src/third_party/skia/src/gpu/effects/GrDistanceFieldTextureEffect.h

   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