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/Mutex.h>
25#include <utils/Vector.h>
26
27#include "Texture.h"
28#include "utils/Compare.h"
29#include "utils/GenerationCache.h"
30
31namespace android {
32namespace uirenderer {
33
34struct GradientCacheEntry {
35    GradientCacheEntry() {
36        count = 0;
37        colors = NULL;
38        positions = NULL;
39    }
40
41    GradientCacheEntry(uint32_t* colors, float* positions, int count) {
42        copy(colors, positions, count);
43    }
44
45    GradientCacheEntry(const GradientCacheEntry& entry) {
46        copy(entry.colors, entry.positions, entry.count);
47    }
48
49    ~GradientCacheEntry() {
50        delete[] colors;
51        delete[] positions;
52    }
53
54    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
55        if (this != &entry) {
56            delete[] colors;
57            delete[] positions;
58
59            copy(entry.colors, entry.positions, entry.count);
60        }
61
62        return *this;
63    }
64
65    bool operator<(const GradientCacheEntry& r) const {
66        const GradientCacheEntry& rhs = (const GradientCacheEntry&) r;
67        LTE_INT(count) {
68            int result = memcmp(colors, rhs.colors, count * sizeof(uint32_t));
69            if (result< 0) return true;
70            else if (result == 0) {
71                result = memcmp(positions, rhs.positions, count * sizeof(float));
72                if (result < 0) return true;
73            }
74        }
75        return false;
76    }
77
78    uint32_t* colors;
79    float* positions;
80    int count;
81    SkShader::TileMode tileMode;
82
83private:
84
85    void copy(uint32_t* colors, float* positions, int count) {
86        this->count = count;
87        this->colors = new uint32_t[count];
88        this->positions = new float[count];
89
90        memcpy(this->colors, colors, count * sizeof(uint32_t));
91        memcpy(this->positions, positions, count * sizeof(float));
92    }
93
94}; // GradientCacheEntry
95
96/**
97 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
98 * Any texture added to the cache causing the cache to grow beyond the maximum
99 * allowed size will also cause the oldest texture to be kicked out.
100 */
101class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
102public:
103    GradientCache();
104    GradientCache(uint32_t maxByteSize);
105    ~GradientCache();
106
107    /**
108     * Used as a callback when an entry is removed from the cache.
109     * Do not invoke directly.
110     */
111    void operator()(GradientCacheEntry& shader, Texture*& texture);
112
113    /**
114     * Returns the texture associated with the specified shader.
115     */
116    Texture* get(uint32_t* colors, float* positions, int count);
117
118    /**
119     * Clears the cache. This causes all textures to be deleted.
120     */
121    void clear();
122
123    /**
124     * Sets the maximum size of the cache in bytes.
125     */
126    void setMaxSize(uint32_t maxSize);
127    /**
128     * Returns the maximum size of the cache in bytes.
129     */
130    uint32_t getMaxSize();
131    /**
132     * Returns the current size of the cache in bytes.
133     */
134    uint32_t getSize();
135
136private:
137    /**
138     * Adds a new linear gradient to the cache. The generated texture is
139     * returned.
140     */
141    Texture* addLinearGradient(GradientCacheEntry& gradient,
142            uint32_t* colors, float* positions, int count);
143
144    void generateTexture(uint32_t* colors, float* positions, int count, Texture* texture);
145
146    struct GradientInfo {
147        uint32_t width;
148        bool hasAlpha;
149    };
150
151    void getGradientInfo(const uint32_t* colors, const int count, GradientInfo& info);
152
153    GenerationCache<GradientCacheEntry, Texture*> mCache;
154
155    uint32_t mSize;
156    uint32_t mMaxSize;
157
158    GLint mMaxTextureSize;
159
160    Vector<SkShader*> mGarbage;
161    mutable Mutex mLock;
162}; // class GradientCache
163
164}; // namespace uirenderer
165}; // namespace android
166
167#endif // ANDROID_HWUI_GRADIENT_CACHE_H
168