GradientCache.h revision e5df231434357424cea8d2b8d0cdf31253a98110 
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 <SkShader.h>
21
22#include <utils/Vector.h>
23
24#include "Texture.h"
25#include "utils/Compare.h"
26#include "utils/GenerationCache.h"
27
28namespace android {
29namespace uirenderer {
30
31struct GradientCacheEntry {
32    GradientCacheEntry() {
33        count = 0;
34        colors = NULL;
35        positions = NULL;
36        tileMode = SkShader::kClamp_TileMode;
37    }
38
39    GradientCacheEntry(uint32_t* colors, float* positions, int count,
40            SkShader::TileMode tileMode) {
41        copy(colors, positions, count, tileMode);
42    }
43
44    GradientCacheEntry(const GradientCacheEntry& entry) {
45        copy(entry.colors, entry.positions, entry.count, entry.tileMode);
46    }
47
48    ~GradientCacheEntry() {
49        delete[] colors;
50        delete[] positions;
51    }
52
53    GradientCacheEntry& operator=(const GradientCacheEntry& entry) {
54        if (this != &entry) {
55            delete[] colors;
56            delete[] positions;
57
58            copy(entry.colors, entry.positions, entry.count, entry.tileMode);
59        }
60
61        return *this;
62    }
63
64    bool operator<(const GradientCacheEntry& r) const {
65        const GradientCacheEntry& rhs = (const GradientCacheEntry&) r;
66        LTE_INT(count) {
67            LTE_INT(tileMode) {
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        }
76        return false;
77    }
78
79    uint32_t* colors;
80    float* positions;
81    int count;
82    SkShader::TileMode tileMode;
83
84private:
85
86    void copy(uint32_t* colors, float* positions, int count, SkShader::TileMode tileMode) {
87        this->count = count;
88        this->colors = new uint32_t[count];
89        this->positions = new float[count];
90        this->tileMode = tileMode;
91
92        memcpy(this->colors, colors, count * sizeof(uint32_t));
93        memcpy(this->positions, positions, count * sizeof(float));
94    }
95
96}; // GradientCacheEntry
97
98/**
99 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
100 * Any texture added to the cache causing the cache to grow beyond the maximum
101 * allowed size will also cause the oldest texture to be kicked out.
102 */
103class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
104public:
105    GradientCache();
106    GradientCache(uint32_t maxByteSize);
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);
114
115    /**
116     * Returns the texture associated with the specified shader.
117     */
118    Texture* get(uint32_t* colors, float* positions,
119            int count, SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
120    /**
121     * Clears the cache. This causes all textures to be deleted.
122     */
123    void clear();
124
125    /**
126     * Sets the maximum size of the cache in bytes.
127     */
128    void setMaxSize(uint32_t maxSize);
129    /**
130     * Returns the maximum size of the cache in bytes.
131     */
132    uint32_t getMaxSize();
133    /**
134     * Returns the current size of the cache in bytes.
135     */
136    uint32_t getSize();
137
138private:
139    /**
140     * Adds a new linear gradient to the cache. The generated texture is
141     * returned.
142     */
143    Texture* addLinearGradient(GradientCacheEntry& gradient,
144            uint32_t* colors, float* positions, int count,
145            SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
146
147    void generateTexture(SkBitmap* bitmap, Texture* texture);
148
149    GenerationCache<GradientCacheEntry, Texture*> mCache;
150
151    uint32_t mSize;
152    uint32_t mMaxSize;
153
154    Vector<SkShader*> mGarbage;
155    mutable Mutex mLock;
156}; // class GradientCache
157
158}; // namespace uirenderer
159}; // namespace android
160
161#endif // ANDROID_HWUI_GRADIENT_CACHE_H
162