Add LCD support for distance field text

src/gpu/effects/GrDistanceFieldTextureEffect.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDistanceFieldTextureEffect_DEFINED
 #define GrDistanceFieldTextureEffect_DEFINED
 
 #include "GrEffect.h"
 #include "GrVertexEffect.h"
 
 class GrGLDistanceFieldTextureEffect;
+class GrGLDistanceFieldLCDTextureEffect;
 
 /**
  * The output color of this effect is a modulation of the input color and a sample from a
  * distance field texture (using a smoothed step function near 0.5).
  * It allows explicit specification of the filtering and wrap modes (GrTextureParams). The input
  * coords are a custom attribute.
  */
 class GrDistanceFieldTextureEffect : public GrVertexEffect {
 public:
-    static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& para, bool uniformScale) {
-        AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, para, uniformScale)));
+    static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& params, bool similarity) {
+        AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, params, similarity)));
         return CreateEffectRef(effect);
     }
 
     virtual ~GrDistanceFieldTextureEffect() {}
 
     static const char* Name() { return "DistanceFieldTexture"; }
 
     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
-    bool isUniformScale() const { return fUniformScale; }
+    bool isSimilarity() const { return fIsSimilarity; }
 
     typedef GrGLDistanceFieldTextureEffect GLEffect;
 
     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
 
 private:
     GrDistanceFieldTextureEffect(GrTexture* texture, const GrTextureParams& params,
                                  bool uniformScale);
 
     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
 
     GrTextureAccess fTextureAccess;
-    bool            fUniformScale;
+    bool            fIsSimilarity;
 
     GR_DECLARE_EFFECT_TEST;
 
     typedef GrVertexEffect INHERITED;
 };
 
+/**
+ * The output color of this effect is a modulation of the input color and samples from a
+ * distance field texture (using a smoothed step function near 0.5), adjusted for LCD displays.
+ * It allows explicit specification of the filtering and wrap modes (GrTextureParams). The input
+ * coords are a custom attribute.
+ */
+class GrDistanceFieldLCDTextureEffect : public GrVertexEffect {
+public:
+    static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& params,
+                               bool uniformScale, bool useBGR) {
+        AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldLCDTextureEffect,
+                                          (tex, params, uniformScale, useBGR)));
+        return CreateEffectRef(effect);
+    }
+
+    virtual ~GrDistanceFieldLCDTextureEffect() {}
+
+    static const char* Name() { return "DistanceFieldLCDTexture"; }
+
+    virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
+    bool isUniformScale() const { return fUniformScale; }
+    bool useBGR() const { return fUseBGR; }
+
+    typedef GrGLDistanceFieldLCDTextureEffect GLEffect;
+
+    virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
+
+private:
+    GrDistanceFieldLCDTextureEffect(GrTexture* texture, const GrTextureParams& params,
+                                    bool uniformScale, bool useBGR);
+
+    virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
+
+    GrTextureAccess fTextureAccess;
+    bool            fUniformScale;
+    bool            fUseBGR;
+
+    GR_DECLARE_EFFECT_TEST;
+
+    typedef GrVertexEffect INHERITED;
+};
+
+
 #endif