GradientCache.h revision 272a685f17cc4828257e521a6f62b7b17870f75e 
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
29namespace android {
30namespace uirenderer {
31
32class Texture;
33
34struct GradientCacheEntry {
35    GradientCacheEntry() {
36        count = 0;
37        colors = nullptr;
38        positions = nullptr;
39    }
40
41    GradientCacheEntry(uint32_t* colors, float* positions, uint32_t count) {
42        copy(colors, positions, count);
43    }
44
45    GradientCacheEntry(const GradientCacheEntry& entry) {
46        copy(entry.colors.get(), entry.positions.get(), entry.count);
47    }
48
49    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
50        if (this != &entry) {
51            copy(entry.colors.get(), entry.positions.get(), entry.count);
52        }
53
54        return *this;
55    }
56
57    hash_t hash() const;
58
59    static int compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs);
60
61    bool operator==(const GradientCacheEntry& other) const {
62        return compare(*this, other) == 0;
63    }
64
65    bool operator!=(const GradientCacheEntry& other) const {
66        return compare(*this, other) != 0;
67    }
68
69    std::unique_ptr<uint32_t[]> colors;
70    std::unique_ptr<float[]> positions;
71    uint32_t count;
72
73private:
74    void copy(uint32_t* colors, float* positions, uint32_t count) {
75        this->count = count;
76        this->colors.reset(new uint32_t[count]);
77        this->positions.reset(new float[count]);
78
79        memcpy(this->colors.get(), colors, count * sizeof(uint32_t));
80        memcpy(this->positions.get(), positions, count * sizeof(float));
81    }
82
83}; // GradientCacheEntry
84
85// Caching support
86
87inline int strictly_order_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
88    return GradientCacheEntry::compare(lhs, rhs) < 0;
89}
90
91inline int compare_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
92    return GradientCacheEntry::compare(lhs, rhs);
93}
94
95inline hash_t hash_type(const GradientCacheEntry& entry) {
96    return entry.hash();
97}
98
99/**
100 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
101 * Any texture added to the cache causing the cache to grow beyond the maximum
102 * allowed size will also cause the oldest texture to be kicked out.
103 */
104class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
105public:
106    GradientCache(Extensions& extensions);
107    ~GradientCache();
108
109    /**
110     * Used as a callback when an entry is removed from the cache.
111     * Do not invoke directly.
112     */
113    void operator()(GradientCacheEntry& shader, Texture*& texture) override;
114
115    /**
116     * Returns the texture associated with the specified shader.
117     */
118    Texture* get(uint32_t* colors, float* positions, int count);
119
120    /**
121     * Clears the cache. This causes all textures to be deleted.
122     */
123    void clear();
124
125    /**
126     * Sets the maximum size of the cache in bytes.
127     */
128    void setMaxSize(uint32_t maxSize);
129    /**
130     * Returns the maximum size of the cache in bytes.
131     */
132    uint32_t getMaxSize();
133    /**
134     * Returns the current size of the cache in bytes.
135     */
136    uint32_t getSize();
137
138private:
139    /**
140     * Adds a new linear gradient to the cache. The generated texture is
141     * returned.
142     */
143    Texture* addLinearGradient(GradientCacheEntry& gradient,
144            uint32_t* colors, float* positions, int count);
145
146    void generateTexture(uint32_t* colors, float* positions, Texture* texture);
147
148    struct GradientInfo {
149        uint32_t width;
150        bool hasAlpha;
151    };
152
153    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
154
155    size_t bytesPerPixel() const;
156
157    struct GradientColor {
158        float r;
159        float g;
160        float b;
161        float a;
162    };
163
164    typedef void (GradientCache::*ChannelSplitter)(uint32_t inColor,
165            GradientColor& outColor) const;
166
167    void splitToBytes(uint32_t inColor, GradientColor& outColor) const;
168    void splitToFloats(uint32_t inColor, GradientColor& outColor) const;
169
170    typedef void (GradientCache::*ChannelMixer)(GradientColor& start, GradientColor& end,
171            float amount, uint8_t*& dst) const;
172
173    void mixBytes(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
174    void mixFloats(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
175
176    LruCache<GradientCacheEntry, Texture*> mCache;
177
178    uint32_t mSize;
179    uint32_t mMaxSize;
180
181    GLint mMaxTextureSize;
182    bool mUseFloatTexture;
183    bool mHasNpot;
184
185    mutable Mutex mLock;
186}; // class GradientCache
187
188}; // namespace uirenderer
189}; // namespace android
190
191#endif // ANDROID_HWUI_GRADIENT_CACHE_H
192