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     GrGLConfigConversionEffect() {}
  20
  21     virtual void emitCode(EmitArgs& args) override {
  22         const GrConfigConversionEffect& cce = args.fFp.cast<GrConfigConversionEffect>();
  23         const GrSwizzle& swizzle = cce.swizzle();
  24         GrConfigConversionEffect::PMConversion pmConversion = cce.pmConversion();
  25
  26         // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
  27         GrGLSLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, kHigh_GrSLPrecision);
  28         SkString tmpDecl;
  29         tmpVar.appendDecl(args.fGLSLCaps, &tmpDecl);
  30
  31         GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
  32
  33         fragBuilder->codeAppendf("%s;", tmpDecl.c_str());
  34
  35         fragBuilder->codeAppendf("%s = ", tmpVar.c_str());
  36         fragBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str(),
  37                                        args.fCoords[0].getType());
  38         fragBuilder->codeAppend(";");
  39
  40         if (GrConfigConversionEffect::kNone_PMConversion == pmConversion) {
  41             SkASSERT(GrSwizzle::RGBA() != swizzle);
  42             fragBuilder->codeAppendf("%s = %s.%s;", args.fOutputColor, tmpVar.c_str(),
  43                                      swizzle.c_str());
  44         } else {
  45             switch (pmConversion) {
  46                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
  47                     fragBuilder->codeAppendf(
  48                         "%s = vec4(ceil(%s.rgb * %s.a * 255.0) / 255.0, %s.a);",
  49                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str());
  50                     break;
  51                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
  52                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
  53                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
  54                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
  55                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
  56                     fragBuilder->codeAppendf(
  57                         "%s = vec4(floor(%s.rgb * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
  58                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str());
  59
  60                     break;
  61                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
  62                     fragBuilder->codeAppendf(
  63                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.rgb / %s.a * 255.0) / 255.0, %s.a);",
  64                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(),
  65                         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.rgb / %s.a * 255.0) / 255.0, %s.a);",
  70                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(),
  71                         tmpVar.c_str());
  72                     break;
  73                 default:
  74                     SkFAIL("Unknown conversion op.");
  75                     break;
  76             }
  77             fragBuilder->codeAppendf("%s = %s.%s;", args.fOutputColor, tmpVar.c_str(),
  78                                      swizzle.c_str());
  79         }
  80         SkString modulate;
  81         GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
  82         fragBuilder->codeAppend(modulate.c_str());
  83     }
  84
  85     static inline void GenKey(const GrProcessor& processor, const GrGLSLCaps&,
  86                               GrProcessorKeyBuilder* b) {
  87         const GrConfigConversionEffect& cce = processor.cast<GrConfigConversionEffect>();
  88         uint32_t key = (cce.swizzle().asKey()) | (cce.pmConversion() << 16);
  89         b->add32(key);
  90     }
  91
  92 private:
  93     typedef GrGLSLFragmentProcessor INHERITED;
  94
  95 };
  96
  97 ///////////////////////////////////////////////////////////////////////////////
  98
  99 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
 100                                                    const GrSwizzle& swizzle,
 101                                                    PMConversion pmConversion,
 102                                                    const SkMatrix& matrix)
 103     : INHERITED(texture, matrix)
 104     , fSwizzle(swizzle)
 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(swizzle != GrSwizzle::RGBA() || kNone_PMConversion != pmConversion);
 114 }
 115
 116 bool GrConfigConversionEffect::onIsEqual(const GrFragmentProcessor& s) const {
 117     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 118     return other.fSwizzle == fSwizzle &&
 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     GrSwizzle swizzle;
 133     do {
 134         swizzle = GrSwizzle::CreateRandom(d->fRandom);
 135     } while (pmConv == kNone_PMConversion && swizzle == GrSwizzle::RGBA());
 136     return new GrConfigConversionEffect(d->fTextures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 137                                         swizzle, pmConv, GrTest::TestMatrix(d->fRandom));
 138 }
 139
 140 ///////////////////////////////////////////////////////////////////////////////
 141
 142 void GrConfigConversionEffect::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
 143                                                      GrProcessorKeyBuilder* b) const {
 144     GrGLConfigConversionEffect::GenKey(*this, caps, b);
 145 }
 146
 147 GrGLSLFragmentProcessor* GrConfigConversionEffect::onCreateGLSLInstance() const {
 148     return new GrGLConfigConversionEffect();
 149 }
 150
 151
 152
 153 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
 154                                                               PMConversion* pmToUPMRule,
 155                                                               PMConversion* upmToPMRule) {
 156     *pmToUPMRule = kNone_PMConversion;
 157     *upmToPMRule = kNone_PMConversion;
 158     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
 159     uint32_t* srcData = data.get();
 160     uint32_t* firstRead = data.get() + 256 * 256;
 161     uint32_t* secondRead = data.get() + 2 * 256 * 256;
 162
 163     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
 164     // values in row y. We set r,g, and b to the same value since they are handled identically.
 165     for (int y = 0; y < 256; ++y) {
 166         for (int x = 0; x < 256; ++x) {
 167             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
 168             color[3] = y;
 169             color[2] = SkTMin(x, y);
 170             color[1] = SkTMin(x, y);
 171             color[0] = SkTMin(x, y);
 172         }
 173     }
 174
 175     GrSurfaceDesc desc;
 176     desc.fFlags = kRenderTarget_GrSurfaceFlag;
 177     desc.fWidth = 256;
 178     desc.fHeight = 256;
 179     desc.fConfig = kRGBA_8888_GrPixelConfig;
 180
 181     SkAutoTUnref<GrTexture> readTex(context->textureProvider()->createTexture(desc, true, nullptr, 0));
 182     if (!readTex.get()) {
 183         return;
 184     }
 185     SkAutoTUnref<GrTexture> tempTex(context->textureProvider()->createTexture(desc, true, nullptr, 0));
 186     if (!tempTex.get()) {
 187         return;
 188     }
 189     desc.fFlags = kNone_GrSurfaceFlags;
 190     SkAutoTUnref<GrTexture> dataTex(context->textureProvider()->createTexture(desc, true, data, 0));
 191     if (!dataTex.get()) {
 192         return;
 193     }
 194
 195     static const PMConversion kConversionRules[][2] = {
 196         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 197         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 198     };
 199
 200     bool failed = true;
 201
 202     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 203         *pmToUPMRule = kConversionRules[i][0];
 204         *upmToPMRule = kConversionRules[i][1];
 205
 206         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 207         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 208         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 209         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 210         // We then verify that two reads produced the same values.
 211
 212         GrPaint paint1;
 213         GrPaint paint2;
 214         GrPaint paint3;
 215         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(new GrConfigConversionEffect(
 216                 dataTex, GrSwizzle::RGBA(), *pmToUPMRule, SkMatrix::I()));
 217         SkAutoTUnref<GrFragmentProcessor> upmToPM(new GrConfigConversionEffect(
 218                 readTex, GrSwizzle::RGBA(), *upmToPMRule, SkMatrix::I()));
 219         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(new GrConfigConversionEffect(
 220                 tempTex, GrSwizzle::RGBA(), *pmToUPMRule, SkMatrix::I()));
 221
 222         paint1.addColorFragmentProcessor(pmToUPM1);
 223         paint1.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 224
 225
 226         SkAutoTUnref<GrDrawContext> readDrawContext(
 227                                     context->drawContext(readTex->asRenderTarget()));
 228         if (!readDrawContext) {
 229             failed = true;
 230             break;
 231         }
 232
 233         readDrawContext->fillRectToRect(GrClip::WideOpen(),
 234                                         paint1,
 235                                         SkMatrix::I(),
 236                                         kDstRect,
 237                                         kSrcRect);
 238
 239         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 240
 241         paint2.addColorFragmentProcessor(upmToPM);
 242         paint2.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 243
 244         SkAutoTUnref<GrDrawContext> tempDrawContext(
 245                                     context->drawContext(tempTex->asRenderTarget()));
 246         if (!tempDrawContext) {
 247             failed = true;
 248             break;
 249         }
 250         tempDrawContext->fillRectToRect(GrClip::WideOpen(),
 251                                         paint2,
 252                                         SkMatrix::I(),
 253                                         kDstRect,
 254                                         kSrcRect);
 255
 256         paint3.addColorFragmentProcessor(pmToUPM2);
 257         paint3.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 258
 259         readDrawContext.reset(context->drawContext(readTex->asRenderTarget()));
 260         if (!readDrawContext) {
 261             failed = true;
 262             break;
 263         }
 264
 265         readDrawContext->fillRectToRect(GrClip::WideOpen(),
 266                                         paint3,
 267                                         SkMatrix::I(),
 268                                         kDstRect,
 269                                         kSrcRect);
 270
 271         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 272
 273         failed = false;
 274         for (int y = 0; y < 256 && !failed; ++y) {
 275             for (int x = 0; x <= y; ++x) {
 276                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 277                     failed = true;
 278                     break;
 279                 }
 280             }
 281         }
 282     }
 283     if (failed) {
 284         *pmToUPMRule = kNone_PMConversion;
 285         *upmToPMRule = kNone_PMConversion;
 286     }
 287 }
 288
 289 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrTexture* texture,
 290                                                             const GrSwizzle& swizzle,
 291                                                             PMConversion pmConversion,
 292                                                             const SkMatrix& matrix) {
 293     if (swizzle == GrSwizzle::RGBA() && kNone_PMConversion == pmConversion) {
 294         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 295         // then we may pollute our texture cache with redundant shaders. So in the case that no
 296         // conversions were requested we instead return a GrSimpleTextureEffect.
 297         return GrSimpleTextureEffect::Create(texture, matrix);
 298     } else {
 299         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 300             kBGRA_8888_GrPixelConfig != texture->config() &&
 301             kNone_PMConversion != pmConversion) {
 302             // The PM conversions assume colors are 0..255
 303             return nullptr;
 304         }
 305         return new GrConfigConversionEffect(texture, swizzle, pmConversion, matrix);
 306     }
 307 }