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_TEXTURE_CACHE_H
18#define ANDROID_HWUI_TEXTURE_CACHE_H
19
20#include <SkBitmap.h>
21
22#include <utils/LruCache.h>
23#include <utils/Mutex.h>
24#include <utils/Vector.h>
25
26#include "Debug.h"
27#include "Texture.h"
28
29namespace android {
30namespace uirenderer {
31
32///////////////////////////////////////////////////////////////////////////////
33// Defines
34///////////////////////////////////////////////////////////////////////////////
35
36// Debug
37#if DEBUG_TEXTURES
38    #define TEXTURE_LOGD(...) ALOGD(__VA_ARGS__)
39#else
40    #define TEXTURE_LOGD(...)
41#endif
42
43///////////////////////////////////////////////////////////////////////////////
44// Classes
45///////////////////////////////////////////////////////////////////////////////
46
47class AssetAtlas;
48
49/**
50 * A simple LRU texture cache. The cache has a maximum size expressed in bytes.
51 * Any texture added to the cache causing the cache to grow beyond the maximum
52 * allowed size will also cause the oldest texture to be kicked out.
53 */
54class TextureCache: public OnEntryRemoved<uint32_t, Texture*> {
55public:
56    TextureCache();
57    TextureCache(uint32_t maxByteSize);
58    ~TextureCache();
59
60    /**
61     * Used as a callback when an entry is removed from the cache.
62     * Do not invoke directly.
63     */
64    void operator()(uint32_t&, Texture*& texture);
65
66    /**
67     * Resets all Textures to not be marked as in use
68     */
69    void resetMarkInUse();
70
71    /**
72     * Attempts to precache the SkBitmap. Returns true if a Texture was successfully
73     * acquired for the bitmap, false otherwise. If a Texture was acquired it is
74     * marked as in use.
75     */
76    bool prefetchAndMarkInUse(const SkBitmap* bitmap);
77
78    /**
79     * Returns the texture associated with the specified bitmap. If the texture
80     * cannot be found in the cache, a new texture is generated.
81     */
82    Texture* get(const SkBitmap* bitmap);
83    /**
84     * Returns the texture associated with the specified bitmap. The generated
85     * texture is not kept in the cache. The caller must destroy the texture.
86     */
87    Texture* getTransient(const SkBitmap* bitmap);
88
89    /**
90     * Removes the texture associated with the specified bitmap. This is meant
91     * to be called from threads that are not the EGL context thread.
92     */
93    void releaseTexture(const SkBitmap* bitmap);
94    /**
95     * Process deferred removals.
96     */
97    void clearGarbage();
98
99    /**
100     * Clears the cache. This causes all textures to be deleted.
101     */
102    void clear();
103
104    /**
105     * Sets the maximum size of the cache in bytes.
106     */
107    void setMaxSize(uint32_t maxSize);
108    /**
109     * Returns the maximum size of the cache in bytes.
110     */
111    uint32_t getMaxSize();
112    /**
113     * Returns the current size of the cache in bytes.
114     */
115    uint32_t getSize();
116
117    /**
118     * Partially flushes the cache. The amount of memory freed by a flush
119     * is defined by the flush rate.
120     */
121    void flush();
122    /**
123     * Indicates the percentage of the cache to retain when a
124     * memory trim is requested (see Caches::flush).
125     */
126    void setFlushRate(float flushRate);
127
128    void setAssetAtlas(AssetAtlas* assetAtlas);
129
130private:
131
132    bool canMakeTextureFromBitmap(const SkBitmap* bitmap);
133
134    Texture* getCachedTexture(const SkBitmap* bitmap);
135
136    /**
137     * Generates the texture from a bitmap into the specified texture structure.
138     *
139     * @param regenerate If true, the bitmap data is reuploaded into the texture, but
140     *        no new texture is generated.
141     */
142    void generateTexture(const SkBitmap* bitmap, Texture* texture, bool regenerate = false);
143
144    void uploadLoFiTexture(bool resize, const SkBitmap* bitmap, uint32_t width, uint32_t height);
145    void uploadToTexture(bool resize, GLenum format, GLsizei stride, GLsizei bpp,
146            GLsizei width, GLsizei height, GLenum type, const GLvoid * data);
147
148    void init();
149
150    LruCache<uint32_t, Texture*> mCache;
151
152    uint32_t mSize;
153    uint32_t mMaxSize;
154    GLint mMaxTextureSize;
155
156    float mFlushRate;
157
158    bool mDebugEnabled;
159
160    Vector<uint32_t> mGarbage;
161    mutable Mutex mLock;
162
163    AssetAtlas* mAssetAtlas;
164}; // class TextureCache
165
166}; // namespace uirenderer
167}; // namespace android
168
169#endif // ANDROID_HWUI_TEXTURE_CACHE_H
170