SkBlurImageFilter.cpp revision 6ae6383f56704928838032ce6c46829e06201853
1/* 2 * Copyright 2011 The Android Open Source Project 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8#include "SkBitmap.h" 9#include "SkBlurImageFilter.h" 10#include "SkColorPriv.h" 11#include "SkFlattenableBuffers.h" 12#include "SkGpuBlurUtils.h" 13#if SK_SUPPORT_GPU 14#include "GrContext.h" 15#include "SkImageFilterUtils.h" 16#endif 17 18SkBlurImageFilter::SkBlurImageFilter(SkFlattenableReadBuffer& buffer) 19 : INHERITED(buffer) { 20 fSigma.fWidth = buffer.readScalar(); 21 fSigma.fHeight = buffer.readScalar(); 22} 23 24SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX, 25 SkScalar sigmaY, 26 SkImageFilter* input, 27 const SkIRect* cropRect) 28 : INHERITED(input, cropRect), fSigma(SkSize::Make(sigmaX, sigmaY)) { 29 SkASSERT(sigmaX >= 0 && sigmaY >= 0); 30} 31 32void SkBlurImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const { 33 this->INHERITED::flatten(buffer); 34 buffer.writeScalar(fSigma.fWidth); 35 buffer.writeScalar(fSigma.fHeight); 36} 37 38static void boxBlurX(const SkBitmap& src, SkBitmap* dst, int kernelSize, 39 int leftOffset, int rightOffset, const SkIRect& bounds) 40{ 41 int width = bounds.width(), height = bounds.height(); 42 int rightBorder = SkMin32(rightOffset + 1, width); 43 for (int y = 0; y < height; ++y) { 44 int sumA = 0, sumR = 0, sumG = 0, sumB = 0; 45 SkPMColor* p = src.getAddr32(bounds.fLeft, y + bounds.fTop); 46 for (int i = 0; i < rightBorder; ++i) { 47 sumA += SkGetPackedA32(*p); 48 sumR += SkGetPackedR32(*p); 49 sumG += SkGetPackedG32(*p); 50 sumB += SkGetPackedB32(*p); 51 p++; 52 } 53 54 const SkColor* sptr = src.getAddr32(bounds.fLeft, bounds.fTop + y); 55 SkColor* dptr = dst->getAddr32(0, y); 56 for (int x = 0; x < width; ++x) { 57 *dptr = SkPackARGB32(sumA / kernelSize, 58 sumR / kernelSize, 59 sumG / kernelSize, 60 sumB / kernelSize); 61 if (x >= leftOffset) { 62 SkColor l = *(sptr - leftOffset); 63 sumA -= SkGetPackedA32(l); 64 sumR -= SkGetPackedR32(l); 65 sumG -= SkGetPackedG32(l); 66 sumB -= SkGetPackedB32(l); 67 } 68 if (x + rightOffset + 1 < width) { 69 SkColor r = *(sptr + rightOffset + 1); 70 sumA += SkGetPackedA32(r); 71 sumR += SkGetPackedR32(r); 72 sumG += SkGetPackedG32(r); 73 sumB += SkGetPackedB32(r); 74 } 75 sptr++; 76 dptr++; 77 } 78 } 79} 80 81static void boxBlurY(const SkBitmap& src, SkBitmap* dst, int kernelSize, 82 int topOffset, int bottomOffset, const SkIRect& bounds) 83{ 84 int width = bounds.width(), height = bounds.height(); 85 int bottomBorder = SkMin32(bottomOffset + 1, height); 86 int srcStride = src.rowBytesAsPixels(); 87 int dstStride = dst->rowBytesAsPixels(); 88 for (int x = 0; x < width; ++x) { 89 int sumA = 0, sumR = 0, sumG = 0, sumB = 0; 90 SkColor* p = src.getAddr32(bounds.fLeft + x, bounds.fTop); 91 for (int i = 0; i < bottomBorder; ++i) { 92 sumA += SkGetPackedA32(*p); 93 sumR += SkGetPackedR32(*p); 94 sumG += SkGetPackedG32(*p); 95 sumB += SkGetPackedB32(*p); 96 p += srcStride; 97 } 98 99 const SkColor* sptr = src.getAddr32(bounds.fLeft + x, bounds.fTop); 100 SkColor* dptr = dst->getAddr32(x, 0); 101 for (int y = 0; y < height; ++y) { 102 *dptr = SkPackARGB32(sumA / kernelSize, 103 sumR / kernelSize, 104 sumG / kernelSize, 105 sumB / kernelSize); 106 if (y >= topOffset) { 107 SkColor l = *(sptr - topOffset * srcStride); 108 sumA -= SkGetPackedA32(l); 109 sumR -= SkGetPackedR32(l); 110 sumG -= SkGetPackedG32(l); 111 sumB -= SkGetPackedB32(l); 112 } 113 if (y + bottomOffset + 1 < height) { 114 SkColor r = *(sptr + (bottomOffset + 1) * srcStride); 115 sumA += SkGetPackedA32(r); 116 sumR += SkGetPackedR32(r); 117 sumG += SkGetPackedG32(r); 118 sumB += SkGetPackedB32(r); 119 } 120 sptr += srcStride; 121 dptr += dstStride; 122 } 123 } 124} 125 126static void getBox3Params(SkScalar s, int *kernelSize, int* kernelSize3, int *lowOffset, 127 int *highOffset) 128{ 129 float pi = SkScalarToFloat(SK_ScalarPI); 130 int d = static_cast<int>(floorf(SkScalarToFloat(s) * 3.0f * sqrtf(2.0f * pi) / 4.0f + 0.5f)); 131 *kernelSize = d; 132 if (d % 2 == 1) { 133 *lowOffset = *highOffset = (d - 1) / 2; 134 *kernelSize3 = d; 135 } else { 136 *highOffset = d / 2; 137 *lowOffset = *highOffset - 1; 138 *kernelSize3 = d + 1; 139 } 140} 141 142bool SkBlurImageFilter::onFilterImage(Proxy* proxy, 143 const SkBitmap& source, const SkMatrix& ctm, 144 SkBitmap* dst, SkIPoint* offset) { 145 SkBitmap src = source; 146 if (getInput(0) && !getInput(0)->filterImage(proxy, source, ctm, &src, offset)) { 147 return false; 148 } 149 150 if (src.config() != SkBitmap::kARGB_8888_Config) { 151 return false; 152 } 153 154 SkAutoLockPixels alp(src); 155 if (!src.getPixels()) { 156 return false; 157 } 158 159 SkIRect srcBounds, dstBounds; 160 src.getBounds(&srcBounds); 161 if (!this->applyCropRect(&srcBounds)) { 162 return false; 163 } 164 165 dst->setConfig(src.config(), srcBounds.width(), srcBounds.height()); 166 dst->getBounds(&dstBounds); 167 dst->allocPixels(); 168 int kernelSizeX, kernelSizeX3, lowOffsetX, highOffsetX; 169 int kernelSizeY, kernelSizeY3, lowOffsetY, highOffsetY; 170 getBox3Params(fSigma.width(), &kernelSizeX, &kernelSizeX3, &lowOffsetX, &highOffsetX); 171 getBox3Params(fSigma.height(), &kernelSizeY, &kernelSizeY3, &lowOffsetY, &highOffsetY); 172 173 if (kernelSizeX < 0 || kernelSizeY < 0) { 174 return false; 175 } 176 177 if (kernelSizeX == 0 && kernelSizeY == 0) { 178 src.copyTo(dst, dst->config()); 179 return true; 180 } 181 182 SkBitmap temp; 183 temp.setConfig(dst->config(), dst->width(), dst->height()); 184 if (!temp.allocPixels()) { 185 return false; 186 } 187 188 if (kernelSizeX > 0 && kernelSizeY > 0) { 189 boxBlurX(src, &temp, kernelSizeX, lowOffsetX, highOffsetX, srcBounds); 190 boxBlurY(temp, dst, kernelSizeY, lowOffsetY, highOffsetY, dstBounds); 191 boxBlurX(*dst, &temp, kernelSizeX, highOffsetX, lowOffsetX, dstBounds); 192 boxBlurY(temp, dst, kernelSizeY, highOffsetY, lowOffsetY, dstBounds); 193 boxBlurX(*dst, &temp, kernelSizeX3, highOffsetX, highOffsetX, dstBounds); 194 boxBlurY(temp, dst, kernelSizeY3, highOffsetY, highOffsetY, dstBounds); 195 } else if (kernelSizeX > 0) { 196 boxBlurX(src, dst, kernelSizeX, lowOffsetX, highOffsetX, srcBounds); 197 boxBlurX(*dst, &temp, kernelSizeX, highOffsetX, lowOffsetX, dstBounds); 198 boxBlurX(temp, dst, kernelSizeX3, highOffsetX, highOffsetX, dstBounds); 199 } else if (kernelSizeY > 0) { 200 boxBlurY(src, dst, kernelSizeY, lowOffsetY, highOffsetY, srcBounds); 201 boxBlurY(*dst, &temp, kernelSizeY, highOffsetY, lowOffsetY, dstBounds); 202 boxBlurY(temp, dst, kernelSizeY3, highOffsetY, highOffsetY, dstBounds); 203 } 204 offset->fX += srcBounds.fLeft; 205 offset->fY += srcBounds.fTop; 206 return true; 207} 208 209bool SkBlurImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, SkBitmap* result, 210 SkIPoint* offset) { 211#if SK_SUPPORT_GPU 212 SkBitmap input; 213 if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, &input, offset)) { 214 return false; 215 } 216 GrTexture* source = input.getTexture(); 217 SkIRect rect; 218 src.getBounds(&rect); 219 if (!this->applyCropRect(&rect)) { 220 return false; 221 } 222 SkAutoTUnref<GrTexture> tex(SkGpuBlurUtils::GaussianBlur(source->getContext(), 223 source, false, SkRect::Make(rect), 224 fSigma.width(), fSigma.height())); 225 offset->fX += rect.fLeft; 226 offset->fY += rect.fTop; 227 return SkImageFilterUtils::WrapTexture(tex, rect.width(), rect.height(), result); 228#else 229 SkDEBUGFAIL("Should not call in GPU-less build"); 230 return false; 231#endif 232} 233