1 /* 2 * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann (at) kde.org> 3 * Copyright (C) 2004, 2005 Rob Buis <buis (at) kde.org> 4 * Copyright (C) 2005 Eric Seidel <eric (at) webkit.org> 5 * Copyright (C) 2009 Dirk Schulze <krit (at) webkit.org> 6 * 7 * This library is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Library General Public 9 * License as published by the Free Software Foundation; either 10 * version 2 of the License, or (at your option) any later version. 11 * 12 * This library is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Library General Public License for more details. 16 * 17 * You should have received a copy of the GNU Library General Public License 18 * along with this library; see the file COPYING.LIB. If not, write to 19 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 20 * Boston, MA 02110-1301, USA. 21 */ 22 23 #include "config.h" 24 25 #if ENABLE(FILTERS) 26 #include "FEBlend.h" 27 28 #include "Filter.h" 29 #include "FloatPoint.h" 30 #include "GraphicsContext.h" 31 #include "RenderTreeAsText.h" 32 #include "TextStream.h" 33 34 #include <wtf/ByteArray.h> 35 36 typedef unsigned char (*BlendType)(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB); 37 38 namespace WebCore { 39 40 FEBlend::FEBlend(Filter* filter, BlendModeType mode) 41 : FilterEffect(filter) 42 , m_mode(mode) 43 { 44 } 45 46 PassRefPtr<FEBlend> FEBlend::create(Filter* filter, BlendModeType mode) 47 { 48 return adoptRef(new FEBlend(filter, mode)); 49 } 50 51 BlendModeType FEBlend::blendMode() const 52 { 53 return m_mode; 54 } 55 56 bool FEBlend::setBlendMode(BlendModeType mode) 57 { 58 if (m_mode == mode) 59 return false; 60 m_mode = mode; 61 return true; 62 } 63 64 static unsigned char unknown(unsigned char, unsigned char, unsigned char, unsigned char) 65 { 66 return 0; 67 } 68 69 static unsigned char normal(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char) 70 { 71 return (((255 - alphaA) * colorB + colorA * 255) / 255); 72 } 73 74 static unsigned char multiply(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB) 75 { 76 return (((255 - alphaA) * colorB + (255 - alphaB + colorB) * colorA) / 255); 77 } 78 79 static unsigned char screen(unsigned char colorA, unsigned char colorB, unsigned char, unsigned char) 80 { 81 return (((colorB + colorA) * 255 - colorA * colorB) / 255); 82 } 83 84 static unsigned char darken(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB) 85 { 86 return ((std::min((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255)) / 255); 87 } 88 89 static unsigned char lighten(unsigned char colorA, unsigned char colorB, unsigned char alphaA, unsigned char alphaB) 90 { 91 return ((std::max((255 - alphaA) * colorB + colorA * 255, (255 - alphaB) * colorA + colorB * 255)) / 255); 92 } 93 94 void FEBlend::apply() 95 { 96 if (hasResult()) 97 return; 98 FilterEffect* in = inputEffect(0); 99 FilterEffect* in2 = inputEffect(1); 100 in->apply(); 101 in2->apply(); 102 if (!in->hasResult() || !in2->hasResult()) 103 return; 104 105 if (m_mode <= FEBLEND_MODE_UNKNOWN || m_mode > FEBLEND_MODE_LIGHTEN) 106 return; 107 108 ByteArray* dstPixelArray = createPremultipliedImageResult(); 109 if (!dstPixelArray) 110 return; 111 112 IntRect effectADrawingRect = requestedRegionOfInputImageData(in->absolutePaintRect()); 113 RefPtr<ByteArray> srcPixelArrayA = in->asPremultipliedImage(effectADrawingRect); 114 115 IntRect effectBDrawingRect = requestedRegionOfInputImageData(in2->absolutePaintRect()); 116 RefPtr<ByteArray> srcPixelArrayB = in2->asPremultipliedImage(effectBDrawingRect); 117 118 // Keep synchronized with BlendModeType 119 static const BlendType callEffect[] = {unknown, normal, multiply, screen, darken, lighten}; 120 121 unsigned pixelArrayLength = srcPixelArrayA->length(); 122 ASSERT(pixelArrayLength == srcPixelArrayB->length()); 123 for (unsigned pixelOffset = 0; pixelOffset < pixelArrayLength; pixelOffset += 4) { 124 unsigned char alphaA = srcPixelArrayA->get(pixelOffset + 3); 125 unsigned char alphaB = srcPixelArrayB->get(pixelOffset + 3); 126 for (unsigned channel = 0; channel < 3; ++channel) { 127 unsigned char colorA = srcPixelArrayA->get(pixelOffset + channel); 128 unsigned char colorB = srcPixelArrayB->get(pixelOffset + channel); 129 130 unsigned char result = (*callEffect[m_mode])(colorA, colorB, alphaA, alphaB); 131 dstPixelArray->set(pixelOffset + channel, result); 132 } 133 unsigned char alphaR = 255 - ((255 - alphaA) * (255 - alphaB)) / 255; 134 dstPixelArray->set(pixelOffset + 3, alphaR); 135 } 136 } 137 138 void FEBlend::dump() 139 { 140 } 141 142 static TextStream& operator<<(TextStream& ts, const BlendModeType& type) 143 { 144 switch (type) { 145 case FEBLEND_MODE_UNKNOWN: 146 ts << "UNKNOWN"; 147 break; 148 case FEBLEND_MODE_NORMAL: 149 ts << "NORMAL"; 150 break; 151 case FEBLEND_MODE_MULTIPLY: 152 ts << "MULTIPLY"; 153 break; 154 case FEBLEND_MODE_SCREEN: 155 ts << "SCREEN"; 156 break; 157 case FEBLEND_MODE_DARKEN: 158 ts << "DARKEN"; 159 break; 160 case FEBLEND_MODE_LIGHTEN: 161 ts << "LIGHTEN"; 162 break; 163 } 164 return ts; 165 } 166 167 TextStream& FEBlend::externalRepresentation(TextStream& ts, int indent) const 168 { 169 writeIndent(ts, indent); 170 ts << "[feBlend"; 171 FilterEffect::externalRepresentation(ts); 172 ts << " mode=\"" << m_mode << "\"]\n"; 173 inputEffect(0)->externalRepresentation(ts, indent + 1); 174 inputEffect(1)->externalRepresentation(ts, indent + 1); 175 return ts; 176 } 177 178 } // namespace WebCore 179 180 #endif // ENABLE(FILTERS) 181
