Make swizzling in read/write pixel copy code more generic

src/gpu/effects/GrConfigConversionEffect.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrConfigConversionEffect.h"
 #include "GrContext.h"
 #include "GrDrawContext.h"
 #include "GrInvariantOutput.h"
 #include "GrSimpleTextureEffect.h"
 #include "SkMatrix.h"
 #include "glsl/GrGLSLFragmentProcessor.h"
 #include "glsl/GrGLSLFragmentShaderBuilder.h"
 
 class GrGLConfigConversionEffect : public GrGLSLFragmentProcessor {
 public:
-    GrGLConfigConversionEffect(const GrProcessor& processor) {
-        const GrConfigConversionEffect& configConversionEffect =
-                processor.cast<GrConfigConversionEffect>();
-        fSwapRedAndBlue = configConversionEffect.swapsRedAndBlue();
-        fPMConversion = configConversionEffect.pmConversion();
-    }
+    GrGLConfigConversionEffect() {}
 
     virtual void emitCode(EmitArgs& args) override {
+        const GrConfigConversionEffect& cce = args.fFp.cast<GrConfigConversionEffect>();
+        const GrSwizzle& swizzle = cce.swizzle();
+        GrConfigConversionEffect::PMConversion pmConversion = cce.pmConversion();
+
         // Using highp for GLES here in order to avoid some precision issues on specific GPUs.
         GrGLSLShaderVar tmpVar("tmpColor", kVec4f_GrSLType, 0, kHigh_GrSLPrecision);
         SkString tmpDecl;
         tmpVar.appendDecl(args.fGLSLCaps, &tmpDecl);
 
         GrGLSLFragmentBuilder* fragBuilder = args.fFragBuilder;
 
         fragBuilder->codeAppendf("%s;", tmpDecl.c_str());
 
         fragBuilder->codeAppendf("%s = ", tmpVar.c_str());
         fragBuilder->appendTextureLookup(args.fSamplers[0], args.fCoords[0].c_str(),
                                        args.fCoords[0].getType());
         fragBuilder->codeAppend(";");
 
-        if (GrConfigConversionEffect::kNone_PMConversion == fPMConversion) {
-            SkASSERT(fSwapRedAndBlue);
-            fragBuilder->codeAppendf("%s = %s.bgra;", args.fOutputColor, tmpVar.c_str());
+        if (GrConfigConversionEffect::kNone_PMConversion == pmConversion) {
+            SkASSERT(GrSwizzle::RGBA() != swizzle);
+            fragBuilder->codeAppendf("%s = %s.%s;", args.fOutputColor, tmpVar.c_str(),
+                                     swizzle.c_str());
         } else {
-            const char* swiz = fSwapRedAndBlue ? "bgr" : "rgb";
-            switch (fPMConversion) {
+            switch (pmConversion) {
                 case GrConfigConversionEffect::kMulByAlpha_RoundUp_PMConversion:
                     fragBuilder->codeAppendf(
-                        "%s = vec4(ceil(%s.%s * %s.a * 255.0) / 255.0, %s.a);",
-                        tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
+                        "%s = vec4(ceil(%s.rgb * %s.a * 255.0) / 255.0, %s.a);",
+                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str());
                     break;
                 case GrConfigConversionEffect::kMulByAlpha_RoundDown_PMConversion:
                     // Add a compensation(0.001) here to avoid the side effect of the floor operation.
                     // In Intel GPUs, the integer value converted from floor(%s.r * 255.0) / 255.0
                     // is less than the integer value converted from  %s.r by 1 when the %s.r is
                     // converted from the integer value 2^n, such as 1, 2, 4, 8, etc.
                     fragBuilder->codeAppendf(
-                        "%s = vec4(floor(%s.%s * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
-                        tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
+                        "%s = vec4(floor(%s.rgb * %s.a * 255.0 + 0.001) / 255.0, %s.a);",
+                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str());
+
                     break;
                 case GrConfigConversionEffect::kDivByAlpha_RoundUp_PMConversion:
                     fragBuilder->codeAppendf(
-                        "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
-                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
+                        "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(ceil(%s.rgb / %s.a * 255.0) / 255.0, %s.a);",
+                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(),
+                        tmpVar.c_str());
                     break;
                 case GrConfigConversionEffect::kDivByAlpha_RoundDown_PMConversion:
                     fragBuilder->codeAppendf(
-                        "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.%s / %s.a * 255.0) / 255.0, %s.a);",
-                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), swiz, tmpVar.c_str(), tmpVar.c_str());
+                        "%s = %s.a <= 0.0 ? vec4(0,0,0,0) : vec4(floor(%s.rgb / %s.a * 255.0) / 255.0, %s.a);",
+                        tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(), tmpVar.c_str(),
+                        tmpVar.c_str());
                     break;
                 default:
                     SkFAIL("Unknown conversion op.");
                     break;
             }
-            fragBuilder->codeAppendf("%s = %s;", args.fOutputColor, tmpVar.c_str());
+            fragBuilder->codeAppendf("%s = %s.%s;", args.fOutputColor, tmpVar.c_str(),
+                                     swizzle.c_str());
         }
         SkString modulate;
         GrGLSLMulVarBy4f(&modulate, args.fOutputColor, args.fInputColor);
         fragBuilder->codeAppend(modulate.c_str());
     }
 
     static inline void GenKey(const GrProcessor& processor, const GrGLSLCaps&,
                               GrProcessorKeyBuilder* b) {
-        const GrConfigConversionEffect& conv = processor.cast<GrConfigConversionEffect>();
-        uint32_t key = (conv.swapsRedAndBlue() ? 0 : 1) | (conv.pmConversion() << 1);
+        const GrConfigConversionEffect& cce = processor.cast<GrConfigConversionEffect>();
+        uint32_t key = (cce.swizzle().asKey()) | (cce.pmConversion() << 16);
         b->add32(key);
     }
 
 private:
-    bool                                    fSwapRedAndBlue;
-    GrConfigConversionEffect::PMConversion  fPMConversion;
-
     typedef GrGLSLFragmentProcessor INHERITED;
 
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 GrConfigConversionEffect::GrConfigConversionEffect(GrTexture* texture,
-                                                   bool swapRedAndBlue,
+                                                   const GrSwizzle& swizzle,
                                                    PMConversion pmConversion,
                                                    const SkMatrix& matrix)
     : INHERITED(texture, matrix)
-    , fSwapRedAndBlue(swapRedAndBlue)
+    , fSwizzle(swizzle)
     , fPMConversion(pmConversion) {
     this->initClassID<GrConfigConversionEffect>();
     // We expect to get here with non-BGRA/RGBA only if we're doing not doing a premul/unpremul
     // conversion.
     SkASSERT((kRGBA_8888_GrPixelConfig == texture->config() ||
               kBGRA_8888_GrPixelConfig == texture->config()) ||
               kNone_PMConversion == pmConversion);
     // Why did we pollute our texture cache instead of using a GrSingleTextureEffect?
-    SkASSERT(swapRedAndBlue || kNone_PMConversion != pmConversion);
+    SkASSERT(swizzle != GrSwizzle::RGBA() || kNone_PMConversion != pmConversion);
 }
 
 bool GrConfigConversionEffect::onIsEqual(const GrFragmentProcessor& s) const {
     const GrConfigConversionEffect& other = s.cast<GrConfigConversionEffect>();
-    return other.fSwapRedAndBlue == fSwapRedAndBlue &&
+    return other.fSwizzle == fSwizzle &&
            other.fPMConversion == fPMConversion;
 }
 
 void GrConfigConversionEffect::onComputeInvariantOutput(GrInvariantOutput* inout) const {
     this->updateInvariantOutputForModulation(inout);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 GR_DEFINE_FRAGMENT_PROCESSOR_TEST(GrConfigConversionEffect);
 
 const GrFragmentProcessor* GrConfigConversionEffect::TestCreate(GrProcessorTestData* d) {
     PMConversion pmConv = static_cast<PMConversion>(d->fRandom->nextULessThan(kPMConversionCnt));
-    bool swapRB;
-    if (kNone_PMConversion == pmConv) {
-        swapRB = true;
-    } else {
-        swapRB = d->fRandom->nextBool();
-    }
+    GrSwizzle swizzle;
+    do {
+        swizzle = GrSwizzle::CreateRandom(d->fRandom);
+    } while (pmConv == kNone_PMConversion && swizzle == GrSwizzle::RGBA());
     return new GrConfigConversionEffect(d->fTextures[GrProcessorUnitTest::kSkiaPMTextureIdx],
-                                        swapRB, pmConv, GrTest::TestMatrix(d->fRandom));
+                                        swizzle, pmConv, GrTest::TestMatrix(d->fRandom));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 void GrConfigConversionEffect::onGetGLSLProcessorKey(const GrGLSLCaps& caps,
                                                      GrProcessorKeyBuilder* b) const {
     GrGLConfigConversionEffect::GenKey(*this, caps, b);
 }
 
 GrGLSLFragmentProcessor* GrConfigConversionEffect::onCreateGLSLInstance() const {
-    return new GrGLConfigConversionEffect(*this);
+    return new GrGLConfigConversionEffect();
 }
 
 
 
 void GrConfigConversionEffect::TestForPreservingPMConversions(GrContext* context,
                                                               PMConversion* pmToUPMRule,
                                                               PMConversion* upmToPMRule) {
     *pmToUPMRule = kNone_PMConversion;
     *upmToPMRule = kNone_PMConversion;
     SkAutoTMalloc<uint32_t> data(256 * 256 * 3);
@@ skipping 47 matching lines @@
         static const SkRect kDstRect = SkRect::MakeWH(SkIntToScalar(256), SkIntToScalar(256));
         static const SkRect kSrcRect = SkRect::MakeWH(SK_Scalar1, SK_Scalar1);
         // We do a PM->UPM draw from dataTex to readTex and read the data. Then we do a UPM->PM draw
         // from readTex to tempTex followed by a PM->UPM draw to readTex and finally read the data.
         // We then verify that two reads produced the same values.
 
         GrPaint paint1;
         GrPaint paint2;
         GrPaint paint3;
         SkAutoTUnref<GrFragmentProcessor> pmToUPM1(new GrConfigConversionEffect(
-                dataTex, false, *pmToUPMRule, SkMatrix::I()));
+                dataTex, GrSwizzle::RGBA(), *pmToUPMRule, SkMatrix::I()));
         SkAutoTUnref<GrFragmentProcessor> upmToPM(new GrConfigConversionEffect(
-                readTex, false, *upmToPMRule, SkMatrix::I()));
+                readTex, GrSwizzle::RGBA(), *upmToPMRule, SkMatrix::I()));
         SkAutoTUnref<GrFragmentProcessor> pmToUPM2(new GrConfigConversionEffect(
-                tempTex, false, *pmToUPMRule, SkMatrix::I()));
+                tempTex, GrSwizzle::RGBA(), *pmToUPMRule, SkMatrix::I()));
 
         paint1.addColorFragmentProcessor(pmToUPM1);
         paint1.setPorterDuffXPFactory(SkXfermode::kSrc_Mode);
 
 
         SkAutoTUnref<GrDrawContext> readDrawContext(
                                     context->drawContext(readTex->asRenderTarget()));
         if (!readDrawContext) {
             failed = true;
             break;
@@ skipping 49 matching lines @@
             }
         }
     }
     if (failed) {
         *pmToUPMRule = kNone_PMConversion;
         *upmToPMRule = kNone_PMConversion;
     }
 }
 
 const GrFragmentProcessor* GrConfigConversionEffect::Create(GrTexture* texture,
-                                                            bool swapRedAndBlue,
+                                                            const GrSwizzle& swizzle,
                                                             PMConversion pmConversion,
                                                             const SkMatrix& matrix) {
-    if (!swapRedAndBlue && kNone_PMConversion == pmConversion) {
+    if (swizzle == GrSwizzle::RGBA() && kNone_PMConversion == pmConversion) {
         // If we returned a GrConfigConversionEffect that was equivalent to a GrSimpleTextureEffect
         // then we may pollute our texture cache with redundant shaders. So in the case that no
         // conversions were requested we instead return a GrSimpleTextureEffect.
         return GrSimpleTextureEffect::Create(texture, matrix);
     } else {
         if (kRGBA_8888_GrPixelConfig != texture->config() &&
             kBGRA_8888_GrPixelConfig != texture->config() &&
             kNone_PMConversion != pmConversion) {
             // The PM conversions assume colors are 0..255
             return nullptr;
         }
-        return new GrConfigConversionEffect(texture, swapRedAndBlue, pmConversion, matrix);
+        return new GrConfigConversionEffect(texture, swizzle, pmConversion, matrix);
     }
 }