Source/WebCore/rendering/svg/RenderSVGResourceFilterPrimitive.cpp

/*
 * Copyright (C) 2010 University of Szeged
 * Copyright (C) 2010 Zoltan Herczeg
 * Copyright (C) 2011 Renata Hodovan (reni@webkit.org)
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include "RenderSVGResourceFilterPrimitive.h"

#include "SVGFEDiffuseLightingElement.h"
#include "SVGFEFloodElement.h"
#include "SVGFEImage.h"
#include "SVGFESpecularLightingElement.h"
#include "SVGFilterPrimitiveStandardAttributes.h"
#include "SVGNames.h"
#include <wtf/IsoMallocInlines.h>

namespace WebCore {

WTF_MAKE_ISO_ALLOCATED_IMPL(RenderSVGResourceFilterPrimitive);

RenderSVGResourceFilterPrimitive::RenderSVGResourceFilterPrimitive(SVGFilterPrimitiveStandardAttributes& filterPrimitiveElement, RenderStyle&& style)
    : RenderSVGHiddenContainer(filterPrimitiveElement, WTFMove(style))
{
}

SVGFilterPrimitiveStandardAttributes& RenderSVGResourceFilterPrimitive::filterPrimitiveElement() const
{
    return static_cast<SVGFilterPrimitiveStandardAttributes&>(RenderSVGHiddenContainer::element());
}

void RenderSVGResourceFilterPrimitive::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
    RenderSVGHiddenContainer::styleDidChange(diff, oldStyle);

    auto* filter = parent();
    if (!filter)
        return;

    if (diff == StyleDifferenceEqual || !oldStyle)
        return;

    const SVGRenderStyle& newStyle = style().svgStyle();
    if (is<SVGFEFloodElement>(filterPrimitiveElement())) {
        if (newStyle.floodColor() != oldStyle->svgStyle().floodColor())
            downcast<RenderSVGResourceFilter>(*filter).primitiveAttributeChanged(this, SVGNames::flood_colorAttr);
        if (newStyle.floodOpacity() != oldStyle->svgStyle().floodOpacity())
            downcast<RenderSVGResourceFilter>(*filter).primitiveAttributeChanged(this, SVGNames::flood_opacityAttr);
    } else if (is<SVGFEDiffuseLightingElement>(filterPrimitiveElement()) || is<SVGFESpecularLightingElement>(filterPrimitiveElement())) {
        if (newStyle.lightingColor() != oldStyle->svgStyle().lightingColor())
            downcast<RenderSVGResourceFilter>(*filter).primitiveAttributeChanged(this, SVGNames::lighting_colorAttr);
    }
}

FloatRect RenderSVGResourceFilterPrimitive::determineFilterPrimitiveSubregion(FilterEffect& effect)
{
    auto& filter = downcast<SVGFilter>(effect.filter());

    // FETile, FETurbulence, FEFlood don't have input effects, take the filter region as unite rect.
    FloatRect subregion;
    if (unsigned numberOfInputEffects = effect.inputEffects().size()) {
        subregion = determineFilterPrimitiveSubregion(*effect.inputEffect(0));
        for (unsigned i = 1; i < numberOfInputEffects; ++i)
            subregion.unite(determineFilterPrimitiveSubregion(*effect.inputEffect(i)));
    } else
        subregion = filter.filterRegionInUserSpace();

    // After calling determineFilterPrimitiveSubregion on the target effect, reset the subregion again for <feTile>.
    if (effect.filterEffectType() == FilterEffectTypeTile)
        subregion = filter.filterRegionInUserSpace();

    FloatRect effectBoundaries = effect.effectBoundaries();
    if (effect.hasX())
        subregion.setX(effectBoundaries.x());
    if (effect.hasY())
        subregion.setY(effectBoundaries.y());
    if (effect.hasWidth())
        subregion.setWidth(effectBoundaries.width());
    if (effect.hasHeight())
        subregion.setHeight(effectBoundaries.height());

    effect.setFilterPrimitiveSubregion(subregion);

    FloatRect absoluteSubregion = filter.absoluteTransform().mapRect(subregion);
    FloatSize filterResolution = filter.filterResolution();
    absoluteSubregion.scale(filterResolution);
    // Save this before clipping so we can use it to map lighting points from user space to buffer coordinates.
    effect.setUnclippedAbsoluteSubregion(absoluteSubregion);

    // Clip every filter effect to the filter region.
    FloatRect absoluteScaledFilterRegion = filter.filterRegion();
    absoluteScaledFilterRegion.scale(filterResolution);
    absoluteSubregion.intersect(absoluteScaledFilterRegion);

    effect.setMaxEffectRect(absoluteSubregion);
    return subregion;
}

} // namespace WebCore