C++ GrPipelineBuilder::stencil方法代码示例

////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
// (as opposed to canvas) coordinates
bool GrClipMaskManager::createStencilClipMask(GrRenderTarget* rt,
                                              int32_t elementsGenID,
                                              GrReducedClip::InitialState initialState,
                                              const GrReducedClip::ElementList& elements,
                                              const SkIRect& clipSpaceIBounds,
                                              const SkIPoint& clipSpaceToStencilOffset) {
    SkASSERT(rt);

    GrStencilAttachment* stencilAttachment =
        fDrawTarget->cmmAccess().resourceProvider()->attachStencilAttachment(rt);
    if (nullptr == stencilAttachment) {
        return false;
    }

    if (stencilAttachment->mustRenderClip(elementsGenID, clipSpaceIBounds, clipSpaceToStencilOffset)) {
        stencilAttachment->setLastClip(elementsGenID, clipSpaceIBounds, clipSpaceToStencilOffset);
        // Set the matrix so that rendered clip elements are transformed from clip to stencil space.
        SkVector translate = {
            SkIntToScalar(clipSpaceToStencilOffset.fX),
            SkIntToScalar(clipSpaceToStencilOffset.fY)
        };
        SkMatrix viewMatrix;
        viewMatrix.setTranslate(translate);

        // We set the current clip to the bounds so that our recursive draws are scissored to them.
        SkIRect stencilSpaceIBounds(clipSpaceIBounds);
        stencilSpaceIBounds.offset(clipSpaceToStencilOffset);
        GrClip clip(stencilSpaceIBounds);

        int clipBit = stencilAttachment->bits();
        SkASSERT((clipBit <= 16) && "Ganesh only handles 16b or smaller stencil buffers");
        clipBit = (1 << (clipBit-1));

        fDrawTarget->cmmAccess().clearStencilClip(stencilSpaceIBounds,
            GrReducedClip::kAllIn_InitialState == initialState, rt);

        // walk through each clip element and perform its set op
        // with the existing clip.
        for (GrReducedClip::ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
            const Element* element = iter.get();

            GrPipelineBuilder pipelineBuilder;
            pipelineBuilder.setClip(clip);
            pipelineBuilder.setRenderTarget(rt);

            pipelineBuilder.setDisableColorXPFactory();

            // if the target is MSAA then we want MSAA enabled when the clip is soft
            if (rt->isStencilBufferMultisampled()) {
                pipelineBuilder.setState(GrPipelineBuilder::kHWAntialias_Flag, element->isAA());
            }

            bool fillInverted = false;
            // enabled at bottom of loop
            fClipMode = kIgnoreClip_StencilClipMode;

            // This will be used to determine whether the clip shape can be rendered into the
            // stencil with arbitrary stencil settings.
            GrPathRenderer::StencilSupport stencilSupport;

            GrStrokeInfo stroke(SkStrokeRec::kFill_InitStyle);
            SkRegion::Op op = element->getOp();

            GrPathRenderer* pr = nullptr;
            SkPath clipPath;
            if (Element::kRect_Type == element->getType()) {
                stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
                fillInverted = false;
            } else {
                element->asPath(&clipPath);
                fillInverted = clipPath.isInverseFillType();
                if (fillInverted) {
                    clipPath.toggleInverseFillType();
                }
                pr = this->getContext()->getPathRenderer(fDrawTarget,
                                                         &pipelineBuilder,
                                                         viewMatrix,
                                                         clipPath,
                                                         stroke,
                                                         false,
                                                         GrPathRendererChain::kStencilOnly_DrawType,
                                                         &stencilSupport);
                if (nullptr == pr) {
                    return false;
                }
            }

            int passes;
            GrStencilSettings stencilSettings[GrStencilSettings::kMaxStencilClipPasses];

            bool canRenderDirectToStencil =
                GrPathRenderer::kNoRestriction_StencilSupport == stencilSupport;
            bool canDrawDirectToClip; // Given the renderer, the element,
                                      // fill rule, and set operation can
                                      // we render the element directly to
                                      // stencil bit used for clipping.
            canDrawDirectToClip = GrStencilSettings::GetClipPasses(op,
//.........这里部分代码省略.........

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;
}