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