GradientCache.h revision 4974bc1be68a77cf9709a8c50ef6de06ce8a3a0d 
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        this->count = count;
42        this->colors = new uint32_t[count];
43        this->positions = new float[count];
44        this->tileMode = tileMode;
45
46        memcpy(this->colors, colors, count * sizeof(uint32_t));
47        memcpy(this->positions, positions, count * sizeof(float));
48    }
49
50    GradientCacheEntry(const GradientCacheEntry& entry) {
51        this->count = entry.count;
52        this->colors = new uint32_t[count];
53        this->positions = new float[count];
54        this->tileMode = entry.tileMode;
55
56        memcpy(this->colors, entry.colors, count * sizeof(uint32_t));
57        memcpy(this->positions, entry.positions, count * sizeof(float));
58    }
59
60    ~GradientCacheEntry() {
61        if (colors) delete[] colors;
62        if (positions) delete[] positions;
63    }
64
65    bool operator<(const GradientCacheEntry& r) const {
66        const GradientCacheEntry& rhs = (const GradientCacheEntry&) r;
67        LTE_INT(count) {
68            LTE_INT(tileMode) {
69                int result = memcmp(colors, rhs.colors, count * sizeof(uint32_t));
70                if (result< 0) return true;
71                else if (result == 0) {
72                    result = memcmp(positions, rhs.positions, count * sizeof(float));
73                    if (result < 0) return true;
74                }
75            }
76        }
77        return false;
78    }
79
80    uint32_t* colors;
81    float* positions;
82    int count;
83    SkShader::TileMode tileMode;
84
85}; // GradientCacheEntry
86
87/**
88 * A simple LRU gradient cache. The cache has a maximum size expressed in bytes.
89 * Any texture added to the cache causing the cache to grow beyond the maximum
90 * allowed size will also cause the oldest texture to be kicked out.
91 */
92class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
93public:
94    GradientCache();
95    GradientCache(uint32_t maxByteSize);
96    ~GradientCache();
97
98    /**
99     * Used as a callback when an entry is removed from the cache.
100     * Do not invoke directly.
101     */
102    void operator()(GradientCacheEntry& shader, Texture*& texture);
103
104    /**
105     * Returns the texture associated with the specified shader.
106     */
107    Texture* get(uint32_t* colors, float* positions,
108            int count, SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
109    /**
110     * Clears the cache. This causes all textures to be deleted.
111     */
112    void clear();
113
114    /**
115     * Sets the maximum size of the cache in bytes.
116     */
117    void setMaxSize(uint32_t maxSize);
118    /**
119     * Returns the maximum size of the cache in bytes.
120     */
121    uint32_t getMaxSize();
122    /**
123     * Returns the current size of the cache in bytes.
124     */
125    uint32_t getSize();
126
127private:
128    /**
129     * Adds a new linear gradient to the cache. The generated texture is
130     * returned.
131     */
132    Texture* addLinearGradient(GradientCacheEntry& gradient,
133            uint32_t* colors, float* positions, int count,
134            SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
135
136    void generateTexture(SkBitmap* bitmap, Texture* texture);
137
138    GenerationCache<GradientCacheEntry, Texture*> mCache;
139
140    uint32_t mSize;
141    uint32_t mMaxSize;
142
143    Vector<SkShader*> mGarbage;
144    mutable Mutex mLock;
145}; // class GradientCache
146
147}; // namespace uirenderer
148}; // namespace android
149
150#endif // ANDROID_HWUI_GRADIENT_CACHE_H
151