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.
filterData->filter->setRenderingMode(renderingMode);
GraphicsContext* sourceGraphicContext = sourceGraphic->context();
ASSERT(sourceGraphicContext);
filterData->sourceGraphicBuffer = WTF::move(sourceGraphic);
filterData->savedContext = context;
context = sourceGraphicContext;
ASSERT(!m_filter.contains(&renderer));
m_filter.set(&renderer, WTF::move(filterData));
return true;
}
