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.
40 #include "glimports.h"
44 #include "gridvertex.h"
45 #include "gridtrimvertex.h"
49 #include "trimregion.h"
57 /*----------------------------------------------------------------------
58 * Hull:init - this routine does the initialization needed before any
59 * calls to nextupper or nextlower can be made.
60 *----------------------------------------------------------------------
65 TrimVertex *lfirst = left.first();
66 TrimVertex *llast = left.last();
67 if( lfirst->param[0] <= llast->param[0] ) {
68 fakeleft.init( left.first() );
69 upper.left = &fakeleft;
72 fakeleft.init( left.last() );
73 lower.left = &fakeleft;
79 if( top.ustart <= top.uend ) {
81 upper.index = top.ustart;
85 if( bot.ustart <= bot.uend ) {
87 lower.index = bot.ustart;
91 TrimVertex *rfirst = right.first();
92 TrimVertex *rlast = right.last();
93 if( rfirst->param[0] <= rlast->param[0] ) {
94 fakeright.init( right.last() );
95 lower.right = &fakeright;
98 fakeright.init( right.first() );
99 upper.right = &fakeright;
100 lower.right = &right;
102 upper.right->first();
106 /*----------------------------------------------------------------------
107 * nextupper - find next vertex on upper hull of trim region.
108 * - if vertex is on trim curve, set vtop point to
109 * that vertex. if vertex is on grid, set vtop to
110 * point to temporary area and stuff coordinants into
111 * temporary vertex. Also, place grid coords in temporary
113 *----------------------------------------------------------------------
116 Hull::nextupper( GridTrimVertex *gv )
119 gv->set( upper.left->prev() );
120 if( gv->isTrimVert() ) return gv;
125 assert( upper.index <= upper.line->uend );
126 gv->set( uarray.uarray[upper.index], upper.line->vval );
127 gv->set( upper.index, upper.line->vindex );
128 if( upper.index++ == upper.line->uend ) upper.line = 0;
133 gv->set( upper.right->next() );
134 if( gv->isTrimVert() ) return gv;
142 Hull::nextlower( register GridTrimVertex *gv )
145 gv->set( lower.left->next() );
146 if( gv->isTrimVert() ) return gv;
151 gv->set( uarray.uarray[lower.index], lower.line->vval );
152 gv->set( lower.index, lower.line->vindex );
153 if( lower.index++ == lower.line->uend ) lower.line = 0;
158 gv->set( lower.right->prev() );
159 if( gv->isTrimVert() ) return gv;