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) 2013 Google Inc. All rights reserved. 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#ifndef FEGaussianBlur_h 24#define FEGaussianBlur_h 25 26#include "platform/graphics/filters/Filter.h" 27#include "platform/graphics/filters/FilterEffect.h" 28 29namespace WebCore { 30 31class PLATFORM_EXPORT FEGaussianBlur : public FilterEffect { 32public: 33 static PassRefPtr<FEGaussianBlur> create(Filter*, float, float); 34 35 float stdDeviationX() const; 36 void setStdDeviationX(float); 37 38 float stdDeviationY() const; 39 void setStdDeviationY(float); 40 41 static float calculateStdDeviation(float); 42 43 virtual void determineAbsolutePaintRect(); 44 virtual FloatRect mapRect(const FloatRect&, bool forward = true) OVERRIDE FINAL; 45 static void calculateKernelSize(Filter*, unsigned& kernelSizeX, unsigned& kernelSizeY, float stdX, float stdY); 46 static void calculateUnscaledKernelSize(unsigned& kernelSizeX, unsigned& kernelSizeY, float stdX, float stdY); 47 48 virtual TextStream& externalRepresentation(TextStream&, int indention) const; 49 50private: 51 static const int s_minimalRectDimension = 100 * 100; // Empirical data limit for parallel jobs 52 53 template<typename Type> 54 friend class ParallelJobs; 55 56 struct PlatformApplyParameters { 57 FEGaussianBlur* filter; 58 RefPtr<Uint8ClampedArray> srcPixelArray; 59 RefPtr<Uint8ClampedArray> dstPixelArray; 60 int width; 61 int height; 62 unsigned kernelSizeX; 63 unsigned kernelSizeY; 64 }; 65 66 static void platformApplyWorker(PlatformApplyParameters*); 67 68 FEGaussianBlur(Filter*, float, float); 69 70 virtual void applySoftware() OVERRIDE; 71 virtual bool applySkia() OVERRIDE; 72 73 static inline void kernelPosition(int boxBlur, unsigned& std, int& dLeft, int& dRight); 74 inline void platformApply(Uint8ClampedArray* srcPixelArray, Uint8ClampedArray* tmpPixelArray, unsigned kernelSizeX, unsigned kernelSizeY, IntSize& paintSize); 75 76 inline void platformApplyGeneric(Uint8ClampedArray* srcPixelArray, Uint8ClampedArray* tmpPixelArray, unsigned kernelSizeX, unsigned kernelSizeY, IntSize& paintSize); 77 virtual PassRefPtr<SkImageFilter> createImageFilter(SkiaImageFilterBuilder*) OVERRIDE; 78 79 float m_stdX; 80 float m_stdY; 81}; 82 83inline void FEGaussianBlur::kernelPosition(int boxBlur, unsigned& std, int& dLeft, int& dRight) 84{ 85 // check http://www.w3.org/TR/SVG/filters.html#feGaussianBlurElement for details 86 switch (boxBlur) { 87 case 0: 88 if (!(std % 2)) { 89 dLeft = std / 2 - 1; 90 dRight = std - dLeft; 91 } else { 92 dLeft = std / 2; 93 dRight = std - dLeft; 94 } 95 break; 96 case 1: 97 if (!(std % 2)) { 98 dLeft++; 99 dRight--; 100 } 101 break; 102 case 2: 103 if (!(std % 2)) { 104 dRight++; 105 std++; 106 } 107 break; 108 } 109} 110 111} // namespace WebCore 112 113#endif // FEGaussianBlur_h 114