michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #include "GrConfigConversionEffect.h"
michael@0: #include "GrContext.h"
michael@0: #include "GrTBackendEffectFactory.h"
michael@0: #include "GrSimpleTextureEffect.h"
michael@0: #include "gl/GrGLEffect.h"
michael@0: #include "SkMatrix.h"
michael@0: 
michael@0: class GrGLConfigConversionEffect : public GrGLEffect {
michael@0: public:
michael@0:     GrGLConfigConversionEffect(const GrBackendEffectFactory& factory,
michael@0:                                const GrDrawEffect& drawEffect)
michael@0:     : INHERITED (factory) {
michael@0:         const GrConfigConversionEffect& effect = drawEffect.castEffect<GrConfigConversionEffect>();
michael@0:         fSwapRedAndBlue = effect.swapsRedAndBlue();
michael@0:         fPMConversion = effect.pmConversion();
michael@0:     }
michael@0: 
michael@0:     virtual void emitCode(GrGLShaderBuilder* builder,
michael@0:                           const GrDrawEffect&,
michael@0:                           EffectKey key,
michael@0:                           const char* outputColor,
michael@0:                           const char* inputColor,
michael@0:                           const TransformedCoordsArray& coords,
michael@0:                           const TextureSamplerArray& samplers) SK_OVERRIDE {
michael@0:         builder->fsCodeAppendf("\t\t%s = ", outputColor);
michael@0:         builder->fsAppendTextureLookup(samplers[0], coords[0].c_str(), coords[0].type());
michael@0:         builder->fsCodeAppend(";\n");
michael@0:         if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
michael@0:             SkASSERT(fSwapRedAndBlue);
michael@0:             builder->fsCodeAppendf("\t%s = %s.bgra;\n", outputColor, outputColor);
michael@0:         } else {
michael@0:             const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
michael@0:             switch (fPMConversion) {
michael@0:                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
michael@0:                     builder->fsCodeAppendf(
michael@0:                         "\t\t%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);\n",
michael@0:                         outputColor, outputColor, swiz, outputColor, outputColor);
michael@0:                     break;
michael@0:                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
michael@0:                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
michael@0:                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
michael@0:                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
michael@0:                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
michael@0:                     builder->fsCodeAppendf(
michael@0:                         "\t\t%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);\n",
michael@0:                         outputColor, outputColor, swiz, outputColor, outputColor);
michael@0:                     break;
michael@0:                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
michael@0:                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
michael@0:                         outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
michael@0:                     break;
michael@0:                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
michael@0:                     builder->fsCodeAppendf("\t\t%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);\n",
michael@0:                         outputColor, outputColor, outputColor, swiz, outputColor, outputColor);
michael@0:                     break;
michael@0:                 default:
michael@0:                     GrCrash("Unknown conversion op.");
michael@0:                     break;
michael@0:             }
michael@0:         }
michael@0:         SkString modulate;
michael@0:         GrGLSLMulVarBy4f(&modulate, 2, outputColor, inputColor);
michael@0:         builder->fsCodeAppend(modulate.c_str());
michael@0:     }
michael@0: 
michael@0:     static inline EffectKey GenKey(const GrDrawEffect& drawEffect, const GrGLCaps&) {
michael@0:         const GrConfigConversionEffect& conv = drawEffect.castEffect<GrConfigConversionEffect>();
michael@0:         return static_cast<EffectKey>(conv.swapsRedAndBlue()) | (conv.pmConversion() << 1);
michael@0:     }
michael@0: 
michael@0: private:
michael@0:     bool                                    fSwapRedAndBlue;
michael@0:     GrConfigConversionEffect::PMConversion  fPMConversion;
michael@0: 
michael@0:     typedef GrGLEffect INHERITED;
michael@0: 
michael@0: };
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
michael@0:                                                    bool swapRedAndBlue,
michael@0:                                                    PMConversion pmConversion,
michael@0:                                                    const SkMatrix& matrix)
michael@0:     : GrSingleTextureEffect(texture, matrix)
michael@0:     , fSwapRedAndBlue(swapRedAndBlue)
michael@0:     , fPMConversion(pmConversion) {
michael@0:     SkASSERT(kRGBA_8888_GrPixelConfig == texture->config() ||
michael@0:              kBGRA_8888_GrPixelConfig == texture->config());
michael@0:     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
michael@0:     SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
michael@0: }
michael@0: 
michael@0: const GrBackendEffectFactory& GrConfigConversionEffect::getFactory() const {
michael@0:     return GrTBackendEffectFactory<GrConfigConversionEffect>::getInstance();
michael@0: }
michael@0: 
michael@0: bool GrConfigConversionEffect::onIsEqual(const GrEffect& s) const {
michael@0:     const GrConfigConversionEffect& other = CastEffect<GrConfigConversionEffect>(s);
michael@0:     return this->texture(0) == s.texture(0) &&
michael@0:            other.fSwapRedAndBlue == fSwapRedAndBlue &&
michael@0:            other.fPMConversion == fPMConversion;
michael@0: }
michael@0: 
michael@0: void GrConfigConversionEffect::getConstantColorComponents(GrColor* color,
michael@0:                                                           uint32_t* validFlags) const {
michael@0:     this->updateConstantColorComponentsForModulation(color, validFlags);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: 
michael@0: GR_DEFINE_EFFECT_TEST(GrConfigConversionEffect);
michael@0: 
michael@0: GrEffectRef* GrConfigConversionEffect::TestCreate(SkRandom* random,
michael@0:                                                   GrContext*,
michael@0:                                                   const GrDrawTargetCaps&,
michael@0:                                                   GrTexture* textures[]) {
michael@0:     PMConversion pmConv = static_cast<PMConversion>(random->nextULessThan(kPMConversionCnt));
michael@0:     bool swapRB;
michael@0:     if (kNone_PMConversion == pmConv) {
michael@0:         swapRB = true;
michael@0:     } else {
michael@0:         swapRB = random->nextBool();
michael@0:     }
michael@0:     AutoEffectUnref effect(SkNEW_ARGS(GrConfigConversionEffect,
michael@0:                                       (textures[GrEffectUnitTest::kSkiaPMTextureIdx],
michael@0:                                        swapRB,
michael@0:                                        pmConv,
michael@0:                                        GrEffectUnitTest::TestMatrix(random))));
michael@0:     return CreateEffectRef(effect);
michael@0: }
michael@0: 
michael@0: ///////////////////////////////////////////////////////////////////////////////
michael@0: void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
michael@0:                                                               PMConversion* pmToUPMRule,
michael@0:                                                               PMConversion* upmToPMRule) {
michael@0:     *pmToUPMRule = kNone_PMConversion;
michael@0:     *upmToPMRule = kNone_PMConversion;
michael@0:     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
michael@0:     uint32_t* srcData = data.get();
michael@0:     uint32_t* firstRead = data.get() + 256 * 256;
michael@0:     uint32_t* secondRead = data.get() + 2 * 256 * 256;
michael@0: 
michael@0:     // Fill with every possible premultiplied A, color channel value. There will be 256-y duplicate
michael@0:     // values in row y. We set r,g, and b to the same value since they are handled identically.
michael@0:     for (int y = 0; y < 256; ++y) {
michael@0:         for (int x = 0; x < 256; ++x) {
michael@0:             uint8_t* color = reinterpret_cast<uint8_t*>(&srcData[256*y + x]);
michael@0:             color[3] = y;
michael@0:             color[2] = GrMin(x, y);
michael@0:             color[1] = GrMin(x, y);
michael@0:             color[0] = GrMin(x, y);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     GrTextureDesc desc;
michael@0:     desc.fFlags = kRenderTarget_GrTextureFlagBit |
michael@0:                   kNoStencil_GrTextureFlagBit;
michael@0:     desc.fWidth = 256;
michael@0:     desc.fHeight = 256;
michael@0:     desc.fConfig = kRGBA_8888_GrPixelConfig;
michael@0: 
michael@0:     SkAutoTUnref<GrTexture> readTex(context->createUncachedTexture(desc, NULL, 0));
michael@0:     if (!readTex.get()) {
michael@0:         return;
michael@0:     }
michael@0:     SkAutoTUnref<GrTexture> tempTex(context->createUncachedTexture(desc, NULL, 0));
michael@0:     if (!tempTex.get()) {
michael@0:         return;
michael@0:     }
michael@0:     desc.fFlags = kNone_GrTextureFlags;
michael@0:     SkAutoTUnref<GrTexture> dataTex(context->createUncachedTexture(desc, data, 0));
michael@0:     if (!dataTex.get()) {
michael@0:         return;
michael@0:     }
michael@0: 
michael@0:     static const PMConversion kConversionRules[][2] = {
michael@0:         {kDivByAlpha_RoundDown_PMConversion, kMulByAlpha_RoundUp_PMConversion},
michael@0:         {kDivByAlpha_RoundUp_PMConversion, kMulByAlpha_RoundDown_PMConversion},
michael@0:     };
michael@0: 
michael@0:     GrContext::AutoWideOpenIdentityDraw awoid(context, NULL);
michael@0: 
michael@0:     bool failed = true;
michael@0: 
michael@0:     for (size_t i = 0; i < GR_ARRAY_COUNT(kConversionRules) && failed; ++i) {
michael@0:         *pmToUPMRule = kConversionRules[i][0];
michael@0:         *upmToPMRule = kConversionRules[i][1];
michael@0: 
michael@0:         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
michael@0:         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
michael@0:         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
michael@0:         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
michael@0:         // We then verify that two reads produced the same values.
michael@0: 
michael@0:         AutoEffectUnref pmToUPM1(SkNEW_ARGS(GrConfigConversionEffect, (dataTex,
michael@0:                                                                        false,
michael@0:                                                                        *pmToUPMRule,
michael@0:                                                                        SkMatrix::I())));
michael@0:         AutoEffectUnref upmToPM(SkNEW_ARGS(GrConfigConversionEffect, (readTex,
michael@0:                                                                       false,
michael@0:                                                                       *upmToPMRule,
michael@0:                                                                       SkMatrix::I())));
michael@0:         AutoEffectUnref pmToUPM2(SkNEW_ARGS(GrConfigConversionEffect, (tempTex,
michael@0:                                                                        false,
michael@0:                                                                        *pmToUPMRule,
michael@0:                                                                        SkMatrix::I())));
michael@0: 
michael@0:         SkAutoTUnref<GrEffectRef> pmToUPMEffect1(CreateEffectRef(pmToUPM1));
michael@0:         SkAutoTUnref<GrEffectRef> upmToPMEffect(CreateEffectRef(upmToPM));
michael@0:         SkAutoTUnref<GrEffectRef> pmToUPMEffect2(CreateEffectRef(pmToUPM2));
michael@0: 
michael@0:         context->setRenderTarget(readTex->asRenderTarget());
michael@0:         GrPaint paint1;
michael@0:         paint1.addColorEffect(pmToUPMEffect1);
michael@0:         context->drawRectToRect(paint1, kDstRect, kSrcRect);
michael@0: 
michael@0:         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, firstRead);
michael@0: 
michael@0:         context->setRenderTarget(tempTex->asRenderTarget());
michael@0:         GrPaint paint2;
michael@0:         paint2.addColorEffect(upmToPMEffect);
michael@0:         context->drawRectToRect(paint2, kDstRect, kSrcRect);
michael@0:         context->setRenderTarget(readTex->asRenderTarget());
michael@0: 
michael@0:         GrPaint paint3;
michael@0:         paint3.addColorEffect(pmToUPMEffect2);
michael@0:         context->drawRectToRect(paint3, kDstRect, kSrcRect);
michael@0: 
michael@0:         readTex->readPixels(0, 0, 256, 256, kRGBA_8888_GrPixelConfig, secondRead);
michael@0: 
michael@0:         failed = false;
michael@0:         for (int y = 0; y < 256 && !failed; ++y) {
michael@0:             for (int x = 0; x <= y; ++x) {
michael@0:                 if (firstRead[256 * y + x] != secondRead[256 * y + x]) {
michael@0:                     failed = true;
michael@0:                     break;
michael@0:                 }
michael@0:             }
michael@0:         }
michael@0:     }
michael@0:     if (failed) {
michael@0:         *pmToUPMRule = kNone_PMConversion;
michael@0:         *upmToPMRule = kNone_PMConversion;
michael@0:     }
michael@0: }
michael@0: 
michael@0: const GrEffectRef* GrConfigConversionEffect::Create(GrTexture* texture,
michael@0:                                                     bool swapRedAndBlue,
michael@0:                                                     PMConversion pmConversion,
michael@0:                                                     const SkMatrix& matrix) {
michael@0:     if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
michael@0:         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
michael@0:         // then we may pollute our texture cache with redundant shaders. So in the case that no
michael@0:         // conversions were requested we instead return a GrSimpleTextureEffect.
michael@0:         return GrSimpleTextureEffect::Create(texture, matrix);
michael@0:     } else {
michael@0:         if (kRGBA_8888_GrPixelConfig != texture->config() &&
michael@0:             kBGRA_8888_GrPixelConfig != texture->config() &&
michael@0:             kNone_PMConversion != pmConversion) {
michael@0:             // The PM conversions assume colors are 0..255
michael@0:             return NULL;
michael@0:         }
michael@0:         AutoEffectUnref effect(SkNEW_ARGS(GrConfigConversionEffect, (texture,
michael@0:                                                                      swapRedAndBlue,
michael@0:                                                                      pmConversion,
michael@0:                                                                      matrix)));
michael@0:         return CreateEffectRef(effect);
michael@0:     }
michael@0: }