GradientCache.h revision 96a5c4c7bab6718524de7253da8309143ab48bef 
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#include <utils/Vector.h>
29
30namespace android {
31namespace uirenderer {
32
33class Texture;
34
35struct GradientCacheEntry {
36    GradientCacheEntry() {
37        count = 0;
38        colors = nullptr;
39        positions = nullptr;
40    }
41
42    GradientCacheEntry(uint32_t* colors, float* positions, uint32_t count) {
43        copy(colors, positions, count);
44    }
45
46    GradientCacheEntry(const GradientCacheEntry& entry) {
47        copy(entry.colors.get(), entry.positions.get(), entry.count);
48    }
49
50    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
51        if (this != &entry) {
52            copy(entry.colors.get(), entry.positions.get(), entry.count);
53        }
54
55        return *this;
56    }
57
58    hash_t hash() const;
59
60    static int compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs);
61
62    bool operator==(const GradientCacheEntry& other) const {
63        return compare(*this, other) == 0;
64    }
65
66    bool operator!=(const GradientCacheEntry& other) const {
67        return compare(*this, other) != 0;
68    }
69
70    std::unique_ptr<uint32_t[]> colors;
71    std::unique_ptr<float[]> positions;
72    uint32_t count;
73
74private:
75    void copy(uint32_t* colors, float* positions, uint32_t count) {
76        this->count = count;
77        this->colors.reset(new uint32_t[count]);
78        this->positions.reset(new float[count]);
79
80        memcpy(this->colors.get(), colors, count * sizeof(uint32_t));
81        memcpy(this->positions.get(), positions, count * sizeof(float));
82    }
83
84}; // GradientCacheEntry
85
86// Caching support
87
88inline int strictly_order_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
89    return GradientCacheEntry::compare(lhs, rhs) < 0;
90}
91
92inline int compare_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
93    return GradientCacheEntry::compare(lhs, rhs);
94}
95
96inline hash_t hash_type(const GradientCacheEntry& entry) {
97    return entry.hash();
98}
99
100/**
101 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
102 * Any texture added to the cache causing the cache to grow beyond the maximum
103 * allowed size will also cause the oldest texture to be kicked out.
104 */
105class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
106public:
107    GradientCache();
108    GradientCache(uint32_t maxByteSize);
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     * Sets the maximum size of the cache in bytes.
129     */
130    void setMaxSize(uint32_t maxSize);
131    /**
132     * Returns the maximum size of the cache in bytes.
133     */
134    uint32_t getMaxSize();
135    /**
136     * Returns the current size of the cache in bytes.
137     */
138    uint32_t getSize();
139
140private:
141    /**
142     * Adds a new linear gradient to the cache. The generated texture is
143     * returned.
144     */
145    Texture* addLinearGradient(GradientCacheEntry& gradient,
146            uint32_t* colors, float* positions, int count);
147
148    void generateTexture(uint32_t* colors, float* positions, Texture* texture);
149
150    struct GradientInfo {
151        uint32_t width;
152        bool hasAlpha;
153    };
154
155    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
156
157    size_t bytesPerPixel() const;
158
159    struct GradientColor {
160        float r;
161        float g;
162        float b;
163        float a;
164    };
165
166    typedef void (GradientCache::*ChannelSplitter)(uint32_t inColor,
167            GradientColor& outColor) const;
168
169    void splitToBytes(uint32_t inColor, GradientColor& outColor) const;
170    void splitToFloats(uint32_t inColor, GradientColor& outColor) const;
171
172    typedef void (GradientCache::*ChannelMixer)(GradientColor& start, GradientColor& end,
173            float amount, uint8_t*& dst) const;
174
175    void mixBytes(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
176    void mixFloats(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
177
178    LruCache<GradientCacheEntry, Texture*> mCache;
179
180    uint32_t mSize;
181    uint32_t mMaxSize;
182
183    GLint mMaxTextureSize;
184    bool mUseFloatTexture;
185    bool mHasNpot;
186
187    Vector<SkShader*> mGarbage;
188    mutable Mutex mLock;
189}; // class GradientCache
190
191}; // namespace uirenderer
192}; // namespace android
193
194#endif // ANDROID_HWUI_GRADIENT_CACHE_H
195