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 #include "platform/graphics/filters/SourceAlpha.h"
23
24 #include "platform/graphics/Color.h"
25 #include "platform/graphics/GraphicsContext.h"
26 #include "platform/graphics/filters/Filter.h"
27 #include "platform/graphics/filters/SkiaImageFilterBuilder.h"
28 #include "platform/graphics/filters/SourceGraphic.h"
29 #include "platform/text/TextStream.h"
30 #include "third_party/skia/include/effects/SkColorFilterImageFilter.h"
31 #include "third_party/skia/include/effects/SkColorMatrixFilter.h"
32 #include "wtf/StdLibExtras.h"
33 #include "wtf/text/WTFString.h"
34
35 namespace blink {
36
create(Filter * filter)37 PassRefPtr<SourceAlpha> SourceAlpha::create(Filter* filter)
38 {
39 return adoptRef(new SourceAlpha(filter));
40 }
41
effectName()42 const AtomicString& SourceAlpha::effectName()
43 {
44 DEFINE_STATIC_LOCAL(const AtomicString, s_effectName, ("SourceAlpha", AtomicString::ConstructFromLiteral));
45 return s_effectName;
46 }
47
determineAbsolutePaintRect(const FloatRect & requestedRect)48 FloatRect SourceAlpha::determineAbsolutePaintRect(const FloatRect& requestedRect)
49 {
50 FloatRect srcRect = filter()->sourceImageRect();
51 srcRect.intersect(requestedRect);
52 addAbsolutePaintRect(srcRect);
53 return srcRect;
54 }
55
applySoftware()56 void SourceAlpha::applySoftware()
57 {
58 ImageBuffer* resultImage = createImageBufferResult();
59 Filter* filter = this->filter();
60 if (!resultImage || !filter->sourceImage())
61 return;
62
63 setIsAlphaImage(true);
64
65 FloatRect imageRect(FloatPoint(), absolutePaintRect().size());
66 GraphicsContext* filterContext = resultImage->context();
67 filterContext->fillRect(imageRect, Color::black);
68
69 IntRect srcRect = filter->sourceImageRect();
70 if (ImageBuffer* sourceImageBuffer = filter->sourceImage()) {
71 filterContext->drawImageBuffer(sourceImageBuffer,
72 FloatRect(IntPoint(srcRect.location() - absolutePaintRect().location()), sourceImageBuffer->size()),
73 0, CompositeDestinationIn);
74 }
75 }
76
createImageFilter(SkiaImageFilterBuilder * builder)77 PassRefPtr<SkImageFilter> SourceAlpha::createImageFilter(SkiaImageFilterBuilder* builder)
78 {
79 RefPtr<SkImageFilter> sourceGraphic(builder->build(builder->sourceGraphic(), operatingColorSpace()));
80 SkScalar matrix[20] = {
81 0, 0, 0, 0, 0,
82 0, 0, 0, 0, 0,
83 0, 0, 0, 0, 0,
84 0, 0, 0, SK_Scalar1, 0
85 };
86 RefPtr<SkColorFilter> colorFilter(adoptRef(SkColorMatrixFilter::Create(matrix)));
87 return adoptRef(SkColorFilterImageFilter::Create(colorFilter.get(), sourceGraphic.get()));
88 }
89
externalRepresentation(TextStream & ts,int indent) const90 TextStream& SourceAlpha::externalRepresentation(TextStream& ts, int indent) const
91 {
92 writeIndent(ts, indent);
93 ts << "[SourceAlpha]\n";
94 return ts;
95 }
96
97 } // namespace blink
98