GradientCache.h revision 117bdbcfa3e8306dad21e7e01fa71b00cdfa7265 
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(Extensions& extensions);
108    ~GradientCache();
109
110    /**
111     * Used as a callback when an entry is removed from the cache.
112     * Do not invoke directly.
113     */
114    void operator()(GradientCacheEntry& shader, Texture*& texture) override;
115
116    /**
117     * Returns the texture associated with the specified shader.
118     */
119    Texture* get(uint32_t* colors, float* positions, int count);
120
121    /**
122     * Clears the cache. This causes all textures to be deleted.
123     */
124    void clear();
125
126    /**
127     * Sets the maximum size of the cache in bytes.
128     */
129    void setMaxSize(uint32_t maxSize);
130    /**
131     * Returns the maximum size of the cache in bytes.
132     */
133    uint32_t getMaxSize();
134    /**
135     * Returns the current size of the cache in bytes.
136     */
137    uint32_t getSize();
138
139private:
140    /**
141     * Adds a new linear gradient to the cache. The generated texture is
142     * returned.
143     */
144    Texture* addLinearGradient(GradientCacheEntry& gradient,
145            uint32_t* colors, float* positions, int count);
146
147    void generateTexture(uint32_t* colors, float* positions, Texture* texture);
148
149    struct GradientInfo {
150        uint32_t width;
151        bool hasAlpha;
152    };
153
154    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
155
156    size_t bytesPerPixel() const;
157
158    struct GradientColor {
159        float r;
160        float g;
161        float b;
162        float a;
163    };
164
165    typedef void (GradientCache::*ChannelSplitter)(uint32_t inColor,
166            GradientColor& outColor) const;
167
168    void splitToBytes(uint32_t inColor, GradientColor& outColor) const;
169    void splitToFloats(uint32_t inColor, GradientColor& outColor) const;
170
171    typedef void (GradientCache::*ChannelMixer)(GradientColor& start, GradientColor& end,
172            float amount, uint8_t*& dst) const;
173
174    void mixBytes(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
175    void mixFloats(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
176
177    LruCache<GradientCacheEntry, Texture*> mCache;
178
179    uint32_t mSize;
180    uint32_t mMaxSize;
181
182    GLint mMaxTextureSize;
183    bool mUseFloatTexture;
184    bool mHasNpot;
185
186    Vector<SkShader*> mGarbage;
187    mutable Mutex mLock;
188}; // class GradientCache
189
190}; // namespace uirenderer
191}; // namespace android
192
193#endif // ANDROID_HWUI_GRADIENT_CACHE_H
194