SGI SI GLU library

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diff --git a/src/glu/sgi/libnurbs/internals/tobezier.cc b/src/glu/sgi/libnurbs/internals/tobezier.cc
new file mode 100644
index 0000000000..4f1c02df59
--- /dev/null
+++ b/src/glu/sgi/libnurbs/internals/tobezier.cc
@@ -0,0 +1,689 @@
+/*
+** 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.
+*/
+
+/* 
+ * tobezier.c++
+ *
+ * $Date: 2001/03/17 00:25:41 $ $Revision: 1.1 $
+ * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/tobezier.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $
+ */
+
+#include "glimports.h"
+#include "myassert.h"
+#include "mystdio.h"
+#include "mystring.h"
+#include "quilt.h"
+#include "knotvector.h"
+
+/* local type definitions */
+struct Breakpt {		/* breakpoints	*/
+    Knot		value;		/* value	*/
+    int			multi;		/* multiplicity	*/
+    int			def;		/* deficit */
+};
+
+struct Knotspec {		/* knotvector format */
+    long		order;		/* order of spline  */
+    Knot_ptr		inkbegin;	/* input knot sequence */
+    Knot_ptr		inkend;		/* location after last knot */
+    Knot_ptr		outkbegin;	/* in-process knot subsequence */
+    Knot_ptr		outkend;	/* location after last knot */
+    Knot_ptr		kleft;		/* */
+    Knot_ptr		kright;		/* */
+    Knot_ptr		kfirst;		/* */
+    Knot_ptr		klast;		/* */
+    Knot_ptr		sbegin;		/* conversion factor values */
+    Breakpt *		bbegin;		/* in-process breakpoints */
+    Breakpt *		bend;		/* last breakpoint */
+    int			ncoords;	/* coordinates per control point */
+    int			prestride;	/* stride between input points */
+    int			poststride;	/* stride between output points	*/
+    int 		preoffset;	/* scaled point offset	*/
+    int 		postoffset;	/* scaled point offset	*/
+    int 		prewidth;	/* width of dimension	*/
+    int 		postwidth;	/* width of dimension	*/
+    int 		istransformed;	/* was dimension transformed */
+    Knotspec *		next;   	/* next knotspec */
+    Knotspec *		kspectotrans;   /* knotspec in transformation direction */
+
+			Knotspec( void );
+			~Knotspec( void );
+    void		factors( void );
+    void		insert( REAL * );
+    void		preselect();
+    void		select( void );
+    void		copy( INREAL *, REAL * );
+    void		breakpoints( void );
+    void		knots( void );
+    void		transform( REAL * );
+    void		showpts( REAL * );
+    
+    void		pt_io_copy( REAL *, INREAL * );
+    void		pt_oo_copy( REAL *, REAL * );
+    void		pt_oo_sum( REAL*, REAL*, REAL*, Knot, Knot );
+};
+
+struct Splinespec {		/* a non-uniform tensor element */
+			Splinespec( int );
+                        ~Splinespec(void);
+    Knotspec		*kspec;	/* format of each param. dir. */
+    int			dim;		/* domain dimension */
+    REAL *		outcpts;	/* Bezier control points */
+
+    void		kspecinit( Knotvector & );
+    void		kspecinit( Knotvector &, Knotvector & );
+    void		select( void );
+    void		layout( long );
+    void		setupquilt( Quilt_ptr );
+    void		copy( INREAL * );
+    void		transform( void );
+};
+
+/*-----------------------------------------------------------------------------
+ * Quilt::toBezier - convert from NURBS to rational Bezier 
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Quilt::toBezier( 
+    Knotvector& knotvector,	/* a knot vector */
+    INREAL *ctlpts,		/* input contol points */
+    long ncoords )		/* number of coordinates per control point */
+{
+    Splinespec spline( 1 );
+    spline.kspecinit( knotvector );
+    spline.select();
+    spline.layout( ncoords );
+    spline.setupquilt( this );
+    spline.copy( ctlpts );
+    spline.transform();
+}
+
+void
+Quilt::toBezier( 
+    Knotvector& sknotvector,	/* a knot vector */
+    Knotvector& tknotvector,	/* a knot vector */
+    INREAL *ctlpts,		/* input contol points */
+    long ncoords )		/* number of coordinates per control point */
+{
+    Splinespec spline( 2 );
+    spline.kspecinit( sknotvector, tknotvector );
+    spline.select();
+    spline.layout( ncoords );
+    spline.setupquilt( this );
+    spline.copy( ctlpts );
+    spline.transform();
+}
+Splinespec::Splinespec( int dimen )
+{
+    dim = dimen;
+}
+
+Splinespec::~Splinespec( void )
+{
+    /* Note: do NOT delete 'outcpts' here since its address (not contents)
+     * is copied in 'cpts' in this file in function Splinespec::setupquilt().
+     * This block of memory will eventually be deleted in file quilt.c++ in
+     * function Quilt::deleteMe() through 'cpts' so do NOT delete it here!
+     */	
+    Knotspec *ktrav= kspec;         //start at beginning of list 
+    while (ktrav != 0) {            //any items to delete? 
+       Knotspec *deleteThis= ktrav; //remember to delete this 
+       ktrav= ktrav->next;          //go to next item if any
+       delete deleteThis;           //delete it
+    }	
+} /* ~Splinespec() */
+
+/*-----------------------------------------------------------------------------
+ * Splinespec::kspecinit - initialize Splinespec structure
+ *
+ * Client: Quilt::toBezier
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Splinespec::kspecinit( Knotvector& knotvector )
+{
+    kspec = new Knotspec;
+    kspec->inkbegin = knotvector.knotlist;
+    kspec->inkend = knotvector.knotlist + knotvector.knotcount;
+    kspec->prestride = (int) knotvector.stride; 
+    kspec->order = knotvector.order;
+    kspec->next = NULL;
+}
+
+void
+Splinespec::kspecinit( Knotvector& sknotvector, Knotvector& tknotvector )
+{
+    kspec = new Knotspec;
+    Knotspec *tkspec = new Knotspec;
+
+    kspec->inkbegin = sknotvector.knotlist;
+    kspec->inkend = sknotvector.knotlist + sknotvector.knotcount;
+    kspec->prestride = (int) sknotvector.stride; 
+    kspec->order = sknotvector.order;
+    kspec->next = tkspec;
+
+    tkspec->inkbegin = tknotvector.knotlist;
+    tkspec->inkend = tknotvector.knotlist + tknotvector.knotcount;
+    tkspec->prestride = (int) tknotvector.stride; 
+    tkspec->order = tknotvector.order;
+    tkspec->next = NULL;
+}
+
+
+/*-----------------------------------------------------------------------------
+ * Splinespec::select - select the subsegments to copy
+ *
+ * Client: gl_quilt_to_bezier	
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Splinespec::select( )
+{
+    for( Knotspec *knotspec = kspec; knotspec; knotspec = knotspec->next ) {
+	knotspec->preselect();
+	knotspec->select();
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * Splinespec::layout - 
+ *
+ * Client: gl_quilt_to_bezier	
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Splinespec::layout( long ncoords )
+{
+
+    long stride = ncoords;
+    for( Knotspec *knotspec = kspec; knotspec; knotspec=knotspec->next ) {
+	knotspec->poststride = (int) stride;
+	stride *= ((knotspec->bend-knotspec->bbegin)*knotspec->order + knotspec->postoffset);
+        knotspec->preoffset  *= knotspec->prestride;
+	knotspec->prewidth  *= knotspec->poststride;
+	knotspec->postwidth *= knotspec->poststride;
+	knotspec->postoffset *= knotspec->poststride;
+        knotspec->ncoords = (int) ncoords;
+    }
+    outcpts = new REAL[stride];
+    assert( outcpts != 0 );  
+}
+
+/*-----------------------------------------------------------------------------
+ * Splinespec::copy - copy the control points of current subobject
+ *
+ * Client: gl_quilt_to_bezier
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Splinespec::copy( INREAL *incpts )
+{
+    kspec->copy( incpts, outcpts );
+}
+
+/*-----------------------------------------------------------------------------
+ * Splinespec::setupquilt - assign all quilt variables from knotspec 
+ *
+ * Client: gl_quilt_to_bezier
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Splinespec::setupquilt( Quilt_ptr quilt )
+{
+    Quiltspec_ptr qspec = quilt->qspec;
+    quilt->eqspec = qspec + dim;
+    for( Knotspec *knotspec = kspec; knotspec; knotspec=knotspec->next, qspec++ ) {
+	qspec->stride	= knotspec->poststride;
+	qspec->width	= knotspec->bend - knotspec->bbegin;
+	qspec->order	= (int) knotspec->order;
+	qspec->offset	= knotspec->postoffset;
+	qspec->index	= 0;
+	qspec->bdry[0]	= (knotspec->kleft == knotspec->kfirst) ? 1 : 0;
+	qspec->bdry[1]	= (knotspec->kright == knotspec->klast) ? 1 : 0;
+	qspec->breakpoints = new Knot[qspec->width+1];
+	Knot_ptr k =  qspec->breakpoints;
+	for( Breakpt *bk = knotspec->bbegin; bk <= knotspec->bend; bk++ )
+	    *(k++) = bk->value;
+    }
+    quilt->cpts = outcpts;
+    quilt->next = 0;
+}
+
+/*-----------------------------------------------------------------------------
+ * Splinespec::transform - convert a spline to Bezier format
+ *
+ * Client: gl_quilt_to_bezier
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Splinespec::transform( void )
+{
+    Knotspec *knotspec;
+    for( knotspec = kspec; knotspec; knotspec=knotspec->next )
+        knotspec->istransformed = 0;
+
+    for( knotspec = kspec; knotspec; knotspec=knotspec->next ) {
+	for( Knotspec *kspec2 = kspec; kspec2; kspec2=kspec2->next )
+	    kspec2->kspectotrans = knotspec;
+	kspec->transform( outcpts );
+	knotspec->istransformed = 1;
+    }
+}
+
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::Knotspec -  constuct a knot spec 
+ *-----------------------------------------------------------------------------
+ */
+
+Knotspec::Knotspec( void )
+{
+    bbegin = 0;
+    sbegin = 0;
+    outkbegin = 0;
+}
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::copy -  copy the control points along minor direction 
+ *
+ * Client: Splinespec::copy
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::copy( INREAL *inpt, REAL *outpt )
+{
+    inpt = (INREAL *) (((char *) inpt) + preoffset);
+
+    if( next ) {
+        for( REAL *lpt=outpt+prewidth; outpt != lpt; outpt += poststride ) {
+	    next->copy( inpt, outpt );
+	    inpt = (INREAL *) (((char *) inpt) + prestride);
+	}
+   } else {
+        for( REAL *lpt=outpt+prewidth; outpt != lpt; outpt += poststride ) {
+	    pt_io_copy( outpt, inpt );
+	    inpt = (INREAL *) (((char *) inpt) + prestride);
+	}
+     }
+}
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::showpts - print out points before transformation
+ *
+ * Client: Knotspec::select
+ *-----------------------------------------------------------------------------
+ */
+void
+Knotspec::showpts( REAL *outpt )
+{
+    if( next ) {
+        for( REAL *lpt=outpt+prewidth; outpt != lpt; outpt += poststride )
+	    next->showpts( outpt );
+    } else {
+        for( REAL *lpt=outpt+prewidth; outpt != lpt; outpt += poststride )
+	    dprintf(  "show %g %g %g\n", outpt[0], outpt[1], outpt[2] );
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::factors - precompute scale factors 	
+ *	   - overwrites knot vector, actual new knot vector is NOT produced
+ *
+ * Client: Knotspec::select
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::factors( void )
+{
+    Knot *mid = (outkend - 1) - order + bend->multi;
+    Knot_ptr fptr = sbegin;
+
+    for( Breakpt *bpt = bend; bpt >= bbegin; bpt-- ) {
+    	mid -= bpt->multi;		// last knot less than knot to insert
+	int def = bpt->def - 1;		// number of knots to insert
+	if( def <= 0 ) continue;
+	Knot kv = bpt->value;		// knot to insert
+
+	Knot *kf = (mid-def) + (order-1);
+	for( Knot *kl = kf + def; kl != kf; kl-- ) {
+	    Knot *kh, *kt;
+	    for( kt=kl, kh=mid; kt != kf; kh--, kt-- ) 
+		*(fptr++) = (kv - *kh) / (*kt - *kh);
+	    *kl = kv;
+	}
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::insert - convert subobject in direction of kspec into Bezier
+ *
+ * Client: Knotspec::transform
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::insert( REAL *p )
+{
+    Knot_ptr fptr = sbegin;
+    REAL *srcpt = p + prewidth - poststride;
+    REAL *dstpt = p + postwidth + postoffset - poststride;
+    Breakpt *bpt = bend;
+
+   for( REAL *pend = srcpt - poststride*bpt->def; srcpt != pend; pend +=poststride ) {
+	REAL *p1 = srcpt;
+	for( REAL *p2 = srcpt-poststride; p2 != pend; p1 = p2, p2 -= poststride ) {
+	    pt_oo_sum( p1, p1, p2, *fptr, 1.0-*fptr );
+	    fptr++;
+	}
+    }
+
+    for( --bpt; bpt >= bbegin; bpt-- ) {
+
+	for( int multi = bpt->multi; multi > 0; multi-- ) {
+	    pt_oo_copy( dstpt, srcpt );
+	    dstpt -= poststride;
+	    srcpt -= poststride;	
+	}
+    
+	for( REAL *pend = srcpt - poststride*bpt->def; srcpt != pend; pend +=poststride, dstpt-=poststride ) {
+	    pt_oo_copy( dstpt, srcpt );
+	    REAL *p1 = srcpt;
+
+	    for( REAL *p2 = srcpt-poststride; p2 != pend; p1=p2, p2 -= poststride ) {
+		pt_oo_sum( p1, p1, p2, *fptr, 1.0-*fptr );
+		fptr++;
+	    }
+	}
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::preselect - initialize kspec for processing
+ *
+ * Client: Splinespec::select
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::preselect( void )
+{
+    Knot kval; 
+
+    /* position klast after last knot of "last" breakpoint */
+    for( klast = inkend - order, kval = *klast; klast != inkend; klast++ ) 
+	if( ! identical( *klast, kval ) ) break;
+
+    /* position kfirst after last knot of "first" breakpoint */
+    for( kfirst = inkbegin+order-1, kval= *kfirst;  kfirst != inkend; kfirst++ )
+	if( ! identical( *kfirst, kval ) ) break;
+
+    /* compute multiplicity of first breakpoint */
+    Knot_ptr k;
+    for( k  = kfirst - 1; k >= inkbegin; k-- ) 
+	if( ! identical( kval, *k ) ) break;    
+    k++;
+
+    /* allocate space for breakpoints -
+       use worst case estimate on number of breakpoints */
+
+    bbegin = new Breakpt[(klast - kfirst)+1];
+    /* record multiplicity and value of first breakpoint */
+    bbegin->multi = kfirst - k;
+    bbegin->value = kval;
+    bend = bbegin;
+
+    kleft = kright = kfirst;
+}
+
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::select - Knotspec::select segments and precompute scale factors
+ *
+ * Client: Splinespec::select
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::select( void )
+{
+    breakpoints();
+    knots();
+    factors();
+    
+    preoffset	= kleft - (inkbegin + order);
+    postwidth	= (int)((bend - bbegin) * order);
+    prewidth 	= (int)((outkend - outkbegin) - order);
+    postoffset  = (bbegin->def > 1) ? (bbegin->def-1) : 0;
+}
+ 
+/*-----------------------------------------------------------------------------
+ * Knotspec::breakpoints - compute breakpoints for knotspec
+ *
+ * Client: Knotspec::select
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::breakpoints( void )
+{
+    Breakpt *ubpt	= bbegin;
+    Breakpt *ubend	= bend;
+    long    nfactors  	= 0;
+
+    ubpt->value	= ubend->value;
+    ubpt->multi	= ubend->multi;
+
+    kleft = kright;
+
+    for( ; kright != klast; kright++ ) {
+        if ( identical(*kright,ubpt->value) ) {
+	    (ubpt->multi)++;
+	} else {
+    	    ubpt->def = (int) (order - ubpt->multi);
+    	    nfactors += (ubpt->def * (ubpt->def - 1)) / 2;
+	    (++ubpt)->value = *kright;
+	    ubpt->multi = 1;
+	}
+    }
+    ubpt->def = (int) (order - ubpt->multi);
+    nfactors += (ubpt->def * (ubpt->def - 1)) / 2;
+
+    bend = ubpt;
+
+    if( nfactors ) {	    
+        sbegin = new Knot[nfactors];
+    } else {
+	sbegin = NULL;
+    }
+}
+
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::knots - copy relevant subsequence of knots into temporary area
+ *
+ * Client: Knotspec::select
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::knots( void )
+{
+    Knot_ptr inkpt = kleft - order;
+    Knot_ptr inkend = kright  + bend->def;
+
+    /* allocate space for knots and factors */
+    outkbegin = new Knot[inkend-inkpt];
+    Knot_ptr outkpt;
+    for( outkpt = outkbegin; inkpt != inkend; inkpt++, outkpt++ ) 
+	*outkpt = *inkpt;
+
+    outkend = outkpt;
+}
+
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::transform -	convert a spline along a given direction 
+ *
+ * Client: Splienspec::transform
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::transform( REAL *p )
+{
+   if( next ) {
+	if( this == kspectotrans ) {
+	    next->transform( p );
+	} else {
+	    if( istransformed ) {
+		p += postoffset;
+		for( REAL *pend = p + postwidth; p != pend; p += poststride )
+		    next->transform( p );
+	    } else {
+		REAL *pend = p + prewidth;
+		for( ; p != pend; p += poststride )
+		    next->transform( p );
+	    }
+	}
+   } else {
+	if( this == kspectotrans ) {
+	    insert( p );
+	} else {
+	    if( istransformed ) {
+		p += postoffset;
+		for( REAL *pend = p + postwidth; p != pend; p += poststride )
+		    kspectotrans->insert( p );
+	    } else {
+		REAL *pend = p + prewidth;
+		for( ; p != pend; p += poststride )
+		    kspectotrans->insert( p );
+	    }
+	}
+   }
+}
+
+/*-----------------------------------------------------------------------------
+ * Knotspec::~Knotspec - free space alocated for knotspec
+ *-----------------------------------------------------------------------------
+ */
+
+Knotspec::~Knotspec( void )
+{
+    if( bbegin ) delete[] bbegin;
+    if( sbegin ) delete[] sbegin;
+    if( outkbegin ) delete[] outkbegin;
+}
+
+
+/*-----------------------------------------------------------------------------
+ * pt_io_copy - make internal copy of input cntrl pt. of x coords
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::pt_io_copy( REAL *topt, INREAL *frompt )
+{
+    switch( ncoords ) {
+    case 4:
+        topt[3] = (REAL) frompt[3];
+    case 3:
+        topt[2] = (REAL) frompt[2];
+    case 2:
+        topt[1] = (REAL) frompt[1];
+    case 1:
+        topt[0] = (REAL) frompt[0];
+	break;
+    default: {
+	    for( int i = 0; i < ncoords; i++ )
+		*topt++ = (REAL) *frompt++;
+	}
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * pt_oo_copy - make internal copy of internal cntrl pt. of x coords
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::pt_oo_copy( REAL *topt, REAL *frompt )
+{
+    switch( ncoords ) {
+    case 4:
+        topt[3] = frompt[3];
+    case 3:
+        topt[2] = frompt[2];
+    case 2:
+        topt[1] = frompt[1];
+    case 1:
+        topt[0] = frompt[0];
+	break;
+    default:
+	memcpy( topt, frompt, ncoords * sizeof( REAL ) );
+    }
+}
+
+/*-----------------------------------------------------------------------------
+ * pt_oo_sum - compute affine combination of internal cntrl pts
+ *-----------------------------------------------------------------------------
+ */
+
+void
+Knotspec::pt_oo_sum( REAL *x, REAL *y, REAL *z, Knot a, Knot b )
+{
+    switch( ncoords ) {
+    case 4:
+        x[3] = a * y[3]  +  b * z[3];
+    case 3:
+        x[2] = a * y[2]  +  b * z[2];
+    case 2:
+        x[1] = a * y[1]  +  b * z[1];
+    case 1:
+        x[0] = a * y[0]  +  b * z[0];
+	break;
+    default: {
+          for( int i = 0; i < ncoords; i++ )
+              *x++ = a * *y++   +   b * *z++;
+    }
+    }
+}