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 "GrInvariantOutput.h"
  11 #include "GrSimpleTextureEffect.h"
  12 #include "SkMatrix.h"
  13 #include "gl/GrGLProcessor.h"
  14 #include "gl/builders/GrGLProgramBuilder.h"
  15
  16 class GrGLConfigConversionEffect : public GrGLFragmentProcessor {
  17 public:
  18     GrGLConfigConversionEffect(const GrProcessor& processor) {
  19         const GrConfigConversionEffect& configConversionEffect =
  20                 processor.cast<GrConfigConversionEffect>();
  21         fSwapRedAndBlue = configConversionEffect.swapsRedAndBlue();
  22         fPMConversion = configConversionEffect.pmConversion();
  23     }
  24
  25     virtual void emitCode(GrGLFPBuilder* builder,
  26                           const GrFragmentProcessor&,
  27                           const char* outputColor,
  28                           const char* inputColor,
  29                           const TransformedCoordsArray& coords,
  30                           const TextureSamplerArray& samplers) SK_OVERRIDE {
  31         // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
  32         GrGLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, kHigh_GrSLPrecision);
  33         SkString tmpDecl;
  34         tmpVar.appendDecl(builder->ctxInfo(), &tmpDecl);
  35
  36         GrGLFPFragmentBuilder* fsBuilder = builder->getFragmentShaderBuilder();
  37
  38         fsBuilder->codeAppendf("%s;", tmpDecl.c_str());
  39
  40         fsBuilder->codeAppendf("%s = ", tmpVar.c_str());
  41         fsBuilder->appendTextureLookup(samplers[0], coords[0].c_str(), coords[0].getType());
  42         fsBuilder->codeAppend(";");
  43
  44         if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
  45             SkASSERT(fSwapRedAndBlue);
  46             fsBuilder->codeAppendf("%s = %s.bgra;", outputColor, tmpVar.c_str());
  47         } else {
  48             const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
  49             switch (fPMConversion) {
  50                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
  51                     fsBuilder->codeAppendf(
  52                         "%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);",
  53                         tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  54                     break;
  55                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
  56                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
  57                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
  58                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
  59                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
  60                     fsBuilder->codeAppendf(
  61                         "%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
  62                         tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  63                     break;
  64                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
  65                     fsBuilder->codeAppendf(
  66                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
  67                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  68                     break;
  69                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
  70                     fsBuilder->codeAppendf(
  71                         "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
  72                         tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
  73                     break;
  74                 default:
  75                     SkFAIL("Unknown conversion op.");
  76                     break;
  77             }
  78             fsBuilder->codeAppendf("%s = %s;", outputColor, tmpVar.c_str());
  79         }
  80         SkString modulate;
  81         GrGLSLMulVarBy4f(&modulate, outputColor, inputColor);
  82         fsBuilder->codeAppend(modulate.c_str());
  83     }
  84
  85     static inline void GenKey(const GrProcessor& processor, const GrGLCaps&,
  86                               GrProcessorKeyBuilder* b) {
  87         const GrConfigConversionEffect& conv = processor.cast<GrConfigConversionEffect>();
  88         uint32_t key = (conv.swapsRedAndBlue() ? 0 : 1) | (conv.pmConversion() << 1);
  89         b->add32(key);
  90     }
  91
  92 private:
  93     bool                                    fSwapRedAndBlue;
  94     GrConfigConversionEffect::PMConversion  fPMConversion;
  95
  96     typedef GrGLFragmentProcessor INHERITED;
  97
  98 };
  99
 100 ///////////////////////////////////////////////////////////////////////////////
 101
 102 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
 103                                                    bool swapRedAndBlue,
 104                                                    PMConversion pmConversion,
 105                                                    const SkMatrix& matrix)
 106     : GrSingleTextureEffect(texture, matrix)
 107     , fSwapRedAndBlue(swapRedAndBlue)
 108     , fPMConversion(pmConversion) {
 109     this->initClassID<GrConfigConversionEffect>();
 110     SkASSERT(kRGBA_8888_GrPixelConfig == texture->config() ||
 111              kBGRA_8888_GrPixelConfig == texture->config());
 112     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
 113     SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
 114 }
 115
 116 bool GrConfigConversionEffect::onIsEqual(const GrFragmentProcessor& s) const {
 117     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
 118     return other.fSwapRedAndBlue == fSwapRedAndBlue &&
 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 GrFragmentProcessor* GrConfigConversionEffect::TestCreate(SkRandom* random,
 131                                                           GrContext*,
 132                                                           const GrDrawTargetCaps&,
 133                                                           GrTexture* textures[]) {
 134     PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
 135     bool swapRB;
 136     if (kNone_PMConversion == pmConv) {
 137         swapRB = true;
 138     } else {
 139         swapRB = random->nextBool();
 140     }
 141     return SkNEW_ARGS(GrConfigConversionEffect,
 142                                       (textures[GrProcessorUnitTest::kSkiaPMTextureIdx],
 143                                        swapRB,
 144                                        pmConv,
 145                                        GrProcessorUnitTest::TestMatrix(random)));
 146 }
 147
 148 ///////////////////////////////////////////////////////////////////////////////
 149
 150 void GrConfigConversionEffect::getGLProcessorKey(const GrGLCaps& 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                   kNoStencil_GrSurfaceFlag;
 186     desc.fWidth = 256;
 187     desc.fHeight = 256;
 188     desc.fConfig = kRGBA_8888_GrPixelConfig;
 189
 190     SkAutoTUnref<GrTexture> readTex(context->createTexture(desc, true, NULL, 0));
 191     if (!readTex.get()) {
 192         return;
 193     }
 194     SkAutoTUnref<GrTexture> tempTex(context->createTexture(desc, true, NULL, 0));
 195     if (!tempTex.get()) {
 196         return;
 197     }
 198     desc.fFlags = kNone_GrSurfaceFlags;
 199     SkAutoTUnref<GrTexture> dataTex(context->createTexture(desc, true, data, 0));
 200     if (!dataTex.get()) {
 201         return;
 202     }
 203
 204     static const PMConversion kConversionRules[][2] = {
 205         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
 206         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
 207     };
 208
 209     GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
 210
 211     bool failed = true;
 212
 213     for (size_t i = 0; i < SK_ARRAY_COUNT(kConversionRules) && failed; ++i) {
 214         *pmToUPMRule = kConversionRules[i][0];
 215         *upmToPMRule = kConversionRules[i][1];
 216
 217         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
 218         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
 219         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
 220         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
 221         // We then verify that two reads produced the same values.
 222
 223         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(
 224                 SkNEW_ARGS(GrConfigConversionEffect,
 225                            (dataTex, false, *pmToUPMRule, SkMatrix::I())));
 226         SkAutoTUnref<GrFragmentProcessor> upmToPM(
 227                 SkNEW_ARGS(GrConfigConversionEffect,
 228                            (readTex, false, *upmToPMRule, SkMatrix::I())));
 229         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(
 230                 SkNEW_ARGS(GrConfigConversionEffect,
 231                            (tempTex, false, *pmToUPMRule, SkMatrix::I())));
 232
 233         context->setRenderTarget(readTex->asRenderTarget());
 234         GrPaint paint1;
 235         paint1.addColorProcessor(pmToUPM1);
 236         context->drawNonAARectToRect(paint1, SkMatrix::I(), kDstRect, kSrcRect);
 237
 238         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
 239
 240         context->setRenderTarget(tempTex->asRenderTarget());
 241         GrPaint paint2;
 242         paint2.addColorProcessor(upmToPM);
 243         context->drawNonAARectToRect(paint2, SkMatrix::I(), kDstRect, kSrcRect);
 244         context->setRenderTarget(readTex->asRenderTarget());
 245
 246         GrPaint paint3;
 247         paint3.addColorProcessor(pmToUPM2);
 248         context->drawNonAARectToRect(paint3, SkMatrix::I(), kDstRect, kSrcRect);
 249
 250         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
 251
 252         failed = false;
 253         for (int y = 0; y < 256 && !failed; ++y) {
 254             for (int x = 0; x <= y; ++x) {
 255                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
 256                     failed = true;
 257                     break;
 258                 }
 259             }
 260         }
 261     }
 262     if (failed) {
 263         *pmToUPMRule = kNone_PMConversion;
 264         *upmToPMRule = kNone_PMConversion;
 265     }
 266 }
 267
 268 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrTexture* texture,
 269                                                  bool swapRedAndBlue,
 270                                                  PMConversion pmConversion,
 271                                                  const SkMatrix& matrix) {
 272     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
 273         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
 274         // then we may pollute our texture cache with redundant shaders. So in the case that no
 275         // conversions were requested we instead return a GrSimpleTextureEffect.
 276         return GrSimpleTextureEffect::Create(texture, matrix);
 277     } else {
 278         if (kRGBA_8888_GrPixelConfig != texture->config() &&
 279             kBGRA_8888_GrPixelConfig != texture->config() &&
 280             kNone_PMConversion != pmConversion) {
 281             // The PM conversions assume colors are 0..255
 282             return NULL;
 283         }
 284         return SkNEW_ARGS(GrConfigConversionEffect, (texture,
 285                                                      swapRedAndBlue,
 286                                                      pmConversion,
 287                                                      matrix));
 288     }
 289 }