reactos/lib/glu32/libnurbs/internals/splitarcs.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  * splitarcs.c++
  37  *
  38  * $Date$ $Revision: 1.1 $
  39  * $Header: /cygdrive/c/RCVS/CVS/ReactOS/reactos/lib/glu32/libnurbs/internals/splitarcs.cc,v 1.1 2004/02/02 16:39:12 navaraf Exp $
  40  */
  41
  42 #include "glimports.h"
  43 #include "myassert.h"
  44 #include "mysetjmp.h"
  45 #include "mystdio.h"
  46 #include "subdivider.h"
  47 #include "arcsorter.h"
  48 #include "arc.h"
  49 #include "bin.h"
  50
  51 /* local preprocessor definitions */
  52 #define MAXARCS 10
  53
  54 /*----------------------------------------------------------------------------
  55  * Subdivider::split - split trim regions in source bin by line (param == value).
  56  *----------------------------------------------------------------------------
  57  */
  58
  59 void
  60 Subdivider::split( Bin& bin, Bin& left, Bin& right, int param, REAL value )
  61 {
  62     Bin intersections, unknown;
  63
  64     partition( bin, left, intersections, right, unknown, param, value );
  65
  66     int count = intersections.numarcs();
  67     if( count % 2 ) {
  68 #ifndef NDEBUG
  69         left.show( "left" );
  70         intersections.show( "intersections" );
  71         right.show( "right" );
  72 #endif
  73         ::mylongjmp( jumpbuffer, 29 );
  74     }
  75
  76     Arc_ptr arclist[MAXARCS], *list;
  77     if( count >= MAXARCS ) {
  78         list = new Arc_ptr[count];
  79     } else {
  80         list = arclist;
  81     }
  82
  83     Arc_ptr jarc, *last, *lptr;
  84     for( last = list; (jarc=intersections.removearc()) != NULL; last++ )
  85         *last = jarc;
  86
  87     if( param == 0 ) { /* sort into increasing t order */
  88         ArcSdirSorter sorter(*this);
  89         sorter.qsort( list, count );
  90
  91         //::qsort ((void *)list, count, sizeof(Arc_ptr), (cmpfunc)compare_s);
  92         for( lptr=list; lptr<last; lptr+=2 )
  93             check_s ( lptr[0], lptr[1] );
  94         for( lptr=list; lptr<last; lptr+=2 )
  95             join_s ( left, right, lptr[0], lptr[1] );
  96         for( lptr=list; lptr != last; lptr++ ) {
  97             if( ((*lptr)->head()[0] <= value) && ((*lptr)->tail()[0] <= value) )
  98                 left.addarc( *lptr  );
  99             else
 100                 right.addarc( *lptr  );
 101         }
 102     } else { /* sort into decreasing s order */
 103         ArcTdirSorter sorter(*this);
 104         sorter.qsort( list, count );
 105         //::qsort ((void *)list, count, sizeof(Arc_ptr), (cmpfunc)compare_t);
 106         for( lptr=list; lptr<last; lptr+=2 )
 107             check_t ( lptr[0], lptr[1] );
 108         for( lptr=list; lptr<last; lptr+=2 )
 109             join_t ( left, right, lptr[0], lptr[1] );
 110         for( lptr=list; lptr != last; lptr++ ) {
 111             if( ((*lptr)->head()[1] <= value) && ((*lptr)->tail()[1] <= value) )
 112                 left.addarc( *lptr  );
 113             else
 114                 right.addarc( *lptr  );
 115         }
 116     }
 117
 118     if( list != arclist ) delete[] list;
 119     unknown.adopt();
 120 }
 121
 122
 123 void
 124 Subdivider::check_s( Arc_ptr jarc1, Arc_ptr jarc2 )
 125 {
 126     assert( jarc1->check( ) != 0 );
 127     assert( jarc2->check( ) != 0 );
 128     assert( jarc1->next->check( ) != 0 );
 129     assert( jarc2->next->check( ) != 0 );
 130     assert( jarc1 != jarc2 );
 131
 132     /* XXX - if these assertions fail, it is due to user error or
 133              undersampling */
 134     if( ! ( jarc1->tail()[0] < (jarc1)->head()[0] ) ) {
 135 #ifndef NDEBUG
 136         dprintf( "s difference %f\n",  (jarc1)->tail()[0] - (jarc1)->head()[0] );
 137 #endif
 138         ::mylongjmp( jumpbuffer, 28 );
 139     }
 140
 141     if( ! ( jarc2->tail()[0] > (jarc2)->head()[0] ) ) {
 142 #ifndef NDEBUG
 143         dprintf( "s difference %f\n",  (jarc2)->tail()[0] - (jarc2)->head()[0] );
 144 #endif
 145         ::mylongjmp( jumpbuffer, 28 );
 146     }
 147 }
 148
 149 inline void
 150 Subdivider::link( Arc_ptr jarc1, Arc_ptr jarc2, Arc_ptr up, Arc_ptr down )
 151 {
 152     up->nuid = down->nuid = 0;          // XXX
 153
 154     up->next = jarc2;
 155     down->next = jarc1;
 156     up->prev = jarc1->prev;
 157     down->prev = jarc2->prev;
 158
 159     down->next->prev = down;
 160     up->next->prev = up;
 161     down->prev->next = down;
 162     up->prev->next = up;
 163 }
 164
 165 inline void
 166 Subdivider::simple_link( Arc_ptr jarc1, Arc_ptr jarc2 )
 167 {
 168     Arc_ptr tmp = jarc2->prev;
 169     jarc2->prev = jarc1->prev;
 170     jarc1->prev = tmp;
 171     jarc2->prev->next = jarc2;
 172     jarc1->prev->next = jarc1;
 173 }
 174
 175
 176 /*----------------------------------------------------------------------------
 177  * join - add a pair of oppositely directed jordan arcs between two arcs
 178  *----------------------------------------------------------------------------
 179  */
 180
 181 void
 182 Subdivider::join_s( Bin& left, Bin& right, Arc_ptr jarc1, Arc_ptr jarc2 )
 183 {
 184     assert( jarc1->check( ) != 0);
 185     assert( jarc2->check( ) != 0);
 186     assert( jarc1 != jarc2 );
 187
 188     if( ! jarc1->getitail() )
 189         jarc1 = jarc1->next;
 190
 191     if( ! jarc2->getitail() )
 192         jarc2 = jarc2->next;
 193
 194     REAL s = jarc1->tail()[0];
 195     REAL t1 = jarc1->tail()[1];
 196     REAL t2 = jarc2->tail()[1];
 197
 198     if( t1 == t2 ) {
 199         simple_link( jarc1, jarc2 );
 200     } else {
 201         Arc_ptr newright = new(arcpool) Arc( arc_right, 0 );
 202         Arc_ptr newleft = new(arcpool) Arc( arc_left, 0 );
 203         assert( t1 < t2 );
 204         if( isBezierArcType() ) {
 205             arctessellator.bezier( newright, s, s, t1, t2 );
 206             arctessellator.bezier( newleft, s, s, t2, t1 );
 207         } else {
 208             arctessellator.pwl_right( newright, s, t1, t2, stepsizes[0] );
 209             arctessellator.pwl_left( newleft, s, t2, t1, stepsizes[2] );
 210         }
 211         link( jarc1, jarc2, newright, newleft );
 212         left.addarc( newright  );
 213         right.addarc( newleft  );
 214     }
 215
 216     assert( jarc1->check( ) != 0 );
 217     assert( jarc2->check( ) != 0 );
 218     assert( jarc1->next->check( ) != 0);
 219     assert( jarc2->next->check( ) != 0);
 220 }
 221
 222 void
 223 Subdivider::check_t( Arc_ptr jarc1, Arc_ptr jarc2 )
 224 {
 225     assert( jarc1->check( ) != 0 );
 226     assert( jarc2->check( ) != 0 );
 227     assert( jarc1->next->check( ) != 0 );
 228     assert( jarc2->next->check( ) != 0 );
 229     assert( jarc1 != jarc2 );
 230
 231     /* XXX - if these assertions fail, it is due to user error or
 232              undersampling */
 233     if( ! ( jarc1->tail()[1] < (jarc1)->head()[1] ) ) {
 234 #ifndef NDEBUG
 235         dprintf( "t difference %f\n",  jarc1->tail()[1] - (jarc1)->head()[1] );
 236 #endif
 237         ::mylongjmp( jumpbuffer, 28 );
 238     }
 239
 240     if( ! ( jarc2->tail()[1] > (jarc2)->head()[1] ) ) {
 241 #ifndef NDEBUG
 242         dprintf( "t difference %f\n",  jarc2->tail()[1] - (jarc2)->head()[1] );
 243 #endif
 244         ::mylongjmp( jumpbuffer, 28 );
 245     }
 246 }
 247
 248 /*----------------------------------------------------------------------------
 249  * join_t - add a pair of oppositely directed jordan arcs between two arcs
 250  *----------------------------------------------------------------------------
 251  */
 252
 253 void
 254 Subdivider::join_t( Bin& bottom, Bin& top, Arc_ptr jarc1, Arc_ptr jarc2 )
 255 {
 256     assert( jarc1->check( ) != 0 );
 257     assert( jarc2->check( ) != 0 );
 258     assert( jarc1->next->check( ) != 0 );
 259     assert( jarc2->next->check( ) != 0 );
 260     assert( jarc1 != jarc2 );
 261
 262     if( ! jarc1->getitail() )
 263         jarc1 = jarc1->next;
 264
 265     if( ! jarc2->getitail() )
 266         jarc2 = jarc2->next;
 267
 268     REAL s1 = jarc1->tail()[0];
 269     REAL s2 = jarc2->tail()[0];
 270     REAL t  = jarc1->tail()[1];
 271
 272     if( s1 == s2 ) {
 273         simple_link( jarc1, jarc2 );
 274     } else {
 275         Arc_ptr newtop = new(arcpool) Arc( arc_top, 0 );
 276         Arc_ptr newbot = new(arcpool) Arc( arc_bottom, 0 );
 277         assert( s1 > s2 );
 278         if( isBezierArcType() ) {
 279             arctessellator.bezier( newtop, s1, s2, t, t );
 280             arctessellator.bezier( newbot, s2, s1, t, t );
 281         } else {
 282             arctessellator.pwl_top( newtop, t, s1, s2, stepsizes[1] );
 283             arctessellator.pwl_bottom( newbot, t, s2, s1, stepsizes[3] );
 284         }
 285         link( jarc1, jarc2, newtop, newbot );
 286         bottom.addarc( newtop  );
 287         top.addarc( newbot  );
 288     }
 289
 290     assert( jarc1->check( ) != 0 );
 291     assert( jarc2->check( ) != 0 );
 292     assert( jarc1->next->check( ) != 0 );
 293     assert( jarc2->next->check( ) != 0 );
 294 }
 295