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