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