RenderSVGImage.cpp   [plain text]

/*
    Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
    Copyright (C) 2006 Apple Computer, Inc.
    Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>

    This file is part of the WebKit project

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
*/

#include "config.h"

#if ENABLE(SVG)
#include "RenderSVGImage.h"

#include "Attr.h"
#include "FloatConversion.h"
#include "GraphicsContext.h"
#include "PointerEventsHitRules.h"
#include "SVGImageElement.h"
#include "SVGImageElement.h"
#include "SVGLength.h"
#include "SVGPreserveAspectRatio.h"
#include "SVGResourceClipper.h"
#include "SVGResourceFilter.h"
#include "SVGResourceMasker.h"

namespace WebCore {

RenderSVGImage::RenderSVGImage(SVGImageElement* impl)
    : RenderImage(impl)
{
}

RenderSVGImage::~RenderSVGImage()
{
}

void RenderSVGImage::adjustRectsForAspectRatio(FloatRect& destRect, FloatRect& srcRect, SVGPreserveAspectRatio* aspectRatio)
{
    float origDestWidth = destRect.width();
    float origDestHeight = destRect.height();
    if (aspectRatio->meetOrSlice() == SVGPreserveAspectRatio::SVG_MEETORSLICE_MEET) {
        float widthToHeightMultiplier = srcRect.height() / srcRect.width();
        if (origDestHeight > (origDestWidth * widthToHeightMultiplier)) {
            destRect.setHeight(origDestWidth * widthToHeightMultiplier);
            switch(aspectRatio->align()) {
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
                    destRect.setY(origDestHeight / 2 - destRect.height() / 2);
                    break;
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMAX:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
                    destRect.setY(origDestHeight - destRect.height());
                    break;
            }
        }
        if (origDestWidth > (origDestHeight / widthToHeightMultiplier)) {
            destRect.setWidth(origDestHeight / widthToHeightMultiplier);
            switch(aspectRatio->align()) {
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMIN:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
                    destRect.setX(origDestWidth / 2 - destRect.width() / 2);
                    break;
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMIN:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
                    destRect.setX(origDestWidth - destRect.width());
                    break;
            }
        }
    } else if (aspectRatio->meetOrSlice() == SVGPreserveAspectRatio::SVG_MEETORSLICE_SLICE) {
        float widthToHeightMultiplier = srcRect.height() / srcRect.width();
        // if the destination height is less than the height of the image we'll be drawing
        if (origDestHeight < (origDestWidth * widthToHeightMultiplier)) {
            float destToSrcMultiplier = srcRect.width() / destRect.width();
            srcRect.setHeight(destRect.height() * destToSrcMultiplier);
            switch(aspectRatio->align()) {
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
                    srcRect.setY(image()->height() / 2 - srcRect.height() / 2);
                    break;
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMINYMAX:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
                    srcRect.setY(image()->height() - srcRect.height());
                    break;
            }
        }
        // if the destination width is less than the width of the image we'll be drawing
        if (origDestWidth < (origDestHeight / widthToHeightMultiplier)) {
            float destToSrcMultiplier = srcRect.height() / destRect.height();
            srcRect.setWidth(destRect.width() * destToSrcMultiplier);
            switch(aspectRatio->align()) {
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMIN:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMIDYMAX:
                    srcRect.setX(image()->width() / 2 - srcRect.width() / 2);
                    break;
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMIN:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMID:
                case SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_XMAXYMAX:
                    srcRect.setX(image()->width() - srcRect.width());
                    break;
            }
        }
    }
}

void RenderSVGImage::paint(PaintInfo& paintInfo, int parentX, int parentY)
{
    if (paintInfo.context->paintingDisabled() || (paintInfo.phase != PaintPhaseForeground) || style()->visibility() == HIDDEN)
        return;
    
    paintInfo.context->save();
    paintInfo.context->concatCTM(AffineTransform().translate(parentX, parentY));
    paintInfo.context->concatCTM(localTransform());
    paintInfo.context->concatCTM(translationForAttributes());

    FloatRect boundingBox = FloatRect(0, 0, width(), height());

    SVGElement* svgElement = static_cast<SVGElement*>(element());
    ASSERT(svgElement && svgElement->document() && svgElement->isStyled());

    SVGStyledElement* styledElement = static_cast<SVGStyledElement*>(svgElement);
    const SVGRenderStyle* svgStyle = style()->svgStyle();

    AtomicString filterId(SVGURIReference::getTarget(svgStyle->filter()));
    AtomicString clipperId(SVGURIReference::getTarget(svgStyle->clipPath()));
    AtomicString maskerId(SVGURIReference::getTarget(svgStyle->maskElement()));

#if ENABLE(SVG_EXPERIMENTAL_FEATURES)
    SVGResourceFilter* filter = getFilterById(document(), filterId);
#endif
    SVGResourceClipper* clipper = getClipperById(document(), clipperId);
    SVGResourceMasker* masker = getMaskerById(document(), maskerId);

#if ENABLE(SVG_EXPERIMENTAL_FEATURES)
    if (filter)
        filter->prepareFilter(paintInfo.context, boundingBox);
    else if (!filterId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(filterId, styledElement);
#endif

    if (clipper) {
        clipper->addClient(styledElement);
        clipper->applyClip(paintInfo.context, boundingBox);
    } else if (!clipperId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(clipperId, styledElement);

    if (masker) {
        masker->addClient(styledElement);
        masker->applyMask(paintInfo.context, boundingBox);
    } else if (!maskerId.isEmpty())
        svgElement->document()->accessSVGExtensions()->addPendingResource(maskerId, styledElement);

    float opacity = style()->opacity();
    if (opacity < 1.0f) {
        paintInfo.context->clip(enclosingIntRect(boundingBox));
        paintInfo.context->beginTransparencyLayer(opacity);
    }

    PaintInfo pi(paintInfo);
    pi.rect = absoluteTransform().inverse().mapRect(pi.rect);

    SVGImageElement* imageElt = static_cast<SVGImageElement*>(node());

    FloatRect destRect(m_x, m_y, contentWidth(), contentHeight());
    FloatRect srcRect(0, 0, image()->width(), image()->height());

    if (imageElt->preserveAspectRatio()->align() != SVGPreserveAspectRatio::SVG_PRESERVEASPECTRATIO_NONE)
        adjustRectsForAspectRatio(destRect, srcRect, imageElt->preserveAspectRatio());

    paintInfo.context->drawImage(image(), destRect, srcRect);

#if ENABLE(SVG_EXPERIMENTAL_FEATURES)
    if (filter)
        filter->applyFilter(paintInfo.context, boundingBox);
#endif

    if (opacity < 1.0f)
        paintInfo.context->endTransparencyLayer();

    paintInfo.context->restore();
}

bool RenderSVGImage::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, int _x, int _y, int _tx, int _ty, HitTestAction hitTestAction)
{
    // We only draw in the forground phase, so we only hit-test then.
    if (hitTestAction != HitTestForeground)
        return false;

    PointerEventsHitRules hitRules(PointerEventsHitRules::SVG_IMAGE_HITTESTING, style()->svgStyle()->pointerEvents());
    
    bool isVisible = (style()->visibility() == VISIBLE);
    if (isVisible || !hitRules.requireVisible) {
        double localX, localY;
        absoluteTransform().inverse().map(_x, _y, &localX, &localY);
        translationForAttributes().inverse().map(localX, localY, &localX, &localY);

        if (hitRules.canHitFill) {
            if (FloatRect(0.0f, 0.0f, m_width, m_height).contains(narrowPrecisionToFloat(localX), narrowPrecisionToFloat(localY))) {
                updateHitTestResult(result, IntPoint(_x, _y));
                return true;
            }
        }
    }

    return false;
}

bool RenderSVGImage::requiresLayer()
{
    return false;
}

FloatRect RenderSVGImage::relativeBBox(bool includeStroke) const
{
    SVGImageElement* image = static_cast<SVGImageElement*>(node());
    return FloatRect(image->x().value(), image->y().value(), width(), height());
}

void RenderSVGImage::imageChanged(CachedImage* image)
{
    RenderImage::imageChanged(image);

    // We override to invalidate a larger rect, since SVG images can draw outside their "bounds"
    repaintRectangle(absoluteClippedOverflowRect());
}

IntRect RenderSVGImage::absoluteClippedOverflowRect()
{
    FloatRect repaintRect = relativeBBox(true);
    repaintRect = absoluteTransform().mapRect(repaintRect);

#if ENABLE(SVG_EXPERIMENTAL_FEATURES)
    // Filters can expand the bounding box
    SVGResourceFilter* filter = getFilterById(document(), SVGURIReference::getTarget(style()->svgStyle()->filter()));
    if (filter)
        repaintRect.unite(filter->filterBBoxForItemBBox(repaintRect));
#endif

    if (!repaintRect.isEmpty())
        repaintRect.inflate(1); // inflate 1 pixel for antialiasing

    return enclosingIntRect(repaintRect);
}

void RenderSVGImage::absoluteRects(Vector<IntRect>& rects, int, int, bool)
{
    rects.append(absoluteClippedOverflowRect());
}

AffineTransform RenderSVGImage::translationForAttributes()
{
    SVGImageElement *image = static_cast<SVGImageElement*>(node());
    return AffineTransform().translate(image->x().value(), image->y().value());
}

}

#endif // ENABLE(SVG)