
    GrStencilSettings settings;

    // The GrGpu client may not be using the stencil buffer but we may need to
    // enable it in order to respect a stencil clip.
    if (pipelineBuilder.getStencil().isDisabled()) {
        if (GrClipMaskManager::kRespectClip_StencilClipMode == fClipMode) {
            settings = basic_apply_stencil_clip_settings();
        } else {
            return;
        }
    } else {
        settings = pipelineBuilder.getStencil();
    }

    int stencilBits = 0;
    GrRenderTarget* rt = pipelineBuilder.getRenderTarget();
    GrStencilAttachment* stencilAttachment = 
        fDrawTarget->cmmAccess().resourceProvider()->attachStencilAttachment(rt);
    if (stencilAttachment) {
        stencilBits = stencilAttachment->bits();
    }

    SkASSERT(fDrawTarget->caps()->stencilWrapOpsSupport() || !settings.usesWrapOp());
    SkASSERT(fDrawTarget->caps()->twoSidedStencilSupport() || !settings.isTwoSided());
    this->adjustStencilParams(&settings, fClipMode, stencilBits);
    ars->set(&pipelineBuilder);
    ars->setStencil(settings);
}

GrPipeline::GrPipeline(const GrPipelineBuilder& pipelineBuilder,
                       const GrProcOptInfo& colorPOI,
                       const GrProcOptInfo& coveragePOI,
                       const GrDrawTargetCaps& caps,
                       const GrScissorState& scissorState,
                       const GrDeviceCoordTexture* dstCopy) {
    // Create XferProcessor from DS's XPFactory
    SkAutoTUnref<GrXferProcessor> xferProcessor(
        pipelineBuilder.getXPFactory()->createXferProcessor(colorPOI, coveragePOI, dstCopy, caps));

    GrColor overrideColor = GrColor_ILLEGAL;
    if (colorPOI.firstEffectiveStageIndex() != 0) {
        overrideColor = colorPOI.inputColorToEffectiveStage();
    }

    GrXferProcessor::OptFlags optFlags;
    if (xferProcessor) {
        fXferProcessor.reset(xferProcessor.get());

        optFlags = xferProcessor->getOptimizations(colorPOI,
                                                   coveragePOI,
                                                   pipelineBuilder.getStencil().doesWrite(),
                                                   &overrideColor,
                                                   caps);
    }

    // When path rendering the stencil settings are not always set on the GrPipelineBuilder
    // so we must check the draw type. In cases where we will skip drawing we simply return a
    // null GrPipeline.
    if (!xferProcessor || (GrXferProcessor::kSkipDraw_OptFlag & optFlags)) {
        // Set the fields that don't default init and return. The lack of a render target will
        // indicate that this can be skipped.
        fFlags = 0;
        fDrawFace = GrPipelineBuilder::kInvalid_DrawFace;
        return;
    }

    fRenderTarget.reset(pipelineBuilder.fRenderTarget.get());
    SkASSERT(fRenderTarget);
    fScissorState = scissorState;
    fStencilSettings = pipelineBuilder.getStencil();
    fDrawFace = pipelineBuilder.getDrawFace();

    fFlags = 0;
    if (pipelineBuilder.isHWAntialias()) {
        fFlags |= kHWAA_Flag;
    }
    if (pipelineBuilder.isDither()) {
        fFlags |= kDither_Flag;
    }
    if (pipelineBuilder.snapVerticesToPixelCenters()) {
        fFlags |= kSnapVertices_Flag;
    }

    int firstColorStageIdx = colorPOI.firstEffectiveStageIndex();

    // TODO: Once we can handle single or four channel input into coverage stages then we can use
    // GrPipelineBuilder's coverageProcInfo (like color above) to set this initial information.
    int firstCoverageStageIdx = 0;

    this->adjustProgramFromOptimizations(pipelineBuilder, optFlags, colorPOI, coveragePOI,
                                         &firstColorStageIdx, &firstCoverageStageIdx);

    bool usesLocalCoords = false;

    // Copy Stages from PipelineBuilder to Pipeline
    for (int i = firstColorStageIdx; i < pipelineBuilder.numColorFragmentStages(); ++i) {
        SkNEW_APPEND_TO_TARRAY(&fFragmentStages,
                               GrPendingFragmentStage,
                               (pipelineBuilder.fColorStages[i]));
        usesLocalCoords = usesLocalCoords ||
                          pipelineBuilder.fColorStages[i].processor()->usesLocalCoords();
    }

    fNumColorStages = fFragmentStages.count();
    for (int i = firstCoverageStageIdx; i < pipelineBuilder.numCoverageFragmentStages(); ++i) {
        SkNEW_APPEND_TO_TARRAY(&fFragmentStages,
                               GrPendingFragmentStage,
                               (pipelineBuilder.fCoverageStages[i]));
        usesLocalCoords = usesLocalCoords ||
                          pipelineBuilder.fCoverageStages[i].processor()->usesLocalCoords();
    }

    // let the GP init the batch tracker
    fInitBT.fColorIgnored = SkToBool(optFlags & GrXferProcessor::kIgnoreColor_OptFlag);
    fInitBT.fOverrideColor = fInitBT.fColorIgnored ? GrColor_ILLEGAL : overrideColor;
    fInitBT.fCoverageIgnored = SkToBool(optFlags & GrXferProcessor::kIgnoreCoverage_OptFlag);
    fInitBT.fUsesLocalCoords = usesLocalCoords;
    fInitBT.fCanTweakAlphaForCoverage =
        SkToBool(optFlags & GrXferProcessor::kCanTweakAlphaForCoverage_OptFlag);
}

bool GrStencilAndCoverPathRenderer::onDrawPath(const DrawPathArgs& args) {
    SkASSERT(!args.fStroke->isHairlineStyle());
    const SkPath& path = *args.fPath;
    GrPipelineBuilder* pipelineBuilder = args.fPipelineBuilder;
    const SkMatrix& viewMatrix = *args.fViewMatrix;

    SkASSERT(pipelineBuilder->getStencil().isDisabled());

    if (args.fAntiAlias) {
        SkASSERT(pipelineBuilder->getRenderTarget()->isStencilBufferMultisampled());
        pipelineBuilder->enableState(GrPipelineBuilder::kHWAntialias_Flag);
    }

    SkAutoTUnref<GrPath> p(get_gr_path(fResourceProvider, path, *args.fStroke));

    if (path.isInverseFillType()) {
        GR_STATIC_CONST_SAME_STENCIL(kInvertedStencilPass,
            kKeep_StencilOp,
            kZero_StencilOp,
            // We know our rect will hit pixels outside the clip and the user bits will be 0
            // outside the clip. So we can't just fill where the user bits are 0. We also need to
            // check that the clip bit is set.
            kEqualIfInClip_StencilFunc,
            0xffff,
            0x0000,
            0xffff);

        pipelineBuilder->setStencil(kInvertedStencilPass);

        // fake inverse with a stencil and cover
        SkAutoTUnref<GrPathProcessor> pp(GrPathProcessor::Create(GrColor_WHITE, viewMatrix));
        args.fTarget->stencilPath(*pipelineBuilder, pp, p,
                                  convert_skpath_filltype(path.getFillType()));

        SkMatrix invert = SkMatrix::I();
        SkRect bounds =
            SkRect::MakeLTRB(0, 0, SkIntToScalar(pipelineBuilder->getRenderTarget()->width()),
                             SkIntToScalar(pipelineBuilder->getRenderTarget()->height()));
        SkMatrix vmi;
        // mapRect through persp matrix may not be correct
        if (!viewMatrix.hasPerspective() && viewMatrix.invert(&vmi)) {
            vmi.mapRect(&bounds);
            // theoretically could set bloat = 0, instead leave it because of matrix inversion
            // precision.
            SkScalar bloat = viewMatrix.getMaxScale() * SK_ScalarHalf;
            bounds.outset(bloat, bloat);
        } else {
            if (!viewMatrix.invert(&invert)) {
                return false;
            }
        }
        const SkMatrix& viewM = viewMatrix.hasPerspective() ? SkMatrix::I() : viewMatrix;
        args.fTarget->drawNonAARect(*pipelineBuilder, args.fColor, viewM, bounds, invert);
    } else {
        GR_STATIC_CONST_SAME_STENCIL(kStencilPass,
            kZero_StencilOp,
            kKeep_StencilOp,
            kNotEqual_StencilFunc,
            0xffff,
            0x0000,
            0xffff);

        pipelineBuilder->setStencil(kStencilPass);
        SkAutoTUnref<GrPathProcessor> pp(GrPathProcessor::Create(args.fColor, viewMatrix));
        args.fTarget->drawPath(*pipelineBuilder, pp, p,
                               convert_skpath_filltype(path.getFillType()));
    }

    pipelineBuilder->stencil()->setDisabled();
    return true;
}