GradientCache.h revision efb4b06493fe7b1604c762a448b13c7af2845a8d 
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_GRADIENT_CACHE_H
18#define ANDROID_HWUI_GRADIENT_CACHE_H
19
20#include <memory>
21
22#include <GLES3/gl3.h>
23
24#include <SkShader.h>
25
26#include <utils/LruCache.h>
27#include <utils/Mutex.h>
28
29#include "FloatColor.h"
30
31namespace android {
32namespace uirenderer {
33
34class Texture;
35
36struct GradientCacheEntry {
37    GradientCacheEntry() {
38        count = 0;
39        colors = nullptr;
40        positions = nullptr;
41    }
42
43    GradientCacheEntry(uint32_t* colors, float* positions, uint32_t count) {
44        copy(colors, positions, count);
45    }
46
47    GradientCacheEntry(const GradientCacheEntry& entry) {
48        copy(entry.colors.get(), entry.positions.get(), entry.count);
49    }
50
51    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
52        if (this != &entry) {
53            copy(entry.colors.get(), entry.positions.get(), entry.count);
54        }
55
56        return *this;
57    }
58
59    hash_t hash() const;
60
61    static int compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs);
62
63    bool operator==(const GradientCacheEntry& other) const {
64        return compare(*this, other) == 0;
65    }
66
67    bool operator!=(const GradientCacheEntry& other) const {
68        return compare(*this, other) != 0;
69    }
70
71    std::unique_ptr<uint32_t[]> colors;
72    std::unique_ptr<float[]> positions;
73    uint32_t count;
74
75private:
76    void copy(uint32_t* colors, float* positions, uint32_t count) {
77        this->count = count;
78        this->colors.reset(new uint32_t[count]);
79        this->positions.reset(new float[count]);
80
81        memcpy(this->colors.get(), colors, count * sizeof(uint32_t));
82        memcpy(this->positions.get(), positions, count * sizeof(float));
83    }
84
85}; // GradientCacheEntry
86
87// Caching support
88
89inline int strictly_order_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
90    return GradientCacheEntry::compare(lhs, rhs) < 0;
91}
92
93inline int compare_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
94    return GradientCacheEntry::compare(lhs, rhs);
95}
96
97inline hash_t hash_type(const GradientCacheEntry& entry) {
98    return entry.hash();
99}
100
101/**
102 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
103 * Any texture added to the cache causing the cache to grow beyond the maximum
104 * allowed size will also cause the oldest texture to be kicked out.
105 */
106class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
107public:
108    explicit GradientCache(Extensions& extensions);
109    ~GradientCache();
110
111    /**
112     * Used as a callback when an entry is removed from the cache.
113     * Do not invoke directly.
114     */
115    void operator()(GradientCacheEntry& shader, Texture*& texture) override;
116
117    /**
118     * Returns the texture associated with the specified shader.
119     */
120    Texture* get(uint32_t* colors, float* positions, int count);
121
122    /**
123     * Clears the cache. This causes all textures to be deleted.
124     */
125    void clear();
126
127    /**
128     * Returns the maximum size of the cache in bytes.
129     */
130    uint32_t getMaxSize();
131    /**
132     * Returns the current size of the cache in bytes.
133     */
134    uint32_t getSize();
135
136private:
137    /**
138     * Adds a new linear gradient to the cache. The generated texture is
139     * returned.
140     */
141    Texture* addLinearGradient(GradientCacheEntry& gradient,
142            uint32_t* colors, float* positions, int count);
143
144    void generateTexture(uint32_t* colors, float* positions,
145            const uint32_t width, const uint32_t height, Texture* texture);
146
147    struct GradientInfo {
148        uint32_t width;
149        bool hasAlpha;
150    };
151
152    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
153
154    size_t bytesPerPixel() const;
155    size_t sourceBytesPerPixel() const;
156
157    typedef void (GradientCache::*ChannelMixer)(const FloatColor& start, const FloatColor& end,
158            float amount, uint8_t*& dst) const;
159
160    void mixBytes(const FloatColor& start, const FloatColor& end,
161            float amount, uint8_t*& dst) const;
162    void mixFloats(const FloatColor& start, const FloatColor& end,
163            float amount, uint8_t*& dst) const;
164
165    LruCache<GradientCacheEntry, Texture*> mCache;
166
167    uint32_t mSize;
168    const uint32_t mMaxSize;
169
170    GLint mMaxTextureSize;
171    bool mUseFloatTexture;
172    bool mHasNpot;
173    bool mHasLinearBlending;
174
175    mutable Mutex mLock;
176}; // class GradientCache
177
178}; // namespace uirenderer
179}; // namespace android
180
181#endif // ANDROID_HWUI_GRADIENT_CACHE_H
182