1/*
2 * Copyright (C) 2013 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_ASSET_ATLAS_H
18#define ANDROID_HWUI_ASSET_ATLAS_H
19
20#include <GLES2/gl2.h>
21
22#include <ui/GraphicBuffer.h>
23
24#include <utils/KeyedVector.h>
25
26#include <cutils/compiler.h>
27
28#include <SkBitmap.h>
29
30#include "Texture.h"
31#include "UvMapper.h"
32
33namespace android {
34namespace uirenderer {
35
36class Caches;
37class Image;
38
39/**
40 * An asset atlas holds a collection of framework bitmaps in a single OpenGL
41 * texture. Each bitmap is associated with a location, defined in pixels,
42 * inside the atlas. The atlas is generated by the framework and bound as
43 * an external texture using the EGLImageKHR extension.
44 */
45class AssetAtlas {
46public:
47    /**
48     * Entry representing the texture and uvMapper of a PixelRef in the
49     * atlas
50     */
51    class Entry {
52    public:
53        /*
54         * A "virtual texture" object that represents the texture
55         * this entry belongs to. This texture should never be
56         * modified.
57         */
58        Texture* texture;
59
60        /**
61         * Maps texture coordinates in the [0..1] range into the
62         * correct range to sample this entry from the atlas.
63         */
64        const UvMapper uvMapper;
65
66        /**
67         * Unique identifier used to merge bitmaps and 9-patches stored
68         * in the atlas.
69         */
70        const void* getMergeId() const {
71            return texture->blend ? &atlas.mBlendKey : &atlas.mOpaqueKey;
72        }
73
74    private:
75        /**
76         * The pixel ref that generated this atlas entry.
77         */
78        SkPixelRef* pixelRef;
79
80        /**
81         * Atlas this entry belongs to.
82         */
83        const AssetAtlas& atlas;
84
85        Entry(SkPixelRef* pixelRef, Texture* texture, const UvMapper& mapper,
86                    const AssetAtlas& atlas)
87                : texture(texture)
88                , uvMapper(mapper)
89                , pixelRef(pixelRef)
90                , atlas(atlas) {
91        }
92
93        ~Entry() {
94            delete texture;
95        }
96
97        friend class AssetAtlas;
98    };
99
100    AssetAtlas(): mTexture(nullptr), mImage(nullptr),
101            mBlendKey(true), mOpaqueKey(false) { }
102    ~AssetAtlas() { terminate(); }
103
104    /**
105     * Initializes the atlas with the specified buffer and
106     * map. The buffer is a gralloc'd texture that will be
107     * used as an EGLImage. The map is a list of SkBitmap*
108     * and their (x, y) positions
109     *
110     * This method returns immediately if the atlas is already
111     * initialized. To re-initialize the atlas, you must
112     * first call terminate().
113     */
114    ANDROID_API void init(sp<GraphicBuffer> buffer, int64_t* map, int count);
115
116    /**
117     * Destroys the atlas texture. This object can be
118     * re-initialized after calling this method.
119     *
120     * After calling this method, the width, height
121     * and texture are set to 0.
122     */
123    void terminate();
124
125    /**
126     * Returns the width of this atlas in pixels.
127     * Can return 0 if the atlas is not initialized.
128     */
129    uint32_t getWidth() const {
130        return mTexture ? mTexture->width : 0;
131    }
132
133    /**
134     * Returns the height of this atlas in pixels.
135     * Can return 0 if the atlas is not initialized.
136     */
137    uint32_t getHeight() const {
138        return mTexture ? mTexture->height : 0;
139    }
140
141    /**
142     * Returns the OpenGL name of the texture backing this atlas.
143     * Can return 0 if the atlas is not initialized.
144     */
145    GLuint getTexture() const {
146        return mTexture ? mTexture->id : 0;
147    }
148
149    /**
150     * Returns the entry in the atlas associated with the specified
151     * bitmap. If the bitmap is not in the atlas, return NULL.
152     */
153    Entry* getEntry(const SkBitmap* bitmap) const;
154
155    /**
156     * Returns the texture for the atlas entry associated with the
157     * specified bitmap. If the bitmap is not in the atlas, return NULL.
158     */
159    Texture* getEntryTexture(const SkBitmap* bitmap) const;
160
161private:
162    void createEntries(Caches& caches, int64_t* map, int count);
163    void updateTextureId();
164
165    Texture* mTexture;
166    Image* mImage;
167
168    const bool mBlendKey;
169    const bool mOpaqueKey;
170
171    KeyedVector<const SkPixelRef*, Entry*> mEntries;
172}; // class AssetAtlas
173
174}; // namespace uirenderer
175}; // namespace android
176
177#endif // ANDROID_HWUI_ASSET_ATLAS_H
178