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 * Copyright (C) 2010 Igalia, S.L. 7 * Copyright (C) Research In Motion Limited 2010. All rights reserved. 8 * Copyright (C) 2013 Google Inc. All rights reserved. 9 * 10 * This library is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU Library General Public 12 * License as published by the Free Software Foundation; either 13 * version 2 of the License, or (at your option) any later version. 14 * 15 * This library is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 18 * Library General Public License for more details. 19 * 20 * You should have received a copy of the GNU Library General Public License 21 * along with this library; see the file COPYING.LIB. If not, write to 22 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 23 * Boston, MA 02110-1301, USA. 24 */ 25 26 #include "config.h" 27 28 #include "platform/graphics/filters/FEGaussianBlur.h" 29 30 #include "platform/graphics/GraphicsContext.h" 31 #include "platform/graphics/cpu/arm/filters/FEGaussianBlurNEON.h" 32 #include "platform/graphics/filters/ParallelJobs.h" 33 #include "platform/graphics/filters/SkiaImageFilterBuilder.h" 34 #include "platform/text/TextStream.h" 35 #include "wtf/MathExtras.h" 36 #include "wtf/Uint8ClampedArray.h" 37 38 #include "SkBlurImageFilter.h" 39 40 using namespace std; 41 42 static inline float gaussianKernelFactor() 43 { 44 return 3 / 4.f * sqrtf(twoPiFloat); 45 } 46 47 static const int gMaxKernelSize = 1000; 48 49 namespace WebCore { 50 51 FEGaussianBlur::FEGaussianBlur(Filter* filter, float x, float y) 52 : FilterEffect(filter) 53 , m_stdX(x) 54 , m_stdY(y) 55 { 56 } 57 58 PassRefPtr<FEGaussianBlur> FEGaussianBlur::create(Filter* filter, float x, float y) 59 { 60 return adoptRef(new FEGaussianBlur(filter, x, y)); 61 } 62 63 float FEGaussianBlur::stdDeviationX() const 64 { 65 return m_stdX; 66 } 67 68 void FEGaussianBlur::setStdDeviationX(float x) 69 { 70 m_stdX = x; 71 } 72 73 float FEGaussianBlur::stdDeviationY() const 74 { 75 return m_stdY; 76 } 77 78 void FEGaussianBlur::setStdDeviationY(float y) 79 { 80 m_stdY = y; 81 } 82 83 IntSize FEGaussianBlur::calculateUnscaledKernelSize(const FloatPoint& std) 84 { 85 ASSERT(std.x() >= 0 && std.y() >= 0); 86 87 IntSize kernelSize; 88 // Limit the kernel size to 1000. A bigger radius won't make a big difference for the result image but 89 // inflates the absolute paint rect to much. This is compatible with Firefox' behavior. 90 if (std.x()) { 91 int size = max<unsigned>(2, static_cast<unsigned>(floorf(std.x() * gaussianKernelFactor() + 0.5f))); 92 kernelSize.setWidth(min(size, gMaxKernelSize)); 93 } 94 95 if (std.y()) { 96 int size = max<unsigned>(2, static_cast<unsigned>(floorf(std.y() * gaussianKernelFactor() + 0.5f))); 97 kernelSize.setHeight(min(size, gMaxKernelSize)); 98 } 99 100 return kernelSize; 101 } 102 103 IntSize FEGaussianBlur::calculateKernelSize(Filter* filter, const FloatPoint& std) 104 { 105 FloatPoint stdError(filter->applyHorizontalScale(std.x()), filter->applyVerticalScale(std.y())); 106 107 return calculateUnscaledKernelSize(stdError); 108 } 109 110 FloatRect FEGaussianBlur::mapRect(const FloatRect& rect, bool) 111 { 112 FloatRect result = rect; 113 IntSize kernelSize = calculateKernelSize(filter(), FloatPoint(m_stdX, m_stdY)); 114 115 // We take the half kernel size and multiply it with three, because we run box blur three times. 116 result.inflateX(3 * kernelSize.width() * 0.5f); 117 result.inflateY(3 * kernelSize.height() * 0.5f); 118 return result; 119 } 120 121 FloatRect FEGaussianBlur::determineAbsolutePaintRect(const FloatRect& originalRequestedRect) 122 { 123 FloatRect requestedRect = originalRequestedRect; 124 if (clipsToBounds()) 125 requestedRect.intersect(maxEffectRect()); 126 127 FilterEffect* input = inputEffect(0); 128 FloatRect inputRect = input->determineAbsolutePaintRect(mapRect(requestedRect, false)); 129 FloatRect outputRect = mapRect(inputRect, true); 130 outputRect.intersect(requestedRect); 131 addAbsolutePaintRect(outputRect); 132 133 // Blur needs space for both input and output pixels in the paint area. 134 // Input is also clipped to subregion. 135 if (clipsToBounds()) 136 inputRect.intersect(maxEffectRect()); 137 addAbsolutePaintRect(inputRect); 138 return outputRect; 139 } 140 141 void FEGaussianBlur::applySoftware() 142 { 143 ImageBuffer* resultImage = createImageBufferResult(); 144 if (!resultImage) 145 return; 146 147 FilterEffect* in = inputEffect(0); 148 149 IntRect drawingRegion = drawingRegionOfInputImage(in->absolutePaintRect()); 150 151 setIsAlphaImage(in->isAlphaImage()); 152 153 float stdX = filter()->applyHorizontalScale(m_stdX); 154 float stdY = filter()->applyVerticalScale(m_stdY); 155 156 RefPtr<Image> image = in->asImageBuffer()->copyImage(DontCopyBackingStore); 157 158 SkPaint paint; 159 GraphicsContext* dstContext = resultImage->context(); 160 paint.setImageFilter(SkBlurImageFilter::Create(stdX, stdY))->unref(); 161 162 SkRect bounds = SkRect::MakeWH(absolutePaintRect().width(), absolutePaintRect().height()); 163 dstContext->saveLayer(&bounds, &paint); 164 paint.setColor(0xFFFFFFFF); 165 dstContext->drawImage(image.get(), drawingRegion.location(), CompositeCopy); 166 dstContext->restoreLayer(); 167 } 168 169 PassRefPtr<SkImageFilter> FEGaussianBlur::createImageFilter(SkiaImageFilterBuilder* builder) 170 { 171 RefPtr<SkImageFilter> input(builder->build(inputEffect(0), operatingColorSpace())); 172 float stdX = filter()->applyHorizontalScale(m_stdX); 173 float stdY = filter()->applyVerticalScale(m_stdY); 174 SkImageFilter::CropRect rect = getCropRect(builder->cropOffset()); 175 return adoptRef(SkBlurImageFilter::Create(SkFloatToScalar(stdX), SkFloatToScalar(stdY), input.get(), &rect)); 176 } 177 178 TextStream& FEGaussianBlur::externalRepresentation(TextStream& ts, int indent) const 179 { 180 writeIndent(ts, indent); 181 ts << "[feGaussianBlur"; 182 FilterEffect::externalRepresentation(ts); 183 ts << " stdDeviation=\"" << m_stdX << ", " << m_stdY << "\"]\n"; 184 inputEffect(0)->externalRepresentation(ts, indent + 1); 185 return ts; 186 } 187 188 } // namespace WebCore 189
