bool RenderSVGResourceClipper::applyClippingToContext(RenderObject* target, const FloatRect& targetBoundingBox,
    const FloatRect& repaintRect, GraphicsContext* context, ClipperContext& clipperContext)
{
    ASSERT(target);
    ASSERT(context);
    ASSERT(clipperContext.state == ClipperContext::NotAppliedState);
    ASSERT_WITH_SECURITY_IMPLICATION(!needsLayout());

    if (repaintRect.isEmpty() || m_inClipExpansion)
        return false;
    TemporaryChange<bool> inClipExpansionChange(m_inClipExpansion, true);

    // First, try to apply the clip as a clipPath.
    AffineTransform animatedLocalTransform = toSVGClipPathElement(element())->animatedLocalTransform();
    if (tryPathOnlyClipping(context, animatedLocalTransform, targetBoundingBox)) {
        clipperContext.state = ClipperContext::AppliedPathState;
        return true;
    }

    // Fall back to masking.
    clipperContext.state = ClipperContext::AppliedMaskState;

    // Mask layer start
    context->beginTransparencyLayer(1, &repaintRect);
    {
        GraphicsContextStateSaver maskContentSaver(*context);
        context->concatCTM(animatedLocalTransform);

        // clipPath can also be clipped by another clipPath.
        SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(this);
        RenderSVGResourceClipper* clipPathClipper = 0;
        ClipperContext clipPathClipperContext;
        if (resources && (clipPathClipper = resources->clipper())) {
            if (!clipPathClipper->applyClippingToContext(this, targetBoundingBox, repaintRect, context, clipPathClipperContext)) {
                // FIXME: Awkward state micro-management. Ideally, GraphicsContextStateSaver should
                //   a) pop saveLayers also
                //   b) pop multiple states if needed (similarly to SkCanvas::restoreToCount())
                // Then we should be able to replace this mess with a single, top-level GCSS.
                maskContentSaver.restore();
                context->restoreLayer();
                return false;
            }
        }

        drawClipMaskContent(context, targetBoundingBox);

        if (clipPathClipper)
            clipPathClipper->postApplyStatefulResource(this, context, clipPathClipperContext);
    }

    // Masked content layer start.
    context->beginLayer(1, CompositeSourceIn, &repaintRect);

    return true;
}
Ejemplo n.º 2
0
bool RenderSVGResourceClipper::applyClippingToContext(RenderObject* target, const FloatRect& targetBoundingBox,
    const FloatRect& paintInvalidationRect, GraphicsContext* context, ClipperState& clipperState)
{
    ASSERT(target);
    ASSERT(context);
    ASSERT(clipperState == ClipperNotApplied);
    ASSERT_WITH_SECURITY_IMPLICATION(!needsLayout());

    if (paintInvalidationRect.isEmpty() || m_inClipExpansion)
        return false;
    TemporaryChange<bool> inClipExpansionChange(m_inClipExpansion, true);

    AffineTransform animatedLocalTransform = toSVGClipPathElement(element())->animatedLocalTransform();
    // When drawing a clip for non-SVG elements, the CTM does not include the zoom factor.
    // In this case, we need to apply the zoom scale explicitly - but only for clips with
    // userSpaceOnUse units (the zoom is accounted for objectBoundingBox-resolved lengths).
    if (!target->isSVG() && clipPathUnits() == SVGUnitTypes::SVG_UNIT_TYPE_USERSPACEONUSE) {
        ASSERT(style());
        animatedLocalTransform.scale(style()->effectiveZoom());
    }

    // First, try to apply the clip as a clipPath.
    if (tryPathOnlyClipping(context, animatedLocalTransform, targetBoundingBox)) {
        clipperState = ClipperAppliedPath;
        return true;
    }

    // Fall back to masking.
    clipperState = ClipperAppliedMask;

    // Mask layer start
    context->beginTransparencyLayer(1, &paintInvalidationRect);
    {
        GraphicsContextStateSaver maskContentSaver(*context);
        context->concatCTM(animatedLocalTransform);

        // clipPath can also be clipped by another clipPath.
        SVGResources* resources = SVGResourcesCache::cachedResourcesForRenderObject(this);
        RenderSVGResourceClipper* clipPathClipper = resources ? resources->clipper() : 0;
        ClipperState clipPathClipperState = ClipperNotApplied;
        if (clipPathClipper && !clipPathClipper->applyClippingToContext(this, targetBoundingBox, paintInvalidationRect, context, clipPathClipperState)) {
            // FIXME: Awkward state micro-management. Ideally, GraphicsContextStateSaver should
            //   a) pop saveLayers also
            //   b) pop multiple states if needed (similarly to SkCanvas::restoreToCount())
            // Then we should be able to replace this mess with a single, top-level GCSS.
            maskContentSaver.restore();
            context->restoreLayer();
            return false;
        }

        drawClipMaskContent(context, targetBoundingBox);

        if (clipPathClipper)
            clipPathClipper->postApplyStatefulResource(this, context, clipPathClipperState);
    }

    // Masked content layer start.
    context->beginLayer(1, CompositeSourceIn, &paintInvalidationRect);

    return true;
}