AssetAtlas.h revision a404e16e4933857464046d763ed7629cd0c86cbf
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 "Image.h" 31#include "Texture.h" 32#include "UvMapper.h" 33 34namespace android { 35namespace uirenderer { 36 37/** 38 * An asset atlas holds a collection of framework bitmaps in a single OpenGL 39 * texture. Each bitmap is associated with a location, defined in pixels, 40 * inside the atlas. The atlas is generated by the framework and bound as 41 * an external texture using the EGLImageKHR extension. 42 */ 43class AssetAtlas { 44public: 45 /** 46 * Entry representing the position and rotation of a 47 * bitmap inside the atlas. 48 */ 49 struct Entry { 50 /** 51 * The bitmap that generated this atlas entry. 52 */ 53 SkBitmap* bitmap; 54 55 /** 56 * Location of the bitmap inside the atlas, in pixels. 57 */ 58 int x; 59 int y; 60 61 /** 62 * If set, the bitmap is rotated 90 degrees (clockwise) 63 * inside the atlas. 64 */ 65 bool rotated; 66 67 /* 68 * A "virtual texture" object that represents the texture 69 * this entry belongs to. This texture should never be 70 * modified. 71 */ 72 Texture* texture; 73 74 /** 75 * Maps texture coordinates in the [0..1] range into the 76 * correct range to sample this entry from the atlas. 77 */ 78 const UvMapper uvMapper; 79 80 /** 81 * Atlas this entry belongs to. 82 */ 83 const AssetAtlas& atlas; 84 85 private: 86 Entry(SkBitmap* bitmap, int x, int y, bool rotated, 87 Texture* texture, const UvMapper& mapper, const AssetAtlas& atlas): 88 bitmap(bitmap), x(x), y(y), rotated(rotated), 89 texture(texture), uvMapper(mapper), atlas(atlas) { } 90 91 ~Entry() { 92 delete texture; 93 } 94 95 friend class AssetAtlas; 96 }; 97 98 AssetAtlas(): mTexture(NULL), mImage(NULL) { } 99 ~AssetAtlas() { terminate(); } 100 101 /** 102 * Initializes the atlas with the specified buffer and 103 * map. The buffer is a gralloc'd texture that will be 104 * used as an EGLImage. The map is a list of SkBitmap* 105 * and their (x, y) positions as well as their rotation 106 * flags. 107 * 108 * This method returns immediately if the atlas is already 109 * initialized. To re-initialize the atlas, you must 110 * first call terminate(). 111 */ 112 ANDROID_API void init(sp<GraphicBuffer> buffer, int* map, int count); 113 114 /** 115 * Destroys the atlas texture. This object can be 116 * re-initialized after calling this method. 117 * 118 * After calling this method, the width, height 119 * and texture are set to 0. 120 */ 121 ANDROID_API void terminate(); 122 123 /** 124 * Returns the width of this atlas in pixels. 125 * Can return 0 if the atlas is not initialized. 126 */ 127 uint32_t getWidth() const { 128 return mTexture ? mTexture->width : 0; 129 } 130 131 /** 132 * Returns the height of this atlas in pixels. 133 * Can return 0 if the atlas is not initialized. 134 */ 135 uint32_t getHeight() const { 136 return mTexture ? mTexture->height : 0; 137 } 138 139 /** 140 * Returns the OpenGL name of the texture backing this atlas. 141 * Can return 0 if the atlas is not initialized. 142 */ 143 GLuint getTexture() const { 144 return mTexture ? mTexture->id : 0; 145 } 146 147 /** 148 * Returns the entry in the atlas associated with the specified 149 * bitmap. If the bitmap is not in the atlas, return NULL. 150 */ 151 Entry* getEntry(SkBitmap* const bitmap) const; 152 153 /** 154 * Returns the texture for the atlas entry associated with the 155 * specified bitmap. If the bitmap is not in the atlas, return NULL. 156 */ 157 Texture* getEntryTexture(SkBitmap* const bitmap) const; 158 159private: 160 void createEntries(int* map, int count); 161 162 Texture* mTexture; 163 Image* mImage; 164 165 KeyedVector<SkBitmap*, Entry*> mEntries; 166}; // class AssetAtlas 167 168}; // namespace uirenderer 169}; // namespace android 170 171#endif // ANDROID_HWUI_ASSET_ATLAS_H 172