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/Mutex.h>
23#include <utils/Vector.h>
24
25#include "Texture.h"
26#include "utils/Compare.h"
27#include "utils/GenerationCache.h"
28
29namespace android {
30namespace uirenderer {
31
32struct GradientCacheEntry {
33    GradientCacheEntry() {
34        count = 0;
35        colors = NULL;
36        positions = NULL;
37        tileMode = SkShader::kClamp_TileMode;
38    }
39
40    GradientCacheEntry(uint32_t* colors, float* positions, int count,
41            SkShader::TileMode tileMode) {
42        copy(colors, positions, count, tileMode);
43    }
44
45    GradientCacheEntry(const GradientCacheEntry& entry) {
46        copy(entry.colors, entry.positions, entry.count, entry.tileMode);
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, entry.tileMode);
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            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
85private:
86
87    void copy(uint32_t* colors, float* positions, int count, SkShader::TileMode tileMode) {
88        this->count = count;
89        this->colors = new uint32_t[count];
90        this->positions = new float[count];
91        this->tileMode = tileMode;
92
93        memcpy(this->colors, colors, count * sizeof(uint32_t));
94        memcpy(this->positions, positions, count * sizeof(float));
95    }
96
97}; // GradientCacheEntry
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 */
104class GradientCache: public OnEntryRemoved<GradientCacheEntry, Texture*> {
105public:
106    GradientCache();
107    GradientCache(uint32_t maxByteSize);
108    ~GradientCache();
109
110    /**
111     * Used as a callback when an entry is removed from the cache.
112     * Do not invoke directly.
113     */
114    void operator()(GradientCacheEntry& shader, Texture*& texture);
115
116    /**
117     * Returns the texture associated with the specified shader.
118     */
119    Texture* get(uint32_t* colors, float* positions,
120            int count, SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
121    /**
122     * Clears the cache. This causes all textures to be deleted.
123     */
124    void clear();
125
126    /**
127     * Sets the maximum size of the cache in bytes.
128     */
129    void setMaxSize(uint32_t maxSize);
130    /**
131     * Returns the maximum size of the cache in bytes.
132     */
133    uint32_t getMaxSize();
134    /**
135     * Returns the current size of the cache in bytes.
136     */
137    uint32_t getSize();
138
139private:
140    /**
141     * Adds a new linear gradient to the cache. The generated texture is
142     * returned.
143     */
144    Texture* addLinearGradient(GradientCacheEntry& gradient,
145            uint32_t* colors, float* positions, int count,
146            SkShader::TileMode tileMode = SkShader::kClamp_TileMode);
147
148    void generateTexture(SkBitmap* bitmap, Texture* texture);
149
150    GenerationCache<GradientCacheEntry, Texture*> mCache;
151
152    uint32_t mSize;
153    uint32_t mMaxSize;
154
155    Vector<SkShader*> mGarbage;
156    mutable Mutex mLock;
157}; // class GradientCache
158
159}; // namespace uirenderer
160}; // namespace android
161
162#endif // ANDROID_HWUI_GRADIENT_CACHE_H
163