1 /* 2 * Copyright (C) 2009 Dirk Schulze <krit (at) 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 37 PassRefPtr<SourceAlpha> SourceAlpha::create(Filter* filter) 38 { 39 return adoptRef(new SourceAlpha(filter)); 40 } 41 42 const AtomicString& SourceAlpha::effectName() 43 { 44 DEFINE_STATIC_LOCAL(const AtomicString, s_effectName, ("SourceAlpha", AtomicString::ConstructFromLiteral)); 45 return s_effectName; 46 } 47 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 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 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 90 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