PathCache.cpp revision 1e45aae5de003657e5d18f74d34998f5de5db5b7 
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
26namespace android {
27namespace uirenderer {
28
29///////////////////////////////////////////////////////////////////////////////
30// Constructors/destructor
31///////////////////////////////////////////////////////////////////////////////
32
33PathCache::PathCache(uint32_t maxByteSize):
34        mCache(GenerationCache<PathCacheEntry, PathTexture*>::kUnlimitedCapacity),
35        mSize(0), mMaxSize(maxByteSize) {
36    mCache.setOnEntryRemovedListener(this);
37
38    GLint maxTextureSize;
39    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxTextureSize);
40    mMaxTextureSize = maxTextureSize;
41}
42
43PathCache::~PathCache() {
44    mCache.clear();
45}
46
47///////////////////////////////////////////////////////////////////////////////
48// Size management
49///////////////////////////////////////////////////////////////////////////////
50
51uint32_t PathCache::getSize() {
52    return mSize;
53}
54
55uint32_t PathCache::getMaxSize() {
56    return mMaxSize;
57}
58
59void PathCache::setMaxSize(uint32_t maxSize) {
60    mMaxSize = maxSize;
61    while (mSize > mMaxSize) {
62        mCache.removeOldest();
63    }
64}
65
66///////////////////////////////////////////////////////////////////////////////
67// Callbacks
68///////////////////////////////////////////////////////////////////////////////
69
70void PathCache::operator()(PathCacheEntry& path, PathTexture*& texture) {
71    const uint32_t size = texture->width * texture->height;
72    mSize -= size;
73
74    if (texture) {
75        glDeleteTextures(1, &texture->id);
76        delete texture;
77    }
78}
79
80///////////////////////////////////////////////////////////////////////////////
81// Caching
82///////////////////////////////////////////////////////////////////////////////
83
84PathTexture* PathCache::get(SkPath* path, SkPaint* paint) {
85    PathCacheEntry entry(path, paint);
86    PathTexture* texture = mCache.get(entry);
87
88    if (!texture) {
89        texture = addTexture(entry, path, paint);
90    } else if (path->getGenerationID() != texture->generation) {
91        mCache.remove(entry);
92        texture = addTexture(entry, path, paint);
93    }
94
95    return texture;
96}
97
98PathTexture* PathCache::addTexture(const PathCacheEntry& entry,
99        const SkPath *path, const SkPaint* paint) {
100    const SkRect& bounds = path->getBounds();
101
102    const float pathWidth = bounds.width();
103    const float pathHeight = bounds.height();
104
105    if (pathWidth > mMaxTextureSize || pathHeight > mMaxTextureSize) {
106        LOGW("Path too large to be rendered into a texture");
107        return NULL;
108    }
109
110    const float offset = entry.strokeWidth * 1.5f;
111    const uint32_t width = uint32_t(pathWidth + offset * 2.0 + 0.5);
112    const uint32_t height = uint32_t(pathHeight + offset * 2.0 + 0.5);
113
114    const uint32_t size = width * height;
115    // Don't even try to cache a bitmap that's bigger than the cache
116    if (size < mMaxSize) {
117        while (mSize + size > mMaxSize) {
118            mCache.removeOldest();
119        }
120    }
121
122    PathTexture* texture = new PathTexture;
123    texture->left = bounds.fLeft;
124    texture->top = bounds.fTop;
125    texture->offset = offset;
126    texture->width = width;
127    texture->height = height;
128    texture->generation = path->getGenerationID();
129
130    SkBitmap bitmap;
131    bitmap.setConfig(SkBitmap::kA8_Config, width, height);
132    bitmap.allocPixels();
133    bitmap.eraseColor(0);
134
135    SkCanvas canvas(bitmap);
136    canvas.translate(-bounds.fLeft + offset, -bounds.fTop + offset);
137    canvas.drawPath(*path, *paint);
138
139    generateTexture(bitmap, texture);
140
141    if (size < mMaxSize) {
142        mSize += size;
143        mCache.put(entry, texture);
144    } else {
145        texture->cleanup = true;
146    }
147
148    return texture;
149}
150
151void PathCache::clear() {
152    mCache.clear();
153}
154
155void PathCache::generateTexture(SkBitmap& bitmap, Texture* texture) {
156    SkAutoLockPixels alp(bitmap);
157    if (!bitmap.readyToDraw()) {
158        LOGE("Cannot generate texture from bitmap");
159        return;
160    }
161
162    glGenTextures(1, &texture->id);
163
164    glBindTexture(GL_TEXTURE_2D, texture->id);
165    // Textures are Alpha8
166    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
167
168    texture->blend = true;
169    glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, texture->width, texture->height, 0,
170            GL_ALPHA, GL_UNSIGNED_BYTE, bitmap.getPixels());
171
172    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
173    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
174
175    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
176    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
177}
178
179}; // namespace uirenderer
180}; // namespace android
181