GradientCache.h revision 059e12ccd20f5c249724a8362d6bac325334ea76 
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 <GLES2/gl2.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    SkShader::TileMode tileMode;
80
81private:
82
83    void copy(uint32_t* colors, float* positions, uint32_t count) {
84        this->count = count;
85        this->colors = new uint32_t[count];
86        this->positions = new float[count];
87
88        memcpy(this->colors, colors, count * sizeof(uint32_t));
89        memcpy(this->positions, positions, count * sizeof(float));
90    }
91
92}; // GradientCacheEntry
93
94// Caching support
95
96inline int strictly_order_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
97    return GradientCacheEntry::compare(lhs, rhs) < 0;
98}
99
100inline int compare_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
101    return GradientCacheEntry::compare(lhs, rhs);
102}
103
104inline hash_t hash_type(const GradientCacheEntry& entry) {
105    return entry.hash();
106}
107
108/**
109 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
110 * Any texture added to the cache causing the cache to grow beyond the maximum
111 * allowed size will also cause the oldest texture to be kicked out.
112 */
113class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
114public:
115    GradientCache();
116    GradientCache(uint32_t maxByteSize);
117    ~GradientCache();
118
119    /**
120     * Used as a callback when an entry is removed from the cache.
121     * Do not invoke directly.
122     */
123    void operator()(GradientCacheEntry& shader, Texture*& texture);
124
125    /**
126     * Returns the texture associated with the specified shader.
127     */
128    Texture* get(uint32_t* colors, float* positions, int count);
129
130    /**
131     * Clears the cache. This causes all textures to be deleted.
132     */
133    void clear();
134
135    /**
136     * Sets the maximum size of the cache in bytes.
137     */
138    void setMaxSize(uint32_t maxSize);
139    /**
140     * Returns the maximum size of the cache in bytes.
141     */
142    uint32_t getMaxSize();
143    /**
144     * Returns the current size of the cache in bytes.
145     */
146    uint32_t getSize();
147
148private:
149    /**
150     * Adds a new linear gradient to the cache. The generated texture is
151     * returned.
152     */
153    Texture* addLinearGradient(GradientCacheEntry& gradient,
154            uint32_t* colors, float* positions, int count);
155
156    void generateTexture(uint32_t* colors, float* positions, int count, Texture* texture);
157
158    struct GradientInfo {
159        uint32_t width;
160        bool hasAlpha;
161    };
162
163    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
164
165    LruCache<GradientCacheEntry, Texture*> mCache;
166
167    uint32_t mSize;
168    uint32_t mMaxSize;
169
170    GLint mMaxTextureSize;
171
172    Vector<SkShader*> mGarbage;
173    mutable Mutex mLock;
174}; // class GradientCache
175
176}; // namespace uirenderer
177}; // namespace android
178
179#endif // ANDROID_HWUI_GRADIENT_CACHE_H
180