Potentially optimize some GrGLEffects for known input color values

src/effects/SkDisplacementMapEffect.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 "SkDisplacementMapEffect.h"
 #include "SkFlattenableBuffers.h"
 #include "SkUnPreMultiply.h"
@@ skipping 190 matching lines @@
 class GrGLDisplacementMapEffect : public GrGLEffect {
 public:
     GrGLDisplacementMapEffect(const GrBackendEffectFactory& factory,
                               const GrDrawEffect& drawEffect);
     virtual ~GrGLDisplacementMapEffect();
 
     virtual void emitCode(GrGLShaderBuilder*,
                           const GrDrawEffect&,
                           EffectKey,
                           const char* outputColor,
-                          const char* inputColor,
+                          const GrGLSLExpr4& inputColor,
                           const TransformedCoordsArray&,
                           const TextureSamplerArray&) SK_OVERRIDE;
 
     static inline EffectKey GenKey(const GrDrawEffect&, const GrGLCaps&);
 
     virtual void setData(const GrGLUniformManager&, const GrDrawEffect&) SK_OVERRIDE;
 
 private:
     SkDisplacementMapEffect::ChannelSelectorType fXChannelSelector;
     SkDisplacementMapEffect::ChannelSelectorType fYChannelSelector;
@@ skipping 178 matching lines @@
     , fYChannelSelector(drawEffect.castEffect<GrDisplacementMapEffect>().yChannelSelector()) {
 }
 
 GrGLDisplacementMapEffect::~GrGLDisplacementMapEffect() {
 }
 
 void GrGLDisplacementMapEffect::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);
 
     fScaleUni = builder->addUniform(GrGLShaderBuilder::kFragment_Visibility,
                                     kVec2f_GrSLType, "Scale");
     const char* scaleUni = builder->getUniformCStr(fScaleUni);
     const char* dColor = "dColor";
     const char* cCoords = "cCoords";
     const char* outOfBounds = "outOfBounds";
@@ skipping 75 matching lines @@
                                                         const GrGLCaps&) {
     const GrDisplacementMapEffect& displacementMap =
         drawEffect.castEffect<GrDisplacementMapEffect>();
 
     EffectKey xKey = displacementMap.xChannelSelector();
     EffectKey yKey = displacementMap.yChannelSelector() << SkDisplacementMapEffect::kKeyBits;
 
     return xKey | yKey;
 }
 #endif