src/gpu/effects/GrConfigConversionEffect.cpp

   1 /*
   2  * Copyright 2012 Google Inc.
   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 "GrConfigConversionEffect.h"
   9 #include "GrContext.h"
  10 #include "GrTBackendEffectFactory.h"
  11 #include "GrSimpleTextureEffect.h"
  12 #include "gl/GrGLEffect.h"
  13 #include "SkMatrix.h"
  14
  15 class GrGLConfigConversionEffect : public GrGLEffect {
  16 public:
  17     GrGLConfigConversionEffect(const GrBackendEffectFactory& factory,
  18                                const GrDrawEffect& drawEffect)
  19     : INHERITED (factory) {
  20         const GrConfigConversionEffect& effect = drawEffect.castEffect<GrConfigConversionEffect>();
  21         fSwapRedAndBlue = effect.swapsRedAndBlue();
  22         fPMConversion = effect.pmConversion();
  23     }
  24
  25     virtual void emitCode(GrGLShaderBuilder* builder,
  26                           const GrDrawEffect&,
  27                           EffectKey key,
  28                           const char* outputColor,
  29                           const char* inputColor,
  30                           const TransformedCoordsArray& coords,
  31                           const TextureSamplerArray& samplers) SK_OVERRIDE {
  32         builder->fsCodeAppendf("\t\t%s = ", outputColor);
  33         builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
  34         builder->fsCodeAppend(";\n");
  35         if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
  36             SkASSERT(fSwapRedAndBlue);
  37             builder->fsCodeAppendf("\t%s = %s.bgra;\n", outputColor, outputColor);
  38         } else {
  39             const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
  40             const char* outputColorH = "outputColorH";
  41             switch (fPMConversion) {
  42                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
  43                     builder->fsCodeAppendf(
  44                         "\t\t%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
  45                         outputColor, outputColor, swiz, outputColor, outputColor);
  46                     break;
  47                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
  48                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
  49                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
  50                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
  51                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
  52                     builder->fsCodeAppendf(
  53                         "\t\t%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);\n",
  54                         outputColor, outputColor, swiz, outputColor, outputColor);
  55                     break;
  56                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
  57                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
  58                         outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
  59                     break;
  60                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
  61                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
  62                         outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
  63                     break;
  64                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_HIGHP_PMConversion:
  65                     builder->fsCodeAppendf("\thighp vec4 %s;\n", outputColorH);
  66                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColorH, outputColor);
  67                     builder->fsCodeAppendf(
  68                         "\t\t%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
  69                         outputColorH, outputColorH, swiz, outputColorH, outputColorH);
  70                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
  71                     break;
  72                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_HIGHP_PMConversion:
  73                     builder->fsCodeAppendf("\thighp vec4 %s;\n", outputColorH);
  74                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColorH, outputColor);
  75                     builder->fsCodeAppendf(
  76                         "\t\t%s = vec4(floor(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
  77                         outputColorH, outputColorH, swiz, outputColorH, outputColorH);
  78                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
  79                     break;
  80                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_HIGHP_PMConversion:
  81                     builder->fsCodeAppendf("\thighp vec4 %s;\n", outputColorH);
  82                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColorH, outputColor);
  83                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
  84                         outputColorH, outputColorH, outputColorH, swiz, outputColorH, outputColorH);
  85                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
  86                     break;
  87                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_HIGHP_PMConversion:
  88                     builder->fsCodeAppendf("\thighp vec4 %s;\n", outputColorH);
  89                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColorH, outputColor);
  90                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
  91                         outputColorH, outputColorH, outputColorH, swiz, outputColorH, outputColorH);
  92                     builder->fsCodeAppendf("\t\t%s = %s;\n", outputColor, outputColorH);
  93                     break;
  94                 default:
  95                     SkFAIL("Unknown conversion op.");
  96                     break;
  97             }
  98         }
  99         SkString modulate;
 100         GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
 101         builder->fsCodeAppend(modulate.c_str());
 102     }
 103
 104     static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
 105         const GrConfigConversionEffect& conv = drawEffect.castEffect<GrConfigConversionEffect>();
 106         return static_cast<EffectKey>(conv.swapsRedAndBlue()) | (conv.pmConversion() << 1);
 107     }
 108
 109 private:
 110     bool                                    fSwapRedAndBlue;
 111     GrConfigConversionEffect::PMConversion  fPMConversion;
 112
 113     typedef GrGLEffect INHERITED;
 114
 115 };
 116
 117 ///////////////////////////////////////////////////////////////////////////////
 118
 119 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
 120                                                    bool swapRedAndBlue,
 121                                                    PMConversion pmConversion,
 122                                                    const SkMatrix& matrix)
 123     : GrSingleTextureEffect(texture, matrix)
 124     , fSwapRedAndBlue(swapRedAndBlue)
 125     , fPMConversion(pmConversion) {
 126     SkASSERT(kRGBA_8888_GrPixelConfig == texture->config() ||
 127              kBGRA_8888_GrPixelConfig == texture->config());
 128     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
 129     SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
 130 }
 131
 132 const GrBackendEffectFactory& GrConfigConversionEffect::getFactory() const {
 133     return GrTBackendEffectFactory<GrConfigConversionEffect>::getInstance();
 134 }
 135
 136 bool GrConfigConversionEffect::onIsEqual(const GrEffect& s) const {
 137     const GrConfigConversionEffect& other = CastEffect<GrConfigConversionEffect>(s);
 138     return this->texture(0) == s.texture(0) &&
 139            other.fSwapRedAndBlue == fSwapRedAndBlue &&
 140            other.fPMConversion == fPMConversion;
 141 }
 142
 143 void GrConfigConversionEffect::getConstantColorComponents(GrColor* color,
 144                                                           uint32_t* validFlags) const {
 145     this->updateConstantColorComponentsForModulation(color, validFlags);
 146 }
 147
 148 ///////////////////////////////////////////////////////////////////////////////
 149
 150 GR_DEFINE_EFFECT_TEST(GrConfigConversionEffect);
 151
 152 GrEffect* GrConfigConversionEffect::TestCreate(SkRandom* random,
 153                                                GrContext*,
 154                                                const GrDrawTargetCaps&,
 155                                                GrTexture* textures[]) {
 156     PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
 157     bool swapRB;
 158     if (kNone_PMConversion == pmConv) {
 159         swapRB = true;
 160     } else {
 161         swapRB = random->nextBool();
 162     }
 163     return SkNEW_ARGS(GrConfigConversionEffect,
 164                                       (textures[GrEffectUnitTest::kSkiaPMTextureIdx],
 165                                        swapRB,
 166                                        pmConv,
 167                                        GrEffectUnitTest::TestMatrix(random)));
 168 }
 169
 170 ///////////////////////////////////////////////////////////////////////////////
 171 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
 172                                                               PMConversion* pmToUPMRule,
 173                                                               PMConversion* upmToPMRule) {
 174     *pmToUPMRule = kNone_PMConversion;
 175     *upmToPMRule = kNone_PMConversion;
 176     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
 177     uint32_t* srcData = data.get();
 178     uint32_t* firstRead = data.get() + 256 * 256;
 179     uint32_t* secondRead = data.get() + 2 * 256 * 256;
 180
 181     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
 182     // values in row y. We set r,g, and b to the same value since they are handled identically.
 183     for (int y = 0; y < 256; ++y) {
 184         for (int x = 0; x < 256; ++x) {
 185             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
 186             color[3] = y;
 187             color[2] = SkTMin(x, y);
 188             color[1] = SkTMin(x, y);
 189             color[0] = SkTMin(x, y);
 190         }
 191     }
 192
 193     GrTextureDesc desc;
 194     desc.fFlags = kRenderTarget_GrTextureFlagBit |
 195                   kNoStencil_GrTextureFlagBit;
 196     desc.fWidth = 256;
 197     desc.fHeight = 256;
 198     desc.fConfig = kRGBA_8888_GrPixelConfig;
 199
 200     SkAutoTUnref<GrTexture> readTex(context->createUncachedTexture(desc, NULL, 0));
 201     if (!readTex.get()) {
 202         return;
 203     }
 204     SkAutoTUnref<GrTexture> tempTex(context->createUncachedTexture(desc, NULL, 0));
 205     if (!tempTex.get()) {
 206         return;
 207     }
 208     desc.fFlags = kNone_GrTextureFlags;
 209     SkAutoTUnref<GrTexture> dataTex(context->createUncachedTexture(desc, data, 0));
 210     if (!dataTex.get()) {
 211         return;
 212     }
 213
 214     static const PMConversion kConversionRules[][2] = {
 215         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 216         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 217         {kDivByAlpha_RoundDown_HIGHP_PMConversion, kMulByAlpha_RoundUp_HIGHP_PMConversion},
 218         {kDivByAlpha_RoundUp_HIGHP_PMConversion, kMulByAlpha_RoundDown_HIGHP_PMConversion},
 219     };
 220
 221     GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
 222
 223     bool failed = true;
 224
 225     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 226         *pmToUPMRule = kConversionRules[i][0];
 227         *upmToPMRule = kConversionRules[i][1];
 228
 229         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 230         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 231         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 232         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 233         // We then verify that two reads produced the same values.
 234
 235         SkAutoTUnref<GrEffect> pmToUPM1(SkNEW_ARGS(GrConfigConversionEffect, (dataTex,
 236                                                                               false,
 237                                                                               *pmToUPMRule,
 238                                                                               SkMatrix::I())));
 239         SkAutoTUnref<GrEffect> upmToPM(SkNEW_ARGS(GrConfigConversionEffect, (readTex,
 240                                                                              false,
 241                                                                              *upmToPMRule,
 242                                                                              SkMatrix::I())));
 243         SkAutoTUnref<GrEffect> pmToUPM2(SkNEW_ARGS(GrConfigConversionEffect, (tempTex,
 244                                                                               false,
 245                                                                               *pmToUPMRule,
 246                                                                               SkMatrix::I())));
 247
 248         context->setRenderTarget(readTex->asRenderTarget());
 249         GrPaint paint1;
 250         paint1.addColorEffect(pmToUPM1);
 251         context->drawRectToRect(paint1, kDstRect, kSrcRect);
 252
 253         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 254
 255         context->setRenderTarget(tempTex->asRenderTarget());
 256         GrPaint paint2;
 257         paint2.addColorEffect(upmToPM);
 258         context->drawRectToRect(paint2, kDstRect, kSrcRect);
 259         context->setRenderTarget(readTex->asRenderTarget());
 260
 261         GrPaint paint3;
 262         paint3.addColorEffect(pmToUPM2);
 263         context->drawRectToRect(paint3, kDstRect, kSrcRect);
 264
 265         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 266
 267         failed = false;
 268         for (int y = 0; y < 256 && !failed; ++y) {
 269             for (int x = 0; x <= y; ++x) {
 270                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 271                     failed = true;
 272                     break;
 273                 }
 274             }
 275         }
 276     }
 277     if (failed) {
 278         *pmToUPMRule = kNone_PMConversion;
 279         *upmToPMRule = kNone_PMConversion;
 280     }
 281 }
 282
 283 const GrEffect* GrConfigConversionEffect::Create(GrTexture* texture,
 284                                                  bool swapRedAndBlue,
 285                                                  PMConversion pmConversion,
 286                                                  const SkMatrix& matrix) {
 287     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
 288         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 289         // then we may pollute our texture cache with redundant shaders. So in the case that no
 290         // conversions were requested we instead return a GrSimpleTextureEffect.
 291         return GrSimpleTextureEffect::Create(texture, matrix);
 292     } else {
 293         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 294             kBGRA_8888_GrPixelConfig != texture->config() &&
 295             kNone_PMConversion != pmConversion) {
 296             // The PM conversions assume colors are 0..255
 297             return NULL;
 298         }
 299         return SkNEW_ARGS(GrConfigConversionEffect, (texture,
 300                                                      swapRedAndBlue,
 301                                                      pmConversion,
 302                                                      matrix));
 303     }
 304 }