LayerCache.cpp revision f607bdc167f66b3e7003acaa4736ae46d78c1492 
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#define LOG_TAG "OpenGLRenderer"
18
19#include <GLES2/gl2.h>
20
21#include <utils/Log.h>
22
23#include "LayerCache.h"
24#include "Properties.h"
25
26namespace android {
27namespace uirenderer {
28
29///////////////////////////////////////////////////////////////////////////////
30// Constructors/destructor
31///////////////////////////////////////////////////////////////////////////////
32
33LayerCache::LayerCache():
34        mCache(GenerationCache<LayerSize, Layer*>::kUnlimitedCapacity),
35        mIdGenerator(1), mSize(0), mMaxSize(MB(DEFAULT_LAYER_CACHE_SIZE)) {
36    char property[PROPERTY_VALUE_MAX];
37    if (property_get(PROPERTY_LAYER_CACHE_SIZE, property, NULL) > 0) {
38        LOGD("  Setting layer cache size to %sMB", property);
39        setMaxSize(MB(atof(property)));
40    } else {
41        LOGD("  Using default layer cache size of %.2fMB", DEFAULT_LAYER_CACHE_SIZE);
42    }
43}
44
45LayerCache::LayerCache(uint32_t maxByteSize):
46        mCache(GenerationCache<LayerSize, Layer*>::kUnlimitedCapacity),
47        mIdGenerator(1), mSize(0), mMaxSize(maxByteSize) {
48}
49
50LayerCache::~LayerCache() {
51    clear();
52}
53
54///////////////////////////////////////////////////////////////////////////////
55// Size management
56///////////////////////////////////////////////////////////////////////////////
57
58uint32_t LayerCache::getSize() {
59    return mSize;
60}
61
62uint32_t LayerCache::getMaxSize() {
63    return mMaxSize;
64}
65
66void LayerCache::setMaxSize(uint32_t maxSize) {
67    mMaxSize = maxSize;
68    while (mSize > mMaxSize) {
69        Layer* oldest = mCache.removeOldest();
70        deleteLayer(oldest);
71    }
72}
73
74///////////////////////////////////////////////////////////////////////////////
75// Callbacks
76///////////////////////////////////////////////////////////////////////////////
77
78void LayerCache::operator()(LayerSize& size, Layer*& layer) {
79    deleteLayer(layer);
80}
81
82///////////////////////////////////////////////////////////////////////////////
83// Caching
84///////////////////////////////////////////////////////////////////////////////
85
86void LayerCache::deleteLayer(Layer* layer) {
87    if (layer) {
88        mSize -= layer->layer.getWidth() * layer->layer.getHeight() * 4;
89
90        glDeleteTextures(1, &layer->texture);
91        delete layer;
92    }
93}
94
95void LayerCache::clear() {
96    mCache.setOnEntryRemovedListener(this);
97    mCache.clear();
98    mCache.setOnEntryRemovedListener(NULL);
99}
100
101Layer* LayerCache::get(LayerSize& size) {
102    Layer* layer = mCache.remove(size);
103    if (layer) {
104        LAYER_LOGD("Reusing layer");
105
106        mSize -= layer->layer.getWidth() * layer->layer.getHeight() * 4;
107    } else {
108        LAYER_LOGD("Creating new layer");
109
110        layer = new Layer;
111        layer->blend = true;
112
113        // Generate the texture in which the FBO will draw
114        glGenTextures(1, &layer->texture);
115        glBindTexture(GL_TEXTURE_2D, layer->texture);
116
117        // The FBO will not be scaled, so we can use lower quality filtering
118        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
119        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
120
121        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
122        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
123
124        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, size.width, size.height, 0,
125                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
126    }
127
128    return layer;
129}
130
131bool LayerCache::put(LayerSize& layerSize, Layer* layer) {
132    const uint32_t size = layerSize.width * layerSize.height * 4;
133    // Don't even try to cache a layer that's bigger than the cache
134    if (size < mMaxSize) {
135        while (mSize + size > mMaxSize) {
136            Layer* oldest = mCache.removeOldest();
137            deleteLayer(oldest);
138        }
139
140        layerSize.id = mIdGenerator++;
141        mCache.put(layerSize, layer);
142        mSize += size;
143
144        return true;
145    }
146    return false;
147}
148
149}; // namespace uirenderer
150}; // namespace android
151