massive reduction of unneeded files

1 files changed, 0 insertions, 1358 deletions

diff --git a/nx-X11/extras/ogl-sample/main/gfx/lib/glu/libtess/sweep.c b/nx-X11/extras/ogl-sample/main/gfx/lib/glu/libtess/sweep.c
deleted file mode 100644
index 1e49a5800..000000000
--- a/nx-X11/extras/ogl-sample/main/gfx/lib/glu/libtess/sweep.c
+++ /dev/null
@@ -1,1358 +0,0 @@
-/*
-** License Applicability. Except to the extent portions of this file are
-** made subject to an alternative license as permitted in the SGI Free
-** Software License B, Version 1.1 (the "License"), the contents of this
-** file are subject only to the provisions of the License. You may not use
-** this file except in compliance with the License. You may obtain a copy
-** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
-** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
-** 
-** http://oss.sgi.com/projects/FreeB
-** 
-** Note that, as provided in the License, the Software is distributed on an
-** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
-** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
-** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
-** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
-** 
-** Original Code. The Original Code is: OpenGL Sample Implementation,
-** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
-** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
-** Copyright in any portions created by third parties is as indicated
-** elsewhere herein. All Rights Reserved.
-** 
-** Additional Notice Provisions: The application programming interfaces
-** established by SGI in conjunction with the Original Code are The
-** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
-** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
-** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
-** Window System(R) (Version 1.3), released October 19, 1998. This software
-** was created using the OpenGL(R) version 1.2.1 Sample Implementation
-** published by SGI, but has not been independently verified as being
-** compliant with the OpenGL(R) version 1.2.1 Specification.
-**
-*/
-/*
-** Author: Eric Veach, July 1994.
-**
-*/
-/* $XFree86: xc/extras/ogl-sample/main/gfx/lib/glu/libtess/sweep.c,v 1.2 2001/10/28 03:32:22 tsi Exp $ */
-
-#include "gluos.h"
-#include <assert.h>
-#include <stddef.h>
-#include <setjmp.h>		/* longjmp */
-#include <limits.h>		/* LONG_MAX */
-
-#include "mesh.h"
-#include "geom.h"
-#include "tess.h"
-#include "dict.h"
-#include "priorityq.h"
-#include "memalloc.h"
-#include "sweep.h"
-
-#define TRUE 1
-#define FALSE 0
-
-#ifdef FOR_TRITE_TEST_PROGRAM
-extern void DebugEvent( GLUtesselator *tess );
-#else
-#define DebugEvent( tess )
-#endif
-
-/*
- * Invariants for the Edge Dictionary.
- * - each pair of adjacent edges e2=Succ(e1) satisfies EdgeLeq(e1,e2)
- *   at any valid location of the sweep event
- * - if EdgeLeq(e2,e1) as well (at any valid sweep event), then e1 and e2
- *   share a common endpoint
- * - for each e, e->Dst has been processed, but not e->Org
- * - each edge e satisfies VertLeq(e->Dst,event) && VertLeq(event,e->Org)
- *   where "event" is the current sweep line event.
- * - no edge e has zero length
- *
- * Invariants for the Mesh (the processed portion).
- * - the portion of the mesh left of the sweep line is a planar graph,
- *   ie. there is *some* way to embed it in the plane
- * - no processed edge has zero length
- * - no two processed vertices have identical coordinates
- * - each "inside" region is monotone, ie. can be broken into two chains
- *   of monotonically increasing vertices according to VertLeq(v1,v2)
- *   - a non-invariant: these chains may intersect (very slightly)
- *
- * Invariants for the Sweep.
- * - if none of the edges incident to the event vertex have an activeRegion
- *   (ie. none of these edges are in the edge dictionary), then the vertex
- *   has only right-going edges.
- * - if an edge is marked "fixUpperEdge" (it is a temporary edge introduced
- *   by ConnectRightVertex), then it is the only right-going edge from
- *   its associated vertex.  (This says that these edges exist only
- *   when it is necessary.)
- */
-
-#define MAX(x,y)	((x) >= (y) ? (x) : (y))
-#define MIN(x,y)	((x) <= (y) ? (x) : (y))
-
-/* When we merge two edges into one, we need to compute the combined
- * winding of the new edge.
- */
-#define AddWinding(eDst,eSrc)	(eDst->winding += eSrc->winding, \
-				 eDst->Sym->winding += eSrc->Sym->winding)
-
-static void SweepEvent( GLUtesselator *tess, GLUvertex *vEvent );
-static void WalkDirtyRegions( GLUtesselator *tess, ActiveRegion *regUp );
-static int CheckForRightSplice( GLUtesselator *tess, ActiveRegion *regUp );
-
-static int EdgeLeq( GLUtesselator *tess, ActiveRegion *reg1,
-		    ActiveRegion *reg2 )
-/*
- * Both edges must be directed from right to left (this is the canonical
- * direction for the upper edge of each region).
- *
- * The strategy is to evaluate a "t" value for each edge at the
- * current sweep line position, given by tess->event.  The calculations
- * are designed to be very stable, but of course they are not perfect.
- *
- * Special case: if both edge destinations are at the sweep event,
- * we sort the edges by slope (they would otherwise compare equally).
- */
-{
-  GLUvertex *event = tess->event;
-  GLUhalfEdge *e1, *e2;
-  GLdouble t1, t2;
-
-  e1 = reg1->eUp;
-  e2 = reg2->eUp;
-
-  if( e1->Dst == event ) {
-    if( e2->Dst == event ) {
-      /* Two edges right of the sweep line which meet at the sweep event.
-       * Sort them by slope.
-       */
-      if( VertLeq( e1->Org, e2->Org )) {
-	return EdgeSign( e2->Dst, e1->Org, e2->Org ) <= 0;
-      }
-      return EdgeSign( e1->Dst, e2->Org, e1->Org ) >= 0;
-    }
-    return EdgeSign( e2->Dst, event, e2->Org ) <= 0;
-  }
-  if( e2->Dst == event ) {
-    return EdgeSign( e1->Dst, event, e1->Org ) >= 0;
-  }
-
-  /* General case - compute signed distance *from* e1, e2 to event */
-  t1 = EdgeEval( e1->Dst, event, e1->Org );
-  t2 = EdgeEval( e2->Dst, event, e2->Org );
-  return (t1 >= t2);
-}
-
-
-static void DeleteRegion( GLUtesselator *tess, ActiveRegion *reg )
-{
-  if( reg->fixUpperEdge ) {
-    /* It was created with zero winding number, so it better be
-     * deleted with zero winding number (ie. it better not get merged
-     * with a real edge).
-     */
-    assert( reg->eUp->winding == 0 );
-  }
-  reg->eUp->activeRegion = NULL;
-  dictDelete( tess->dict, reg->nodeUp ); /* __gl_dictListDelete */
-  memFree( reg );
-}
-
-
-static int FixUpperEdge( ActiveRegion *reg, GLUhalfEdge *newEdge )
-/*
- * Replace an upper edge which needs fixing (see ConnectRightVertex).
- */
-{
-  assert( reg->fixUpperEdge );
-  if ( !__gl_meshDelete( reg->eUp ) ) return 0;
-  reg->fixUpperEdge = FALSE;
-  reg->eUp = newEdge;
-  newEdge->activeRegion = reg;
-
-  return 1; 
-}
-
-static ActiveRegion *TopLeftRegion( ActiveRegion *reg )
-{
-  GLUvertex *org = reg->eUp->Org;
-  GLUhalfEdge *e;
-
-  /* Find the region above the uppermost edge with the same origin */
-  do {
-    reg = RegionAbove( reg );
-  } while( reg->eUp->Org == org );
-
-  /* If the edge above was a temporary edge introduced by ConnectRightVertex,
-   * now is the time to fix it.
-   */
-  if( reg->fixUpperEdge ) {
-    e = __gl_meshConnect( RegionBelow(reg)->eUp->Sym, reg->eUp->Lnext );
-    if (e == NULL) return NULL;
-    if ( !FixUpperEdge( reg, e ) ) return NULL;
-    reg = RegionAbove( reg );
-  }
-  return reg;
-}
-
-static ActiveRegion *TopRightRegion( ActiveRegion *reg )
-{
-  GLUvertex *dst = reg->eUp->Dst;
-
-  /* Find the region above the uppermost edge with the same destination */
-  do {
-    reg = RegionAbove( reg );
-  } while( reg->eUp->Dst == dst );
-  return reg;
-}
-
-static ActiveRegion *AddRegionBelow( GLUtesselator *tess,
-				     ActiveRegion *regAbove,
-				     GLUhalfEdge *eNewUp )
-/*
- * Add a new active region to the sweep line, *somewhere* below "regAbove"
- * (according to where the new edge belongs in the sweep-line dictionary).
- * The upper edge of the new region will be "eNewUp".
- * Winding number and "inside" flag are not updated.
- */
-{
-  ActiveRegion *regNew = (ActiveRegion *)memAlloc( sizeof( ActiveRegion ));
-  if (regNew == NULL) longjmp(tess->env,1);
-
-  regNew->eUp = eNewUp;
-  /* __gl_dictListInsertBefore */ 
-  regNew->nodeUp = dictInsertBefore( tess->dict, regAbove->nodeUp, regNew );
-  if (regNew->nodeUp == NULL) longjmp(tess->env,1);
-  regNew->fixUpperEdge = FALSE;
-  regNew->sentinel = FALSE;
-  regNew->dirty = FALSE;
-
-  eNewUp->activeRegion = regNew;
-  return regNew;
-}
-
-static GLboolean IsWindingInside( GLUtesselator *tess, int n )
-{
-  switch( tess->windingRule ) {
-  case GLU_TESS_WINDING_ODD:
-    return (n & 1);
-  case GLU_TESS_WINDING_NONZERO:
-    return (n != 0);
-  case GLU_TESS_WINDING_POSITIVE:
-    return (n > 0);
-  case GLU_TESS_WINDING_NEGATIVE:
-    return (n < 0);
-  case GLU_TESS_WINDING_ABS_GEQ_TWO:
-    return (n >= 2) || (n <= -2);
-  default:
-    return FALSE;
-  }
-}
-
-
-static void ComputeWinding( GLUtesselator *tess, ActiveRegion *reg )
-{
-  reg->windingNumber = RegionAbove(reg)->windingNumber + reg->eUp->winding;
-  reg->inside = IsWindingInside( tess, reg->windingNumber );
-}
-
-
-static void FinishRegion( GLUtesselator *tess, ActiveRegion *reg )
-/*
- * Delete a region from the sweep line.  This happens when the upper
- * and lower chains of a region meet (at a vertex on the sweep line).
- * The "inside" flag is copied to the appropriate mesh face (we could
- * not do this before -- since the structure of the mesh is always
- * changing, this face may not have even existed until now).
- */
-{
-  GLUhalfEdge *e = reg->eUp;
-  GLUface *f = e->Lface;
-
-  f->inside = reg->inside;
-  f->anEdge = e;   /* optimization for __gl_meshTessellateMonoRegion() */
-  DeleteRegion( tess, reg );
-}
-
-
-static GLUhalfEdge *FinishLeftRegions( GLUtesselator *tess,
-	       ActiveRegion *regFirst, ActiveRegion *regLast )
-/*
- * We are given a vertex with one or more left-going edges.  All affected
- * edges should be in the edge dictionary.  Starting at regFirst->eUp,
- * we walk down deleting all regions where both edges have the same
- * origin vOrg.  At the same time we copy the "inside" flag from the
- * active region to the face, since at this point each face will belong
- * to at most one region (this was not necessarily true until this point
- * in the sweep).  The walk stops at the region above regLast; if regLast
- * is NULL we walk as far as possible.  At the same time we relink the
- * mesh if necessary, so that the ordering of edges around vOrg is the
- * same as in the dictionary.
- */
-{
-  ActiveRegion *reg, *regPrev;
-  GLUhalfEdge *e, *ePrev;
-
-  regPrev = regFirst;
-  ePrev = regFirst->eUp;
-  while( regPrev != regLast ) {
-    regPrev->fixUpperEdge = FALSE;	/* placement was OK */
-    reg = RegionBelow( regPrev );
-    e = reg->eUp;
-    if( e->Org != ePrev->Org ) {
-      if( ! reg->fixUpperEdge ) {
-	/* Remove the last left-going edge.  Even though there are no further
-	 * edges in the dictionary with this origin, there may be further
-	 * such edges in the mesh (if we are adding left edges to a vertex
-	 * that has already been processed).  Thus it is important to call
-	 * FinishRegion rather than just DeleteRegion.
-	 */
-	FinishRegion( tess, regPrev );
-	break;
-      }
-      /* If the edge below was a temporary edge introduced by
-       * ConnectRightVertex, now is the time to fix it.
-       */
-      e = __gl_meshConnect( ePrev->Lprev, e->Sym );
-      if (e == NULL) longjmp(tess->env,1);
-      if ( !FixUpperEdge( reg, e ) ) longjmp(tess->env,1);
-    }
-
-    /* Relink edges so that ePrev->Onext == e */
-    if( ePrev->Onext != e ) {
-      if ( !__gl_meshSplice( e->Oprev, e ) ) longjmp(tess->env,1);
-      if ( !__gl_meshSplice( ePrev, e ) ) longjmp(tess->env,1);
-    }
-    FinishRegion( tess, regPrev );	/* may change reg->eUp */
-    ePrev = reg->eUp;
-    regPrev = reg;
-  }
-  return ePrev;
-}
-
-
-static void AddRightEdges( GLUtesselator *tess, ActiveRegion *regUp,
-       GLUhalfEdge *eFirst, GLUhalfEdge *eLast, GLUhalfEdge *eTopLeft,
-       GLboolean cleanUp )
-/*
- * Purpose: insert right-going edges into the edge dictionary, and update
- * winding numbers and mesh connectivity appropriately.  All right-going
- * edges share a common origin vOrg.  Edges are inserted CCW starting at
- * eFirst; the last edge inserted is eLast->Oprev.  If vOrg has any
- * left-going edges already processed, then eTopLeft must be the edge
- * such that an imaginary upward vertical segment from vOrg would be
- * contained between eTopLeft->Oprev and eTopLeft; otherwise eTopLeft
- * should be NULL.
- */
-{
-  ActiveRegion *reg, *regPrev;
-  GLUhalfEdge *e, *ePrev;
-  int firstTime = TRUE;
-
-  /* Insert the new right-going edges in the dictionary */
-  e = eFirst;
-  do {
-    assert( VertLeq( e->Org, e->Dst ));
-    AddRegionBelow( tess, regUp, e->Sym );
-    e = e->Onext;
-  } while ( e != eLast );
-
-  /* Walk *all* right-going edges from e->Org, in the dictionary order,
-   * updating the winding numbers of each region, and re-linking the mesh
-   * edges to match the dictionary ordering (if necessary).
-   */
-  if( eTopLeft == NULL ) {
-    eTopLeft = RegionBelow( regUp )->eUp->Rprev;
-  }
-  regPrev = regUp;
-  ePrev = eTopLeft;
-  for( ;; ) {
-    reg = RegionBelow( regPrev );
-    e = reg->eUp->Sym;
-    if( e->Org != ePrev->Org ) break;
-
-    if( e->Onext != ePrev ) {
-      /* Unlink e from its current position, and relink below ePrev */
-      if ( !__gl_meshSplice( e->Oprev, e ) ) longjmp(tess->env,1);
-      if ( !__gl_meshSplice( ePrev->Oprev, e ) ) longjmp(tess->env,1);
-    }
-    /* Compute the winding number and "inside" flag for the new regions */
-    reg->windingNumber = regPrev->windingNumber - e->winding;
-    reg->inside = IsWindingInside( tess, reg->windingNumber );
-
-    /* Check for two outgoing edges with same slope -- process these
-     * before any intersection tests (see example in __gl_computeInterior).
-     */
-    regPrev->dirty = TRUE;
-    if( ! firstTime && CheckForRightSplice( tess, regPrev )) {
-      AddWinding( e, ePrev );
-      DeleteRegion( tess, regPrev );
-      if ( !__gl_meshDelete( ePrev ) ) longjmp(tess->env,1);
-    }
-    firstTime = FALSE;
-    regPrev = reg;
-    ePrev = e;
-  }
-  regPrev->dirty = TRUE;
-  assert( regPrev->windingNumber - e->winding == reg->windingNumber );
-
-  if( cleanUp ) {
-    /* Check for intersections between newly adjacent edges. */
-    WalkDirtyRegions( tess, regPrev );
-  }
-}
-
-
-static void CallCombine( GLUtesselator *tess, GLUvertex *isect,
-			 void *data[4], GLfloat weights[4], int needed )
-{
-  GLdouble coords[3];
-
-  /* Copy coord data in case the callback changes it. */
-  coords[0] = isect->coords[0];
-  coords[1] = isect->coords[1];
-  coords[2] = isect->coords[2];
-
-  isect->data = NULL;
-  CALL_COMBINE_OR_COMBINE_DATA( coords, data, weights, &isect->data );
-  if( isect->data == NULL ) {
-    if( ! needed ) {
-      isect->data = data[0];
-    } else if( ! tess->fatalError ) {
-      /* The only way fatal error is when two edges are found to intersect,
-       * but the user has not provided the callback necessary to handle
-       * generated intersection points.
-       */
-      CALL_ERROR_OR_ERROR_DATA( GLU_TESS_NEED_COMBINE_CALLBACK );
-      tess->fatalError = TRUE;
-    }
-  }
-}
-
-static void SpliceMergeVertices( GLUtesselator *tess, GLUhalfEdge *e1,
-				 GLUhalfEdge *e2 )
-/*
- * Two vertices with idential coordinates are combined into one.
- * e1->Org is kept, while e2->Org is discarded.
- */
-{
-  void *data[4] = { NULL, NULL, NULL, NULL };
-  GLfloat weights[4] = { 0.5, 0.5, 0.0, 0.0 };
-
-  data[0] = e1->Org->data;
-  data[1] = e2->Org->data;
-  CallCombine( tess, e1->Org, data, weights, FALSE );
-  if ( !__gl_meshSplice( e1, e2 ) ) longjmp(tess->env,1); 
-}
-
-static void VertexWeights( GLUvertex *isect, GLUvertex *org, GLUvertex *dst,
-                           GLfloat *weights )
-/*
- * Find some weights which describe how the intersection vertex is
- * a linear combination of "org" and "dest".  Each of the two edges
- * which generated "isect" is allocated 50% of the weight; each edge
- * splits the weight between its org and dst according to the
- * relative distance to "isect".
- */
-{
-  GLdouble t1 = VertL1dist( org, isect );
-  GLdouble t2 = VertL1dist( dst, isect );
-
-  weights[0] = 0.5 * t2 / (t1 + t2);
-  weights[1] = 0.5 * t1 / (t1 + t2);
-  isect->coords[0] += weights[0]*org->coords[0] + weights[1]*dst->coords[0];
-  isect->coords[1] += weights[0]*org->coords[1] + weights[1]*dst->coords[1];
-  isect->coords[2] += weights[0]*org->coords[2] + weights[1]*dst->coords[2];
-}
-
-
-static void GetIntersectData( GLUtesselator *tess, GLUvertex *isect,
-       GLUvertex *orgUp, GLUvertex *dstUp,
-       GLUvertex *orgLo, GLUvertex *dstLo )
-/*
- * We've computed a new intersection point, now we need a "data" pointer
- * from the user so that we can refer to this new vertex in the
- * rendering callbacks.
- */
-{
-  void *data[4];
-  GLfloat weights[4];
-
-  data[0] = orgUp->data;
-  data[1] = dstUp->data;
-  data[2] = orgLo->data;
-  data[3] = dstLo->data;
-
-  isect->coords[0] = isect->coords[1] = isect->coords[2] = 0;
-  VertexWeights( isect, orgUp, dstUp, &weights[0] );
-  VertexWeights( isect, orgLo, dstLo, &weights[2] );
-
-  CallCombine( tess, isect, data, weights, TRUE );
-}
-
-static int CheckForRightSplice( GLUtesselator *tess, ActiveRegion *regUp )
-/*
- * Check the upper and lower edge of "regUp", to make sure that the
- * eUp->Org is above eLo, or eLo->Org is below eUp (depending on which
- * origin is leftmost).
- *
- * The main purpose is to splice right-going edges with the same
- * dest vertex and nearly identical slopes (ie. we can't distinguish
- * the slopes numerically).  However the splicing can also help us
- * to recover from numerical errors.  For example, suppose at one
- * point we checked eUp and eLo, and decided that eUp->Org is barely
- * above eLo.  Then later, we split eLo into two edges (eg. from
- * a splice operation like this one).  This can change the result of
- * our test so that now eUp->Org is incident to eLo, or barely below it.
- * We must correct this condition to maintain the dictionary invariants.
- *
- * One possibility is to check these edges for intersection again
- * (ie. CheckForIntersect).  This is what we do if possible.  However
- * CheckForIntersect requires that tess->event lies between eUp and eLo,
- * so that it has something to fall back on when the intersection
- * calculation gives us an unusable answer.  So, for those cases where
- * we can't check for intersection, this routine fixes the problem
- * by just splicing the offending vertex into the other edge.
- * This is a guaranteed solution, no matter how degenerate things get.
- * Basically this is a combinatorial solution to a numerical problem.
- */
-{
-  ActiveRegion *regLo = RegionBelow(regUp);
-  GLUhalfEdge *eUp = regUp->eUp;
-  GLUhalfEdge *eLo = regLo->eUp;
-
-  if( VertLeq( eUp->Org, eLo->Org )) {
-    if( EdgeSign( eLo->Dst, eUp->Org, eLo->Org ) > 0 ) return FALSE;
-
-    /* eUp->Org appears to be below eLo */
-    if( ! VertEq( eUp->Org, eLo->Org )) {
-      /* Splice eUp->Org into eLo */
-      if ( __gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
-      if ( !__gl_meshSplice( eUp, eLo->Oprev ) ) longjmp(tess->env,1);
-      regUp->dirty = regLo->dirty = TRUE;
-
-    } else if( eUp->Org != eLo->Org ) {
-      /* merge the two vertices, discarding eUp->Org */
-      pqDelete( tess->pq, eUp->Org->pqHandle ); /* __gl_pqSortDelete */
-      SpliceMergeVertices( tess, eLo->Oprev, eUp );
-    }
-  } else {
-    if( EdgeSign( eUp->Dst, eLo->Org, eUp->Org ) < 0 ) return FALSE;
-
-    /* eLo->Org appears to be above eUp, so splice eLo->Org into eUp */
-    RegionAbove(regUp)->dirty = regUp->dirty = TRUE;
-    if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
-    if ( !__gl_meshSplice( eLo->Oprev, eUp ) ) longjmp(tess->env,1);
-  }
-  return TRUE;
-}
-
-static int CheckForLeftSplice( GLUtesselator *tess, ActiveRegion *regUp )
-/*
- * Check the upper and lower edge of "regUp", to make sure that the
- * eUp->Dst is above eLo, or eLo->Dst is below eUp (depending on which
- * destination is rightmost).
- *
- * Theoretically, this should always be true.  However, splitting an edge
- * into two pieces can change the results of previous tests.  For example,
- * suppose at one point we checked eUp and eLo, and decided that eUp->Dst
- * is barely above eLo.  Then later, we split eLo into two edges (eg. from
- * a splice operation like this one).  This can change the result of
- * the test so that now eUp->Dst is incident to eLo, or barely below it.
- * We must correct this condition to maintain the dictionary invariants
- * (otherwise new edges might get inserted in the wrong place in the
- * dictionary, and bad stuff will happen).
- *
- * We fix the problem by just splicing the offending vertex into the
- * other edge.
- */
-{
-  ActiveRegion *regLo = RegionBelow(regUp);
-  GLUhalfEdge *eUp = regUp->eUp;
-  GLUhalfEdge *eLo = regLo->eUp;
-  GLUhalfEdge *e;
-
-  assert( ! VertEq( eUp->Dst, eLo->Dst ));
-
-  if( VertLeq( eUp->Dst, eLo->Dst )) {
-    if( EdgeSign( eUp->Dst, eLo->Dst, eUp->Org ) < 0 ) return FALSE;
-
-    /* eLo->Dst is above eUp, so splice eLo->Dst into eUp */
-    RegionAbove(regUp)->dirty = regUp->dirty = TRUE;
-    e = __gl_meshSplitEdge( eUp );
-    if (e == NULL) longjmp(tess->env,1);
-    if ( !__gl_meshSplice( eLo->Sym, e ) ) longjmp(tess->env,1);
-    e->Lface->inside = regUp->inside;
-  } else {
-    if( EdgeSign( eLo->Dst, eUp->Dst, eLo->Org ) > 0 ) return FALSE;
-
-    /* eUp->Dst is below eLo, so splice eUp->Dst into eLo */
-    regUp->dirty = regLo->dirty = TRUE;
-    e = __gl_meshSplitEdge( eLo );
-    if (e == NULL) longjmp(tess->env,1);    
-    if ( !__gl_meshSplice( eUp->Lnext, eLo->Sym ) ) longjmp(tess->env,1);
-    e->Rface->inside = regUp->inside;
-  }
-  return TRUE;
-}
-
-
-static int CheckForIntersect( GLUtesselator *tess, ActiveRegion *regUp )
-/*
- * Check the upper and lower edges of the given region to see if
- * they intersect.  If so, create the intersection and add it
- * to the data structures.
- *
- * Returns TRUE if adding the new intersection resulted in a recursive
- * call to AddRightEdges(); in this case all "dirty" regions have been
- * checked for intersections, and possibly regUp has been deleted.
- */
-{
-  ActiveRegion *regLo = RegionBelow(regUp);
-  GLUhalfEdge *eUp = regUp->eUp;
-  GLUhalfEdge *eLo = regLo->eUp;
-  GLUvertex *orgUp = eUp->Org;
-  GLUvertex *orgLo = eLo->Org;
-  GLUvertex *dstUp = eUp->Dst;
-  GLUvertex *dstLo = eLo->Dst;
-  GLdouble tMinUp, tMaxLo;
-  GLUvertex isect, *orgMin;
-  GLUhalfEdge *e;
-
-  assert( ! VertEq( dstLo, dstUp ));
-  assert( EdgeSign( dstUp, tess->event, orgUp ) <= 0 );
-  assert( EdgeSign( dstLo, tess->event, orgLo ) >= 0 );
-  assert( orgUp != tess->event && orgLo != tess->event );
-  assert( ! regUp->fixUpperEdge && ! regLo->fixUpperEdge );
-
-  if( orgUp == orgLo ) return FALSE;	/* right endpoints are the same */
-
-  tMinUp = MIN( orgUp->t, dstUp->t );
-  tMaxLo = MAX( orgLo->t, dstLo->t );
-  if( tMinUp > tMaxLo ) return FALSE;	/* t ranges do not overlap */
-
-  if( VertLeq( orgUp, orgLo )) {
-    if( EdgeSign( dstLo, orgUp, orgLo ) > 0 ) return FALSE;
-  } else {
-    if( EdgeSign( dstUp, orgLo, orgUp ) < 0 ) return FALSE;
-  }
-
-  /* At this point the edges intersect, at least marginally */
-  DebugEvent( tess );
-
-  __gl_edgeIntersect( dstUp, orgUp, dstLo, orgLo, &isect );
-  /* The following properties are guaranteed: */
-  assert( MIN( orgUp->t, dstUp->t ) <= isect.t );
-  assert( isect.t <= MAX( orgLo->t, dstLo->t ));
-  assert( MIN( dstLo->s, dstUp->s ) <= isect.s );
-  assert( isect.s <= MAX( orgLo->s, orgUp->s ));
-
-  if( VertLeq( &isect, tess->event )) {
-    /* The intersection point lies slightly to the left of the sweep line,
-     * so move it until it''s slightly to the right of the sweep line.
-     * (If we had perfect numerical precision, this would never happen
-     * in the first place).  The easiest and safest thing to do is
-     * replace the intersection by tess->event.
-     */
-    isect.s = tess->event->s;
-    isect.t = tess->event->t;
-  }
-  /* Similarly, if the computed intersection lies to the right of the
-   * rightmost origin (which should rarely happen), it can cause
-   * unbelievable inefficiency on sufficiently degenerate inputs.
-   * (If you have the test program, try running test54.d with the
-   * "X zoom" option turned on).
-   */
-  orgMin = VertLeq( orgUp, orgLo ) ? orgUp : orgLo;
-  if( VertLeq( orgMin, &isect )) {
-    isect.s = orgMin->s;
-    isect.t = orgMin->t;
-  }
-
-  if( VertEq( &isect, orgUp ) || VertEq( &isect, orgLo )) {
-    /* Easy case -- intersection at one of the right endpoints */
-    (void) CheckForRightSplice( tess, regUp );
-    return FALSE;
-  }
-
-  if(    (! VertEq( dstUp, tess->event )
-	  && EdgeSign( dstUp, tess->event, &isect ) >= 0)
-      || (! VertEq( dstLo, tess->event )
-	  && EdgeSign( dstLo, tess->event, &isect ) <= 0 ))
-  {
-    /* Very unusual -- the new upper or lower edge would pass on the
-     * wrong side of the sweep event, or through it.  This can happen
-     * due to very small numerical errors in the intersection calculation.
-     */
-    if( dstLo == tess->event ) {
-      /* Splice dstLo into eUp, and process the new region(s) */
-      if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
-      if ( !__gl_meshSplice( eLo->Sym, eUp ) ) longjmp(tess->env,1);
-      regUp = TopLeftRegion( regUp );
-      if (regUp == NULL) longjmp(tess->env,1);
-      eUp = RegionBelow(regUp)->eUp;
-      FinishLeftRegions( tess, RegionBelow(regUp), regLo );
-      AddRightEdges( tess, regUp, eUp->Oprev, eUp, eUp, TRUE );
-      return TRUE;
-    }
-    if( dstUp == tess->event ) {
-      /* Splice dstUp into eLo, and process the new region(s) */
-      if (__gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
-      if ( !__gl_meshSplice( eUp->Lnext, eLo->Oprev ) ) longjmp(tess->env,1); 
-      regLo = regUp;
-      regUp = TopRightRegion( regUp );
-      e = RegionBelow(regUp)->eUp->Rprev;
-      regLo->eUp = eLo->Oprev;
-      eLo = FinishLeftRegions( tess, regLo, NULL );
-      AddRightEdges( tess, regUp, eLo->Onext, eUp->Rprev, e, TRUE );
-      return TRUE;
-    }
-    /* Special case: called from ConnectRightVertex.  If either
-     * edge passes on the wrong side of tess->event, split it
-     * (and wait for ConnectRightVertex to splice it appropriately).
-     */
-    if( EdgeSign( dstUp, tess->event, &isect ) >= 0 ) {
-      RegionAbove(regUp)->dirty = regUp->dirty = TRUE;
-      if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
-      eUp->Org->s = tess->event->s;
-      eUp->Org->t = tess->event->t;
-    }
-    if( EdgeSign( dstLo, tess->event, &isect ) <= 0 ) {
-      regUp->dirty = regLo->dirty = TRUE;
-      if (__gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
-      eLo->Org->s = tess->event->s;
-      eLo->Org->t = tess->event->t;
-    }
-    /* leave the rest for ConnectRightVertex */
-    return FALSE;
-  }
-
-  /* General case -- split both edges, splice into new vertex.
-   * When we do the splice operation, the order of the arguments is
-   * arbitrary as far as correctness goes.  However, when the operation
-   * creates a new face, the work done is proportional to the size of
-   * the new face.  We expect the faces in the processed part of
-   * the mesh (ie. eUp->Lface) to be smaller than the faces in the
-   * unprocessed original contours (which will be eLo->Oprev->Lface).
-   */
-  if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
-  if (__gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
-  if ( !__gl_meshSplice( eLo->Oprev, eUp ) ) longjmp(tess->env,1);
-  eUp->Org->s = isect.s;
-  eUp->Org->t = isect.t;
-  eUp->Org->pqHandle = pqInsert( tess->pq, eUp->Org ); /* __gl_pqSortInsert */
-  if (eUp->Org->pqHandle == LONG_MAX) {
-     pqDeletePriorityQ(tess->pq);	/* __gl_pqSortDeletePriorityQ */
-     tess->pq = NULL;
-     longjmp(tess->env,1);
-  }
-  GetIntersectData( tess, eUp->Org, orgUp, dstUp, orgLo, dstLo );
-  RegionAbove(regUp)->dirty = regUp->dirty = regLo->dirty = TRUE;
-  return FALSE;
-}
-
-static void WalkDirtyRegions( GLUtesselator *tess, ActiveRegion *regUp )
-/*
- * When the upper or lower edge of any region changes, the region is
- * marked "dirty".  This routine walks through all the dirty regions
- * and makes sure that the dictionary invariants are satisfied
- * (see the comments at the beginning of this file).  Of course
- * new dirty regions can be created as we make changes to restore
- * the invariants.
- */
-{
-  ActiveRegion *regLo = RegionBelow(regUp);
-  GLUhalfEdge *eUp, *eLo;
-
-  for( ;; ) {
-    /* Find the lowest dirty region (we walk from the bottom up). */
-    while( regLo->dirty ) {
-      regUp = regLo;
-      regLo = RegionBelow(regLo);
-    }
-    if( ! regUp->dirty ) {
-      regLo = regUp;
-      regUp = RegionAbove( regUp );
-      if( regUp == NULL || ! regUp->dirty ) {
-	/* We've walked all the dirty regions */
-	return;
-      }
-    }
-    regUp->dirty = FALSE;
-    eUp = regUp->eUp;
-    eLo = regLo->eUp;
-
-    if( eUp->Dst != eLo->Dst ) {
-      /* Check that the edge ordering is obeyed at the Dst vertices. */
-      if( CheckForLeftSplice( tess, regUp )) {
-
-	/* If the upper or lower edge was marked fixUpperEdge, then
-	 * we no longer need it (since these edges are needed only for
-	 * vertices which otherwise have no right-going edges).
-	 */
-	if( regLo->fixUpperEdge ) {
-	  DeleteRegion( tess, regLo );
-	  if ( !__gl_meshDelete( eLo ) ) longjmp(tess->env,1);
-	  regLo = RegionBelow( regUp );
-	  eLo = regLo->eUp;
-	} else if( regUp->fixUpperEdge ) {
-	  DeleteRegion( tess, regUp );
-	  if ( !__gl_meshDelete( eUp ) ) longjmp(tess->env,1);
-	  regUp = RegionAbove( regLo );
-	  eUp = regUp->eUp;
-	}
-      }
-    }
-    if( eUp->Org != eLo->Org ) {
-      if(    eUp->Dst != eLo->Dst
-	  && ! regUp->fixUpperEdge && ! regLo->fixUpperEdge
-          && (eUp->Dst == tess->event || eLo->Dst == tess->event) )
-      {
-	/* When all else fails in CheckForIntersect(), it uses tess->event
-	 * as the intersection location.  To make this possible, it requires
-	 * that tess->event lie between the upper and lower edges, and also
-	 * that neither of these is marked fixUpperEdge (since in the worst
-	 * case it might splice one of these edges into tess->event, and
-	 * violate the invariant that fixable edges are the only right-going
-	 * edge from their associated vertex).
-         */
-	if( CheckForIntersect( tess, regUp )) {
-	  /* WalkDirtyRegions() was called recursively; we're done */
-	  return;
-	}
-      } else {
-	/* Even though we can't use CheckForIntersect(), the Org vertices
-	 * may violate the dictionary edge ordering.  Check and correct this.
-	 */
-	(void) CheckForRightSplice( tess, regUp );
-      }
-    }
-    if( eUp->Org == eLo->Org && eUp->Dst == eLo->Dst ) {
-      /* A degenerate loop consisting of only two edges -- delete it. */
-      AddWinding( eLo, eUp );
-      DeleteRegion( tess, regUp );
-      if ( !__gl_meshDelete( eUp ) ) longjmp(tess->env,1);
-      regUp = RegionAbove( regLo );
-    }
-  }
-}
-
-
-static void ConnectRightVertex( GLUtesselator *tess, ActiveRegion *regUp,
-			        GLUhalfEdge *eBottomLeft )
-/*
- * Purpose: connect a "right" vertex vEvent (one where all edges go left)
- * to the unprocessed portion of the mesh.  Since there are no right-going
- * edges, two regions (one above vEvent and one below) are being merged
- * into one.  "regUp" is the upper of these two regions.
- *
- * There are two reasons for doing this (adding a right-going edge):
- *  - if the two regions being merged are "inside", we must add an edge
- *    to keep them separated (the combined region would not be monotone).
- *  - in any case, we must leave some record of vEvent in the dictionary,
- *    so that we can merge vEvent with features that we have not seen yet.
- *    For example, maybe there is a vertical edge which passes just to
- *    the right of vEvent; we would like to splice vEvent into this edge.
- *
- * However, we don't want to connect vEvent to just any vertex.  We don''t
- * want the new edge to cross any other edges; otherwise we will create
- * intersection vertices even when the input data had no self-intersections.
- * (This is a bad thing; if the user's input data has no intersections,
- * we don't want to generate any false intersections ourselves.)
- *
- * Our eventual goal is to connect vEvent to the leftmost unprocessed
- * vertex of the combined region (the union of regUp and regLo).
- * But because of unseen vertices with all right-going edges, and also
- * new vertices which may be created by edge intersections, we don''t
- * know where that leftmost unprocessed vertex is.  In the meantime, we
- * connect vEvent to the closest vertex of either chain, and mark the region
- * as "fixUpperEdge".  This flag says to delete and reconnect this edge
- * to the next processed vertex on the boundary of the combined region.
- * Quite possibly the vertex we connected to will turn out to be the
- * closest one, in which case we won''t need to make any changes.
- */
-{
-  GLUhalfEdge *eNew;
-  GLUhalfEdge *eTopLeft = eBottomLeft->Onext;
-  ActiveRegion *regLo = RegionBelow(regUp);
-  GLUhalfEdge *eUp = regUp->eUp;
-  GLUhalfEdge *eLo = regLo->eUp;
-  int degenerate = FALSE;
-
-  if( eUp->Dst != eLo->Dst ) {
-    (void) CheckForIntersect( tess, regUp );
-  }
-
-  /* Possible new degeneracies: upper or lower edge of regUp may pass
-   * through vEvent, or may coincide with new intersection vertex
-   */
-  if( VertEq( eUp->Org, tess->event )) {
-    if ( !__gl_meshSplice( eTopLeft->Oprev, eUp ) ) longjmp(tess->env,1);
-    regUp = TopLeftRegion( regUp );
-    if (regUp == NULL) longjmp(tess->env,1);
-    eTopLeft = RegionBelow( regUp )->eUp;
-    FinishLeftRegions( tess, RegionBelow(regUp), regLo );
-    degenerate = TRUE;
-  }
-  if( VertEq( eLo->Org, tess->event )) {
-    if ( !__gl_meshSplice( eBottomLeft, eLo->Oprev ) ) longjmp(tess->env,1);
-    eBottomLeft = FinishLeftRegions( tess, regLo, NULL );
-    degenerate = TRUE;
-  }
-  if( degenerate ) {
-    AddRightEdges( tess, regUp, eBottomLeft->Onext, eTopLeft, eTopLeft, TRUE );
-    return;
-  }
-
-  /* Non-degenerate situation -- need to add a temporary, fixable edge.
-   * Connect to the closer of eLo->Org, eUp->Org.
-   */
-  if( VertLeq( eLo->Org, eUp->Org )) {
-    eNew = eLo->Oprev;
-  } else {
-    eNew = eUp;
-  }
-  eNew = __gl_meshConnect( eBottomLeft->Lprev, eNew );
-  if (eNew == NULL) longjmp(tess->env,1);
-
-  /* Prevent cleanup, otherwise eNew might disappear before we've even
-   * had a chance to mark it as a temporary edge.
-   */
-  AddRightEdges( tess, regUp, eNew, eNew->Onext, eNew->Onext, FALSE );
-  eNew->Sym->activeRegion->fixUpperEdge = TRUE;
-  WalkDirtyRegions( tess, regUp );
-}
-
-/* Because vertices at exactly the same location are merged together
- * before we process the sweep event, some degenerate cases can't occur.
- * However if someone eventually makes the modifications required to
- * merge features which are close together, the cases below marked
- * TOLERANCE_NONZERO will be useful.  They were debugged before the
- * code to merge identical vertices in the main loop was added.
- */
-#define TOLERANCE_NONZERO	FALSE
-
-static void ConnectLeftDegenerate( GLUtesselator *tess,
-				   ActiveRegion *regUp, GLUvertex *vEvent )
-/*
- * The event vertex lies exacty on an already-processed edge or vertex.
- * Adding the new vertex involves splicing it into the already-processed
- * part of the mesh.
- */
-{
-  GLUhalfEdge *e, *eTopLeft, *eTopRight, *eLast;
-  ActiveRegion *reg;
-
-  e = regUp->eUp;
-  if( VertEq( e->Org, vEvent )) {
-    /* e->Org is an unprocessed vertex - just combine them, and wait
-     * for e->Org to be pulled from the queue
-     */
-    assert( TOLERANCE_NONZERO );
-    SpliceMergeVertices( tess, e, vEvent->anEdge );
-    return;
-  }
-  
-  if( ! VertEq( e->Dst, vEvent )) {
-    /* General case -- splice vEvent into edge e which passes through it */
-    if (__gl_meshSplitEdge( e->Sym ) == NULL) longjmp(tess->env,1);
-    if( regUp->fixUpperEdge ) {
-      /* This edge was fixable -- delete unused portion of original edge */
-      if ( !__gl_meshDelete( e->Onext ) ) longjmp(tess->env,1);
-      regUp->fixUpperEdge = FALSE;
-    }
-    if ( !__gl_meshSplice( vEvent->anEdge, e ) ) longjmp(tess->env,1);
-    SweepEvent( tess, vEvent );	/* recurse */
-    return;
-  }
-
-  /* vEvent coincides with e->Dst, which has already been processed.
-   * Splice in the additional right-going edges.
-   */
-  assert( TOLERANCE_NONZERO );
-  regUp = TopRightRegion( regUp );
-  reg = RegionBelow( regUp );
-  eTopRight = reg->eUp->Sym;
-  eTopLeft = eLast = eTopRight->Onext;
-  if( reg->fixUpperEdge ) {
-    /* Here e->Dst has only a single fixable edge going right.
-     * We can delete it since now we have some real right-going edges.
-     */
-    assert( eTopLeft != eTopRight );   /* there are some left edges too */
-    DeleteRegion( tess, reg );
-    if ( !__gl_meshDelete( eTopRight ) ) longjmp(tess->env,1);
-    eTopRight = eTopLeft->Oprev;
-  }
-  if ( !__gl_meshSplice( vEvent->anEdge, eTopRight ) ) longjmp(tess->env,1);
-  if( ! EdgeGoesLeft( eTopLeft )) {
-    /* e->Dst had no left-going edges -- indicate this to AddRightEdges() */
-    eTopLeft = NULL;
-  }
-  AddRightEdges( tess, regUp, eTopRight->Onext, eLast, eTopLeft, TRUE );
-}
-
-
-static void ConnectLeftVertex( GLUtesselator *tess, GLUvertex *vEvent )
-/*
- * Purpose: connect a "left" vertex (one where both edges go right)
- * to the processed portion of the mesh.  Let R be the active region
- * containing vEvent, and let U and L be the upper and lower edge
- * chains of R.  There are two possibilities:
- *
- * - the normal case: split R into two regions, by connecting vEvent to
- *   the rightmost vertex of U or L lying to the left of the sweep line
- *
- * - the degenerate case: if vEvent is close enough to U or L, we
- *   merge vEvent into that edge chain.  The subcases are:
- *	- merging with the rightmost vertex of U or L
- *	- merging with the active edge of U or L
- *	- merging with an already-processed portion of U or L
- */
-{
-  ActiveRegion *regUp, *regLo, *reg;
-  GLUhalfEdge *eUp, *eLo, *eNew;
-  ActiveRegion tmp;
-
-  /* assert( vEvent->anEdge->Onext->Onext == vEvent->anEdge ); */
-
-  /* Get a pointer to the active region containing vEvent */
-  tmp.eUp = vEvent->anEdge->Sym;
-  /* __GL_DICTLISTKEY */ /* __gl_dictListSearch */
-  regUp = (ActiveRegion *)dictKey( dictSearch( tess->dict, &tmp ));
-  regLo = RegionBelow( regUp );
-  eUp = regUp->eUp;
-  eLo = regLo->eUp;
-
-  /* Try merging with U or L first */
-  if( EdgeSign( eUp->Dst, vEvent, eUp->Org ) == 0 ) {
-    ConnectLeftDegenerate( tess, regUp, vEvent );
-    return;
-  }
-
-  /* Connect vEvent to rightmost processed vertex of either chain.
-   * e->Dst is the vertex that we will connect to vEvent.
-   */
-  reg = VertLeq( eLo->Dst, eUp->Dst ) ? regUp : regLo;
-
-  if( regUp->inside || reg->fixUpperEdge) {
-    if( reg == regUp ) {
-      eNew = __gl_meshConnect( vEvent->anEdge->Sym, eUp->Lnext );
-      if (eNew == NULL) longjmp(tess->env,1);
-    } else {
-      GLUhalfEdge *tempHalfEdge= __gl_meshConnect( eLo->Dnext, vEvent->anEdge);
-      if (tempHalfEdge == NULL) longjmp(tess->env,1);
-
-      eNew = tempHalfEdge->Sym;
-    }
-    if( reg->fixUpperEdge ) {
-      if ( !FixUpperEdge( reg, eNew ) ) longjmp(tess->env,1);
-    } else {
-      ComputeWinding( tess, AddRegionBelow( tess, regUp, eNew ));
-    }
-    SweepEvent( tess, vEvent );
-  } else {
-    /* The new vertex is in a region which does not belong to the polygon.
-     * We don''t need to connect this vertex to the rest of the mesh.
-     */
-    AddRightEdges( tess, regUp, vEvent->anEdge, vEvent->anEdge, NULL, TRUE );
-  }
-}
-
-
-static void SweepEvent( GLUtesselator *tess, GLUvertex *vEvent )
-/*
- * Does everything necessary when the sweep line crosses a vertex.
- * Updates the mesh and the edge dictionary.
- */
-{
-  ActiveRegion *regUp, *reg;
-  GLUhalfEdge *e, *eTopLeft, *eBottomLeft;
-
-  tess->event = vEvent;		/* for access in EdgeLeq() */
-  DebugEvent( tess );
-  
-  /* Check if this vertex is the right endpoint of an edge that is
-   * already in the dictionary.  In this case we don't need to waste
-   * time searching for the location to insert new edges.
-   */
-  e = vEvent->anEdge;
-  while( e->activeRegion == NULL ) {
-    e = e->Onext;
-    if( e == vEvent->anEdge ) {
-      /* All edges go right -- not incident to any processed edges */
-      ConnectLeftVertex( tess, vEvent );
-      return;
-    }
-  }
-
-  /* Processing consists of two phases: first we "finish" all the
-   * active regions where both the upper and lower edges terminate
-   * at vEvent (ie. vEvent is closing off these regions).
-   * We mark these faces "inside" or "outside" the polygon according
-   * to their winding number, and delete the edges from the dictionary.
-   * This takes care of all the left-going edges from vEvent.
-   */
-  regUp = TopLeftRegion( e->activeRegion );
-  if (regUp == NULL) longjmp(tess->env,1);
-  reg = RegionBelow( regUp );
-  eTopLeft = reg->eUp;
-  eBottomLeft = FinishLeftRegions( tess, reg, NULL );
-
-  /* Next we process all the right-going edges from vEvent.  This
-   * involves adding the edges to the dictionary, and creating the
-   * associated "active regions" which record information about the
-   * regions between adjacent dictionary edges.
-   */
-  if( eBottomLeft->Onext == eTopLeft ) {
-    /* No right-going edges -- add a temporary "fixable" edge */
-    ConnectRightVertex( tess, regUp, eBottomLeft );
-  } else {
-    AddRightEdges( tess, regUp, eBottomLeft->Onext, eTopLeft, eTopLeft, TRUE );
-  }
-}
-
-
-/* Make the sentinel coordinates big enough that they will never be
- * merged with real input features.  (Even with the largest possible
- * input contour and the maximum tolerance of 1.0, no merging will be
- * done with coordinates larger than 3 * GLU_TESS_MAX_COORD).
- */
-#define SENTINEL_COORD	(4 * GLU_TESS_MAX_COORD)
-
-static void AddSentinel( GLUtesselator *tess, GLdouble t )
-/*
- * We add two sentinel edges above and below all other edges,
- * to avoid special cases at the top and bottom.
- */
-{
-  GLUhalfEdge *e;
-  ActiveRegion *reg = (ActiveRegion *)memAlloc( sizeof( ActiveRegion ));
-  if (reg == NULL) longjmp(tess->env,1);
-
-  e = __gl_meshMakeEdge( tess->mesh );
-  if (e == NULL) longjmp(tess->env,1);
-
-  e->Org->s = SENTINEL_COORD;
-  e->Org->t = t;
-  e->Dst->s = -SENTINEL_COORD;
-  e->Dst->t = t;
-  tess->event = e->Dst;		/* initialize it */
-
-  reg->eUp = e;
-  reg->windingNumber = 0;
-  reg->inside = FALSE;
-  reg->fixUpperEdge = FALSE;
-  reg->sentinel = TRUE;
-  reg->dirty = FALSE;
-  reg->nodeUp = dictInsert( tess->dict, reg ); /* __gl_dictListInsertBefore */
-  if (reg->nodeUp == NULL) longjmp(tess->env,1);
-}
-
-
-static void InitEdgeDict( GLUtesselator *tess )
-/*
- * We maintain an ordering of edge intersections with the sweep line.
- * This order is maintained in a dynamic dictionary.
- */
-{
-  /* __gl_dictListNewDict */
-  tess->dict = dictNewDict( tess, (int (*)(void *, DictKey, DictKey)) EdgeLeq );
-  if (tess->dict == NULL) longjmp(tess->env,1);
-
-  AddSentinel( tess, -SENTINEL_COORD );
-  AddSentinel( tess, SENTINEL_COORD );
-}
-
-
-static void DoneEdgeDict( GLUtesselator *tess )
-{
-  ActiveRegion *reg;
-  int fixedEdges = 0;
-
-  /* __GL_DICTLISTKEY */ /* __GL_DICTLISTMIN */
-  while( (reg = (ActiveRegion *)dictKey( dictMin( tess->dict ))) != NULL ) {
-    /*
-     * At the end of all processing, the dictionary should contain
-     * only the two sentinel edges, plus at most one "fixable" edge
-     * created by ConnectRightVertex().
-     */
-    if( ! reg->sentinel ) {
-      assert( reg->fixUpperEdge );
-      assert( fixedEdges == 0 );
-      ++fixedEdges;
-    }
-    assert( reg->windingNumber == 0 );
-    DeleteRegion( tess, reg );
-/*    __gl_meshDelete( reg->eUp );*/
-  }
-  dictDeleteDict( tess->dict );	/* __gl_dictListDeleteDict */
-}
-
-
-static void RemoveDegenerateEdges( GLUtesselator *tess )
-/*
- * Remove zero-length edges, and contours with fewer than 3 vertices.
- */
-{
-  GLUhalfEdge *e, *eNext, *eLnext;
-  GLUhalfEdge *eHead = &tess->mesh->eHead;
-
-  /*LINTED*/
-  for( e = eHead->next; e != eHead; e = eNext ) {
-    eNext = e->next;
-    eLnext = e->Lnext;
-    
-    if( VertEq( e->Org, e->Dst ) && e->Lnext->Lnext != e ) {
-      /* Zero-length edge, contour has at least 3 edges */
-      
-      SpliceMergeVertices( tess, eLnext, e );	/* deletes e->Org */
-      if ( !__gl_meshDelete( e ) ) longjmp(tess->env,1); /* e is a self-loop */
-      e = eLnext;
-      eLnext = e->Lnext;
-    }
-    if( eLnext->Lnext == e ) {
-      /* Degenerate contour (one or two edges) */
-      
-      if( eLnext != e ) {
-	if( eLnext == eNext || eLnext == eNext->Sym ) { eNext = eNext->next; }
-	if ( !__gl_meshDelete( eLnext ) ) longjmp(tess->env,1);
-      }
-      if( e == eNext || e == eNext->Sym ) { eNext = eNext->next; }
-      if ( !__gl_meshDelete( e ) ) longjmp(tess->env,1);
-    }
-  }
-}
-
-static int InitPriorityQ( GLUtesselator *tess )
-/*
- * Insert all vertices into the priority queue which determines the
- * order in which vertices cross the sweep line.
- */
-{
-  PriorityQ *pq;
-  GLUvertex *v, *vHead;
-
-  /* __gl_pqSortNewPriorityQ */
-  pq = tess->pq = pqNewPriorityQ( (int (*)(PQkey, PQkey)) __gl_vertLeq );
-  if (pq == NULL) return 0;
-
-  vHead = &tess->mesh->vHead;
-  for( v = vHead->next; v != vHead; v = v->next ) {
-    v->pqHandle = pqInsert( pq, v ); /* __gl_pqSortInsert */
-    if (v->pqHandle == LONG_MAX) break;
-  }
-  if (v != vHead || !pqInit( pq ) ) { /* __gl_pqSortInit */
-    pqDeletePriorityQ(tess->pq);	/* __gl_pqSortDeletePriorityQ */
-    tess->pq = NULL;
-    return 0;
-  }
-
-  return 1;
-}
-
-
-static void DonePriorityQ( GLUtesselator *tess )
-{
-  pqDeletePriorityQ( tess->pq ); /* __gl_pqSortDeletePriorityQ */
-}
-
-
-static int RemoveDegenerateFaces( GLUmesh *mesh )
-/*
- * Delete any degenerate faces with only two edges.  WalkDirtyRegions()
- * will catch almost all of these, but it won't catch degenerate faces
- * produced by splice operations on already-processed edges.
- * The two places this can happen are in FinishLeftRegions(), when
- * we splice in a "temporary" edge produced by ConnectRightVertex(),
- * and in CheckForLeftSplice(), where we splice already-processed
- * edges to ensure that our dictionary invariants are not violated
- * by numerical errors.
- *
- * In both these cases it is *very* dangerous to delete the offending
- * edge at the time, since one of the routines further up the stack
- * will sometimes be keeping a pointer to that edge.
- */
-{
-  GLUface *f, *fNext;
-  GLUhalfEdge *e;
-
-  /*LINTED*/
-  for( f = mesh->fHead.next; f != &mesh->fHead; f = fNext ) {
-    fNext = f->next;
-    e = f->anEdge;
-    assert( e->Lnext != e );
-
-    if( e->Lnext->Lnext == e ) {
-      /* A face with only two edges */
-      AddWinding( e->Onext, e );
-      if ( !__gl_meshDelete( e ) ) return 0;
-    }
-  }
-  return 1;
-}
-
-int __gl_computeInterior( GLUtesselator *tess )
-/*
- * __gl_computeInterior( tess ) computes the planar arrangement specified
- * by the given contours, and further subdivides this arrangement
- * into regions.  Each region is marked "inside" if it belongs
- * to the polygon, according to the rule given by tess->windingRule.
- * Each interior region is guaranteed be monotone.
- */
-{
-  GLUvertex *v, *vNext;
-
-  tess->fatalError = FALSE;
-
-  /* Each vertex defines an event for our sweep line.  Start by inserting
-   * all the vertices in a priority queue.  Events are processed in
-   * lexicographic order, ie.
-   *
-   *	e1 < e2  iff  e1.x < e2.x || (e1.x == e2.x && e1.y < e2.y)
-   */
-  RemoveDegenerateEdges( tess );
-  if ( !InitPriorityQ( tess ) ) return 0; /* if error */
-  InitEdgeDict( tess );
-
-  /* __gl_pqSortExtractMin */
-  while( (v = (GLUvertex *)pqExtractMin( tess->pq )) != NULL ) {
-    for( ;; ) {
-      vNext = (GLUvertex *)pqMinimum( tess->pq ); /* __gl_pqSortMinimum */
-      if( vNext == NULL || ! VertEq( vNext, v )) break;
-      
-      /* Merge together all vertices at exactly the same location.
-       * This is more efficient than processing them one at a time,
-       * simplifies the code (see ConnectLeftDegenerate), and is also
-       * important for correct handling of certain degenerate cases.
-       * For example, suppose there are two identical edges A and B
-       * that belong to different contours (so without this code they would
-       * be processed by separate sweep events).  Suppose another edge C
-       * crosses A and B from above.  When A is processed, we split it
-       * at its intersection point with C.  However this also splits C,
-       * so when we insert B we may compute a slightly different
-       * intersection point.  This might leave two edges with a small
-       * gap between them.  This kind of error is especially obvious
-       * when using boundary extraction (GLU_TESS_BOUNDARY_ONLY).
-       */
-      vNext = (GLUvertex *)pqExtractMin( tess->pq ); /* __gl_pqSortExtractMin*/
-      SpliceMergeVertices( tess, v->anEdge, vNext->anEdge );
-    }
-    SweepEvent( tess, v );
-  }
-
-  /* Set tess->event for debugging purposes */
-  /* __GL_DICTLISTKEY */ /* __GL_DICTLISTMIN */ 
-  tess->event = ((ActiveRegion *) dictKey( dictMin( tess->dict )))->eUp->Org;
-  DebugEvent( tess );
-  DoneEdgeDict( tess );
-  DonePriorityQ( tess );
-
-  if ( !RemoveDegenerateFaces( tess->mesh ) ) return 0;
-  __gl_meshCheckMesh( tess->mesh );
-
-  return 1;
-}