Exemplo n.º 1
0
/*
 * 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(const 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.
    SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);

    for (ElementList::Iter iter(elements.headIter()); iter.get(); iter.next()) {
        const Element* element = iter.get();
        // rects can always be drawn directly w/o using the software path
        // so only paths need to be checked
        if (Element::kPath_Type == element->getType() &&
            path_needs_SW_renderer(this->getContext(), fGpu,
                                   element->getPath(),
                                   stroke,
                                   element->isAA())) {
            return true;
        }
    }
    return false;
}
Exemplo n.º 2
0
////////////////////////////////////////////////////////////////////////////////
// Create a 1-bit clip mask in the stencil buffer. 'devClipBounds' are in device
// (as opposed to canvas) coordinates
bool GrClipMaskManager::createStencilClipMask(InitialState initialState,
                                              const ElementList& elements,
                                              const SkIRect& clipSpaceIBounds,
                                              const SkIPoint& clipSpaceToStencilOffset) {

    GrAssert(kNone_ClipMaskType == fCurrClipMaskType);

    GrDrawState* drawState = fGpu->drawState();
    GrAssert(drawState->isClipState());

    GrRenderTarget* rt = drawState->getRenderTarget();
    GrAssert(NULL != rt);

    // TODO: dynamically attach a SB when needed.
    GrStencilBuffer* stencilBuffer = rt->getStencilBuffer();
    if (NULL == stencilBuffer) {
        return false;
    }
    int32_t genID = elements.tail()->getGenID();

    if (stencilBuffer->mustRenderClip(genID, clipSpaceIBounds, clipSpaceToStencilOffset)) {

        stencilBuffer->setLastClip(genID, clipSpaceIBounds, clipSpaceToStencilOffset);

        GrDrawTarget::AutoGeometryAndStatePush agasp(fGpu, GrDrawTarget::kReset_ASRInit);
        drawState = fGpu->drawState();
        drawState->setRenderTarget(rt);

        // We set the current clip to the bounds so that our recursive draws are scissored to them.
        SkIRect stencilSpaceIBounds(clipSpaceIBounds);
        stencilSpaceIBounds.offset(clipSpaceToStencilOffset);
        GrDrawTarget::AutoClipRestore acr(fGpu, stencilSpaceIBounds);
        drawState->enableState(GrDrawState::kClip_StateBit);

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

#if !VISUALIZE_COMPLEX_CLIP
        drawState->enableState(GrDrawState::kNoColorWrites_StateBit);
#endif

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

        fGpu->clearStencilClip(stencilSpaceIBounds, kAllIn_InitialState == initialState);

        // walk through each clip element and perform its set op
        // with the existing clip.
        for (ElementList::Iter iter(elements.headIter()); NULL != iter.get(); iter.next()) {
            const Element* element = iter.get();
            bool fillInverted = false;
            // enabled at bottom of loop
            drawState->disableState(GrGpu::kModifyStencilClip_StateBit);
            // if the target is MSAA then we want MSAA enabled when the clip is soft
            if (rt->isMultisampled()) {
                drawState->setState(GrDrawState::kHWAntialias_StateBit, element->isAA());
            }

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

            SkStrokeRec stroke(SkStrokeRec::kFill_InitStyle);

            SkRegion::Op op = element->getOp();

            GrPathRenderer* pr = NULL;
            SkTCopyOnFirstWrite<SkPath> clipPath;
            if (Element::kRect_Type == element->getType()) {
                stencilSupport = GrPathRenderer::kNoRestriction_StencilSupport;
                fillInverted = false;
            } else {
                GrAssert(Element::kPath_Type == element->getType());
                clipPath.init(element->getPath());
                fillInverted = clipPath->isInverseFillType();
                if (fillInverted) {
                    clipPath.writable()->toggleInverseFillType();
                }
                pr = this->getContext()->getPathRenderer(*clipPath,
                                                         stroke,
                                                         fGpu,
                                                         false,
                                                         GrPathRendererChain::kStencilOnly_DrawType,
                                                         &stencilSupport);
                if (NULL == 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,
                                                                   canRenderDirectToStencil,
                                                                   clipBit,
                                                                   fillInverted,
                                                                   &passes,
                                                                   stencilSettings);

            // draw the element to the client stencil bits if necessary
            if (!canDrawDirectToClip) {
                GR_STATIC_CONST_SAME_STENCIL(gDrawToStencil,
                                             kIncClamp_StencilOp,
                                             kIncClamp_StencilOp,
                                             kAlways_StencilFunc,
                                             0xffff,
                                             0x0000,
                                             0xffff);
                SET_RANDOM_COLOR
                if (Element::kRect_Type == element->getType()) {
                    *drawState->stencil() = gDrawToStencil;
                    fGpu->drawSimpleRect(element->getRect(), NULL);
                } else {
                    GrAssert(Element::kPath_Type == element->getType());
                    if (canRenderDirectToStencil) {
                        *drawState->stencil() = gDrawToStencil;
                        pr->drawPath(*clipPath, stroke, fGpu, false);
                    } else {
                        pr->stencilPath(*clipPath, stroke, fGpu);
                    }
                }
            }

            // now we modify the clip bit by rendering either the clip
            // element directly or a bounding rect of the entire clip.
            drawState->enableState(GrGpu::kModifyStencilClip_StateBit);
            for (int p = 0; p < passes; ++p) {
                *drawState->stencil() = stencilSettings[p];
                if (canDrawDirectToClip) {
                    if (Element::kRect_Type == element->getType()) {
                        SET_RANDOM_COLOR
                        fGpu->drawSimpleRect(element->getRect(), NULL);
                    } else {
                        GrAssert(Element::kPath_Type == element->getType());
                        SET_RANDOM_COLOR
                        pr->drawPath(*clipPath, stroke, fGpu, false);
                    }
                } else {
                    SET_RANDOM_COLOR
                    // The view matrix is setup to do clip space -> stencil space translation, so
                    // draw rect in clip space.
                    fGpu->drawSimpleRect(SkRect::MakeFromIRect(clipSpaceIBounds), NULL);
                }
            }
        }