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

GrTexture* GrClipMaskManager::createAlphaClipMask(int32_t elementsGenID,
                                                  GrReducedClip::InitialState initialState,
                                                  const GrReducedClip::ElementList& elements,
                                                  const SkVector& clipToMaskOffset,
                                                  const SkIRect& clipSpaceIBounds) {
    GrResourceProvider* resourceProvider = fDrawTarget->cmmAccess().resourceProvider();
    GrUniqueKey key;
    GetClipMaskKey(elementsGenID, clipSpaceIBounds, &key);
    if (GrTexture* texture = resourceProvider->findAndRefTextureByUniqueKey(key)) {
        return texture;
    }

    SkAutoTUnref<GrTexture> texture(this->createCachedMask(
        clipSpaceIBounds.width(), clipSpaceIBounds.height(), key, true));

    // There's no texture in the cache. Let's try to allocate it then.
    if (!texture) {
        return nullptr;
    }

    // Set the matrix so that rendered clip elements are transformed to mask space from clip
    // space.
    SkMatrix translate;
    translate.setTranslate(clipToMaskOffset);

    // The texture may be larger than necessary, this rect represents the part of the texture
    // we populate with a rasterization of the clip.
    SkIRect maskSpaceIBounds = SkIRect::MakeWH(clipSpaceIBounds.width(), clipSpaceIBounds.height());

    // The scratch texture that we are drawing into can be substantially larger than the mask. Only
    // clear the part that we care about.
    fDrawTarget->clear(&maskSpaceIBounds,
                       GrReducedClip::kAllIn_InitialState == initialState ? 0xffffffff : 0x00000000,
                       true,
                       texture->asRenderTarget());

    // When we use the stencil in the below loop it is important to have this clip installed.
    // The second pass that zeros the stencil buffer renders the rect maskSpaceIBounds so the first
    // pass must not set values outside of this bounds or stencil values outside the rect won't be
    // cleared.
    GrClip clip(maskSpaceIBounds);
    SkAutoTUnref<GrTexture> temp;

    // walk through each clip element and perform its set op
    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();
        if (invert || SkRegion::kIntersect_Op == op || SkRegion::kReverseDifference_Op == op) {
            GrPipelineBuilder pipelineBuilder;

            pipelineBuilder.setClip(clip);
            GrPathRenderer* pr = nullptr;
            bool useTemp = !this->canStencilAndDrawElement(&pipelineBuilder, texture, &pr, element);
            GrTexture* dst;
            // This is the bounds of the clip element in the space of the alpha-mask. The temporary
            // mask buffer can be substantially larger than the actually clip stack element. We
            // touch the minimum number of pixels necessary and use decal mode to combine it with
            // the accumulator.
            SkIRect maskSpaceElementIBounds;

            if (useTemp) {
                if (invert) {
                    maskSpaceElementIBounds = maskSpaceIBounds;
                } else {
                    SkRect elementBounds = element->getBounds();
                    elementBounds.offset(clipToMaskOffset);
                    elementBounds.roundOut(&maskSpaceElementIBounds);
                }

                if (!temp) {
                    temp.reset(this->createTempMask(maskSpaceIBounds.fRight,
                                                    maskSpaceIBounds.fBottom));
                    if (!temp) {
                        texture->resourcePriv().removeUniqueKey();
                        return nullptr;
                    }
                }
                dst = temp;
                // clear the temp target and set blend to replace
                fDrawTarget->clear(&maskSpaceElementIBounds,
                                   invert ? 0xffffffff : 0x00000000,
                                   true,
                                   dst->asRenderTarget());
                set_coverage_drawing_xpf(SkRegion::kReplace_Op, invert, &pipelineBuilder);
            } else {
                // draw directly into the result with the stencil set to make the pixels affected
                // by the clip shape be non-zero.
                dst = texture;
                GR_STATIC_CONST_SAME_STENCIL(kStencilInElement,
                                             kReplace_StencilOp,
                                             kReplace_StencilOp,
                                             kAlways_StencilFunc,
                                             0xffff,
                                             0xffff,
                                             0xffff);
                pipelineBuilder.setStencil(kStencilInElement);
                set_coverage_drawing_xpf(op, invert, &pipelineBuilder);
            }

//.........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;
}