aboutsummaryrefslogtreecommitdiffstats
path: root/src/jogl/classes/com/sun/opengl/impl/gl2/Util.java
blob: 0fc72daa9aab486a1c3de2598aafff635c47e4f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/* 
 * Copyright (c) 2002-2004 LWJGL Project
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are 
 * met:
 * 
 * * Redistributions of source code must retain the above copyright 
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'LWJGL' nor the names of 
 *   its contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * - Redistribution of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
 * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
 * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * You acknowledge that this software is not designed or intended for use
 * in the design, construction, operation or maintenance of any nuclear
 * facility.
 */

package com.sun.opengl.impl.gl2;

import com.sun.opengl.impl.*;

import java.nio.IntBuffer;
import javax.media.opengl.*;

/**
 * Util.java
 * <p/>
 * <p/>
 * Created 7-jan-2004
 *
 * @author Erik Duijs
 */
class Util {

  /**
   * temp int[] of one for getting an int from some GL functions
   */
  private int[] scratch = new int[1];

  /**
   * Return ceiling of integer division
   *
   * @param a
   * @param b
   *
   * @return int
   */
  protected static int ceil(int a, int b) {
    return (a % b == 0 ? a / b : a / b + 1);
  }

  /**
   * Method compPerPix.
   *
   * @param format
   *
   * @return int
   */
  protected static int compPerPix(int format) {
    /* Determine number of components per pixel */
    switch ( format ) {
    case GL2.GL_COLOR_INDEX:
    case GL2.GL_STENCIL_INDEX:
    case GL2.GL_DEPTH_COMPONENT:
    case GL2.GL_RED:
    case GL2.GL_GREEN:
    case GL2.GL_BLUE:
    case GL2.GL_ALPHA:
    case GL2.GL_LUMINANCE:
      return 1;
    case GL2.GL_LUMINANCE_ALPHA:
      return 2;
    case GL2.GL_RGB:
    case GL2.GL_BGR:
      return 3;
    case GL2.GL_RGBA:
    case GL2.GL_BGRA:
      return 4;
    default :
      return -1;
    }
  }

  /**
   * Method nearestPower.
   * <p/>
   * Compute the nearest power of 2 number.  This algorithm is a little strange, but it works quite well.
   *
   * @param value
   *
   * @return int
   */
  protected static int nearestPower(int value) {
    int i;

    i = 1;

    /* Error! */
    if ( value == 0 )
      return -1;

    for ( ; ; ) {
      if ( value == 1 ) {
        return i;
      } else if ( value == 3 ) {
        return i << 2;
      }
      value >>= 1;
      i <<= 1;
    }
  }

  /**
   * Method bytesPerPixel.
   *
   * @param format
   * @param type
   *
   * @return int
   */
  protected static int bytesPerPixel(int format, int type) {
    int n, m;

    switch ( format ) {
    case GL2.GL_COLOR_INDEX:
    case GL2.GL_STENCIL_INDEX:
    case GL2.GL_DEPTH_COMPONENT:
    case GL2.GL_RED:
    case GL2.GL_GREEN:
    case GL2.GL_BLUE:
    case GL2.GL_ALPHA:
    case GL2.GL_LUMINANCE:
      n = 1;
      break;
    case GL2.GL_LUMINANCE_ALPHA:
      n = 2;
      break;
    case GL2.GL_RGB:
    case GL2.GL_BGR:
      n = 3;
      break;
    case GL2.GL_RGBA:
    case GL2.GL_BGRA:
      n = 4;
      break;
    default :
      n = 0;
    }

    switch ( type ) {
    case GL2.GL_UNSIGNED_BYTE:
      m = 1;
      break;
    case GL2.GL_BYTE:
      m = 1;
      break;
    case GL2.GL_BITMAP:
      m = 1;
      break;
    case GL2.GL_UNSIGNED_SHORT:
      m = 2;
      break;
    case GL2.GL_SHORT:
      m = 2;
      break;
    case GL2.GL_UNSIGNED_INT:
      m = 4;
      break;
    case GL2.GL_INT:
      m = 4;
      break;
    case GL2.GL_FLOAT:
      m = 4;
      break;
    default :
      m = 0;
    }

    return n * m;
  }

  /**
   * Convenience method for returning an int, rather than getting it out of a buffer yourself.
   *
   * @param what
   *
   * @return int
   */
  protected int glGetIntegerv(GL gl, int what) {
    gl.glGetIntegerv(what, scratch, 0);
    return scratch[0];
  }
}