1/*
2 * Copyright (C) 2012 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_DITHER_H
18#define ANDROID_HWUI_DITHER_H
19
20#include <GLES3/gl3.h>
21
22#include "Program.h"
23
24namespace android {
25namespace uirenderer {
26
27class Caches;
28
29// Must be a power of two
30#define DITHER_KERNEL_SIZE 4
31// These must not use the .0f notation as they are used from GLSL
32#define DITHER_KERNEL_SIZE_INV (1.0 / 4.0)
33#define DITHER_KERNEL_SIZE_INV_SQUARE (1.0 / 16.0)
34
35/**
36 * Handles dithering for programs.
37 */
38class Dither {
39public:
40    Dither();
41
42    void clear();
43    void setupProgram(Program* program, GLuint* textureUnit);
44
45private:
46    void bindDitherTexture();
47
48    Caches* mCaches;
49    bool mInitialized;
50    GLuint mDitherTexture;
51};
52
53}; // namespace uirenderer
54}; // namespace android
55
56#endif // ANDROID_HWUI_DITHER_H
57