SkBicubicImageFilter.cpp revision ba6e954140e45e251d67934ed6ad752149fcf72f
1/* 2 * Copyright 2013 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 "SkBicubicImageFilter.h" 9#include "SkBitmap.h" 10#include "SkColorPriv.h" 11#include "SkFlattenableBuffers.h" 12#include "SkMatrix.h" 13#include "SkRect.h" 14#include "SkUnPreMultiply.h" 15 16#if SK_SUPPORT_GPU 17#include "effects/GrBicubicEffect.h" 18#include "GrContext.h" 19#include "GrTexture.h" 20#include "SkImageFilterUtils.h" 21#endif 22 23#define DS(x) SkDoubleToScalar(x) 24 25static const SkScalar gMitchellCoefficients[16] = { 26 DS( 1.0 / 18.0), DS(-9.0 / 18.0), DS( 15.0 / 18.0), DS( -7.0 / 18.0), 27 DS(16.0 / 18.0), DS( 0.0 / 18.0), DS(-36.0 / 18.0), DS( 21.0 / 18.0), 28 DS( 1.0 / 18.0), DS( 9.0 / 18.0), DS( 27.0 / 18.0), DS(-21.0 / 18.0), 29 DS( 0.0 / 18.0), DS( 0.0 / 18.0), DS( -6.0 / 18.0), DS( 7.0 / 18.0), 30}; 31 32SkBicubicImageFilter::SkBicubicImageFilter(const SkSize& scale, const SkScalar coefficients[16], SkImageFilter* input) 33 : INHERITED(input), 34 fScale(scale) { 35 memcpy(fCoefficients, coefficients, sizeof(fCoefficients)); 36} 37 38SkBicubicImageFilter* SkBicubicImageFilter::CreateMitchell(const SkSize& scale, 39 SkImageFilter* input) { 40 return SkNEW_ARGS(SkBicubicImageFilter, (scale, gMitchellCoefficients, input)); 41} 42 43SkBicubicImageFilter::SkBicubicImageFilter(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) { 44 SkDEBUGCODE(uint32_t readSize =) buffer.readScalarArray(fCoefficients); 45 SkASSERT(readSize == 16); 46 fScale.fWidth = buffer.readScalar(); 47 fScale.fHeight = buffer.readScalar(); 48 buffer.validate(SkScalarIsFinite(fScale.fWidth) && 49 SkScalarIsFinite(fScale.fHeight) && 50 (fScale.fWidth >= 0) && 51 (fScale.fHeight >= 0)); 52} 53 54void SkBicubicImageFilter::flatten(SkFlattenableWriteBuffer& buffer) const { 55 this->INHERITED::flatten(buffer); 56 buffer.writeScalarArray(fCoefficients, 16); 57 buffer.writeScalar(fScale.fWidth); 58 buffer.writeScalar(fScale.fHeight); 59} 60 61SkBicubicImageFilter::~SkBicubicImageFilter() { 62} 63 64inline SkPMColor cubicBlend(const SkScalar c[16], SkScalar t, SkPMColor c0, SkPMColor c1, SkPMColor c2, SkPMColor c3) { 65 SkScalar t2 = t * t, t3 = t2 * t; 66 SkScalar cc[4]; 67 // FIXME: For the fractx case, this should be refactored out of this function. 68 cc[0] = c[0] + SkScalarMul(c[1], t) + SkScalarMul(c[2], t2) + SkScalarMul(c[3], t3); 69 cc[1] = c[4] + SkScalarMul(c[5], t) + SkScalarMul(c[6], t2) + SkScalarMul(c[7], t3); 70 cc[2] = c[8] + SkScalarMul(c[9], t) + SkScalarMul(c[10], t2) + SkScalarMul(c[11], t3); 71 cc[3] = c[12] + SkScalarMul(c[13], t) + SkScalarMul(c[14], t2) + SkScalarMul(c[15], t3); 72 SkScalar a = SkScalarClampMax(SkScalarMul(cc[0], SkGetPackedA32(c0)) + SkScalarMul(cc[1], SkGetPackedA32(c1)) + SkScalarMul(cc[2], SkGetPackedA32(c2)) + SkScalarMul(cc[3], SkGetPackedA32(c3)), 255); 73 SkScalar r = SkScalarMul(cc[0], SkGetPackedR32(c0)) + SkScalarMul(cc[1], SkGetPackedR32(c1)) + SkScalarMul(cc[2], SkGetPackedR32(c2)) + SkScalarMul(cc[3], SkGetPackedR32(c3)); 74 SkScalar g = SkScalarMul(cc[0], SkGetPackedG32(c0)) + SkScalarMul(cc[1], SkGetPackedG32(c1)) + SkScalarMul(cc[2], SkGetPackedG32(c2)) + SkScalarMul(cc[3], SkGetPackedG32(c3)); 75 SkScalar b = SkScalarMul(cc[0], SkGetPackedB32(c0)) + SkScalarMul(cc[1], SkGetPackedB32(c1)) + SkScalarMul(cc[2], SkGetPackedB32(c2)) + SkScalarMul(cc[3], SkGetPackedB32(c3)); 76 return SkPackARGB32(SkScalarRoundToInt(a), 77 SkScalarRoundToInt(SkScalarClampMax(r, a)), 78 SkScalarRoundToInt(SkScalarClampMax(g, a)), 79 SkScalarRoundToInt(SkScalarClampMax(b, a))); 80} 81 82bool SkBicubicImageFilter::onFilterImage(Proxy* proxy, 83 const SkBitmap& source, 84 const SkMatrix& matrix, 85 SkBitmap* result, 86 SkIPoint* loc) { 87 SkBitmap src = source; 88 if (getInput(0) && !getInput(0)->filterImage(proxy, source, matrix, &src, loc)) { 89 return false; 90 } 91 92 if (src.config() != SkBitmap::kARGB_8888_Config) { 93 return false; 94 } 95 96 SkAutoLockPixels alp(src); 97 if (!src.getPixels()) { 98 return false; 99 } 100 101 SkRect dstRect = SkRect::MakeWH(SkScalarMul(SkIntToScalar(src.width()), fScale.fWidth), 102 SkScalarMul(SkIntToScalar(src.height()), fScale.fHeight)); 103 SkIRect dstIRect; 104 dstRect.roundOut(&dstIRect); 105 if (dstIRect.isEmpty()) { 106 return false; 107 } 108 result->setConfig(src.config(), dstIRect.width(), dstIRect.height()); 109 result->allocPixels(); 110 if (!result->getPixels()) { 111 return false; 112 } 113 114 SkRect srcRect; 115 src.getBounds(&srcRect); 116 SkMatrix inverse; 117 inverse.setRectToRect(dstRect, srcRect, SkMatrix::kFill_ScaleToFit); 118 inverse.postTranslate(SkFloatToScalar(-0.5f), SkFloatToScalar(-0.5f)); 119 120 for (int y = dstIRect.fTop; y < dstIRect.fBottom; ++y) { 121 SkPMColor* dptr = result->getAddr32(dstIRect.fLeft, y); 122 for (int x = dstIRect.fLeft; x < dstIRect.fRight; ++x) { 123 SkPoint srcPt, dstPt = SkPoint::Make(SkIntToScalar(x), SkIntToScalar(y)); 124 inverse.mapPoints(&srcPt, &dstPt, 1); 125 SkScalar fractx = srcPt.fX - SkScalarFloorToScalar(srcPt.fX); 126 SkScalar fracty = srcPt.fY - SkScalarFloorToScalar(srcPt.fY); 127 int sx = SkScalarFloorToInt(srcPt.fX); 128 int sy = SkScalarFloorToInt(srcPt.fY); 129 int x0 = SkClampMax(sx - 1, src.width() - 1); 130 int x1 = SkClampMax(sx , src.width() - 1); 131 int x2 = SkClampMax(sx + 1, src.width() - 1); 132 int x3 = SkClampMax(sx + 2, src.width() - 1); 133 int y0 = SkClampMax(sy - 1, src.height() - 1); 134 int y1 = SkClampMax(sy , src.height() - 1); 135 int y2 = SkClampMax(sy + 1, src.height() - 1); 136 int y3 = SkClampMax(sy + 2, src.height() - 1); 137 SkPMColor s00 = *src.getAddr32(x0, y0); 138 SkPMColor s10 = *src.getAddr32(x1, y0); 139 SkPMColor s20 = *src.getAddr32(x2, y0); 140 SkPMColor s30 = *src.getAddr32(x3, y0); 141 SkPMColor s0 = cubicBlend(fCoefficients, fractx, s00, s10, s20, s30); 142 SkPMColor s01 = *src.getAddr32(x0, y1); 143 SkPMColor s11 = *src.getAddr32(x1, y1); 144 SkPMColor s21 = *src.getAddr32(x2, y1); 145 SkPMColor s31 = *src.getAddr32(x3, y1); 146 SkPMColor s1 = cubicBlend(fCoefficients, fractx, s01, s11, s21, s31); 147 SkPMColor s02 = *src.getAddr32(x0, y2); 148 SkPMColor s12 = *src.getAddr32(x1, y2); 149 SkPMColor s22 = *src.getAddr32(x2, y2); 150 SkPMColor s32 = *src.getAddr32(x3, y2); 151 SkPMColor s2 = cubicBlend(fCoefficients, fractx, s02, s12, s22, s32); 152 SkPMColor s03 = *src.getAddr32(x0, y3); 153 SkPMColor s13 = *src.getAddr32(x1, y3); 154 SkPMColor s23 = *src.getAddr32(x2, y3); 155 SkPMColor s33 = *src.getAddr32(x3, y3); 156 SkPMColor s3 = cubicBlend(fCoefficients, fractx, s03, s13, s23, s33); 157 *dptr++ = cubicBlend(fCoefficients, fracty, s0, s1, s2, s3); 158 } 159 } 160 return true; 161} 162 163/////////////////////////////////////////////////////////////////////////////// 164 165#if SK_SUPPORT_GPU 166 167bool SkBicubicImageFilter::filterImageGPU(Proxy* proxy, const SkBitmap& src, const SkMatrix& ctm, 168 SkBitmap* result, SkIPoint* offset) { 169 SkBitmap srcBM; 170 if (!SkImageFilterUtils::GetInputResultGPU(getInput(0), proxy, src, ctm, &srcBM, offset)) { 171 return false; 172 } 173 GrTexture* srcTexture = srcBM.getTexture(); 174 GrContext* context = srcTexture->getContext(); 175 176 SkRect dstRect = SkRect::MakeWH(srcBM.width() * fScale.fWidth, 177 srcBM.height() * fScale.fHeight); 178 179 GrTextureDesc desc; 180 desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit; 181 desc.fWidth = SkScalarCeilToInt(dstRect.width()); 182 desc.fHeight = SkScalarCeilToInt(dstRect.height()); 183 desc.fConfig = kSkia8888_GrPixelConfig; 184 185 GrAutoScratchTexture ast(context, desc); 186 SkAutoTUnref<GrTexture> dst(ast.detach()); 187 if (!dst) { 188 return false; 189 } 190 GrContext::AutoRenderTarget art(context, dst->asRenderTarget()); 191 GrPaint paint; 192 paint.addColorEffect(GrBicubicEffect::Create(srcTexture, fCoefficients))->unref(); 193 SkRect srcRect; 194 srcBM.getBounds(&srcRect); 195 context->drawRectToRect(paint, dstRect, srcRect); 196 return SkImageFilterUtils::WrapTexture(dst, desc.fWidth, desc.fHeight, result); 197} 198#endif 199 200/////////////////////////////////////////////////////////////////////////////// 201