GradientCache.h revision b48800428906ae455c2b63acacd44e390e1fee49 
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 <GLES3/gl3.h>
21
22#include <SkShader.h>
23
24#include <utils/LruCache.h>
25#include <utils/Mutex.h>
26#include <utils/Vector.h>
27
28#include "Texture.h"
29
30namespace android {
31namespace uirenderer {
32
33struct GradientCacheEntry {
34    GradientCacheEntry() {
35        count = 0;
36        colors = NULL;
37        positions = NULL;
38    }
39
40    GradientCacheEntry(uint32_t* colors, float* positions, uint32_t count) {
41        copy(colors, positions, count);
42    }
43
44    GradientCacheEntry(const GradientCacheEntry& entry) {
45        copy(entry.colors, entry.positions, entry.count);
46    }
47
48    ~GradientCacheEntry() {
49        delete[] colors;
50        delete[] positions;
51    }
52
53    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
54        if (this != &entry) {
55            delete[] colors;
56            delete[] positions;
57
58            copy(entry.colors, entry.positions, entry.count);
59        }
60
61        return *this;
62    }
63
64    hash_t hash() const;
65
66    static int compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs);
67
68    bool operator==(const GradientCacheEntry& other) const {
69        return compare(*this, other) == 0;
70    }
71
72    bool operator!=(const GradientCacheEntry& other) const {
73        return compare(*this, other) != 0;
74    }
75
76    uint32_t* colors;
77    float* positions;
78    uint32_t count;
79
80private:
81    void copy(uint32_t* colors, float* positions, uint32_t count) {
82        this->count = count;
83        this->colors = new uint32_t[count];
84        this->positions = new float[count];
85
86        memcpy(this->colors, colors, count * sizeof(uint32_t));
87        memcpy(this->positions, positions, count * sizeof(float));
88    }
89
90}; // GradientCacheEntry
91
92// Caching support
93
94inline int strictly_order_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
95    return GradientCacheEntry::compare(lhs, rhs) < 0;
96}
97
98inline int compare_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
99    return GradientCacheEntry::compare(lhs, rhs);
100}
101
102inline hash_t hash_type(const GradientCacheEntry& entry) {
103    return entry.hash();
104}
105
106/**
107 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
108 * Any texture added to the cache causing the cache to grow beyond the maximum
109 * allowed size will also cause the oldest texture to be kicked out.
110 */
111class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
112public:
113    GradientCache();
114    GradientCache(uint32_t maxByteSize);
115    ~GradientCache();
116
117    /**
118     * Used as a callback when an entry is removed from the cache.
119     * Do not invoke directly.
120     */
121    void operator()(GradientCacheEntry& shader, Texture*& texture);
122
123    /**
124     * Returns the texture associated with the specified shader.
125     */
126    Texture* get(uint32_t* colors, float* positions, int count);
127
128    /**
129     * Clears the cache. This causes all textures to be deleted.
130     */
131    void clear();
132
133    /**
134     * Sets the maximum size of the cache in bytes.
135     */
136    void setMaxSize(uint32_t maxSize);
137    /**
138     * Returns the maximum size of the cache in bytes.
139     */
140    uint32_t getMaxSize();
141    /**
142     * Returns the current size of the cache in bytes.
143     */
144    uint32_t getSize();
145
146private:
147    /**
148     * Adds a new linear gradient to the cache. The generated texture is
149     * returned.
150     */
151    Texture* addLinearGradient(GradientCacheEntry& gradient,
152            uint32_t* colors, float* positions, int count);
153
154    void generateTexture(uint32_t* colors, float* positions, int count, Texture* texture);
155
156    struct GradientInfo {
157        uint32_t width;
158        bool hasAlpha;
159    };
160
161    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
162
163    size_t bytesPerPixel() const;
164
165    struct GradientColor {
166        float r;
167        float g;
168        float b;
169        float a;
170    };
171
172    typedef void (GradientCache::*ChannelSplitter)(uint32_t inColor,
173            GradientColor& outColor) const;
174
175    void splitToBytes(uint32_t inColor, GradientColor& outColor) const;
176    void splitToFloats(uint32_t inColor, GradientColor& outColor) const;
177
178    typedef void (GradientCache::*ChannelMixer)(GradientColor& start, GradientColor& end,
179            float amount, uint8_t*& dst) const;
180
181    void mixBytes(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
182    void mixFloats(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
183
184    LruCache<GradientCacheEntry, Texture*> mCache;
185
186    uint32_t mSize;
187    uint32_t mMaxSize;
188
189    GLint mMaxTextureSize;
190    bool mUseFloatTexture;
191    bool mHasNpot;
192
193    Vector<SkShader*> mGarbage;
194    mutable Mutex mLock;
195}; // class GradientCache
196
197}; // namespace uirenderer
198}; // namespace android
199
200#endif // ANDROID_HWUI_GRADIENT_CACHE_H
201