reactos/lib/glu32/libnurbs/internals/sorter.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  * sorter.c++
  37  *
  38  * $Date$ $Revision: 1.1 $
  39  * $Header: /cygdrive/c/RCVS/CVS/ReactOS/reactos/lib/glu32/libnurbs/internals/sorter.cc,v 1.1 2004/02/02 16:39:12 navaraf Exp $
  40  */
  41
  42 #include "glimports.h"
  43 #include "sorter.h"
  44 #include "mystdio.h"
  45
  46 Sorter::Sorter( int _es )
  47 {
  48     es = _es;
  49 }
  50
  51 void
  52 Sorter::qsort( void *a, int n )
  53 {
  54     qs1( (char *)a, ((char *)a)+n*es);
  55 }
  56
  57 int
  58 Sorter::qscmp( char *, char * )
  59 {
  60     dprintf( "Sorter::qscmp: pure virtual called\n" );
  61     return 0;
  62 }
  63
  64
  65 void
  66 Sorter::qsexc( char *, char * )
  67 {
  68     dprintf( "Sorter::qsexc: pure virtual called\n" );
  69 }
  70
  71
  72 void
  73 Sorter::qstexc( char *, char *, char * )
  74 {
  75     dprintf( "Sorter::qstexc: pure virtual called\n" );
  76 }
  77
  78 void
  79 Sorter::qs1( char *a,  char *l )
  80 {
  81     char *i, *j;
  82     char        *lp, *hp;
  83     int c;
  84     unsigned int n;
  85
  86 start:
  87     if((n=l-a) <= (unsigned int)es)
  88             return;
  89     n = es * (n / (2*es));
  90     hp = lp = a+n;
  91     i = a;
  92     j = l-es;
  93     while(1) {
  94         if(i < lp) {
  95             if((c = qscmp(i, lp)) == 0) {
  96                 qsexc(i, lp -= es);
  97                 continue;
  98             }
  99             if(c < 0) {
 100                 i += es;
 101                 continue;
 102             }
 103         }
 104
 105 loop:
 106         if(j > hp) {
 107             if((c = qscmp(hp, j)) == 0) {
 108                 qsexc(hp += es, j);
 109                 goto loop;
 110             }
 111             if(c > 0) {
 112                 if(i == lp) {
 113                     qstexc(i, hp += es, j);
 114                     i = lp += es;
 115                     goto loop;
 116                 }
 117                 qsexc(i, j);
 118                 j -= es;
 119                 i += es;
 120                 continue;
 121             }
 122             j -= es;
 123             goto loop;
 124         }
 125
 126         if(i == lp) {
 127             if(lp-a >= l-hp) {
 128                 qs1(hp+es, l);
 129                 l = lp;
 130             } else {
 131                 qs1(a, lp);
 132                 a = hp+es;
 133             }
 134             goto start;
 135         }
 136
 137         qstexc(j, lp -= es, i);
 138         j = hp -= es;
 139     }
 140 }
 141