1/*
2 * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
3 * Copyright (C) 2013 Google Inc. All rights reserved.
4 *
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
9 *
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * Library General Public License for more details.
14 *
15 * You should have received a copy of the GNU Library General Public License
16 * along with this library; see the file COPYING.LIB.  If not, write to
17 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
19 */
20
21#include "config.h"
22
23#include "core/platform/graphics/filters/SourceAlpha.h"
24
25#include "core/platform/graphics/Color.h"
26#include "core/platform/graphics/GraphicsContext.h"
27#include "core/platform/graphics/filters/Filter.h"
28#include "core/platform/text/TextStream.h"
29#include "core/rendering/RenderTreeAsText.h"
30#include "wtf/StdLibExtras.h"
31#include "wtf/text/WTFString.h"
32
33namespace WebCore {
34
35PassRefPtr<SourceAlpha> SourceAlpha::create(Filter* filter)
36{
37    return adoptRef(new SourceAlpha(filter));
38}
39
40const AtomicString& SourceAlpha::effectName()
41{
42    DEFINE_STATIC_LOCAL(const AtomicString, s_effectName, ("SourceAlpha", AtomicString::ConstructFromLiteral));
43    return s_effectName;
44}
45
46void SourceAlpha::determineAbsolutePaintRect()
47{
48    Filter* filter = this->filter();
49    FloatRect paintRect = filter->sourceImageRect();
50    paintRect.scale(filter->filterResolution().width(), filter->filterResolution().height());
51    setAbsolutePaintRect(enclosingIntRect(paintRect));
52}
53
54void SourceAlpha::applySoftware()
55{
56    ImageBuffer* resultImage = createImageBufferResult();
57    Filter* filter = this->filter();
58    if (!resultImage || !filter->sourceImage())
59        return;
60
61    setIsAlphaImage(true);
62
63    FloatRect imageRect(FloatPoint(), absolutePaintRect().size());
64    GraphicsContext* filterContext = resultImage->context();
65    filterContext->fillRect(imageRect, Color::black);
66    filterContext->drawImageBuffer(filter->sourceImage(), IntPoint(), CompositeDestinationIn);
67}
68
69TextStream& SourceAlpha::externalRepresentation(TextStream& ts, int indent) const
70{
71    writeIndent(ts, indent);
72    ts << "[SourceAlpha]\n";
73    return ts;
74}
75
76} // namespace WebCore
77