1/* 2 * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org> 3 * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org> 4 * Copyright (C) 2005 Eric Seidel <eric@webkit.org> 5 * Copyright (C) 2009 Dirk Schulze <krit@webkit.org> 6 * Copyright (C) Research In Motion Limited 2010. All rights reserved. 7 * Copyright (C) 2013 Google Inc. All rights reserved. 8 * 9 * This library is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Library General Public 11 * License as published by the Free Software Foundation; either 12 * version 2 of the License, or (at your option) any later version. 13 * 14 * This library is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Library General Public License for more details. 18 * 19 * You should have received a copy of the GNU Library General Public License 20 * along with this library; see the file COPYING.LIB. If not, write to 21 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 22 * Boston, MA 02110-1301, USA. 23 */ 24 25#include "config.h" 26#include "platform/graphics/filters/FEComponentTransfer.h" 27 28#include "SkColorFilterImageFilter.h" 29#include "SkTableColorFilter.h" 30#include "platform/graphics/GraphicsContext.h" 31#include "platform/graphics/filters/SkiaImageFilterBuilder.h" 32#include "platform/graphics/skia/NativeImageSkia.h" 33#include "platform/text/TextStream.h" 34#include "wtf/MathExtras.h" 35#include "wtf/StdLibExtras.h" 36#include "wtf/Uint8ClampedArray.h" 37 38namespace blink { 39 40typedef void (*TransferType)(unsigned char*, const ComponentTransferFunction&); 41 42FEComponentTransfer::FEComponentTransfer(Filter* filter, const ComponentTransferFunction& redFunc, const ComponentTransferFunction& greenFunc, 43 const ComponentTransferFunction& blueFunc, const ComponentTransferFunction& alphaFunc) 44 : FilterEffect(filter) 45 , m_redFunc(redFunc) 46 , m_greenFunc(greenFunc) 47 , m_blueFunc(blueFunc) 48 , m_alphaFunc(alphaFunc) 49{ 50} 51 52PassRefPtr<FEComponentTransfer> FEComponentTransfer::create(Filter* filter, const ComponentTransferFunction& redFunc, 53 const ComponentTransferFunction& greenFunc, const ComponentTransferFunction& blueFunc, const ComponentTransferFunction& alphaFunc) 54{ 55 return adoptRef(new FEComponentTransfer(filter, redFunc, greenFunc, blueFunc, alphaFunc)); 56} 57 58ComponentTransferFunction FEComponentTransfer::redFunction() const 59{ 60 return m_redFunc; 61} 62 63void FEComponentTransfer::setRedFunction(const ComponentTransferFunction& func) 64{ 65 m_redFunc = func; 66} 67 68ComponentTransferFunction FEComponentTransfer::greenFunction() const 69{ 70 return m_greenFunc; 71} 72 73void FEComponentTransfer::setGreenFunction(const ComponentTransferFunction& func) 74{ 75 m_greenFunc = func; 76} 77 78ComponentTransferFunction FEComponentTransfer::blueFunction() const 79{ 80 return m_blueFunc; 81} 82 83void FEComponentTransfer::setBlueFunction(const ComponentTransferFunction& func) 84{ 85 m_blueFunc = func; 86} 87 88ComponentTransferFunction FEComponentTransfer::alphaFunction() const 89{ 90 return m_alphaFunc; 91} 92 93void FEComponentTransfer::setAlphaFunction(const ComponentTransferFunction& func) 94{ 95 m_alphaFunc = func; 96} 97 98static void identity(unsigned char*, const ComponentTransferFunction&) 99{ 100} 101 102static void table(unsigned char* values, const ComponentTransferFunction& transferFunction) 103{ 104 const Vector<float>& tableValues = transferFunction.tableValues; 105 unsigned n = tableValues.size(); 106 if (n < 1) 107 return; 108 for (unsigned i = 0; i < 256; ++i) { 109 double c = i / 255.0; 110 unsigned k = static_cast<unsigned>(c * (n - 1)); 111 double v1 = tableValues[k]; 112 double v2 = tableValues[std::min((k + 1), (n - 1))]; 113 double val = 255.0 * (v1 + (c * (n - 1) - k) * (v2 - v1)); 114 val = std::max(0.0, std::min(255.0, val)); 115 values[i] = static_cast<unsigned char>(val); 116 } 117} 118 119static void discrete(unsigned char* values, const ComponentTransferFunction& transferFunction) 120{ 121 const Vector<float>& tableValues = transferFunction.tableValues; 122 unsigned n = tableValues.size(); 123 if (n < 1) 124 return; 125 for (unsigned i = 0; i < 256; ++i) { 126 unsigned k = static_cast<unsigned>((i * n) / 255.0); 127 k = std::min(k, n - 1); 128 double val = 255 * tableValues[k]; 129 val = std::max(0.0, std::min(255.0, val)); 130 values[i] = static_cast<unsigned char>(val); 131 } 132} 133 134static void linear(unsigned char* values, const ComponentTransferFunction& transferFunction) 135{ 136 for (unsigned i = 0; i < 256; ++i) { 137 double val = transferFunction.slope * i + 255 * transferFunction.intercept; 138 val = std::max(0.0, std::min(255.0, val)); 139 values[i] = static_cast<unsigned char>(val); 140 } 141} 142 143static void gamma(unsigned char* values, const ComponentTransferFunction& transferFunction) 144{ 145 for (unsigned i = 0; i < 256; ++i) { 146 double exponent = transferFunction.exponent; // RCVT doesn't like passing a double and a float to pow, so promote this to double 147 double val = 255.0 * (transferFunction.amplitude * pow((i / 255.0), exponent) + transferFunction.offset); 148 val = std::max(0.0, std::min(255.0, val)); 149 values[i] = static_cast<unsigned char>(val); 150 } 151} 152 153void FEComponentTransfer::applySoftware() 154{ 155 FilterEffect* in = inputEffect(0); 156 ImageBuffer* resultImage = createImageBufferResult(); 157 if (!resultImage) 158 return; 159 160 RefPtr<Image> image = in->asImageBuffer()->copyImage(DontCopyBackingStore); 161 RefPtr<NativeImageSkia> nativeImage = image->nativeImageForCurrentFrame(); 162 if (!nativeImage) 163 return; 164 165 unsigned char rValues[256], gValues[256], bValues[256], aValues[256]; 166 getValues(rValues, gValues, bValues, aValues); 167 168 IntRect destRect = drawingRegionOfInputImage(in->absolutePaintRect()); 169 SkPaint paint; 170 paint.setColorFilter(SkTableColorFilter::CreateARGB(aValues, rValues, gValues, bValues))->unref(); 171 paint.setXfermodeMode(SkXfermode::kSrc_Mode); 172 resultImage->context()->drawBitmap(nativeImage->bitmap(), destRect.x(), destRect.y(), &paint); 173 174 if (affectsTransparentPixels()) { 175 IntRect fullRect = IntRect(IntPoint(), absolutePaintRect().size()); 176 resultImage->context()->clipOut(destRect); 177 resultImage->context()->fillRect(fullRect, Color(rValues[0], gValues[0], bValues[0], aValues[0])); 178 } 179} 180 181bool FEComponentTransfer::affectsTransparentPixels() 182{ 183 double intercept = 0; 184 switch (m_alphaFunc.type) { 185 case FECOMPONENTTRANSFER_TYPE_UNKNOWN: 186 case FECOMPONENTTRANSFER_TYPE_IDENTITY: 187 break; 188 case FECOMPONENTTRANSFER_TYPE_TABLE: 189 case FECOMPONENTTRANSFER_TYPE_DISCRETE: 190 if (m_alphaFunc.tableValues.size() > 0) 191 intercept = m_alphaFunc.tableValues[0]; 192 break; 193 case FECOMPONENTTRANSFER_TYPE_LINEAR: 194 intercept = m_alphaFunc.intercept; 195 break; 196 case FECOMPONENTTRANSFER_TYPE_GAMMA: 197 intercept = m_alphaFunc.offset; 198 break; 199 } 200 return 255 * intercept >= 1; 201} 202 203PassRefPtr<SkImageFilter> FEComponentTransfer::createImageFilter(SkiaImageFilterBuilder* builder) 204{ 205 RefPtr<SkImageFilter> input(builder->build(inputEffect(0), operatingColorSpace())); 206 207 unsigned char rValues[256], gValues[256], bValues[256], aValues[256]; 208 getValues(rValues, gValues, bValues, aValues); 209 210 SkAutoTUnref<SkColorFilter> colorFilter(SkTableColorFilter::CreateARGB(aValues, rValues, gValues, bValues)); 211 212 SkImageFilter::CropRect cropRect = getCropRect(builder->cropOffset()); 213 return adoptRef(SkColorFilterImageFilter::Create(colorFilter, input.get(), &cropRect)); 214} 215 216void FEComponentTransfer::getValues(unsigned char rValues[256], unsigned char gValues[256], unsigned char bValues[256], unsigned char aValues[256]) 217{ 218 for (unsigned i = 0; i < 256; ++i) 219 rValues[i] = gValues[i] = bValues[i] = aValues[i] = i; 220 unsigned char* tables[] = { rValues, gValues, bValues, aValues }; 221 ComponentTransferFunction transferFunction[] = {m_redFunc, m_greenFunc, m_blueFunc, m_alphaFunc}; 222 TransferType callEffect[] = {identity, identity, table, discrete, linear, gamma}; 223 224 for (unsigned channel = 0; channel < 4; channel++) { 225 ASSERT_WITH_SECURITY_IMPLICATION(static_cast<size_t>(transferFunction[channel].type) < WTF_ARRAY_LENGTH(callEffect)); 226 (*callEffect[transferFunction[channel].type])(tables[channel], transferFunction[channel]); 227 } 228} 229 230static TextStream& operator<<(TextStream& ts, const ComponentTransferType& type) 231{ 232 switch (type) { 233 case FECOMPONENTTRANSFER_TYPE_UNKNOWN: 234 ts << "UNKNOWN"; 235 break; 236 case FECOMPONENTTRANSFER_TYPE_IDENTITY: 237 ts << "IDENTITY"; 238 break; 239 case FECOMPONENTTRANSFER_TYPE_TABLE: 240 ts << "TABLE"; 241 break; 242 case FECOMPONENTTRANSFER_TYPE_DISCRETE: 243 ts << "DISCRETE"; 244 break; 245 case FECOMPONENTTRANSFER_TYPE_LINEAR: 246 ts << "LINEAR"; 247 break; 248 case FECOMPONENTTRANSFER_TYPE_GAMMA: 249 ts << "GAMMA"; 250 break; 251 } 252 return ts; 253} 254 255static TextStream& operator<<(TextStream& ts, const ComponentTransferFunction& function) 256{ 257 ts << "type=\"" << function.type 258 << "\" slope=\"" << function.slope 259 << "\" intercept=\"" << function.intercept 260 << "\" amplitude=\"" << function.amplitude 261 << "\" exponent=\"" << function.exponent 262 << "\" offset=\"" << function.offset << "\""; 263 return ts; 264} 265 266TextStream& FEComponentTransfer::externalRepresentation(TextStream& ts, int indent) const 267{ 268 writeIndent(ts, indent); 269 ts << "[feComponentTransfer"; 270 FilterEffect::externalRepresentation(ts); 271 ts << " \n"; 272 writeIndent(ts, indent + 2); 273 ts << "{red: " << m_redFunc << "}\n"; 274 writeIndent(ts, indent + 2); 275 ts << "{green: " << m_greenFunc << "}\n"; 276 writeIndent(ts, indent + 2); 277 ts << "{blue: " << m_blueFunc << "}\n"; 278 writeIndent(ts, indent + 2); 279 ts << "{alpha: " << m_alphaFunc << "}]\n"; 280 inputEffect(0)->externalRepresentation(ts, indent + 1); 281 return ts; 282} 283 284} // namespace blink 285