ti.c revision b55148877d473978f0b46d593fd6213fa526fcc5
1/*
2 * Copyright 1990 Sun Microsystems, Inc.  All rights reserved.
3 * Use is subject to license terms.
4 */
5
6/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
7/*	  All Rights Reserved  	*/
8
9/*
10 * Copyright (c) 1980 Regents of the University of California.
11 * All rights reserved. The Berkeley software License Agreement
12 * specifies the terms and conditions for redistribution.
13 */
14
15#pragma ident	"%Z%%M%	%I%	%E% SMI"
16
17 /* ti.c: classify line intersections */
18# include "t..c"
19/* determine local environment for intersections */
20
21int
22interv(int i, int c)
23{
24int ku, kl;
25if (c>=ncol || c == 0)
26	{
27	if (dboxflg)
28		{
29		if (i==0) return(BOT);
30		if (i>=nlin) return(TOP);
31		return(THRU);
32		}
33	if (c>=ncol)
34		return(0);
35	}
36ku = i>0 ? lefdata(i-1,c) : 0;
37if (i+1 >= nlin)
38	kl=0;
39else
40kl = lefdata(allh(i) ? i+1 : i, c);
41if (ku==2 && kl==2) return(THRU);
42if (ku ==2) return(TOP);
43if (kl==BOT) return(2);
44return(0);
45}
46
47int
48interh(int i, int c)
49{
50int kl, kr;
51if (fullbot[i]== '=' || (dboxflg && (i==0 || i>= nlin-1)))
52	{
53	if (c==ncol)
54		return(LEFT);
55	if (c==0)
56		return(RIGHT);
57	return(THRU);
58	}
59if (i>=nlin) return(0);
60kl = c>0 ? thish (i,c-1) : 0;
61if (kl<=1 && i>0 && allh(up1(i)))
62	kl = c>0 ? thish(up1(i),c-1) : 0;
63kr = thish(i,c);
64if (kr<=1 && i>0 && allh(up1(i)))
65	kr = c>0 ? thish(up1(i), c) : 0;
66if (kl== '=' && kr ==  '=') return(THRU);
67if (kl== '=') return(LEFT);
68if (kr== '=') return(RIGHT);
69return(0);
70}
71
72int
73up1(int i)
74{
75i--;
76while (instead[i] && i>0) i--;
77return(i);
78}
79