GLUtils.java revision 54b6cfa9a9e5b861a9930af873580d6dc20f773c 
1/*
2 * Copyright (C) 2006 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
17package android.opengl;
18
19import javax.microedition.khronos.opengles.GL10;
20import android.graphics.Bitmap;
21
22/**
23 *
24 * Utility class to help bridging OpenGL ES and Android APIs.
25 *
26 */
27
28public final class GLUtils {
29
30    /*
31     * We use a class initializer to allow the native code to cache some
32     * field offsets.
33     */
34    static {
35        nativeClassInit();
36    }
37
38    private GLUtils() {
39    }
40
41    /**
42     * return the internal format as defined by OpenGL ES of the supplied bitmap.
43     *
44     * @param bitmap
45     * @return the internal format of the bitmap.
46     */
47    public static int getInternalFormat(Bitmap bitmap) {
48        if (bitmap == null) {
49            throw new NullPointerException("getInternalFormat can't be used with a null Bitmap");
50        }
51        switch (bitmap.getConfig()) {
52            case ALPHA_8:
53                return GL10.GL_ALPHA;
54            case ARGB_4444:
55            case ARGB_8888:
56                return GL10.GL_RGBA;
57            case RGB_565:
58                return GL10.GL_RGB;
59        }
60        throw new IllegalArgumentException("Unknown internalformat");
61    }
62
63    /**
64     * Return the type as defined by OpenGL ES of the supplied bitmap.
65     */
66    public static int getType(Bitmap bitmap) {
67        if (bitmap == null) {
68            throw new NullPointerException("getType can't be used with a null Bitmap");
69        }
70        int type;
71        switch(bitmap.getConfig()) {
72            case ARGB_4444:
73                type = GL10.GL_UNSIGNED_SHORT_4_4_4_4;
74                break;
75            case RGB_565:
76                type = GL10.GL_UNSIGNED_SHORT_5_6_5;
77                break;
78            case ALPHA_8:
79            case ARGB_8888:
80            default:
81                type = GL10.GL_UNSIGNED_BYTE;
82                break;
83        }
84        return type;
85    }
86
87    /**
88     * Calls glTexImage2D() on the current OpenGL context. If no context is
89     * current the behavior is the same as calling glTexImage2D() with  no
90     * current context, that is, eglGetError() will return the appropriate
91     * error.
92     * Unlike glTexImage2D() bitmap cannot be null and will raise an exception
93     * in that case.
94     * All other parameters are identical to those used for glTexImage2D().
95     *
96     * NOTE: this method doesn't change GL_UNPACK_ALIGNMENT, you must make
97     * sure to set it properly according to the supplied bitmap.
98     *
99     * Whether or not bitmap can have non power of two dimensions depends on
100     * the current OpenGL context. Always check glGetError() some time
101     * after calling this method, just like when using OpenGL directly.
102     *
103     * @param target
104     * @param level
105     * @param internalformat
106     * @param bitmap
107     * @param border
108     */
109    public static void texImage2D(int target, int level, int internalformat,
110            Bitmap bitmap, int border) {
111        if (bitmap == null) {
112            throw new NullPointerException("texImage2D can't be used with a null Bitmap");
113        }
114        int type = getType(bitmap);
115        if (native_texImage2D(target, level, internalformat, bitmap, type, border)!=0) {
116            throw new IllegalArgumentException("invalid Bitmap format");
117        }
118    }
119
120    /**
121     * A version of texImage2D() that takes an explicit type parameter
122     * as defined by the OpenGL ES specification.
123     *
124     * @param target
125     * @param level
126     * @param internalformat
127     * @param bitmap
128     * @param type
129     * @param border
130     */
131    public static void texImage2D(int target, int level, int internalformat,
132            Bitmap bitmap, int type, int border) {
133        if (bitmap == null) {
134            throw new NullPointerException("texImage2D can't be used with a null Bitmap");
135        }
136        if (native_texImage2D(target, level, internalformat, bitmap, type, border)!=0) {
137            throw new IllegalArgumentException("invalid Bitmap format");
138        }
139    }
140
141    /**
142     * A version of texImage2D that determines the internalFormat automatically.
143     *
144     * @param target
145     * @param level
146     * @param bitmap
147     * @param border
148     */
149    public static void texImage2D(int target, int level, Bitmap bitmap,
150            int border) {
151        if (bitmap == null) {
152            throw new NullPointerException("texImage2D can't be used with a null Bitmap");
153        }
154        int type = getType(bitmap);
155        if (native_texImage2D(target, level, -1, bitmap, type, border)!=0) {
156            throw new IllegalArgumentException("invalid Bitmap format");
157        }
158    }
159
160    /**
161     * Calls glTexSubImage2D() on the current OpenGL context. If no context is
162     * current the behavior is the same as calling glTexSubImage2D() with  no
163     * current context, that is, eglGetError() will return the appropriate
164     * error.
165     * Unlike glTexSubImage2D() bitmap cannot be null and will raise an exception
166     * in that case.
167     * All other parameters are identical to those used for glTexSubImage2D().
168     *
169     * NOTE: this method doesn't change GL_UNPACK_ALIGNMENT, you must make
170     * sure to set it properly according to the supplied bitmap.
171     *
172     * Whether or not bitmap can have non power of two dimensions depends on
173     * the current OpenGL context. Always check glGetError() some time
174     * after calling this method, just like when using OpenGL directly.
175     *
176     * @param target
177     * @param level
178     * @param xoffset
179     * @param yoffset
180     * @param bitmap
181     */
182    public static void texSubImage2D(int target, int level, int xoffset, int yoffset,
183            Bitmap bitmap) {
184        if (bitmap == null) {
185            throw new NullPointerException("texSubImage2D can't be used with a null Bitmap");
186        }
187        int type = getType(bitmap);
188        if (native_texSubImage2D(target, level, xoffset, yoffset, bitmap, -1, type)!=0) {
189            throw new IllegalArgumentException("invalid Bitmap format");
190        }
191    }
192
193    /**
194     * A version of texSubImage2D() that takes an explicit type parameter
195     * as defined by the OpenGL ES specification.
196     *
197     * @param target
198     * @param level
199     * @param xoffset
200     * @param yoffset
201     * @param bitmap
202     * @param type
203     */
204    public static void texSubImage2D(int target, int level, int xoffset, int yoffset,
205            Bitmap bitmap, int format, int type) {
206        if (bitmap == null) {
207            throw new NullPointerException("texSubImage2D can't be used with a null Bitmap");
208        }
209        if (native_texSubImage2D(target, level, xoffset, yoffset, bitmap, format, type)!=0) {
210            throw new IllegalArgumentException("invalid Bitmap format");
211        }
212    }
213
214    native private static void nativeClassInit();
215
216    native private static int native_texImage2D(int target, int level, int internalformat,
217            Bitmap bitmap, int type, int border);
218    native private static int native_texSubImage2D(int target, int level, int xoffset, int yoffset,
219            Bitmap bitmap, int format, int type);
220}
221