2 ** License Applicability. Except to the extent portions of this file are
3 ** made subject to an alternative license as permitted in the SGI Free
4 ** Software License B, Version 1.1 (the "License"), the contents of this
5 ** file are subject only to the provisions of the License. You may not use
6 ** this file except in compliance with the License. You may obtain a copy
7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
10 ** http://oss.sgi.com/projects/FreeB
12 ** Note that, as provided in the License, the Software is distributed on an
13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
21 ** Copyright in any portions created by third parties is as indicated
22 ** elsewhere herein. All Rights Reserved.
24 ** Additional Notice Provisions: The application programming interfaces
25 ** established by SGI in conjunction with the Original Code are The
26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
31 ** published by SGI, but has not been independently verified as being
32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
38 * $Date$ $Revision: 1.1 $
39 * $Header: /cygdrive/c/RCVS/CVS/ReactOS/reactos/lib/glu32/libnurbs/internals/trimline.cc,v 1.1 2004/02/02 16:39:13 navaraf Exp $
42 #include "glimports.h"
50 size
= 0; pts
= 0; numverts
= 0;
51 tinterp
= &t
; binterp
= &b
;
56 if( pts
) delete[] pts
;
60 Trimline::init( TrimVertex
*v
)
68 Trimline::grow( long npts
)
72 if( pts
) delete[] pts
;
73 pts
= new TrimVertex_p
[size
];
78 Trimline::append( TrimVertex
*v
)
80 assert( numverts
!= size
);
85 Trimline::init( long npts
, Arc_ptr jarc
, long last
)
87 jarcl
.init( jarc
, 0, last
);
94 TrimVertex
*tmp
=tinterp
;
100 Trimline::getNextPt()
102 *binterp
= *jarcl
.getnextpt();
106 Trimline::getPrevPt()
108 *binterp
= *jarcl
.getprevpt();
111 /*----------------------------------------------------------------------
112 * getNextPts - make arrays of pointers to trim points on left and right
113 * hulls of trim strip.
114 *----------------------------------------------------------------------
117 Trimline::getNextPts( REAL vval
, Backend
& backend
)
119 reset(); swap(); append( tinterp
);
120 assert( tinterp
->param
[1] >= vval
);
122 register TrimVertex
*p
;
123 for( p
=jarcl
.getnextpt() ; p
->param
[1] >= vval
; p
=jarcl
.getnextpt() ) {
127 /* compute and copy pointer to final point on left hull */
128 if( interpvert( last(), p
, binterp
, vval
) ) {
129 binterp
->nuid
= p
->nuid
;
130 backend
.triangle( p
, binterp
, last() );
134 (void) jarcl
.getprevpt(); /* reset jarcl to proper position */
139 Trimline::getPrevPts( REAL vval
, Backend
& backend
)
141 reset(); swap(); append( tinterp
);
142 assert( tinterp
->param
[1] >= vval
);
144 register TrimVertex
*q
;
145 for( q
=jarcl
.getprevpt(); q
->param
[1] >= vval
; q
=jarcl
.getprevpt() ) {
149 /* compute and copy pointer to final point on right hull */
150 if( interpvert( q
, last(), binterp
, vval
) ) {
151 binterp
->nuid
= q
->nuid
;
152 backend
.triangle( last(), binterp
, q
);
156 (void) jarcl
.getnextpt(); /* reset jarcl to proper position */
161 Trimline::getNextPts( Arc_ptr botarc
)
163 reset(); swap(); append( tinterp
);
165 PwlArc
*lastpwl
= botarc
->prev
->pwlArc
;
166 TrimVertex
*lastpt1
= &lastpwl
->pts
[lastpwl
->npts
-1];
167 TrimVertex
*lastpt2
= botarc
->pwlArc
->pts
;
169 register TrimVertex
*p
= jarcl
.getnextpt();
170 for( append( p
); p
!= lastpt2
; append( p
) ) {
171 assert( p
!= lastpt1
);
172 p
= jarcl
.getnextpt();
177 Trimline::getPrevPts( Arc_ptr botarc
)
179 reset(); swap(); append( tinterp
);
181 PwlArc
*lastpwl
= botarc
->prev
->pwlArc
;
182 TrimVertex
*lastpt1
= &lastpwl
->pts
[lastpwl
->npts
-1];
183 TrimVertex
*lastpt2
= botarc
->pwlArc
->pts
;
185 register TrimVertex
*q
= jarcl
.getprevpt();
186 for( append( q
); q
!= lastpt1
; append( q
) ) {
187 assert( q
!= lastpt2
);
188 q
= jarcl
.getprevpt();
194 Trimline::interpvert( TrimVertex
*a
, TrimVertex
*b
, TrimVertex
*c
, REAL vval
)
196 REAL denom
= a
->param
[1] - b
->param
[1];
199 if( vval
== a
->param
[1] ) {
200 c
->param
[0] = a
->param
[0];
201 c
->param
[1] = a
->param
[1];
204 } else if( vval
== b
->param
[1] ) {
205 c
->param
[0] = b
->param
[0];
206 c
->param
[1] = b
->param
[1];
210 REAL r
= (a
->param
[1] - vval
)/denom
;
211 c
->param
[0] = a
->param
[0] - r
* (a
->param
[0] - b
->param
[0]);
216 c
->param
[0] = a
->param
[0];
217 c
->param
[1] = a
->param
[1];