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(GrTexture* texture,
 100                                                    bool swapRedAndBlue,
 101                                                    PMConversion pmConversion,
 102                                                    const SkMatrix& matrix)
 103     : INHERITED(texture, matrix)
 104     , fSwapRedAndBlue(swapRedAndBlue)
 105     , fPMConversion(pmConversion) {
 106     this->initClassID<GrConfigConversionEffect>();
 107     // We expect to get here with non-BGRA/RGBA only if we're doing not doing a premul/unpremul
 108     // conversion.
 109     SkASSERT((kRGBA_8888_GrPixelConfig == texture->config() ||
 110               kBGRA_8888_GrPixelConfig == texture->config()) ||
 111               kNone_PMConversion == pmConversion);
 112     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
 113     SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
 114 }
 115
 116 bool GrConfigConversionEffect::onIsEqual(const GrFragmentProcessor& s) const {
 117     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 118     return other.fSwapRedAndBlue == fSwapRedAndBlue &&
 119            other.fPMConversion == fPMConversion;
 120 }
 121
 122 void GrConfigConversionEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
 123     this->updateInvariantOutputForModulation(inout);
 124 }
 125
 126 ///////////////////////////////////////////////////////////////////////////////
 127
 128 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConfigConversionEffect);
 129
 130 const GrFragmentProcessor* GrConfigConversionEffect::TestCreate(GrProcessorTestData* d) {
 131     PMConversion pmConv = static_cast<PMConversion>(d->fRandom->nextULessThan(kPMConversionCnt));
 132     bool swapRB;
 133     if (kNone_PMConversion == pmConv) {
 134         swapRB = true;
 135     } else {
 136         swapRB = d->fRandom->nextBool();
 137     }
 138     return new GrConfigConversionEffect(d->fTextures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 139                                         swapRB, pmConv, GrTest::TestMatrix(d->fRandom));
 140 }
 141
 142 ///////////////////////////////////////////////////////////////////////////////
 143
 144 void GrConfigConversionEffect::onGetGLProcessorKey(const GrGLSLCaps& caps,
 145                                                  GrProcessorKeyBuilder* b) const {
 146     GrGLConfigConversionEffect::GenKey(*this, caps, b);
 147 }
 148
 149 GrGLFragmentProcessor* GrConfigConversionEffect::onCreateGLInstance() const {
 150     return new GrGLConfigConversionEffect(*this);
 151 }
 152
 153
 154
 155 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
 156                                                               PMConversion* pmToUPMRule,
 157                                                               PMConversion* upmToPMRule) {
 158     *pmToUPMRule = kNone_PMConversion;
 159     *upmToPMRule = kNone_PMConversion;
 160     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
 161     uint32_t* srcData = data.get();
 162     uint32_t* firstRead = data.get() + 256 * 256;
 163     uint32_t* secondRead = data.get() + 2 * 256 * 256;
 164
 165     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
 166     // values in row y. We set r,g, and b to the same value since they are handled identically.
 167     for (int y = 0; y < 256; ++y) {
 168         for (int x = 0; x < 256; ++x) {
 169             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
 170             color[3] = y;
 171             color[2] = SkTMin(x, y);
 172             color[1] = SkTMin(x, y);
 173             color[0] = SkTMin(x, y);
 174         }
 175     }
 176
 177     GrSurfaceDesc desc;
 178     desc.fFlags = kRenderTarget_GrSurfaceFlag;
 179     desc.fWidth = 256;
 180     desc.fHeight = 256;
 181     desc.fConfig = kRGBA_8888_GrPixelConfig;
 182
 183     SkAutoTUnref<GrTexture> readTex(context->textureProvider()->createTexture(desc, true, nullptr, 0));
 184     if (!readTex.get()) {
 185         return;
 186     }
 187     SkAutoTUnref<GrTexture> tempTex(context->textureProvider()->createTexture(desc, true, nullptr, 0));
 188     if (!tempTex.get()) {
 189         return;
 190     }
 191     desc.fFlags = kNone_GrSurfaceFlags;
 192     SkAutoTUnref<GrTexture> dataTex(context->textureProvider()->createTexture(desc, true, data, 0));
 193     if (!dataTex.get()) {
 194         return;
 195     }
 196
 197     static const PMConversion kConversionRules[][2] = {
 198         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 199         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 200     };
 201
 202     bool failed = true;
 203
 204     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 205         *pmToUPMRule = kConversionRules[i][0];
 206         *upmToPMRule = kConversionRules[i][1];
 207
 208         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 209         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 210         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 211         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 212         // We then verify that two reads produced the same values.
 213
 214         GrPaint paint1;
 215         GrPaint paint2;
 216         GrPaint paint3;
 217         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(new GrConfigConversionEffect(
 218                 dataTex, false, *pmToUPMRule, SkMatrix::I()));
 219         SkAutoTUnref<GrFragmentProcessor> upmToPM(new GrConfigConversionEffect(
 220                 readTex, false, *upmToPMRule, SkMatrix::I()));
 221         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(new GrConfigConversionEffect(
 222                 tempTex, false, *pmToUPMRule, SkMatrix::I()));
 223
 224         paint1.addColorFragmentProcessor(pmToUPM1);
 225
 226
 227         SkAutoTUnref<GrDrawContext> readDrawContext(
 228                                     context->drawContext(readTex->asRenderTarget()));
 229         if (!readDrawContext) {
 230             failed = true;
 231             break;
 232         }
 233
 234         readDrawContext->drawNonAARectToRect(GrClip::WideOpen(),
 235                                              paint1,
 236                                              SkMatrix::I(),
 237                                              kDstRect,
 238                                              kSrcRect);
 239
 240         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 241
 242         paint2.addColorFragmentProcessor(upmToPM);
 243
 244         SkAutoTUnref<GrDrawContext> tempDrawContext(
 245                                     context->drawContext(tempTex->asRenderTarget()));
 246         if (!tempDrawContext) {
 247             failed = true;
 248             break;
 249         }
 250         tempDrawContext->drawNonAARectToRect(GrClip::WideOpen(),
 251                                              paint2,
 252                                              SkMatrix::I(),
 253                                              kDstRect,
 254                                              kSrcRect);
 255
 256         paint3.addColorFragmentProcessor(pmToUPM2);
 257
 258         readDrawContext.reset(context->drawContext(readTex->asRenderTarget()));
 259         if (!readDrawContext) {
 260             failed = true;
 261             break;
 262         }
 263
 264         readDrawContext->drawNonAARectToRect(GrClip::WideOpen(),
 265                                              paint3,
 266                                              SkMatrix::I(),
 267                                              kDstRect,
 268                                              kSrcRect);
 269
 270         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 271
 272         failed = false;
 273         for (int y = 0; y < 256 && !failed; ++y) {
 274             for (int x = 0; x <= y; ++x) {
 275                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 276                     failed = true;
 277                     break;
 278                 }
 279             }
 280         }
 281     }
 282     if (failed) {
 283         *pmToUPMRule = kNone_PMConversion;
 284         *upmToPMRule = kNone_PMConversion;
 285     }
 286 }
 287
 288 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrTexture* texture,
 289                                                             bool swapRedAndBlue,
 290                                                             PMConversion pmConversion,
 291                                                             const SkMatrix& matrix) {
 292     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
 293         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 294         // then we may pollute our texture cache with redundant shaders. So in the case that no
 295         // conversions were requested we instead return a GrSimpleTextureEffect.
 296         return GrSimpleTextureEffect::Create(texture, matrix);
 297     } else {
 298         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 299             kBGRA_8888_GrPixelConfig != texture->config() &&
 300             kNone_PMConversion != pmConversion) {
 301             // The PM conversions assume colors are 0..255
 302             return nullptr;
 303         }
 304         return new GrConfigConversionEffect(texture, swapRedAndBlue, pmConversion, matrix);
 305     }
 306 }