PathCache.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 <SkCanvas.h>
22#include <SkRect.h>
23
24#include "PathCache.h"
25#include "Properties.h"
26
27namespace android {
28namespace uirenderer {
29
30///////////////////////////////////////////////////////////////////////////////
31// Constructors/destructor
32///////////////////////////////////////////////////////////////////////////////
33
34PathCache::PathCache():
35        mCache(GenerationCache<PathCacheEntry, PathTexture*>::kUnlimitedCapacity),
36        mSize(0), mMaxSize(MB(DEFAULT_PATH_CACHE_SIZE)) {
37    char property[PROPERTY_VALUE_MAX];
38    if (property_get(PROPERTY_PATH_CACHE_SIZE, property, NULL) > 0) {
39        LOGD("  Setting path cache size to %sMB", property);
40        setMaxSize(MB(atof(property)));
41    } else {
42        LOGD("  Using default path cache size of %.2fMB", DEFAULT_PATH_CACHE_SIZE);
43    }
44    init();
45}
46
47PathCache::PathCache(uint32_t maxByteSize):
48        mCache(GenerationCache<PathCacheEntry, PathTexture*>::kUnlimitedCapacity),
49        mSize(0), mMaxSize(maxByteSize) {
50    init();
51}
52
53PathCache::~PathCache() {
54    mCache.clear();
55}
56
57void PathCache::init() {
58    mCache.setOnEntryRemovedListener(this);
59
60    GLint maxTextureSize;
61    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
62    mMaxTextureSize = maxTextureSize;
63}
64
65///////////////////////////////////////////////////////////////////////////////
66// Size management
67///////////////////////////////////////////////////////////////////////////////
68
69uint32_t PathCache::getSize() {
70    return mSize;
71}
72
73uint32_t PathCache::getMaxSize() {
74    return mMaxSize;
75}
76
77void PathCache::setMaxSize(uint32_t maxSize) {
78    mMaxSize = maxSize;
79    while (mSize > mMaxSize) {
80        mCache.removeOldest();
81    }
82}
83
84///////////////////////////////////////////////////////////////////////////////
85// Callbacks
86///////////////////////////////////////////////////////////////////////////////
87
88void PathCache::operator()(PathCacheEntry& path, PathTexture*& texture) {
89    const uint32_t size = texture->width * texture->height;
90    mSize -= size;
91
92    if (texture) {
93        glDeleteTextures(1, &texture->id);
94        delete texture;
95    }
96}
97
98///////////////////////////////////////////////////////////////////////////////
99// Caching
100///////////////////////////////////////////////////////////////////////////////
101
102PathTexture* PathCache::get(SkPath* path, SkPaint* paint) {
103    PathCacheEntry entry(path, paint);
104    PathTexture* texture = mCache.get(entry);
105
106    if (!texture) {
107        texture = addTexture(entry, path, paint);
108    } else if (path->getGenerationID() != texture->generation) {
109        mCache.remove(entry);
110        texture = addTexture(entry, path, paint);
111    }
112
113    return texture;
114}
115
116PathTexture* PathCache::addTexture(const PathCacheEntry& entry,
117        const SkPath *path, const SkPaint* paint) {
118    const SkRect& bounds = path->getBounds();
119
120    const float pathWidth = bounds.width();
121    const float pathHeight = bounds.height();
122
123    if (pathWidth > mMaxTextureSize || pathHeight > mMaxTextureSize) {
124        LOGW("Path too large to be rendered into a texture");
125        return NULL;
126    }
127
128    const float offset = entry.strokeWidth * 1.5f;
129    const uint32_t width = uint32_t(pathWidth + offset * 2.0 + 0.5);
130    const uint32_t height = uint32_t(pathHeight + offset * 2.0 + 0.5);
131
132    const uint32_t size = width * height;
133    // Don't even try to cache a bitmap that's bigger than the cache
134    if (size < mMaxSize) {
135        while (mSize + size > mMaxSize) {
136            mCache.removeOldest();
137        }
138    }
139
140    PathTexture* texture = new PathTexture;
141    texture->left = bounds.fLeft;
142    texture->top = bounds.fTop;
143    texture->offset = offset;
144    texture->width = width;
145    texture->height = height;
146    texture->generation = path->getGenerationID();
147
148    SkBitmap bitmap;
149    bitmap.setConfig(SkBitmap::kA8_Config, width, height);
150    bitmap.allocPixels();
151    bitmap.eraseColor(0);
152
153    SkCanvas canvas(bitmap);
154    canvas.translate(-bounds.fLeft + offset, -bounds.fTop + offset);
155    canvas.drawPath(*path, *paint);
156
157    generateTexture(bitmap, texture);
158
159    if (size < mMaxSize) {
160        mSize += size;
161        mCache.put(entry, texture);
162    } else {
163        texture->cleanup = true;
164    }
165
166    return texture;
167}
168
169void PathCache::clear() {
170    mCache.clear();
171}
172
173void PathCache::generateTexture(SkBitmap& bitmap, Texture* texture) {
174    SkAutoLockPixels alp(bitmap);
175    if (!bitmap.readyToDraw()) {
176        LOGE("Cannot generate texture from bitmap");
177        return;
178    }
179
180    glGenTextures(1, &texture->id);
181
182    glBindTexture(GL_TEXTURE_2D, texture->id);
183    // Textures are Alpha8
184    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
185
186    texture->blend = true;
187    glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, texture->width, texture->height, 0,
188            GL_ALPHA, GL_UNSIGNED_BYTE, bitmap.getPixels());
189
190    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
191    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
192
193    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
194    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
195}
196
197}; // namespace uirenderer
198}; // namespace android
199