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
  17 class GrGLConfigConversionEffect : public GrGLSLFragmentProcessor {
  18 public:
  19     void emitCode(EmitArgs& args) override {
  20         const GrConfigConversionEffect& cce = args.fFp.cast<GrConfigConversionEffect>();
  21         const GrSwizzle& swizzle = cce.swizzle();
  22         GrConfigConversionEffect::PMConversion pmConversion = cce.pmConversion();
  23
  24         // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
  25         GrGLSLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, kHigh_GrSLPrecision);
  26         SkString tmpDecl;
  27         tmpVar.appendDecl(args.fGLSLCaps, &tmpDecl);
  28
  29         GrGLSLFPFragmentBuilder* fragBuilder = args.fFragBuilder;
  30
  31         fragBuilder->codeAppendf("%s;", tmpDecl.c_str());
  32
  33         fragBuilder->codeAppendf("%s = ", tmpVar.c_str());
  34         fragBuilder->appendTextureLookup(args.fTexSamplers[0], args.fCoords[0].c_str(),
  35                                        args.fCoords[0].getType());
  36         fragBuilder->codeAppend(";");
  37
  38         if (GrConfigConversionEffect::kNone_PMConversion == pmConversion) {
  39             SkASSERT(GrSwizzle::RGBA() != swizzle);
  40             fragBuilder->codeAppendf("%s = %s.%s;", args.fOutputColor, tmpVar.c_str(),
  41                                      swizzle.c_str());
  42         } else {
  43             switch (pmConversion) {
  44                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
  45                     fragBuilder->codeAppendf(
  46                         "%s = vec4(ceil(%s.rgb * %s.a * 255.0) / 255.0, %s.a);",
  47                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str());
  48                     break;
  49                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
  50                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
  51                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
  52                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
  53                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
  54                     fragBuilder->codeAppendf(
  55                         "%s = vec4(floor(%s.rgb * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
  56                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str());
  57
  58                     break;
  59                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
  60                     fragBuilder->codeAppendf(
  61                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.rgb / %s.a * 255.0) / 255.0, %s.a);",
  62                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(),
  63                         tmpVar.c_str());
  64                     break;
  65                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
  66                     fragBuilder->codeAppendf(
  67                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.rgb / %s.a * 255.0) / 255.0, %s.a);",
  68                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(),
  69                         tmpVar.c_str());
  70                     break;
  71                 default:
  72                     SkFAIL("Unknown conversion op.");
  73                     break;
  74             }
  75             fragBuilder->codeAppendf("%s = %s.%s;", args.fOutputColor, tmpVar.c_str(),
  76                                      swizzle.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& cce = processor.cast<GrConfigConversionEffect>();
  86         uint32_t key = (cce.swizzle().asKey()) | (cce.pmConversion() << 16);
  87         b->add32(key);
  88     }
  89
  90 private:
  91     typedef GrGLSLFragmentProcessor INHERITED;
  92
  93 };
  94
  95 ///////////////////////////////////////////////////////////////////////////////
  96
  97 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
  98                                                    const GrSwizzle& swizzle,
  99                                                    PMConversion pmConversion,
 100                                                    const SkMatrix& matrix)
 101     : INHERITED(texture, nullptr, matrix)
 102     , fSwizzle(swizzle)
 103     , fPMConversion(pmConversion) {
 104     this->initClassID<GrConfigConversionEffect>();
 105     // We expect to get here with non-BGRA/RGBA only if we're doing not doing a premul/unpremul
 106     // conversion.
 107     SkASSERT((kRGBA_8888_GrPixelConfig == texture->config() ||
 108               kBGRA_8888_GrPixelConfig == texture->config()) ||
 109               kNone_PMConversion == pmConversion);
 110     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
 111     SkASSERT(swizzle != GrSwizzle::RGBA() || kNone_PMConversion != pmConversion);
 112 }
 113
 114 bool GrConfigConversionEffect::onIsEqual(const GrFragmentProcessor& s) const {
 115     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 116     return other.fSwizzle == fSwizzle &&
 117            other.fPMConversion == fPMConversion;
 118 }
 119
 120 void GrConfigConversionEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
 121     this->updateInvariantOutputForModulation(inout);
 122 }
 123
 124 ///////////////////////////////////////////////////////////////////////////////
 125
 126 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConfigConversionEffect);
 127
 128 sk_sp<GrFragmentProcessor> GrConfigConversionEffect::TestCreate(GrProcessorTestData* d) {
 129     PMConversion pmConv = static_cast<PMConversion>(d->fRandom->nextULessThan(kPMConversionCnt));
 130     GrSwizzle swizzle;
 131     do {
 132         swizzle = GrSwizzle::CreateRandom(d->fRandom);
 133     } while (pmConv == kNone_PMConversion && swizzle == GrSwizzle::RGBA());
 134     return sk_sp<GrFragmentProcessor>(
 135         new GrConfigConversionEffect(d->fTextures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 136                                      swizzle, pmConv, GrTest::TestMatrix(d->fRandom)));
 137 }
 138
 139 ///////////////////////////////////////////////////////////////////////////////
 140
 141 void GrConfigConversionEffect::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
 142                                                      GrProcessorKeyBuilder* b) const {
 143     GrGLConfigConversionEffect::GenKey(*this, caps, b);
 144 }
 145
 146 GrGLSLFragmentProcessor* GrConfigConversionEffect::onCreateGLSLInstance() const {
 147     return new GrGLConfigConversionEffect();
 148 }
 149
 150
 151
 152 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
 153                                                               PMConversion* pmToUPMRule,
 154                                                               PMConversion* upmToPMRule) {
 155     *pmToUPMRule = kNone_PMConversion;
 156     *upmToPMRule = kNone_PMConversion;
 157     static constexpr int kSize = 256;
 158     static constexpr GrPixelConfig kConfig = kRGBA_8888_GrPixelConfig;
 159     SkAutoTMalloc<uint32_t> data(kSize * kSize * 3);
 160     uint32_t* srcData = data.get();
 161     uint32_t* firstRead = data.get() + kSize * kSize;
 162     uint32_t* secondRead = data.get() + 2 * kSize * kSize;
 163
 164     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
 165     // values in row y. We set r,g, and b to the same value since they are handled identically.
 166     for (int y = 0; y < kSize; ++y) {
 167         for (int x = 0; x < kSize; ++x) {
 168             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[kSize*y + x]);
 169             color[3] = y;
 170             color[2] = SkTMin(x, y);
 171             color[1] = SkTMin(x, y);
 172             color[0] = SkTMin(x, y);
 173         }
 174     }
 175
 176     sk_sp<GrDrawContext> readDC(context->newDrawContext(SkBackingFit::kExact, kSize, kSize,
 177                                                         kConfig));
 178     sk_sp<GrDrawContext> tempDC(context->newDrawContext(SkBackingFit::kExact, kSize, kSize,
 179                                                         kConfig));
 180     if (!readDC || !tempDC) {
 181         return;
 182     }
 183     GrSurfaceDesc desc;
 184     desc.fWidth = kSize;
 185     desc.fHeight = kSize;
 186     desc.fConfig = kConfig;
 187     SkAutoTUnref<GrTexture> dataTex(context->textureProvider()->createTexture(
 188         desc, SkBudgeted::kYes, data, 0));
 189     if (!dataTex.get()) {
 190         return;
 191     }
 192
 193     static const PMConversion kConversionRules[][2] = {
 194         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 195         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 196     };
 197
 198     bool failed = true;
 199
 200     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 201         *pmToUPMRule = kConversionRules[i][0];
 202         *upmToPMRule = kConversionRules[i][1];
 203
 204         static const SkRect kDstRect = SkRect::MakeIWH(kSize, kSize);
 205         static const SkRect kSrcRect = SkRect::MakeIWH(1, 1);
 206         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 207         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 208         // We then verify that two reads produced the same values.
 209
 210         GrPaint paint1;
 211         GrPaint paint2;
 212         GrPaint paint3;
 213         sk_sp<GrFragmentProcessor> pmToUPM1(new GrConfigConversionEffect(
 214                 dataTex, GrSwizzle::RGBA(), *pmToUPMRule, SkMatrix::I()));
 215         sk_sp<GrFragmentProcessor> upmToPM(new GrConfigConversionEffect(
 216                 readDC->asTexture().get(), GrSwizzle::RGBA(), *upmToPMRule, SkMatrix::I()));
 217         sk_sp<GrFragmentProcessor> pmToUPM2(new GrConfigConversionEffect(
 218                 tempDC->asTexture().get(), GrSwizzle::RGBA(), *pmToUPMRule, SkMatrix::I()));
 219
 220         paint1.addColorFragmentProcessor(std::move(pmToUPM1));
 221         paint1.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 222
 223         readDC->fillRectToRect(GrNoClip(), paint1, SkMatrix::I(), kDstRect, kSrcRect);
 224
 225         readDC->asTexture()->readPixels(0, 0, kSize, kSize, kConfig, firstRead);
 226
 227         paint2.addColorFragmentProcessor(std::move(upmToPM));
 228         paint2.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 229
 230         tempDC->fillRectToRect(GrNoClip(), paint2, SkMatrix::I(), kDstRect, kSrcRect);
 231
 232         paint3.addColorFragmentProcessor(std::move(pmToUPM2));
 233         paint3.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 234
 235         readDC->fillRectToRect(GrNoClip(), paint3, SkMatrix::I(), kDstRect, kSrcRect);
 236
 237         readDC->asTexture()->readPixels(0, 0, kSize, kSize, kConfig, secondRead);
 238
 239         failed = false;
 240         for (int y = 0; y < kSize && !failed; ++y) {
 241             for (int x = 0; x <= y; ++x) {
 242                 if (firstRead[kSize * y + x] != secondRead[kSize * y + x]) {
 243                     failed = true;
 244                     break;
 245                 }
 246             }
 247         }
 248     }
 249     if (failed) {
 250         *pmToUPMRule = kNone_PMConversion;
 251         *upmToPMRule = kNone_PMConversion;
 252     }
 253 }
 254
 255 sk_sp<GrFragmentProcessor> GrConfigConversionEffect::Make(GrTexture* texture,
 256                                                           const GrSwizzle& swizzle,
 257                                                           PMConversion pmConversion,
 258                                                           const SkMatrix& matrix) {
 259     if (swizzle == GrSwizzle::RGBA() && kNone_PMConversion == pmConversion) {
 260         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 261         // then we may pollute our texture cache with redundant shaders. So in the case that no
 262         // conversions were requested we instead return a GrSimpleTextureEffect.
 263         return GrSimpleTextureEffect::Make(texture, nullptr, matrix);
 264     } else {
 265         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 266             kBGRA_8888_GrPixelConfig != texture->config() &&
 267             kNone_PMConversion != pmConversion) {
 268             // The PM conversions assume colors are 0..255
 269             return nullptr;
 270         }
 271         return sk_sp<GrFragmentProcessor>(
 272             new GrConfigConversionEffect(texture, swizzle, pmConversion, matrix));
 273     }
 274 }