src/third_party/skia/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(GrGLFPBuilder* 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         GrGLFPFragmentBuilder* 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, 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 GrFragmentProcessor& s) const {
 123     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 124     return other.fSwapRedAndBlue == fSwapRedAndBlue &&
 125            other.fPMConversion == fPMConversion;
 126 }
 127
 128 void GrConfigConversionEffect::onComputeInvariantOutput(InvariantOutput* inout) const {
 129     this->updateInvariantOutputForModulation(inout);
 130 }
 131
 132 ///////////////////////////////////////////////////////////////////////////////
 133
 134 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConfigConversionEffect);
 135
 136 GrFragmentProcessor* GrConfigConversionEffect::TestCreate(SkRandom* random,
 137                                                           GrContext*,
 138                                                           const GrDrawTargetCaps&,
 139                                                           GrTexture* textures[]) {
 140     PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
 141     bool swapRB;
 142     if (kNone_PMConversion == pmConv) {
 143         swapRB = true;
 144     } else {
 145         swapRB = random->nextBool();
 146     }
 147     return SkNEW_ARGS(GrConfigConversionEffect,
 148                                       (textures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 149                                        swapRB,
 150                                        pmConv,
 151                                        GrProcessorUnitTest::TestMatrix(random)));
 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                   kNoStencil_GrSurfaceFlag;
 180     desc.fWidth = 256;
 181     desc.fHeight = 256;
 182     desc.fConfig = kRGBA_8888_GrPixelConfig;
 183
 184     SkAutoTUnref<GrTexture> readTex(context->createUncachedTexture(desc, NULL, 0));
 185     if (!readTex.get()) {
 186         return;
 187     }
 188     SkAutoTUnref<GrTexture> tempTex(context->createUncachedTexture(desc, NULL, 0));
 189     if (!tempTex.get()) {
 190         return;
 191     }
 192     desc.fFlags = kNone_GrSurfaceFlags;
 193     SkAutoTUnref<GrTexture> dataTex(context->createUncachedTexture(desc, data, 0));
 194     if (!dataTex.get()) {
 195         return;
 196     }
 197
 198     static const PMConversion kConversionRules[][2] = {
 199         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 200         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 201     };
 202
 203     GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
 204
 205     bool failed = true;
 206
 207     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 208         *pmToUPMRule = kConversionRules[i][0];
 209         *upmToPMRule = kConversionRules[i][1];
 210
 211         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 212         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 213         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 214         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 215         // We then verify that two reads produced the same values.
 216
 217         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(
 218                 SkNEW_ARGS(GrConfigConversionEffect,
 219                            (dataTex, false, *pmToUPMRule, SkMatrix::I())));
 220         SkAutoTUnref<GrFragmentProcessor> upmToPM(
 221                 SkNEW_ARGS(GrConfigConversionEffect,
 222                            (readTex, false, *upmToPMRule, SkMatrix::I())));
 223         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(
 224                 SkNEW_ARGS(GrConfigConversionEffect,
 225                            (tempTex, false, *pmToUPMRule, SkMatrix::I())));
 226
 227         context->setRenderTarget(readTex->asRenderTarget());
 228         GrPaint paint1;
 229         paint1.addColorProcessor(pmToUPM1);
 230         context->drawRectToRect(paint1, kDstRect, kSrcRect);
 231
 232         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 233
 234         context->setRenderTarget(tempTex->asRenderTarget());
 235         GrPaint paint2;
 236         paint2.addColorProcessor(upmToPM);
 237         context->drawRectToRect(paint2, kDstRect, kSrcRect);
 238         context->setRenderTarget(readTex->asRenderTarget());
 239
 240         GrPaint paint3;
 241         paint3.addColorProcessor(pmToUPM2);
 242         context->drawRectToRect(paint3, kDstRect, kSrcRect);
 243
 244         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 245
 246         failed = false;
 247         for (int y = 0; y < 256 && !failed; ++y) {
 248             for (int x = 0; x <= y; ++x) {
 249                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 250                     failed = true;
 251                     break;
 252                 }
 253             }
 254         }
 255     }
 256     if (failed) {
 257         *pmToUPMRule = kNone_PMConversion;
 258         *upmToPMRule = kNone_PMConversion;
 259     }
 260 }
 261
 262 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrTexture* texture,
 263                                                  bool swapRedAndBlue,
 264                                                  PMConversion pmConversion,
 265                                                  const SkMatrix& matrix) {
 266     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
 267         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 268         // then we may pollute our texture cache with redundant shaders. So in the case that no
 269         // conversions were requested we instead return a GrSimpleTextureEffect.
 270         return GrSimpleTextureEffect::Create(texture, matrix);
 271     } else {
 272         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 273             kBGRA_8888_GrPixelConfig != texture->config() &&
 274             kNone_PMConversion != pmConversion) {
 275             // The PM conversions assume colors are 0..255
 276             return NULL;
 277         }
 278         return SkNEW_ARGS(GrConfigConversionEffect, (texture,
 279                                                      swapRedAndBlue,
 280                                                      pmConversion,
 281                                                      matrix));
 282     }
 283 }