FreeWRL / FreeX3D 4.3.0
trimregion.cc
1/*
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:
9**
10** http://oss.sgi.com/projects/FreeB
11**
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.
17**
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.
23**
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.
33*/
34
35/*
36 * trimregion.c++
37 *
38 */
39
40#include "glimports.h"
41#include "myassert.h"
42#include "mystdio.h"
43#include "trimregion.h"
44#include "backend.h"
45
46TrimRegion::TrimRegion( void )
47{
48}
49
50void
51TrimRegion::setDu( REAL du )
52{
53 oneOverDu = 1.0/du;
54}
55
56void
57TrimRegion::init( long npts, Arc_ptr extrema )
58{
59 left.init( npts, extrema, extrema->pwlArc->npts - 1 );
60 left.getNextPt();
61
62 right.init( npts, extrema, 0 );
63 right.getPrevPt();
64}
65
66void
67TrimRegion::getPts( Arc_ptr extrema )
68{
69 left.getNextPts( extrema );
70 right.getPrevPts( extrema );
71}
72
73void
74TrimRegion::getPts( Backend &backend )
75{
76 left.getNextPts( bot.vval, backend );
77 right.getPrevPts( bot.vval, backend );
78}
79
80void
81TrimRegion::getGridExtent( void )
82{
83 getGridExtent( left.last(), right.last() );
84}
85
86void
87TrimRegion::getGridExtent( TrimVertex *l, TrimVertex *r )
88{
89 bot.ustart = (long) ((l->param[0] - uarray.uarray[0])*oneOverDu);
90 if( l->param[0] >= uarray.uarray[bot.ustart] ) bot.ustart++;
91// if( l->param[0] > uarray.uarray[bot.ustart] ) bot.ustart++;
92 assert( l->param[0] <= uarray.uarray[bot.ustart] );
93 assert( l->param[0] >= uarray.uarray[bot.ustart-1] );
94
95 bot.uend = (long) ((r->param[0] - uarray.uarray[0])*oneOverDu);
96 if( uarray.uarray[bot.uend] >= r->param[0] ) bot.uend--;
97// if( uarray.uarray[bot.uend] > r->param[0] ) bot.uend--;
98 assert( r->param[0] >= uarray.uarray[bot.uend] );
99 assert( r->param[0] <= uarray.uarray[bot.uend+1] );
100}
101
102int
103TrimRegion::canTile( void )
104{
105 TrimVertex *lf = left.first();
106 TrimVertex *ll = left.last();
107 TrimVertex *l = ( ll->param[0] > lf->param[0] ) ? ll : lf;
108
109 TrimVertex *rf = right.first();
110 TrimVertex *rl = right.last();
111 TrimVertex *r = ( rl->param[0] < rf->param[0] ) ? rl : rf;
112 return (l->param[0] <= r->param[0]) ? 1 : 0;
113}
114