SGI SI GLU library

1 files changed, 222 insertions, 0 deletions

diff --git a/src/glu/sgi/libnurbs/internals/trimline.cc b/src/glu/sgi/libnurbs/internals/trimline.cc
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+/*
+** 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.
+*/
+
+/*
+ * trimline.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/trimline.cc,v 1.1 2001/03/17 00:25:41 brianp Exp $
+ */
+
+#include "glimports.h"
+#include "myassert.h"
+#include "mystdio.h"
+#include "trimline.h"
+#include "backend.h"
+
+Trimline::Trimline()
+{
+    size = 0; pts = 0; numverts = 0;
+    tinterp = &t; binterp = &b; 
+}
+
+Trimline::~Trimline()
+{
+    if( pts ) delete[] pts; 
+}
+
+void 
+Trimline::init( TrimVertex *v )
+{
+    reset();
+    grow(1);
+    append(v);
+}
+
+inline void
+Trimline::grow( long npts )
+{
+    if( size < npts ) {
+	size = 2 * npts;
+	if( pts ) delete[] pts; 
+        pts = new TrimVertex_p[size];
+    }
+}
+
+inline void
+Trimline::append( TrimVertex *v )
+{
+    assert( numverts != size ); 
+    pts[numverts++] = v;
+}
+
+void
+Trimline::init( long npts, Arc_ptr jarc, long last )
+{
+    jarcl.init( jarc, 0, last );
+    grow( npts + 2 );
+}
+
+inline void
+Trimline::swap()
+{
+    TrimVertex *tmp=tinterp; 
+    tinterp=binterp; 
+    binterp=tmp;
+}
+
+void
+Trimline::getNextPt()
+{
+    *binterp = *jarcl.getnextpt();    
+}
+
+void 
+Trimline::getPrevPt()
+{
+    *binterp = *jarcl.getprevpt();
+}
+
+/*----------------------------------------------------------------------
+ * getNextPts - make arrays of pointers to trim points on left and right
+ *		hulls of trim strip.
+ *----------------------------------------------------------------------
+ */
+void
+Trimline::getNextPts( REAL vval, Backend& backend )
+{
+    reset(); swap(); append( tinterp );
+    assert( tinterp->param[1] >= vval );
+
+    register TrimVertex *p;
+    for( p=jarcl.getnextpt() ; p->param[1] >= vval; p=jarcl.getnextpt() ) {
+	append( p ); 
+    }
+
+    /* compute and copy pointer to final point on left hull */
+    if( interpvert( last(), p, binterp, vval ) ) {
+	binterp->nuid = p->nuid;
+	backend.triangle( p, binterp, last() );
+        append( binterp );
+    }
+    jarcl.reverse();
+    (void) jarcl.getprevpt(); 	/* reset jarcl to proper position */
+    jarcl.reverse();
+}
+
+void 
+Trimline::getPrevPts( REAL vval, Backend& backend )
+{
+    reset(); swap(); append( tinterp );
+    assert( tinterp->param[1] >= vval );
+
+    register TrimVertex *q;
+    for( q=jarcl.getprevpt(); q->param[1] >= vval; q=jarcl.getprevpt() ) {
+	append( q );
+    }
+
+    /* compute and copy pointer to final point on right hull */
+    if( interpvert( q, last(), binterp, vval ) ) {
+	binterp->nuid = q->nuid;
+	backend.triangle( last(), binterp, q );
+        append( binterp );
+    }
+    jarcl.reverse();
+    (void) jarcl.getnextpt();  /* reset jarcl to proper position */
+    jarcl.reverse();
+}
+
+void
+Trimline::getNextPts( Arc_ptr botarc )
+{
+    reset(); swap(); append( tinterp );
+
+    PwlArc *lastpwl = botarc->prev->pwlArc;
+    TrimVertex *lastpt1 = &lastpwl->pts[lastpwl->npts-1];
+    TrimVertex *lastpt2 = botarc->pwlArc->pts;
+
+    register TrimVertex *p = jarcl.getnextpt();
+    for( append( p ); p != lastpt2; append( p ) ) {
+	assert( p != lastpt1 );
+	p = jarcl.getnextpt();
+    }
+}
+
+void
+Trimline::getPrevPts( Arc_ptr botarc )
+{
+    reset();  swap(); append( tinterp );
+
+    PwlArc *lastpwl = botarc->prev->pwlArc;
+    TrimVertex *lastpt1 = &lastpwl->pts[lastpwl->npts-1];
+    TrimVertex *lastpt2 = botarc->pwlArc->pts;
+
+    register TrimVertex *q =  jarcl.getprevpt();
+    for( append( q ); q != lastpt1; append( q ) ) {
+	assert( q != lastpt2 );
+	q = jarcl.getprevpt();
+    }
+}
+
+
+long
+Trimline::interpvert( TrimVertex *a, TrimVertex *b, TrimVertex *c, REAL vval )
+{
+    REAL denom = a->param[1] - b->param[1];
+
+    if(denom != 0) {
+	if( vval == a->param[1] ) {
+	    c->param[0] = a->param[0]; 
+	    c->param[1] = a->param[1];
+	    c->nuid = a->nuid;
+	    return 0;
+	} else if( vval == b->param[1] ) {
+	    c->param[0] = b->param[0]; 
+	    c->param[1] = b->param[1];
+	    c->nuid = b->nuid;
+	    return 0;
+	} else {
+	    REAL r = (a->param[1] - vval)/denom;
+	    c->param[0] =  a->param[0] - r * (a->param[0] - b->param[0]);
+	    c->param[1] = vval;
+	    return 1;
+	}
+    } else {
+        c->param[0] = a->param[0]; 
+        c->param[1] = a->param[1];
+	c->nuid = a->nuid;
+	return 0;
+    }
+}
+