WebCore/svg/graphics/SVGResourceClipper.cpp

/*
 * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
 *           (C) 2009 Dirk Schulze <krit@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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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"

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

#include "AffineTransform.h"
#include "GraphicsContext.h"
#include "SVGRenderTreeAsText.h"

#if PLATFORM(CG)
#include <ApplicationServices/ApplicationServices.h>
#endif

namespace WebCore {

SVGResourceClipper::SVGResourceClipper()
    : SVGResource()
{
}

SVGResourceClipper::~SVGResourceClipper()
{
}

void SVGResourceClipper::resetClipData()
{
    m_clipData.clear();
    m_clipperBoundingBox = FloatRect();
}

void SVGResourceClipper::invalidate()
{
    SVGResource::invalidate();
    resetClipData();
}

FloatRect SVGResourceClipper::clipperBoundingBox(const FloatRect& objectBoundingBox)
{
    // FIXME: We need a different calculation for other clip content than paths.
    if (!m_clipperBoundingBox.isEmpty())
        return m_clipperBoundingBox;

    if (m_clipData.clipData().isEmpty())
        return FloatRect();

    for (unsigned x = 0; x < m_clipData.clipData().size(); x++) {
        ClipData clipData = m_clipData.clipData()[x];

        FloatRect clipPathRect = clipData.path.boundingRect();
        if (clipData.bboxUnits) {
            clipPathRect.scale(objectBoundingBox.width(), objectBoundingBox.height());
            clipPathRect.move(objectBoundingBox.x(), objectBoundingBox.y());
        }
        m_clipperBoundingBox.unite(clipPathRect);
    }

    return m_clipperBoundingBox;
}

void SVGResourceClipper::applyClip(GraphicsContext* context, const FloatRect& boundingBox) const
{
    if (m_clipData.clipData().isEmpty())
        return;

    bool heterogenousClipRules = false;
    WindRule clipRule = m_clipData.clipData()[0].windRule;

    context->beginPath();

    for (unsigned x = 0; x < m_clipData.clipData().size(); x++) {
        ClipData clipData = m_clipData.clipData()[x];
        if (clipData.windRule != clipRule)
            heterogenousClipRules = true;
        
        Path clipPath = clipData.path;

        if (clipData.bboxUnits) {
            AffineTransform transform;
            transform.translate(boundingBox.x(), boundingBox.y());
            transform.scaleNonUniform(boundingBox.width(), boundingBox.height());
            clipPath.transform(transform);
        }
        context->addPath(clipPath);
    }

    // FIXME!
    // We don't currently allow for heterogenous clip rules.
    // we would have to detect such, draw to a mask, and then clip
    // to that mask
    context->clipPath(clipRule);
}

void SVGResourceClipper::addClipData(const Path& path, WindRule rule, bool bboxUnits)
{
    m_clipData.addPath(path, rule, bboxUnits);
}

const ClipDataList& SVGResourceClipper::clipData() const
{
    return m_clipData;
}

TextStream& SVGResourceClipper::externalRepresentation(TextStream& ts) const
{
    ts << "[type=CLIPPER]";
    ts << " [clip data=" << clipData().clipData() << "]";
    return ts;
}

TextStream& operator<<(TextStream& ts, WindRule rule)
{
    switch (rule) {
        case RULE_NONZERO:
            ts << "NON-ZERO"; break;
        case RULE_EVENODD:
            ts << "EVEN-ODD"; break;
    }

    return ts;
}

TextStream& operator<<(TextStream& ts, const ClipData& d)
{
    ts << "[winding=" << d.windRule << "]";

    if (d.bboxUnits)
        ts << " [bounding box mode=" << d.bboxUnits << "]";

    ts << " [path=" << d.path.debugString() << "]";
    return ts;
}

SVGResourceClipper* getClipperById(Document* document, const AtomicString& id, const RenderObject* object)
{
    SVGResource* resource = getResourceById(document, id, object);
    if (resource && resource->isClipper())
        return static_cast<SVGResourceClipper*>(resource);

    return 0;
}

} // namespace WebCore

#endif