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
14class GrGLDistanceFieldTextureEffect;
15class 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 */
23class GrDistanceFieldTextureEffect : public GrVertexEffect {
24public:
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
55private:
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 */
82class GrDistanceFieldLCDTextureEffect : public GrVertexEffect {
83public:
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
107private:
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