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Diffstat (limited to 'src/glu/sgi/libnurbs/internals/trimline.cc')
| -rw-r--r-- | src/glu/sgi/libnurbs/internals/trimline.cc | 222 |
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 new file mode 100644 index 0000000000..9ad6e1fed3 --- /dev/null +++ b/src/glu/sgi/libnurbs/internals/trimline.cc @@ -0,0 +1,222 @@ +/* +** 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; + } +} + |