C++ RenderElement::strokeBoundingBox方法代码示例

void SVGRenderingContext::prepareToRenderSVGContent(RenderElement& renderer, PaintInfo& paintInfo, NeedsGraphicsContextSave needsGraphicsContextSave)
{
#ifndef NDEBUG
    // This function must not be called twice!
    ASSERT(!(m_renderingFlags & PrepareToRenderSVGContentWasCalled));
    m_renderingFlags |= PrepareToRenderSVGContentWasCalled;
#endif

    m_renderer = &renderer;
    m_paintInfo = &paintInfo;
    m_filter = 0;

    // We need to save / restore the context even if the initialization failed.
    if (needsGraphicsContextSave == SaveGraphicsContext) {
        m_paintInfo->context().save();
        m_renderingFlags |= RestoreGraphicsContext;
    }

    auto& style = m_renderer->style();

    const SVGRenderStyle& svgStyle = style.svgStyle();

    // Setup transparency layers before setting up SVG resources!
    bool isRenderingMask = isRenderingMaskImage(*m_renderer);
    // RenderLayer takes care of root opacity.
    float opacity = (renderer.isSVGRoot() || isRenderingMask) ? 1 : style.opacity();
    const ShadowData* shadow = svgStyle.shadow();
    bool hasBlendMode = style.hasBlendMode();
    bool hasIsolation = style.hasIsolation();
    bool isolateMaskForBlending = false;

#if ENABLE(CSS_COMPOSITING)
    if (svgStyle.hasMasker() && is<SVGGraphicsElement>(downcast<SVGElement>(*renderer.element()))) {
        SVGGraphicsElement& graphicsElement = downcast<SVGGraphicsElement>(*renderer.element());
        isolateMaskForBlending = graphicsElement.shouldIsolateBlending();
    }
#endif

    if (opacity < 1 || shadow || hasBlendMode || isolateMaskForBlending || hasIsolation) {
        FloatRect repaintRect = m_renderer->repaintRectInLocalCoordinates();
        m_paintInfo->context().clip(repaintRect);

        if (opacity < 1 || hasBlendMode || isolateMaskForBlending || hasIsolation) {

            if (hasBlendMode)
                m_paintInfo->context().setCompositeOperation(m_paintInfo->context().compositeOperation(), style.blendMode());

            m_paintInfo->context().beginTransparencyLayer(opacity);

            if (hasBlendMode)
                m_paintInfo->context().setCompositeOperation(m_paintInfo->context().compositeOperation(), BlendModeNormal);

            m_renderingFlags |= EndOpacityLayer;
        }

        if (shadow) {
            m_paintInfo->context().setShadow(IntSize(roundToInt(shadow->x()), roundToInt(shadow->y())), shadow->radius(), shadow->color());
            m_paintInfo->context().beginTransparencyLayer(1);
            m_renderingFlags |= EndShadowLayer;
        }
    }

    ClipPathOperation* clipPathOperation = style.clipPath();
    if (is<ShapeClipPathOperation>(clipPathOperation)) {
        auto& clipPath = downcast<ShapeClipPathOperation>(*clipPathOperation);
        FloatRect referenceBox;
        if (clipPath.referenceBox() == Stroke)
            // FIXME: strokeBoundingBox() takes dasharray into account but shouldn't.
            referenceBox = renderer.strokeBoundingBox();
        else if (clipPath.referenceBox() == ViewBox && renderer.element()) {
            FloatSize viewportSize;
            SVGLengthContext(downcast<SVGElement>(renderer.element())).determineViewport(viewportSize);
            referenceBox.setWidth(viewportSize.width());
            referenceBox.setHeight(viewportSize.height());
        } else
            referenceBox = renderer.objectBoundingBox();
        m_paintInfo->context().clipPath(clipPath.pathForReferenceRect(referenceBox), clipPath.windRule());
    }

    auto* resources = SVGResourcesCache::cachedResourcesForRenderer(*m_renderer);
    if (!resources) {
        if (style.hasReferenceFilterOnly())
            return;

        m_renderingFlags |= RenderingPrepared;
        return;
    }

    if (!isRenderingMask) {
        if (RenderSVGResourceMasker* masker = resources->masker()) {
            GraphicsContext* contextPtr = &m_paintInfo->context();
            bool result = masker->applyResource(*m_renderer, style, contextPtr, ApplyToDefaultMode);
            m_paintInfo->setContext(*contextPtr);
            if (!result)
                return;
        }
    }

    RenderSVGResourceClipper* clipper = resources->clipper();
    if (!clipPathOperation && clipper) {
//.........这里部分代码省略.........

bool RenderSVGResourceFilter::applyResource(RenderElement& renderer, const RenderStyle&, GraphicsContext*& context, unsigned short resourceMode)
{
    ASSERT(context);
    ASSERT_UNUSED(resourceMode, resourceMode == ApplyToDefaultMode);

    if (m_filter.contains(&renderer)) {
        FilterData* filterData = m_filter.get(&renderer);
        if (filterData->state == FilterData::PaintingSource || filterData->state == FilterData::Applying)
            filterData->state = FilterData::CycleDetected;
        return false; // Already built, or we're in a cycle, or we're marked for removal. Regardless, just do nothing more now.
    }

    auto filterData = std::make_unique<FilterData>();
    FloatRect targetBoundingBox = renderer.objectBoundingBox();

    filterData->boundaries = SVGLengthContext::resolveRectangle<SVGFilterElement>(&filterElement(), filterElement().filterUnits(), targetBoundingBox);
    if (filterData->boundaries.isEmpty())
        return false;

    // Determine absolute transformation matrix for filter.
    AffineTransform absoluteTransform;
    SVGRenderingContext::calculateTransformationToOutermostCoordinateSystem(renderer, absoluteTransform);
    if (!absoluteTransform.isInvertible())
        return false;

    // Eliminate shear of the absolute transformation matrix, to be able to produce unsheared tile images for feTile.
    filterData->shearFreeAbsoluteTransform = AffineTransform(absoluteTransform.xScale(), 0, 0, absoluteTransform.yScale(), 0, 0);

    // Determine absolute boundaries of the filter and the drawing region.
    FloatRect absoluteFilterBoundaries = filterData->shearFreeAbsoluteTransform.mapRect(filterData->boundaries);
    filterData->drawingRegion = renderer.strokeBoundingBox();
    filterData->drawingRegion.intersect(filterData->boundaries);
    FloatRect absoluteDrawingRegion = filterData->shearFreeAbsoluteTransform.mapRect(filterData->drawingRegion);

    // Create the SVGFilter object.
    bool primitiveBoundingBoxMode = filterElement().primitiveUnits() == SVGUnitTypes::SVG_UNIT_TYPE_OBJECTBOUNDINGBOX;
    filterData->filter = SVGFilter::create(filterData->shearFreeAbsoluteTransform, absoluteDrawingRegion, targetBoundingBox, filterData->boundaries, primitiveBoundingBoxMode);

    // Create all relevant filter primitives.
    filterData->builder = buildPrimitives(filterData->filter.get());
    if (!filterData->builder)
        return false;

    // Calculate the scale factor for the use of filterRes.
    // Also see http://www.w3.org/TR/SVG/filters.html#FilterEffectsRegion
    FloatSize scale(1, 1);
    if (filterElement().hasAttribute(SVGNames::filterResAttr)) {
        scale.setWidth(filterElement().filterResX() / absoluteFilterBoundaries.width());
        scale.setHeight(filterElement().filterResY() / absoluteFilterBoundaries.height());
    }

    if (scale.isEmpty())
        return false;

    // Determine scale factor for filter. The size of intermediate ImageBuffers shouldn't be bigger than kMaxFilterSize.
    FloatRect tempSourceRect = absoluteDrawingRegion;
    tempSourceRect.scale(scale.width(), scale.height());
    fitsInMaximumImageSize(tempSourceRect.size(), scale);

    // Set the scale level in SVGFilter.
    filterData->filter->setFilterResolution(scale);

    static const unsigned maxTotalOfEffectInputs = 100;
    FilterEffect* lastEffect = filterData->builder->lastEffect();
    if (!lastEffect || lastEffect->totalNumberOfEffectInputs() > maxTotalOfEffectInputs)
        return false;

    RenderSVGResourceFilterPrimitive::determineFilterPrimitiveSubregion(*lastEffect);
    FloatRect subRegion = lastEffect->maxEffectRect();
    // At least one FilterEffect has a too big image size,
    // recalculate the effect sizes with new scale factors.
    if (!fitsInMaximumImageSize(subRegion.size(), scale)) {
        filterData->filter->setFilterResolution(scale);
        RenderSVGResourceFilterPrimitive::determineFilterPrimitiveSubregion(*lastEffect);
    }

    // If the drawingRegion is empty, we have something like <g filter=".."/>.
    // Even if the target objectBoundingBox() is empty, we still have to draw the last effect result image in postApplyResource.
    if (filterData->drawingRegion.isEmpty()) {
        ASSERT(!m_filter.contains(&renderer));
        filterData->savedContext = context;
        m_filter.set(&renderer, WTF::move(filterData));
        return false;
    }

    // Change the coordinate transformation applied to the filtered element to reflect the resolution of the filter.
    AffineTransform effectiveTransform;
    effectiveTransform.scale(scale.width(), scale.height());
    effectiveTransform.multiply(filterData->shearFreeAbsoluteTransform);

    std::unique_ptr<ImageBuffer> sourceGraphic;
    RenderingMode renderingMode = renderer.frame().settings().acceleratedFiltersEnabled() ? Accelerated : Unaccelerated;
    if (!SVGRenderingContext::createImageBuffer(filterData->drawingRegion, effectiveTransform, sourceGraphic, ColorSpaceLinearRGB, renderingMode)) {
        ASSERT(!m_filter.contains(&renderer));
        filterData->savedContext = context;
        m_filter.set(&renderer, WTF::move(filterData));
        return false;
    }

    // Set the rendering mode from the page's settings.
//.........这里部分代码省略.........