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 
29 namespace android {
30 namespace 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 
47 class 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  */
54 class TextureCache: public OnEntryRemoved<uint32_t, Texture*> {
55 public:
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 
130 private:
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