Synchronize with trunk's revision r57629.
[reactos.git] / dll / opengl / glu32 / src / libnurbs / nurbtess / quicksort.cc
1 /*
2 ** License Applicability. Except to the extent portions of this file are
3 ** made subject to an alternative license as permitted in the SGI Free
4 ** Software License B, Version 1.1 (the "License"), the contents of this
5 ** file are subject only to the provisions of the License. You may not use
6 ** this file except in compliance with the License. You may obtain a copy
7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
9 **
10 ** http://oss.sgi.com/projects/FreeB
11 **
12 ** Note that, as provided in the License, the Software is distributed on an
13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
17 **
18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
21 ** Copyright in any portions created by third parties is as indicated
22 ** elsewhere herein. All Rights Reserved.
23 **
24 ** Additional Notice Provisions: The application programming interfaces
25 ** established by SGI in conjunction with the Original Code are The
26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
31 ** published by SGI, but has not been independently verified as being
32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
33 **
34 */
35 /*
36 */
37
38 #include <stdlib.h>
39 #include <stdio.h>
40
41
42 static void swap(void *v[], int i, int j)
43 {
44 void *temp;
45 temp = v[i];
46 v[i] = v[j];
47 v[j] = temp;
48 }
49
50 /*as an example to use this function to
51 *sort integers, you need to supply the function
52 *int comp(int *i1, int *i2)
53 *{
54 * if( *i1 < * i2) return -1;
55 * else return 1;
56 *}
57 *and an array of pointers to integers:
58 * int *v[100] (allocate space for where each v[i] points to).
59 *then you can call:
60 * quicksort( (void**)v, left, right, (int (*)(void *, void *))comp)
61 */
62 void quicksort(void *v[], int left, int right,
63 int (*comp) (void *, void *))
64 {
65 int i, last;
66 if(left >= right) /*do nothing if array contains */
67 return; /*fewer than two elements*/
68
69 swap(v, left, (left+right)/2);
70 last = left;
71 for(i=left+1; i<=right; i++)
72 if((*comp)(v[i], v[left])<0)
73 swap(v, ++last, i);
74 swap(v, left, last);
75 quicksort(v, left, last-1, comp);
76 quicksort(v, last+1, right, comp);
77 }