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 "GrTBackendProcessorFactory.h"
  11 #include "GrSimpleTextureEffect.h"
  12 #include "gl/GrGLProcessor.h"
  13 #include "gl/builders/GrGLProgramBuilder.h"
  14 #include "SkMatrix.h"
  15
  16 class GrGLConfigConversionEffect : public GrGLFragmentProcessor {
  17 public:
  18     GrGLConfigConversionEffect(const GrBackendProcessorFactory& factory,
  19                                const GrProcessor& processor)
  20     : INHERITED (factory) {
  21         const GrConfigConversionEffect& configConversionEffect =
  22                 processor.cast<GrConfigConversionEffect>();
  23         fSwapRedAndBlue = configConversionEffect.swapsRedAndBlue();
  24         fPMConversion = configConversionEffect.pmConversion();
  25     }
  26
  27     virtual void emitCode(GrGLProgramBuilder* builder,
  28                           const GrFragmentProcessor&,
  29                           const GrProcessorKey& key,
  30                           const char* outputColor,
  31                           const char* inputColor,
  32                           const TransformedCoordsArray& coords,
  33                           const TextureSamplerArray& samplers) SK_OVERRIDE {
  34         // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
  35         GrGLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, GrGLShaderVar::kHigh_Precision);
  36         SkString tmpDecl;
  37         tmpVar.appendDecl(builder->ctxInfo(), &tmpDecl);
  38
  39         GrGLFragmentShaderBuilder* fsBuilder = builder->getFragmentShaderBuilder();
  40
  41         fsBuilder->codeAppendf("%s;", tmpDecl.c_str());
  42
  43         fsBuilder->codeAppendf("%s = ", tmpVar.c_str());
  44         fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
  45         fsBuilder->codeAppend(";");
  46
  47         if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
  48             SkASSERT(fSwapRedAndBlue);
  49             fsBuilder->codeAppendf("%s = %s.bgra;", outputColor, tmpVar.c_str());
  50         } else {
  51             const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
  52             switch (fPMConversion) {
  53                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
  54                     fsBuilder->codeAppendf(
  55                         "%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);",
  56                         tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  57                     break;
  58                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
  59                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
  60                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
  61                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
  62                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
  63                     fsBuilder->codeAppendf(
  64                         "%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
  65                         tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  66                     break;
  67                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
  68                     fsBuilder->codeAppendf(
  69                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%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                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
  73                     fsBuilder->codeAppendf(
  74                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
  75                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  76                     break;
  77                 default:
  78                     SkFAIL("Unknown conversion op.");
  79                     break;
  80             }
  81             fsBuilder->codeAppendf("%s = %s;", outputColor, tmpVar.c_str());
  82         }
  83         SkString modulate;
  84         GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
  85         fsBuilder->codeAppend(modulate.c_str());
  86     }
  87
  88     static inline void GenKey(const GrProcessor& processor, const GrGLCaps&,
  89                               GrProcessorKeyBuilder* b) {
  90         const GrConfigConversionEffect& conv = processor.cast<GrConfigConversionEffect>();
  91         uint32_t key = (conv.swapsRedAndBlue() ? 0 : 1) | (conv.pmConversion() << 1);
  92         b->add32(key);
  93     }
  94
  95 private:
  96     bool                                    fSwapRedAndBlue;
  97     GrConfigConversionEffect::PMConversion  fPMConversion;
  98
  99     typedef GrGLFragmentProcessor INHERITED;
 100
 101 };
 102
 103 ///////////////////////////////////////////////////////////////////////////////
 104
 105 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
 106                                                    bool swapRedAndBlue,
 107                                                    PMConversion pmConversion,
 108                                                    const SkMatrix& matrix)
 109     : GrSingleTextureEffect(texture, matrix)
 110     , fSwapRedAndBlue(swapRedAndBlue)
 111     , fPMConversion(pmConversion) {
 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 const GrBackendFragmentProcessorFactory& GrConfigConversionEffect::getFactory() const {
 119     return GrTBackendFragmentProcessorFactory<GrConfigConversionEffect>::getInstance();
 120 }
 121
 122 bool GrConfigConversionEffect::onIsEqual(const GrProcessor& s) const {
 123     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 124     return this->texture(0) == s.texture(0) &&
 125            other.fSwapRedAndBlue == fSwapRedAndBlue &&
 126            other.fPMConversion == fPMConversion;
 127 }
 128
 129 void GrConfigConversionEffect::getConstantColorComponents(GrColor* color,
 130                                                           uint32_t* validFlags) const {
 131     this->updateConstantColorComponentsForModulation(color, validFlags);
 132 }
 133
 134 ///////////////////////////////////////////////////////////////////////////////
 135
 136 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConfigConversionEffect);
 137
 138 GrFragmentProcessor* GrConfigConversionEffect::TestCreate(SkRandom* random,
 139                                                           GrContext*,
 140                                                           const GrDrawTargetCaps&,
 141                                                           GrTexture* textures[]) {
 142     PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
 143     bool swapRB;
 144     if (kNone_PMConversion == pmConv) {
 145         swapRB = true;
 146     } else {
 147         swapRB = random->nextBool();
 148     }
 149     return SkNEW_ARGS(GrConfigConversionEffect,
 150                                       (textures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 151                                        swapRB,
 152                                        pmConv,
 153                                        GrProcessorUnitTest::TestMatrix(random)));
 154 }
 155
 156 ///////////////////////////////////////////////////////////////////////////////
 157 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
 158                                                               PMConversion* pmToUPMRule,
 159                                                               PMConversion* upmToPMRule) {
 160     *pmToUPMRule = kNone_PMConversion;
 161     *upmToPMRule = kNone_PMConversion;
 162     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
 163     uint32_t* srcData = data.get();
 164     uint32_t* firstRead = data.get() + 256 * 256;
 165     uint32_t* secondRead = data.get() + 2 * 256 * 256;
 166
 167     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
 168     // values in row y. We set r,g, and b to the same value since they are handled identically.
 169     for (int y = 0; y < 256; ++y) {
 170         for (int x = 0; x < 256; ++x) {
 171             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
 172             color[3] = y;
 173             color[2] = SkTMin(x, y);
 174             color[1] = SkTMin(x, y);
 175             color[0] = SkTMin(x, y);
 176         }
 177     }
 178
 179     GrTextureDesc desc;
 180     desc.fFlags = kRenderTarget_GrTextureFlagBit |
 181                   kNoStencil_GrTextureFlagBit;
 182     desc.fWidth = 256;
 183     desc.fHeight = 256;
 184     desc.fConfig = kRGBA_8888_GrPixelConfig;
 185
 186     SkAutoTUnref<GrTexture> readTex(context->createUncachedTexture(desc, NULL, 0));
 187     if (!readTex.get()) {
 188         return;
 189     }
 190     SkAutoTUnref<GrTexture> tempTex(context->createUncachedTexture(desc, NULL, 0));
 191     if (!tempTex.get()) {
 192         return;
 193     }
 194     desc.fFlags = kNone_GrTextureFlags;
 195     SkAutoTUnref<GrTexture> dataTex(context->createUncachedTexture(desc, data, 0));
 196     if (!dataTex.get()) {
 197         return;
 198     }
 199
 200     static const PMConversion kConversionRules[][2] = {
 201         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 202         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 203     };
 204
 205     GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
 206
 207     bool failed = true;
 208
 209     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 210         *pmToUPMRule = kConversionRules[i][0];
 211         *upmToPMRule = kConversionRules[i][1];
 212
 213         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 214         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 215         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 216         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 217         // We then verify that two reads produced the same values.
 218
 219         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(
 220                 SkNEW_ARGS(GrConfigConversionEffect,
 221                            (dataTex, false, *pmToUPMRule, SkMatrix::I())));
 222         SkAutoTUnref<GrFragmentProcessor> upmToPM(
 223                 SkNEW_ARGS(GrConfigConversionEffect,
 224                            (readTex, false, *upmToPMRule, SkMatrix::I())));
 225         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(
 226                 SkNEW_ARGS(GrConfigConversionEffect,
 227                            (tempTex, false, *pmToUPMRule, SkMatrix::I())));
 228
 229         context->setRenderTarget(readTex->asRenderTarget());
 230         GrPaint paint1;
 231         paint1.addColorProcessor(pmToUPM1);
 232         context->drawRectToRect(paint1, kDstRect, kSrcRect);
 233
 234         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 235
 236         context->setRenderTarget(tempTex->asRenderTarget());
 237         GrPaint paint2;
 238         paint2.addColorProcessor(upmToPM);
 239         context->drawRectToRect(paint2, kDstRect, kSrcRect);
 240         context->setRenderTarget(readTex->asRenderTarget());
 241
 242         GrPaint paint3;
 243         paint3.addColorProcessor(pmToUPM2);
 244         context->drawRectToRect(paint3, kDstRect, kSrcRect);
 245
 246         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 247
 248         failed = false;
 249         for (int y = 0; y < 256 && !failed; ++y) {
 250             for (int x = 0; x <= y; ++x) {
 251                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 252                     failed = true;
 253                     break;
 254                 }
 255             }
 256         }
 257     }
 258     if (failed) {
 259         *pmToUPMRule = kNone_PMConversion;
 260         *upmToPMRule = kNone_PMConversion;
 261     }
 262 }
 263
 264 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrTexture* texture,
 265                                                  bool swapRedAndBlue,
 266                                                  PMConversion pmConversion,
 267                                                  const SkMatrix& matrix) {
 268     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
 269         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 270         // then we may pollute our texture cache with redundant shaders. So in the case that no
 271         // conversions were requested we instead return a GrSimpleTextureEffect.
 272         return GrSimpleTextureEffect::Create(texture, matrix);
 273     } else {
 274         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 275             kBGRA_8888_GrPixelConfig != texture->config() &&
 276             kNone_PMConversion != pmConversion) {
 277             // The PM conversions assume colors are 0..255
 278             return NULL;
 279         }
 280         return SkNEW_ARGS(GrConfigConversionEffect, (texture,
 281                                                      swapRedAndBlue,
 282                                                      pmConversion,
 283                                                      matrix));
 284     }
 285 }