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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #ifndef GrDistanceFieldTextureEffect_DEFINED
      9 #define GrDistanceFieldTextureEffect_DEFINED
     10 
     11 #include "GrEffect.h"
     12 #include "GrVertexEffect.h"
     13 
     14 class GrGLDistanceFieldTextureEffect;
     15 class GrGLDistanceFieldLCDTextureEffect;
     16 
     17 /**
     18  * The output color of this effect is a modulation of the input color and a sample from a
     19  * distance field texture (using a smoothed step function near 0.5).
     20  * It allows explicit specification of the filtering and wrap modes (GrTextureParams). The input
     21  * coords are a custom attribute. Gamma correction is handled via a texture LUT.
     22  */
     23 class GrDistanceFieldTextureEffect : public GrVertexEffect {
     24 public:
     25 #ifdef SK_GAMMA_APPLY_TO_A8
     26     static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& params,
     27                                GrTexture* gamma, const GrTextureParams& gammaParams, float lum,
     28                                bool similarity) {
     29         AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, params,
     30                                                                          gamma, gammaParams, lum,
     31                                                                          similarity)));
     32 #else
     33     static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& params,
     34                                bool similarity) {
     35         AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldTextureEffect, (tex, params,
     36                                                                          similarity)));
     37 #endif
     38         return CreateEffectRef(effect);
     39     }
     40 
     41     virtual ~GrDistanceFieldTextureEffect() {}
     42 
     43     static const char* Name() { return "DistanceFieldTexture"; }
     44 
     45     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
     46 #ifdef SK_GAMMA_APPLY_TO_A8
     47     float getLuminance() const { return fLuminance; }
     48 #endif
     49     bool isSimilarity() const { return fIsSimilarity; }
     50 
     51     typedef GrGLDistanceFieldTextureEffect GLEffect;
     52 
     53     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
     54 
     55 private:
     56     GrDistanceFieldTextureEffect(GrTexture* texture, const GrTextureParams& params,
     57 #ifdef SK_GAMMA_APPLY_TO_A8
     58                                  GrTexture* gamma, const GrTextureParams& gammaParams, float lum,
     59 #endif
     60                                  bool uniformScale);
     61 
     62     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
     63 
     64     GrTextureAccess fTextureAccess;
     65 #ifdef SK_GAMMA_APPLY_TO_A8
     66     GrTextureAccess fGammaTextureAccess;
     67     float           fLuminance;
     68 #endif
     69     bool            fIsSimilarity;
     70 
     71     GR_DECLARE_EFFECT_TEST;
     72 
     73     typedef GrVertexEffect INHERITED;
     74 };
     75 
     76 /**
     77  * The output color of this effect is a modulation of the input color and samples from a
     78  * distance field texture (using a smoothed step function near 0.5), adjusted for LCD displays.
     79  * It allows explicit specification of the filtering and wrap modes (GrTextureParams). The input
     80  * coords are a custom attribute. Gamma correction is handled via a texture LUT.
     81  */
     82 class GrDistanceFieldLCDTextureEffect : public GrVertexEffect {
     83 public:
     84     static GrEffectRef* Create(GrTexture* tex, const GrTextureParams& params,
     85                                GrTexture* gamma, const GrTextureParams& gammaParams,
     86                                SkColor textColor,
     87                                bool uniformScale, bool useBGR) {
     88         AutoEffectUnref effect(SkNEW_ARGS(GrDistanceFieldLCDTextureEffect,
     89                                           (tex, params, gamma, gammaParams, textColor, uniformScale,
     90                                            useBGR)));
     91         return CreateEffectRef(effect);
     92     }
     93 
     94     virtual ~GrDistanceFieldLCDTextureEffect() {}
     95 
     96     static const char* Name() { return "DistanceFieldLCDTexture"; }
     97 
     98     virtual void getConstantColorComponents(GrColor* color, uint32_t* validFlags) const SK_OVERRIDE;
     99     GrColor getTextColor() const { return fTextColor; }
    100     bool isUniformScale() const { return fUniformScale; }
    101     bool useBGR() const { return fUseBGR; }
    102 
    103     typedef GrGLDistanceFieldLCDTextureEffect GLEffect;
    104 
    105     virtual const GrBackendEffectFactory& getFactory() const SK_OVERRIDE;
    106 
    107 private:
    108     GrDistanceFieldLCDTextureEffect(GrTexture* texture, const GrTextureParams& params,
    109                                     GrTexture* gamma, const GrTextureParams& gammaParams,
    110                                     SkColor textColor,
    111                                     bool uniformScale, bool useBGR);
    112 
    113     virtual bool onIsEqual(const GrEffect& other) const SK_OVERRIDE;
    114 
    115     GrTextureAccess fTextureAccess;
    116     GrTextureAccess fGammaTextureAccess;
    117     GrColor         fTextColor;
    118     bool            fUniformScale;
    119     bool            fUseBGR;
    120 
    121     GR_DECLARE_EFFECT_TEST;
    122 
    123     typedef GrVertexEffect INHERITED;
    124 };
    125 
    126 #endif
    127