SGI SI GLU library

1 files changed, 912 insertions, 0 deletions

diff --git a/src/glu/sgi/libnurbs/internals/subdivider.cc b/src/glu/sgi/libnurbs/internals/subdivider.cc
new file mode 100644
index 00000000000..e85acacf8b4
--- /dev/null
+++ b/src/glu/sgi/libnurbs/internals/subdivider.cc
@@ -0,0 +1,912 @@
+/*
+** 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.
+*/
+
+/*
+ * subdivider.cxx
+ *
+ * $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
+ * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/subdivider.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $
+ */
+
+#include "glimports.h"
+#include "myassert.h"
+#include "mystdio.h"
+#include "subdivider.h"
+#include "arc.h"
+#include "bezierarc.h"
+#include "bin.h"
+#include "renderhints.h"
+#include "backend.h"
+#include "mapdesc.h"
+#include "quilt.h"
+#include "patchlist.h"
+#include "patch.h"
+#include "nurbsconsts.h"
+#include "trimvertpool.h"
+#include "simplemath.h"
+
+#include "polyUtil.h" //for function area()
+
+//#define  PARTITION_TEST
+#ifdef PARTITION_TEST
+#include "partitionY.h"
+#include "monoTriangulation.h"
+#include "dataTransform.h"
+#include "monoChain.h"
+
+#endif
+
+
+#define OPTIMIZE_UNTRIMED_CASE
+
+
+Bin*
+Subdivider::makePatchBoundary( const REAL *from, const REAL *to )
+{ 
+    Bin* ret = new Bin();
+    REAL smin = from[0];
+    REAL smax = to[0];
+    REAL tmin = from[1];
+    REAL tmax = to[1];
+
+    pjarc = 0;
+
+    Arc_ptr jarc = new(arcpool) Arc( arc_bottom, 0 );
+    arctessellator.bezier( jarc, smin, smax, tmin, tmin );
+    ret->addarc( jarc  );
+    pjarc = jarc->append( pjarc );
+
+    jarc = new(arcpool) Arc( arc_right, 0 );
+    arctessellator.bezier( jarc, smax, smax, tmin, tmax );
+    ret->addarc( jarc  );
+    pjarc = jarc->append( pjarc );
+
+    jarc = new(arcpool) Arc( arc_top, 0 );
+    arctessellator.bezier( jarc, smax, smin, tmax, tmax );
+    ret->addarc( jarc  );
+    pjarc = jarc->append( pjarc );
+
+    jarc = new(arcpool) Arc( arc_left, 0 );
+    arctessellator.bezier( jarc, smin, smin, tmax, tmin );
+    ret->addarc( jarc  );
+    jarc->append( pjarc );
+
+    assert( jarc->check() != 0 );
+    return ret;
+}
+
+/*---------------------------------------------------------------------------
+ * Subdivider - construct a subdivider
+ *---------------------------------------------------------------------------
+ */
+
+Subdivider::Subdivider( Renderhints& r, Backend& b ) 
+	: arcpool( sizeof( Arc), 1, "arcpool" ),
+ 	  bezierarcpool( sizeof( BezierArc ), 1, "Bezarcpool" ),
+	  pwlarcpool( sizeof( PwlArc ), 1, "Pwlarcpool" ),
+	  renderhints( r ),
+	  arctessellator( trimvertexpool, pwlarcpool ), 
+	  backend( b ),
+	  slicer( b )
+{
+}
+
+void
+Subdivider::setJumpbuffer( JumpBuffer *j )
+{
+    jumpbuffer = j;
+}
+
+/*---------------------------------------------------------------------------
+ * clear - reset all state after possible error condition
+ *---------------------------------------------------------------------------
+ */
+
+void		
+Subdivider::clear( void )
+{
+    trimvertexpool.clear();     
+    arcpool.clear();
+    pwlarcpool.clear();
+    bezierarcpool.clear();
+}
+
+/*---------------------------------------------------------------------------
+ * ~Subdivider - destroy a subdivider
+ *---------------------------------------------------------------------------
+ */
+
+Subdivider::~Subdivider( void )
+{
+}
+
+/*---------------------------------------------------------------------------
+ * addArc - add a bezier arc to a trim loop and to a bin
+ *---------------------------------------------------------------------------
+ */
+void
+Subdivider::addArc( REAL *cpts, Quilt *quilt, long _nuid )
+{
+    BezierArc *bezierArc = new(bezierarcpool) BezierArc;
+    Arc *jarc  		= new(arcpool) Arc( arc_none, _nuid );
+    jarc->pwlArc	= 0;
+    jarc->bezierArc	= bezierArc;
+    bezierArc->order	= quilt->qspec->order;
+    bezierArc->stride	= quilt->qspec->stride;
+    bezierArc->mapdesc	= quilt->mapdesc;
+    bezierArc->cpts	= cpts;
+    initialbin.addarc( jarc );
+    pjarc		= jarc->append( pjarc );
+}
+
+/*---------------------------------------------------------------------------
+ * addArc - add a pwl arc to a trim loop and to a bin
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::addArc( int npts, TrimVertex *pts, long _nuid ) 
+{
+    Arc *jarc 		= new(arcpool) Arc( arc_none, _nuid );
+    jarc->pwlArc	= new(pwlarcpool) PwlArc( npts, pts );        
+    initialbin.addarc( jarc  );
+    pjarc		= jarc->append( pjarc );
+}
+
+void
+Subdivider::beginQuilts( void )
+{
+    qlist = 0;
+}
+
+void
+Subdivider::addQuilt( Quilt *quilt )
+{
+    quilt->next = qlist;
+    qlist = quilt;
+}
+
+/*---------------------------------------------------------------------------
+ * drawSurfaces - main entry point for surface tessellation
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::drawSurfaces( long nuid )
+{
+    renderhints.init( );
+
+    if (qlist == NULL) 
+      {
+	//initialbin could be nonempty due to some errors
+	freejarcs(initialbin);
+	return;
+      }
+
+    for( Quilt *q = qlist; q; q = q->next ) {
+	if( q->isCulled( ) == CULL_TRIVIAL_REJECT ) {
+	    freejarcs( initialbin );
+	    return;
+	}
+    }
+
+
+    REAL from[2], to[2];
+    qlist->getRange( from, to, spbrkpts, tpbrkpts );
+#ifdef OPTIMIZE_UNTRIMED_CASE
+    //perform optimization only when the samplng method is 
+    //DOMAIN_DISTANCE and the display methdo is either 
+    //fill or outline_polygon.
+    int optimize = (is_domain_distance_sampling && (renderhints.display_method != N_OUTLINE_PATCH));
+#endif
+
+    if( ! initialbin.isnonempty() ) {
+#ifdef OPTIMIZE_UNTRIMED_CASE
+        if(! optimize )
+	  {	
+
+	  makeBorderTrim( from, to );
+	  }
+#else
+	makeBorderTrim( from, to );
+#endif
+    } else {
+	REAL rate[2];
+	qlist->findRates( spbrkpts, tpbrkpts, rate );
+
+    	if( decompose( initialbin, min(rate[0], rate[1]) ) ) 
+	    mylongjmp( jumpbuffer, 31 );
+    }
+
+    backend.bgnsurf( renderhints.wiretris, renderhints.wirequads, nuid );
+
+#ifdef PARTITION_TEST
+ if(    initialbin.isnonempty() && spbrkpts.end-2 == spbrkpts.start && 
+	tpbrkpts.end-2 == tpbrkpts.start)
+{
+    for(int i=spbrkpts.start; i<spbrkpts.end-1; i++){
+      for(int j=tpbrkpts.start; j<tpbrkpts.end-1; j++){
+	Real pta[2], ptb[2];
+	pta[0] = spbrkpts.pts[i];
+	ptb[0] = spbrkpts.pts[i+1];
+	pta[1] = tpbrkpts.pts[j];
+	ptb[1] = tpbrkpts.pts[j+1];
+	qlist->downloadAll(pta, ptb, backend);
+
+	directedLine *poly;
+
+	  {
+
+	    poly = bin_to_DLineLoops(initialbin);
+	    
+	    poly=poly->deleteDegenerateLinesAllPolygons();	    	
+
+    sampledLine* retSampledLines;
+//printf("before MC_partition\n");	    
+	    poly = MC_partitionY(poly, &retSampledLines);
+//printf("after MC_partition\n");	    
+
+	  }
+
+
+	{
+	  primStream pStream(5000,5000);
+	  directedLine* temp;
+
+	  for(temp=poly; temp != NULL; temp=temp->getNextPolygon())
+
+	    monoTriangulation(temp, &pStream);
+
+	  slicer.evalStream(&pStream);
+
+	}
+	//need to clean up space
+      }
+    }
+    freejarcs( initialbin );
+    backend.endsurf();
+    return;
+
+    /*
+    printf("num_polygons=%i\n", poly->numPolygons());
+    printf("num_edges=%i\n", poly->numEdgesAllPolygons());
+    poly->writeAllPolygons("zloutputFile");
+    return;
+    {
+      primStream pStream(20,20);
+      for(directedLine* tempD = poly; tempD != NULL; tempD = tempD->getNextPolygon())
+	monoTriangulation(tempD, &pStream);
+    }
+    return;
+    */
+}
+#endif //PARTITION_TEST
+
+
+#ifdef OPTIMIZE_UNTRIMED_CASE
+    if( (!initialbin.isnonempty())  && optimize )
+      {
+	int i,j;
+	int num_u_steps;
+        int num_v_steps;
+	for(i=spbrkpts.start; i<spbrkpts.end-1; i++){
+	  for(j=tpbrkpts.start; j<tpbrkpts.end-1; j++){
+	    Real pta[2], ptb[2];
+	    pta[0] = spbrkpts.pts[i];
+	    ptb[0] = spbrkpts.pts[i+1];
+	    pta[1] = tpbrkpts.pts[j];
+	    ptb[1] = tpbrkpts.pts[j+1];
+	    qlist->downloadAll(pta, ptb, backend);
+	   
+            num_u_steps = (int) (domain_distance_u_rate * (ptb[0]-pta[0]));
+            num_v_steps = (int) (domain_distance_v_rate * (ptb[1]-pta[1]));
+
+            if(num_u_steps <= 0) num_u_steps = 1;
+            if(num_v_steps <= 0) num_v_steps = 1;
+
+	    backend.surfgrid(pta[0], ptb[0], num_u_steps, 
+			     ptb[1], pta[1], num_v_steps);
+	    backend.surfmesh(0,0,num_u_steps,num_v_steps);
+
+        
+
+	    continue;
+	    /* the following is left for reference purpose, don't delete
+	    {
+	    Bin* tempSource;	
+	      Patchlist patchlist(qlist, pta, ptb);
+	      patchlist.getstepsize();
+
+	      tempSource=makePatchBoundary(pta, ptb);
+
+	      tessellation(*tempSource, patchlist);
+
+	      render(*tempSource);
+	      delete tempSource;
+	    }
+	    */
+	  }
+	}
+      }
+    else
+      subdivideInS( initialbin );
+#else
+
+    subdivideInS( initialbin );
+#endif
+
+    backend.endsurf();
+
+}
+
+void
+Subdivider::subdivideInS( Bin& source )
+{
+    if( renderhints.display_method == N_OUTLINE_PARAM ) {
+	outline( source );
+	freejarcs( source );
+    } else {
+	setArcTypeBezier();
+	setNonDegenerate();
+	splitInS( source, spbrkpts.start, spbrkpts.end );
+    }
+}
+
+
+/*---------------------------------------------------------------------------
+ * splitInS - split a patch and a bin by an isoparametric line
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::splitInS( Bin& source, int start, int end )
+{
+    if( source.isnonempty() ) {
+        if( start != end ) {
+	    int	i = start + (end - start) / 2;
+	    Bin left, right;
+	    split( source, left, right, 0, spbrkpts.pts[i] );
+	    splitInS( left, start, i );
+	    splitInS( right, i+1, end );
+        } else {
+	    if( start == spbrkpts.start || start == spbrkpts.end ) {
+		freejarcs( source );
+	    } else if( renderhints.display_method == N_OUTLINE_PARAM_S ) {
+		outline( source );
+		freejarcs( source );
+	    } else {
+		setArcTypeBezier();
+		setNonDegenerate();
+		s_index = start;
+		splitInT( source, tpbrkpts.start, tpbrkpts.end );
+	    }
+        }
+    } 
+}
+
+/*---------------------------------------------------------------------------
+ * splitInT - split a patch and a bin by an isoparametric line
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::splitInT( Bin& source, int start, int end )
+{
+    if( source.isnonempty() ) {
+        if( start != end ) {
+	    int	i = start + (end - start) / 2;
+	    Bin left, right;
+	    split( source, left, right, 1, tpbrkpts.pts[i] );
+	    splitInT( left, start, i );
+	    splitInT( right, i+1, end );
+        } else {
+	    if( start == tpbrkpts.start || start == tpbrkpts.end ) {
+		freejarcs( source );
+	    } else if( renderhints.display_method == N_OUTLINE_PARAM_ST ) {
+		outline( source );
+		freejarcs( source );
+	    } else {
+		t_index = start;
+		setArcTypeBezier();
+		setDegenerate();
+
+		REAL pta[2], ptb[2];
+		pta[0] = spbrkpts.pts[s_index-1];
+		pta[1] = tpbrkpts.pts[t_index-1];
+
+		ptb[0] = spbrkpts.pts[s_index];
+		ptb[1] = tpbrkpts.pts[t_index];
+		qlist->downloadAll( pta, ptb, backend );
+	    
+		Patchlist patchlist( qlist, pta, ptb );
+/*
+printf("-------samplingSplit-----\n");
+source.show("samplingSplit source");
+*/
+		samplingSplit( source, patchlist, renderhints.maxsubdivisions, 0 );
+		setNonDegenerate();
+		setArcTypeBezier();
+	    }
+        }
+    } 
+}
+
+/*--------------------------------------------------------------------------
+ * samplingSplit - recursively subdivide patch, cull check each subpatch  
+ *--------------------------------------------------------------------------
+ */
+
+void
+Subdivider::samplingSplit( 
+    Bin& source, 
+    Patchlist& patchlist, 
+    int subdivisions, 
+    int param )
+{
+    if( ! source.isnonempty() ) return;
+
+    if( patchlist.cullCheck() == CULL_TRIVIAL_REJECT ) {
+	freejarcs( source );
+	return;
+    }
+
+    patchlist.getstepsize();
+
+    if( renderhints.display_method == N_OUTLINE_PATCH ) {
+        tessellation( source, patchlist );
+	outline( source );
+	freejarcs( source );
+	return;
+    } 
+
+    //patchlist.clamp();
+
+    tessellation( source, patchlist );
+
+    if( patchlist.needsSamplingSubdivision() && (subdivisions > 0) ) {
+	if( ! patchlist.needsSubdivision( 0 ) )
+	    param = 1;
+	else if( ! patchlist.needsSubdivision( 1 ) )
+	    param = 0;
+	else
+	    param = 1 - param;
+
+	Bin left, right;
+	REAL mid = ( patchlist.pspec[param].range[0] +
+		     patchlist.pspec[param].range[1] ) * 0.5;
+	split( source, left, right, param, mid );
+	Patchlist subpatchlist( patchlist, param, mid );
+	samplingSplit( left, subpatchlist, subdivisions-1, param );
+	samplingSplit( right, patchlist, subdivisions-1, param );
+    } else {
+	setArcTypePwl();
+	setDegenerate();
+	nonSamplingSplit( source, patchlist, subdivisions, param );
+	setDegenerate();
+	setArcTypeBezier();
+    }
+}
+
+void
+Subdivider::nonSamplingSplit( 
+    Bin& source, 
+    Patchlist& patchlist, 
+    int subdivisions, 
+    int param )
+{
+    if( patchlist.needsNonSamplingSubdivision() && (subdivisions > 0) ) {
+	param = 1 - param;
+
+	Bin left, right;
+	REAL mid = ( patchlist.pspec[param].range[0] +
+		     patchlist.pspec[param].range[1] ) * 0.5;
+	split( source, left, right, param, mid );
+	Patchlist subpatchlist( patchlist, param, mid );
+	if( left.isnonempty() )
+	    if( subpatchlist.cullCheck() == CULL_TRIVIAL_REJECT ) 
+		freejarcs( left );
+	    else
+	        nonSamplingSplit( left, subpatchlist, subdivisions-1, param );
+	if( right.isnonempty() ) 
+	    if( patchlist.cullCheck() == CULL_TRIVIAL_REJECT ) 
+		freejarcs( right );
+	    else
+	        nonSamplingSplit( right, patchlist, subdivisions-1, param );
+
+    } else {
+	// make bbox calls
+	patchlist.bbox();
+	backend.patch( patchlist.pspec[0].range[0], patchlist.pspec[0].range[1],
+		       patchlist.pspec[1].range[0], patchlist.pspec[1].range[1] );
+    
+	if( renderhints.display_method == N_OUTLINE_SUBDIV ) {
+	    outline( source );
+	    freejarcs( source );
+	} else {
+	    setArcTypePwl();
+	    setDegenerate();
+	    findIrregularS( source );
+	    monosplitInS( source, smbrkpts.start, smbrkpts.end );
+	}
+    }
+}
+
+/*--------------------------------------------------------------------------
+ * tessellation - set tessellation of interior and boundary of patch
+ *--------------------------------------------------------------------------
+ */
+
+void
+Subdivider::tessellation( Bin& bin, Patchlist &patchlist )
+{
+    // tessellate unsampled trim curves
+    tessellate( bin, patchlist.pspec[1].sidestep[1], patchlist.pspec[0].sidestep[1],
+	 patchlist.pspec[1].sidestep[0], patchlist.pspec[0].sidestep[0] );
+
+    // set interior sampling rates
+    slicer.setstriptessellation( patchlist.pspec[0].stepsize, patchlist.pspec[1].stepsize );
+
+    //added by zl: set the order which will be used in slicer.c++
+    slicer.set_ulinear( (patchlist.get_uorder() == 2));
+    slicer.set_vlinear( (patchlist.get_vorder() == 2));
+
+    // set boundary sampling rates
+    stepsizes[0] = patchlist.pspec[1].stepsize;
+    stepsizes[1] = patchlist.pspec[0].stepsize;
+    stepsizes[2] = patchlist.pspec[1].stepsize;
+    stepsizes[3] = patchlist.pspec[0].stepsize;
+}
+
+/*---------------------------------------------------------------------------
+ * monosplitInS - split a patch and a bin by an isoparametric line
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::monosplitInS( Bin& source, int start, int end )
+{
+    if( source.isnonempty() ) {
+        if( start != end ) {
+	    int	i = start + (end - start) / 2;
+	    Bin left, right;
+	    split( source, left, right, 0, smbrkpts.pts[i] );
+	    monosplitInS( left, start, i );
+	    monosplitInS( right, i+1, end );
+        } else {
+	    if( renderhints.display_method == N_OUTLINE_SUBDIV_S ) {
+		outline( source );
+		freejarcs( source );
+	    } else {
+		setArcTypePwl();
+		setDegenerate();
+		findIrregularT( source );
+		monosplitInT( source, tmbrkpts.start, tmbrkpts.end );
+	    }
+        }
+    } 
+}
+
+/*---------------------------------------------------------------------------
+ * monosplitInT - split a patch and a bin by an isoparametric line
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::monosplitInT( Bin& source, int start, int end )
+{
+    if( source.isnonempty() ) {
+        if( start != end ) {
+	    int	i = start + (end - start) / 2;
+	    Bin left, right;
+	    split( source, left, right, 1, tmbrkpts.pts[i] );
+	    monosplitInT( left, start, i );
+	    monosplitInT( right, i+1, end );
+        } else {
+	    if( renderhints.display_method == N_OUTLINE_SUBDIV_ST ) {
+		outline( source );
+		freejarcs( source );
+	    } else {
+/*
+printf("*******render\n");
+source.show("source\n");
+*/
+		render( source );
+		freejarcs( source );
+	    }
+        }
+    } 
+}
+
+
+/*----------------------------------------------------------------------------
+ * findIrregularS - determine points of non-monotonicity is s direction
+ *----------------------------------------------------------------------------
+ */
+
+void
+Subdivider::findIrregularS( Bin& bin )
+{
+    assert( bin.firstarc()->check() != 0 );
+
+    smbrkpts.grow( bin.numarcs() );
+
+    for( Arc_ptr jarc=bin.firstarc(); jarc; jarc=bin.nextarc() ) {
+	REAL *a = jarc->prev->tail();
+	REAL *b = jarc->tail();
+	REAL *c = jarc->head();
+
+	if( b[1] == a[1] && b[1] == c[1] ) continue;
+
+	//corrected code
+	if((b[1]<=a[1] && b[1] <= c[1]) ||
+	   (b[1]>=a[1] && b[1] >= c[1]))
+	  {
+	    //each arc (jarc, jarc->prev, jarc->next) is a 
+	    //monotone arc consisting of multiple line segements.
+	    //it may happen that jarc->prev and jarc->next are the same,
+	    //that is, jarc->prev and jarc form a closed loop.
+	    //In such case, a and c will be the same.
+            if(a[0]==c[0] && a[1] == c[1])
+	      {
+		if(jarc->pwlArc->npts >2)
+		  {
+		    c = jarc->pwlArc->pts[jarc->pwlArc->npts-2].param;
+		  }
+		else
+		  {
+		    assert(jarc->prev->pwlArc->npts>2);
+		    a = jarc->prev->pwlArc->pts[jarc->prev->pwlArc->npts-2].param;
+		  }
+		    
+	      }
+	    if(area(a,b,c) < 0)
+	      {
+		smbrkpts.add(b[0]);
+	      }
+
+	  }
+
+	/* old code, 
+	if( b[1] <= a[1] && b[1] <= c[1] ) {
+	    if( ! ccwTurn_tr( jarc->prev, jarc ) )
+                smbrkpts.add( b[0] );
+	} else if( b[1] >= a[1] && b[1] >= c[1] ) {
+	    if( ! ccwTurn_tl( jarc->prev, jarc ) )
+                smbrkpts.add( b[0] );
+        }
+	*/
+
+    }
+
+    smbrkpts.filter();
+} 
+
+/*----------------------------------------------------------------------------
+ * findIrregularT - determine points of non-monotonicity in t direction
+ *		     where one arc is parallel to the s axis.
+ *----------------------------------------------------------------------------
+ */
+
+void
+Subdivider::findIrregularT( Bin& bin )
+{
+    assert( bin.firstarc()->check() != 0 );
+
+    tmbrkpts.grow( bin.numarcs() );
+
+    for( Arc_ptr jarc=bin.firstarc(); jarc; jarc=bin.nextarc() ) {
+	REAL *a = jarc->prev->tail();
+	REAL *b = jarc->tail();
+	REAL *c = jarc->head();
+
+	if( b[0] == a[0] && b[0] == c[0] ) continue;
+
+	if( b[0] <= a[0] && b[0] <= c[0] ) {
+	    if( a[1] != b[1] && b[1] != c[1] ) continue; 
+	    if( ! ccwTurn_sr( jarc->prev, jarc ) )
+                tmbrkpts.add( b[1] );
+	} else if ( b[0] >= a[0] && b[0] >= c[0] ) {
+	    if( a[1] != b[1] && b[1] != c[1] ) continue; 
+	    if( ! ccwTurn_sl( jarc->prev, jarc ) )
+                tmbrkpts.add( b[1] );
+	}
+    }
+    tmbrkpts.filter( );
+}
+
+/*-----------------------------------------------------------------------------
+ * makeBorderTrim - if no user input trimming data then create 
+ * a trimming curve around the boundaries of the Quilt.  The curve consists of
+ * four Jordan arcs, one for each side of the Quilt, connected, of course,
+ * head to tail. 
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Subdivider::makeBorderTrim( const REAL *from, const REAL *to )
+{ 
+    REAL smin = from[0];
+    REAL smax = to[0];
+    REAL tmin = from[1];
+    REAL tmax = to[1];
+
+    pjarc = 0;
+
+    Arc_ptr jarc = new(arcpool) Arc( arc_bottom, 0 );
+    arctessellator.bezier( jarc, smin, smax, tmin, tmin );
+    initialbin.addarc( jarc  );
+    pjarc = jarc->append( pjarc );
+
+    jarc = new(arcpool) Arc( arc_right, 0 );
+    arctessellator.bezier( jarc, smax, smax, tmin, tmax );
+    initialbin.addarc( jarc  );
+    pjarc = jarc->append( pjarc );
+
+    jarc = new(arcpool) Arc( arc_top, 0 );
+    arctessellator.bezier( jarc, smax, smin, tmax, tmax );
+    initialbin.addarc( jarc  );
+    pjarc = jarc->append( pjarc );
+
+    jarc = new(arcpool) Arc( arc_left, 0 );
+    arctessellator.bezier( jarc, smin, smin, tmax, tmin );
+    initialbin.addarc( jarc  );
+    jarc->append( pjarc );
+
+    assert( jarc->check() != 0 );
+}
+
+/*----------------------------------------------------------------------------
+ * render - renders all monotone regions in a bin and frees the bin
+ *----------------------------------------------------------------------------
+ */
+
+void
+Subdivider::render( Bin& bin )
+{
+    bin.markall();
+
+#ifdef N_ISOLINE_S
+    slicer.setisolines( ( renderhints.display_method == N_ISOLINE_S ) ? 1 : 0 );
+#else
+    slicer.setisolines( 0 );
+#endif
+
+    for( Arc_ptr jarc=bin.firstarc(); jarc; jarc=bin.nextarc() ) {
+	if( jarc->ismarked() ) {
+	    assert( jarc->check( ) != 0 );
+	    Arc_ptr jarchead = jarc;
+	    do {
+		jarc->clearmark();
+		jarc = jarc->next;
+	    } while (jarc != jarchead);
+	    slicer.slice( jarc );
+	}
+    }
+}
+
+/*---------------------------------------------------------------------------
+ * outline - render the trimmed patch by outlining the boundary 
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::outline( Bin& bin )
+{
+    bin.markall();
+    for( Arc_ptr jarc=bin.firstarc(); jarc; jarc=bin.nextarc() ) {
+	if( jarc->ismarked() ) {
+	    assert( jarc->check( ) != 0 );
+	    Arc_ptr jarchead = jarc;
+	    do {
+		slicer.outline( jarc );
+		jarc->clearmark();
+		jarc = jarc->prev;
+	    } while (jarc != jarchead);
+	}
+    }
+}
+
+/*---------------------------------------------------------------------------
+ * freejarcs - free all arcs in a bin
+ *---------------------------------------------------------------------------
+ */
+
+void
+Subdivider::freejarcs( Bin& bin )
+{
+    bin.adopt();	/* XXX - should not be necessary */
+
+    Arc_ptr jarc;
+    while( (jarc = bin.removearc()) != NULL ) {
+	if( jarc->pwlArc ) jarc->pwlArc->deleteMe( pwlarcpool ); jarc->pwlArc = 0;
+	if( jarc->bezierArc) jarc->bezierArc->deleteMe( bezierarcpool ); jarc->bezierArc = 0;
+	jarc->deleteMe( arcpool );
+    }
+}
+
+/*----------------------------------------------------------------------------
+ * tessellate - tessellate all Bezier arcs in a bin
+ * 		   1) only accepts linear Bezier arcs as input 
+ * 		   2) the Bezier arcs are stored in the pwlArc structure
+ * 		   3) only vertical or horizontal lines work
+ * 		-- should 
+ * 		   1) represent Bezier arcs in BezierArc structure
+ * 		      (this requires a multitude of changes to the code)
+ * 		   2) accept high degree Bezier arcs (hard)
+ * 		   3) map the curve onto the surface to determine tessellation
+ * 		   4) work for curves of arbitrary geometry
+ *----------------------------------------------------------------------------
+ */
+
+
+void
+Subdivider::tessellate( Bin& bin, REAL rrate, REAL trate, REAL lrate, REAL brate )
+{
+    for( Arc_ptr jarc=bin.firstarc(); jarc; jarc=bin.nextarc() ) {
+	if( jarc->isbezier( ) ) {
+    	    assert( jarc->pwlArc->npts == 2 );	
+	    TrimVertex  *pts = jarc->pwlArc->pts;
+    	    REAL s1 = pts[0].param[0];
+    	    REAL t1 = pts[0].param[1];
+    	    REAL s2 = pts[1].param[0];
+    	    REAL t2 = pts[1].param[1];
+	    
+    	    jarc->pwlArc->deleteMe( pwlarcpool ); jarc->pwlArc = 0;
+	    
+	    switch( jarc->getside() ) {
+		case arc_left:
+		    assert( s1 == s2 );
+		    arctessellator.pwl_left( jarc, s1, t1, t2, lrate );
+		    break;
+		case arc_right:
+		    assert( s1 == s2 );
+		    arctessellator.pwl_right( jarc, s1, t1, t2, rrate );
+		    break;
+		case arc_top:
+		    assert( t1 == t2 );
+		    arctessellator.pwl_top( jarc, t1, s1, s2, trate );
+		    break;
+		case arc_bottom:
+		    assert( t1 == t2 );
+		    arctessellator.pwl_bottom( jarc, t1, s1, s2, brate );
+		    break;
+		case arc_none:
+		    (void) abort();
+		    break;
+	    }
+	    assert( ! jarc->isbezier() );
+    	    assert( jarc->check() != 0 );
+	}
+    }
+}