GradientCache.h revision 8dcfd5e836341b4a803b04d104a930bb312182d3 
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        tileMode = SkShader::kClamp_TileMode;
40    }
41
42    GradientCacheEntry(uint32_t* colors, float* positions, int count,
43            SkShader::TileMode tileMode) {
44        copy(colors, positions, count, tileMode);
45    }
46
47    GradientCacheEntry(const GradientCacheEntry& entry) {
48        copy(entry.colors, entry.positions, entry.count, entry.tileMode);
49    }
50
51    ~GradientCacheEntry() {
52        delete[] colors;
53        delete[] positions;
54    }
55
56    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
57        if (this != &entry) {
58            delete[] colors;
59            delete[] positions;
60
61            copy(entry.colors, entry.positions, entry.count, entry.tileMode);
62        }
63
64        return *this;
65    }
66
67    bool operator<(const GradientCacheEntry& r) const {
68        const GradientCacheEntry& rhs = (const GradientCacheEntry&) r;
69        LTE_INT(count) {
70            LTE_INT(tileMode) {
71                int result = memcmp(colors, rhs.colors, count * sizeof(uint32_t));
72                if (result< 0) return true;
73                else if (result == 0) {
74                    result = memcmp(positions, rhs.positions, count * sizeof(float));
75                    if (result < 0) return true;
76                }
77            }
78        }
79        return false;
80    }
81
82    uint32_t* colors;
83    float* positions;
84    int count;
85    SkShader::TileMode tileMode;
86
87private:
88
89    void copy(uint32_t* colors, float* positions, int count, SkShader::TileMode tileMode) {
90        this->count = count;
91        this->colors = new uint32_t[count];
92        this->positions = new float[count];
93        this->tileMode = tileMode;
94
95        memcpy(this->colors, colors, count * sizeof(uint32_t));
96        memcpy(this->positions, positions, count * sizeof(float));
97    }
98
99}; // GradientCacheEntry
100
101/**
102 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
103 * Any texture added to the cache causing the cache to grow beyond the maximum
104 * allowed size will also cause the oldest texture to be kicked out.
105 */
106class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
107public:
108    GradientCache();
109    GradientCache(uint32_t maxByteSize);
110    ~GradientCache();
111
112    /**
113     * Used as a callback when an entry is removed from the cache.
114     * Do not invoke directly.
115     */
116    void operator()(GradientCacheEntry& shader, Texture*& texture);
117
118    /**
119     * Returns the texture associated with the specified shader.
120     */
121    Texture* get(uint32_t* colors, float* positions,
122            int count, SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
123    /**
124     * Clears the cache. This causes all textures to be deleted.
125     */
126    void clear();
127
128    /**
129     * Sets the maximum size of the cache in bytes.
130     */
131    void setMaxSize(uint32_t maxSize);
132    /**
133     * Returns the maximum size of the cache in bytes.
134     */
135    uint32_t getMaxSize();
136    /**
137     * Returns the current size of the cache in bytes.
138     */
139    uint32_t getSize();
140
141private:
142    /**
143     * Adds a new linear gradient to the cache. The generated texture is
144     * returned.
145     */
146    Texture* addLinearGradient(GradientCacheEntry& gradient,
147            uint32_t* colors, float* positions, int count,
148            SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
149
150    void generateTexture(SkBitmap* bitmap, Texture* texture);
151
152    GenerationCache<GradientCacheEntry, Texture*> mCache;
153
154    uint32_t mSize;
155    uint32_t mMaxSize;
156
157    GLint mMaxTextureSize;
158
159    Vector<SkShader*> mGarbage;
160    mutable Mutex mLock;
161}; // class GradientCache
162
163}; // namespace uirenderer
164}; // namespace android
165
166#endif // ANDROID_HWUI_GRADIENT_CACHE_H
167