SVGResourceMasker.cpp revision 5f1ab04193ad0130ca8204aadaceae083aca9881 
1/*
2 * Copyright (C) 2006 Nikolas Zimmermann <zimmermann@kde.org>
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27
28#if ENABLE(SVG)
29#include "SVGResourceMasker.h"
30
31#include "CanvasPixelArray.h"
32#include "Image.h"
33#include "ImageBuffer.h"
34#include "ImageData.h"
35#include "GraphicsContext.h"
36#include "SVGMaskElement.h"
37#include "SVGRenderSupport.h"
38#include "SVGRenderStyle.h"
39#include "TextStream.h"
40
41#include <wtf/ByteArray.h>
42
43using namespace std;
44
45namespace WebCore {
46
47SVGResourceMasker::SVGResourceMasker(const SVGMaskElement* ownerElement)
48    : SVGResource()
49    , m_ownerElement(ownerElement)
50{
51}
52
53SVGResourceMasker::~SVGResourceMasker()
54{
55}
56
57void SVGResourceMasker::invalidate()
58{
59    SVGResource::invalidate();
60    m_mask.clear();
61}
62
63void SVGResourceMasker::applyMask(GraphicsContext* context, const FloatRect& boundingBox)
64{
65    if (!m_mask)
66        m_mask = m_ownerElement->drawMaskerContent(boundingBox, m_maskRect);
67
68    if (!m_mask)
69        return;
70
71    IntSize imageSize(m_mask->size());
72    IntRect intImageRect(0, 0, imageSize.width(), imageSize.height());
73
74    // Create new ImageBuffer to apply luminance
75    OwnPtr<ImageBuffer> luminancedImage = ImageBuffer::create(imageSize, false);
76    if (!luminancedImage)
77        return;
78
79    PassRefPtr<CanvasPixelArray> srcPixelArray(m_mask->getImageData(intImageRect)->data());
80    PassRefPtr<ImageData> destImageData(luminancedImage->getImageData(intImageRect));
81
82    for (unsigned pixelOffset = 0; pixelOffset < srcPixelArray->length(); pixelOffset++) {
83        unsigned pixelByteOffset = pixelOffset * 4;
84
85        unsigned char r = 0, g = 0, b = 0, a = 0;
86        srcPixelArray->get(pixelByteOffset, r);
87        srcPixelArray->get(pixelByteOffset + 1, g);
88        srcPixelArray->get(pixelByteOffset + 2, b);
89        srcPixelArray->get(pixelByteOffset + 3, a);
90
91        double luma = (r * 0.2125 + g * 0.7154 + b * 0.0721) * ((double)a / 255.0);
92
93        destImageData->data()->set(pixelByteOffset + 3, luma);
94    }
95
96    luminancedImage->putImageData(destImageData.get(), intImageRect, IntPoint(0, 0));
97
98    context->clipToImageBuffer(m_maskRect, luminancedImage.get());
99}
100
101TextStream& SVGResourceMasker::externalRepresentation(TextStream& ts) const
102{
103    ts << "[type=MASKER]";
104    return ts;
105}
106
107SVGResourceMasker* getMaskerById(Document* document, const AtomicString& id)
108{
109    SVGResource* resource = getResourceById(document, id);
110    if (resource && resource->isMasker())
111        return static_cast<SVGResourceMasker*>(resource);
112
113    return 0;
114}
115
116} // namespace WebCore
117
118#endif
119