Potentially optimize some GrGLEffects for known input color values

src/effects/SkPerlinNoiseShader.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkDither.h"
 #include "SkPerlinNoiseShader.h"
 #include "SkFlattenableBuffers.h"
@@ skipping 513 matching lines @@
 public:
     GrGLPerlinNoise(const GrBackendEffectFactory& factory,
                     const GrDrawEffect& drawEffect)
       : GrGLNoise(factory, drawEffect) {}
     virtual ~GrGLPerlinNoise() {}
 
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
-                          const char* inputColor,
+                          const GrGLSLExpr4& inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 
 private:
     GrGLUniformManager::UniformHandle fStitchDataUni;
 
     typedef GrGLNoise INHERITED;
 };
 
 class GrGLSimplexNoise : public GrGLNoise {
     // Note : This is for reference only. GrGLPerlinNoise is used for processing.
 public:
     GrGLSimplexNoise(const GrBackendEffectFactory& factory,
                      const GrDrawEffect& drawEffect)
       : GrGLNoise(factory, drawEffect) {}
 
     virtual ~GrGLSimplexNoise() {}
 
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
-                          const char* inputColor,
+                          const GrGLSLExpr4& inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 
 private:
     GrGLUniformManager::UniformHandle fSeedUni;
 
     typedef GrGLNoise INHERITED;
 };
@@ skipping 177 matching lines @@
 
     return effect;
 }
 
 /////////////////////////////////////////////////////////////////////
 
 void GrGLSimplexNoise::emitCode(GrGLShaderBuilder* builder,
                                 const GrDrawEffect&,
                                 EffectKey key,
                                 const char* outputColor,
-                                const char* inputColor,
+                                const GrGLSLExpr4& inputColor,
                                 const TransformedCoordsArray& coords,
                                 const TextureSamplerArray&) {
     sk_ignore_unused_variable(inputColor);
 
     SkString vCoords = builder->ensureFSCoords2D(coords, 0);
 
     fSeedUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                    kFloat_GrSLType, "seed");
     const char* seedUni = builder->getUniformCStr(fSeedUni);
     fInvMatrixUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
@@ skipping 195 matching lines @@
 
     // Pre-multiply the result
     builder->fsCodeAppendf("\t\t%s = vec4(%s.rgb * %s.aaa, %s.a);\n",
                            outputColor, outputColor, outputColor, outputColor);
 }
 
 void GrGLPerlinNoise::emitCode(GrGLShaderBuilder* builder,
                                const GrDrawEffect&,
                                EffectKey key,
                                const char* outputColor,
-                               const char* inputColor,
+                               const GrGLSLExpr4& inputColor,
                                const TransformedCoordsArray& coords,
                                const TextureSamplerArray& samplers) {
     sk_ignore_unused_variable(inputColor);
 
     SkString vCoords = builder->ensureFSCoords2D(coords, 0);
 
     fInvMatrixUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                         kMat33f_GrSLType, "invMatrix");
     const char* invMatrixUni = builder->getUniformCStr(fInvMatrixUni);
     fBaseFrequencyUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
@@ skipping 384 matching lines @@
     str->append(" seed: ");
     str->appendScalar(fSeed);
     str->append(" stitch tiles: ");
     str->append(fStitchTiles ? "true " : "false ");
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif