SkiaColorFilter.h revision d586ad9c9fec80aa1d24d6b53cd2c8d5b47fe868 
1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef ANDROID_HWUI_SKIA_COLOR_FILTER_H
18#define ANDROID_HWUI_SKIA_COLOR_FILTER_H
19
20#include <GLES2/gl2.h>
21#include <SkColorFilter.h>
22
23#include "ProgramCache.h"
24#include "Extensions.h"
25
26namespace android {
27namespace uirenderer {
28
29///////////////////////////////////////////////////////////////////////////////
30// Base color filter
31///////////////////////////////////////////////////////////////////////////////
32
33/**
34 * Represents a Skia color filter. A color filter modifies a ProgramDescription
35 * and sets uniforms on the resulting shaders.
36 */
37struct SkiaColorFilter {
38    /**
39     * Type of Skia color filter in use.
40     */
41    enum Type {
42        kNone,
43        kColorMatrix,
44        kLighting,
45        kBlend,
46    };
47
48    SkiaColorFilter(SkColorFilter *skFilter, Type type, bool blend);
49    virtual ~SkiaColorFilter();
50
51    virtual void describe(ProgramDescription& description, const Extensions& extensions) = 0;
52    virtual void setupProgram(Program* program) = 0;
53
54    inline bool blend() const {
55        return mBlend;
56    }
57
58    Type type() const {
59        return mType;
60    }
61
62    SkColorFilter* getSkColorFilter() {
63        return mSkFilter;
64    }
65
66protected:
67    Type mType;
68    bool mBlend;
69
70private:
71    SkColorFilter *mSkFilter;
72}; // struct SkiaColorFilter
73
74///////////////////////////////////////////////////////////////////////////////
75// Implementations
76///////////////////////////////////////////////////////////////////////////////
77
78/**
79 * A color filter that multiplies the source color with a matrix and adds a vector.
80 */
81struct SkiaColorMatrixFilter: public SkiaColorFilter {
82    SkiaColorMatrixFilter(SkColorFilter *skFilter, float* matrix, float* vector);
83    ~SkiaColorMatrixFilter();
84
85    void describe(ProgramDescription& description, const Extensions& extensions);
86    void setupProgram(Program* program);
87
88private:
89    float* mMatrix;
90    float* mVector;
91}; // struct SkiaColorMatrixFilter
92
93/**
94 * A color filters that multiplies the source color with a fixed value and adds
95 * another fixed value. Ignores the alpha channel of both arguments.
96 */
97struct SkiaLightingFilter: public SkiaColorFilter {
98    SkiaLightingFilter(SkColorFilter *skFilter, int multiply, int add);
99
100    void describe(ProgramDescription& description, const Extensions& extensions);
101    void setupProgram(Program* program);
102
103private:
104    GLfloat mMulR, mMulG, mMulB;
105    GLfloat mAddR, mAddG, mAddB;
106}; // struct SkiaLightingFilter
107
108/**
109 * A color filters that blends the source color with a specified destination color
110 * and PorterDuff blending mode.
111 */
112struct SkiaBlendFilter: public SkiaColorFilter {
113    SkiaBlendFilter(SkColorFilter *skFilter, int color, SkXfermode::Mode mode);
114
115    void describe(ProgramDescription& description, const Extensions& extensions);
116    void setupProgram(Program* program);
117
118private:
119    SkXfermode::Mode mMode;
120    GLfloat mR, mG, mB, mA;
121}; // struct SkiaBlendFilter
122
123}; // namespace uirenderer
124}; // namespace android
125
126#endif // ANDROID_HWUI_SKIA_COLOR_FILTER_H
127