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 "GrDrawContext.h"
  11 #include "GrInvariantOutput.h"
  12 #include "GrSimpleTextureEffect.h"
  13 #include "SkMatrix.h"
  14 #include "gl/GrGLFragmentProcessor.h"
  15 #include "gl/builders/GrGLProgramBuilder.h"
  16
  17 class GrGLConfigConversionEffect : public GrGLFragmentProcessor {
  18 public:
  19     GrGLConfigConversionEffect(const GrProcessor& processor) {
  20         const GrConfigConversionEffect& configConversionEffect =
  21                 processor.cast<GrConfigConversionEffect>();
  22         fSwapRedAndBlue = configConversionEffect.swapsRedAndBlue();
  23         fPMConversion = configConversionEffect.pmConversion();
  24     }
  25
  26     virtual void emitCode(EmitArgs& args) override {
  27         // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
  28         GrGLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, kHigh_GrSLPrecision);
  29         SkString tmpDecl;
  30         tmpVar.appendDecl(args.fBuilder->ctxInfo(), &tmpDecl);
  31
  32         GrGLFragmentBuilder* fsBuilder = args.fBuilder->getFragmentShaderBuilder();
  33
  34         fsBuilder->codeAppendf("%s;", tmpDecl.c_str());
  35
  36         fsBuilder->codeAppendf("%s = ", tmpVar.c_str());
  37         fsBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str(),
  38                                        args.fCoords[0].getType());
  39         fsBuilder->codeAppend(";");
  40
  41         if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
  42             SkASSERT(fSwapRedAndBlue);
  43             fsBuilder->codeAppendf("%s = %s.bgra;", args.fOutputColor, tmpVar.c_str());
  44         } else {
  45             const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
  46             switch (fPMConversion) {
  47                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
  48                     fsBuilder->codeAppendf(
  49                         "%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);",
  50                         tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  51                     break;
  52                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
  53                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
  54                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
  55                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
  56                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
  57                     fsBuilder->codeAppendf(
  58                         "%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
  59                         tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  60                     break;
  61                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
  62                     fsBuilder->codeAppendf(
  63                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
  64                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  65                     break;
  66                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
  67                     fsBuilder->codeAppendf(
  68                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
  69                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  70                     break;
  71                 default:
  72                     SkFAIL("Unknown conversion op.");
  73                     break;
  74             }
  75             fsBuilder->codeAppendf("%s = %s;", args.fOutputColor, tmpVar.c_str());
  76         }
  77         SkString modulate;
  78         GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
  79         fsBuilder->codeAppend(modulate.c_str());
  80     }
  81
  82     static inline void GenKey(const GrProcessor& processor, const GrGLSLCaps&,
  83                               GrProcessorKeyBuilder* b) {
  84         const GrConfigConversionEffect& conv = processor.cast<GrConfigConversionEffect>();
  85         uint32_t key = (conv.swapsRedAndBlue() ? 0 : 1) | (conv.pmConversion() << 1);
  86         b->add32(key);
  87     }
  88
  89 private:
  90     bool                                    fSwapRedAndBlue;
  91     GrConfigConversionEffect::PMConversion  fPMConversion;
  92
  93     typedef GrGLFragmentProcessor INHERITED;
  94
  95 };
  96
  97 ///////////////////////////////////////////////////////////////////////////////
  98
  99 GrConfigConversionEffect::GrConfigConversionEffect(GrProcessorDataManager* procDataManager,
 100                                                    GrTexture* texture,
 101                                                    bool swapRedAndBlue,
 102                                                    PMConversion pmConversion,
 103                                                    const SkMatrix& matrix)
 104     : INHERITED(procDataManager, texture, matrix)
 105     , fSwapRedAndBlue(swapRedAndBlue)
 106     , fPMConversion(pmConversion) {
 107     this->initClassID<GrConfigConversionEffect>();
 108     // We expect to get here with non-BGRA/RGBA only if we're doing not doing a premul/unpremul
 109     // conversion.
 110     SkASSERT((kRGBA_8888_GrPixelConfig == texture->config() ||
 111               kBGRA_8888_GrPixelConfig == texture->config()) ||
 112               kNone_PMConversion == pmConversion);
 113     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
 114     SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
 115 }
 116
 117 bool GrConfigConversionEffect::onIsEqual(const GrFragmentProcessor& s) const {
 118     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 119     return other.fSwapRedAndBlue == fSwapRedAndBlue &&
 120            other.fPMConversion == fPMConversion;
 121 }
 122
 123 void GrConfigConversionEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
 124     this->updateInvariantOutputForModulation(inout);
 125 }
 126
 127 ///////////////////////////////////////////////////////////////////////////////
 128
 129 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConfigConversionEffect);
 130
 131 GrFragmentProcessor* GrConfigConversionEffect::TestCreate(GrProcessorTestData* d) {
 132     PMConversion pmConv = static_cast<PMConversion>(d->fRandom->nextULessThan(kPMConversionCnt));
 133     bool swapRB;
 134     if (kNone_PMConversion == pmConv) {
 135         swapRB = true;
 136     } else {
 137         swapRB = d->fRandom->nextBool();
 138     }
 139     return SkNEW_ARGS(GrConfigConversionEffect,
 140                                       (d->fProcDataManager,
 141                                        d->fTextures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 142                                        swapRB,
 143                                        pmConv,
 144                                        GrTest::TestMatrix(d->fRandom)));
 145 }
 146
 147 ///////////////////////////////////////////////////////////////////////////////
 148
 149 void GrConfigConversionEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
 150                                                  GrProcessorKeyBuilder* b) const {
 151     GrGLConfigConversionEffect::GenKey(*this, caps, b);
 152 }
 153
 154 GrGLFragmentProcessor* GrConfigConversionEffect::createGLInstance() const {
 155     return SkNEW_ARGS(GrGLConfigConversionEffect, (*this));
 156 }
 157
 158
 159
 160 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
 161                                                               PMConversion* pmToUPMRule,
 162                                                               PMConversion* upmToPMRule) {
 163     *pmToUPMRule = kNone_PMConversion;
 164     *upmToPMRule = kNone_PMConversion;
 165     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
 166     uint32_t* srcData = data.get();
 167     uint32_t* firstRead = data.get() + 256 * 256;
 168     uint32_t* secondRead = data.get() + 2 * 256 * 256;
 169
 170     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
 171     // values in row y. We set r,g, and b to the same value since they are handled identically.
 172     for (int y = 0; y < 256; ++y) {
 173         for (int x = 0; x < 256; ++x) {
 174             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
 175             color[3] = y;
 176             color[2] = SkTMin(x, y);
 177             color[1] = SkTMin(x, y);
 178             color[0] = SkTMin(x, y);
 179         }
 180     }
 181
 182     GrSurfaceDesc desc;
 183     desc.fFlags = kRenderTarget_GrSurfaceFlag;
 184     desc.fWidth = 256;
 185     desc.fHeight = 256;
 186     desc.fConfig = kRGBA_8888_GrPixelConfig;
 187
 188     SkAutoTUnref<GrTexture> readTex(context->textureProvider()->createTexture(desc, true, NULL, 0));
 189     if (!readTex.get()) {
 190         return;
 191     }
 192     SkAutoTUnref<GrTexture> tempTex(context->textureProvider()->createTexture(desc, true, NULL, 0));
 193     if (!tempTex.get()) {
 194         return;
 195     }
 196     desc.fFlags = kNone_GrSurfaceFlags;
 197     SkAutoTUnref<GrTexture> dataTex(context->textureProvider()->createTexture(desc, true, data, 0));
 198     if (!dataTex.get()) {
 199         return;
 200     }
 201
 202     static const PMConversion kConversionRules[][2] = {
 203         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 204         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 205     };
 206
 207     bool failed = true;
 208
 209     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 210         *pmToUPMRule = kConversionRules[i][0];
 211         *upmToPMRule = kConversionRules[i][1];
 212
 213         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 214         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 215         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 216         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 217         // We then verify that two reads produced the same values.
 218
 219         GrPaint paint1;
 220         GrPaint paint2;
 221         GrPaint paint3;
 222         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(
 223                 SkNEW_ARGS(GrConfigConversionEffect,
 224                            (paint1.getProcessorDataManager(), dataTex, false, *pmToUPMRule,
 225                             SkMatrix::I())));
 226         SkAutoTUnref<GrFragmentProcessor> upmToPM(
 227                 SkNEW_ARGS(GrConfigConversionEffect,
 228                            (paint2.getProcessorDataManager(), readTex, false, *upmToPMRule,
 229                             SkMatrix::I())));
 230         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(
 231                 SkNEW_ARGS(GrConfigConversionEffect,
 232                            (paint3.getProcessorDataManager(), tempTex, false, *pmToUPMRule,
 233                             SkMatrix::I())));
 234
 235         paint1.addColorProcessor(pmToUPM1);
 236
 237
 238         GrDrawContext* readDrawContext = context->drawContext();
 239         if (!readDrawContext) {
 240             failed = true;
 241             break;
 242         }
 243
 244         readDrawContext->drawNonAARectToRect(readTex->asRenderTarget(),
 245                                              GrClip::WideOpen(),
 246                                              paint1,
 247                                              SkMatrix::I(),
 248                                              kDstRect,
 249                                              kSrcRect);
 250
 251         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 252
 253         paint2.addColorProcessor(upmToPM);
 254
 255         GrDrawContext* tempDrawContext = context->drawContext();
 256         if (!tempDrawContext) {
 257             failed = true;
 258             break;
 259         }
 260         tempDrawContext->drawNonAARectToRect(tempTex->asRenderTarget(),
 261                                              GrClip::WideOpen(),
 262                                              paint2,
 263                                              SkMatrix::I(),
 264                                              kDstRect,
 265                                              kSrcRect);
 266
 267         paint3.addColorProcessor(pmToUPM2);
 268
 269         readDrawContext = context->drawContext();
 270         if (!readDrawContext) {
 271             failed = true;
 272             break;
 273         }
 274
 275         readDrawContext->drawNonAARectToRect(readTex->asRenderTarget(),
 276                                              GrClip::WideOpen(),
 277                                              paint3,
 278                                              SkMatrix::I(),
 279                                              kDstRect,
 280                                              kSrcRect);
 281
 282         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 283
 284         failed = false;
 285         for (int y = 0; y < 256 && !failed; ++y) {
 286             for (int x = 0; x <= y; ++x) {
 287                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 288                     failed = true;
 289                     break;
 290                 }
 291             }
 292         }
 293     }
 294     if (failed) {
 295         *pmToUPMRule = kNone_PMConversion;
 296         *upmToPMRule = kNone_PMConversion;
 297     }
 298 }
 299
 300 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrProcessorDataManager* procDataManager,
 301                                                             GrTexture* texture,
 302                                                             bool swapRedAndBlue,
 303                                                             PMConversion pmConversion,
 304                                                             const SkMatrix& matrix) {
 305     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
 306         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 307         // then we may pollute our texture cache with redundant shaders. So in the case that no
 308         // conversions were requested we instead return a GrSimpleTextureEffect.
 309         return GrSimpleTextureEffect::Create(procDataManager, texture, matrix);
 310     } else {
 311         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 312             kBGRA_8888_GrPixelConfig != texture->config() &&
 313             kNone_PMConversion != pmConversion) {
 314             // The PM conversions assume colors are 0..255
 315             return NULL;
 316         }
 317         return SkNEW_ARGS(GrConfigConversionEffect, (procDataManager,
 318                                                      texture,
 319                                                      swapRedAndBlue,
 320                                                      pmConversion,
 321                                                      matrix));
 322     }
 323 }