LayerCache.cpp revision fb8b763f762ae21923c58d64caa729b012f40e05 
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        glDeleteFramebuffers(1, &layer->fbo);
91        glDeleteTextures(1, &layer->texture);
92        delete layer;
93    }
94}
95
96void LayerCache::clear() {
97    mCache.setOnEntryRemovedListener(this);
98    mCache.clear();
99    mCache.setOnEntryRemovedListener(NULL);
100}
101
102Layer* LayerCache::get(LayerSize& size, GLuint previousFbo) {
103    Layer* layer = mCache.remove(size);
104    if (layer) {
105        LAYER_LOGD("Reusing layer");
106
107        mSize -= layer->layer.getWidth() * layer->layer.getHeight() * 4;
108    } else {
109        LAYER_LOGD("Creating new layer");
110
111        layer = new Layer;
112        layer->blend = true;
113
114        // Generate the FBO and attach the texture
115        glGenFramebuffers(1, &layer->fbo);
116        glBindFramebuffer(GL_FRAMEBUFFER, layer->fbo);
117
118        // Generate the texture in which the FBO will draw
119        glGenTextures(1, &layer->texture);
120        glBindTexture(GL_TEXTURE_2D, layer->texture);
121
122        // The FBO will not be scaled, so we can use lower quality filtering
123        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
124        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
125
126        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
127        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
128
129        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, size.width, size.height, 0,
130                GL_RGBA, GL_UNSIGNED_BYTE, NULL);
131
132        // Bind texture to FBO
133        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D,
134                layer->texture, 0);
135
136        GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
137        if (status != GL_FRAMEBUFFER_COMPLETE) {
138            LOGE("Framebuffer incomplete (GL error code 0x%x)", status);
139
140            glBindFramebuffer(GL_FRAMEBUFFER, previousFbo);
141
142            glDeleteFramebuffers(1, &layer->fbo);
143            glDeleteTextures(1, &layer->texture);
144            delete layer;
145
146            return NULL;
147        }
148    }
149
150    return layer;
151}
152
153bool LayerCache::put(LayerSize& layerSize, Layer* layer) {
154    const uint32_t size = layerSize.width * layerSize.height * 4;
155    // Don't even try to cache a layer that's bigger than the cache
156    if (size < mMaxSize) {
157        while (mSize + size > mMaxSize) {
158            Layer* oldest = mCache.removeOldest();
159            deleteLayer(oldest);
160        }
161
162        layerSize.id = mIdGenerator++;
163        mCache.put(layerSize, layer);
164        mSize += size;
165
166        return true;
167    }
168    return false;
169}
170
171}; // namespace uirenderer
172}; // namespace android
173