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 
29 namespace android {
30 namespace uirenderer {
31 
32 class Texture;
33 
34 struct GradientCacheEntry {
GradientCacheEntryGradientCacheEntry35     GradientCacheEntry() {
36         count = 0;
37         colors = nullptr;
38         positions = nullptr;
39     }
40 
GradientCacheEntryGradientCacheEntry41     GradientCacheEntry(uint32_t* colors, float* positions, uint32_t count) {
42         copy(colors, positions, count);
43     }
44 
GradientCacheEntryGradientCacheEntry45     GradientCacheEntry(const GradientCacheEntry& entry) {
46         copy(entry.colors.get(), entry.positions.get(), entry.count);
47     }
48 
49     GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
50         if (this != &entry) {
51             copy(entry.colors.get(), entry.positions.get(), entry.count);
52         }
53 
54         return *this;
55     }
56 
57     hash_t hash() const;
58 
59     static int compare(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs);
60 
61     bool operator==(const GradientCacheEntry& other) const {
62         return compare(*this, other) == 0;
63     }
64 
65     bool operator!=(const GradientCacheEntry& other) const {
66         return compare(*this, other) != 0;
67     }
68 
69     std::unique_ptr<uint32_t[]> colors;
70     std::unique_ptr<float[]> positions;
71     uint32_t count;
72 
73 private:
copyGradientCacheEntry74     void copy(uint32_t* colors, float* positions, uint32_t count) {
75         this->count = count;
76         this->colors.reset(new uint32_t[count]);
77         this->positions.reset(new float[count]);
78 
79         memcpy(this->colors.get(), colors, count * sizeof(uint32_t));
80         memcpy(this->positions.get(), positions, count * sizeof(float));
81     }
82 
83 }; // GradientCacheEntry
84 
85 // Caching support
86 
strictly_order_type(const GradientCacheEntry & lhs,const GradientCacheEntry & rhs)87 inline int strictly_order_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
88     return GradientCacheEntry::compare(lhs, rhs) < 0;
89 }
90 
compare_type(const GradientCacheEntry & lhs,const GradientCacheEntry & rhs)91 inline int compare_type(const GradientCacheEntry& lhs, const GradientCacheEntry& rhs) {
92     return GradientCacheEntry::compare(lhs, rhs);
93 }
94 
hash_type(const GradientCacheEntry & entry)95 inline hash_t hash_type(const GradientCacheEntry& entry) {
96     return entry.hash();
97 }
98 
99 /**
100  * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
101  * Any texture added to the cache causing the cache to grow beyond the maximum
102  * allowed size will also cause the oldest texture to be kicked out.
103  */
104 class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
105 public:
106     GradientCache(Extensions& extensions);
107     ~GradientCache();
108 
109     /**
110      * Used as a callback when an entry is removed from the cache.
111      * Do not invoke directly.
112      */
113     void operator()(GradientCacheEntry& shader, Texture*& texture) override;
114 
115     /**
116      * Returns the texture associated with the specified shader.
117      */
118     Texture* get(uint32_t* colors, float* positions, int count);
119 
120     /**
121      * Clears the cache. This causes all textures to be deleted.
122      */
123     void clear();
124 
125     /**
126      * Returns the maximum size of the cache in bytes.
127      */
128     uint32_t getMaxSize();
129     /**
130      * Returns the current size of the cache in bytes.
131      */
132     uint32_t getSize();
133 
134 private:
135     /**
136      * Adds a new linear gradient to the cache. The generated texture is
137      * returned.
138      */
139     Texture* addLinearGradient(GradientCacheEntry& gradient,
140             uint32_t* colors, float* positions, int count);
141 
142     void generateTexture(uint32_t* colors, float* positions,
143             const uint32_t width, const uint32_t height, Texture* texture);
144 
145     struct GradientInfo {
146         uint32_t width;
147         bool hasAlpha;
148     };
149 
150     void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
151 
152     size_t bytesPerPixel() const;
153 
154     struct GradientColor {
155         float r;
156         float g;
157         float b;
158         float a;
159     };
160 
161     typedef void (GradientCache::*ChannelSplitter)(uint32_t inColor,
162             GradientColor& outColor) const;
163 
164     void splitToBytes(uint32_t inColor, GradientColor& outColor) const;
165     void splitToFloats(uint32_t inColor, GradientColor& outColor) const;
166 
167     typedef void (GradientCache::*ChannelMixer)(GradientColor& start, GradientColor& end,
168             float amount, uint8_t*& dst) const;
169 
170     void mixBytes(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
171     void mixFloats(GradientColor& start, GradientColor& end, float amount, uint8_t*& dst) const;
172 
173     LruCache<GradientCacheEntry, Texture*> mCache;
174 
175     uint32_t mSize;
176     const uint32_t mMaxSize;
177 
178     GLint mMaxTextureSize;
179     bool mUseFloatTexture;
180     bool mHasNpot;
181 
182     mutable Mutex mLock;
183 }; // class GradientCache
184 
185 }; // namespace uirenderer
186 }; // namespace android
187 
188 #endif // ANDROID_HWUI_GRADIENT_CACHE_H
189