xref: /original-bsd/usr.bin/window/wwdelchar.c (revision 279692fa)
1 /*
2  * Copyright (c) 1983 Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 static char sccsid[] = "@(#)wwdelchar.c	3.13 (Berkeley) 06/29/88";
20 #endif /* not lint */
21 
22 #include "ww.h"
23 #include "tt.h"
24 
25 wwdelchar(w, row, col)
26 register struct ww *w;
27 {
28 	register i;
29 	int nvis;
30 
31 	/*
32 	 * First, shift the line.
33 	 */
34 	{
35 		register union ww_char *p, *q;
36 
37 		p = &w->ww_buf[row][col];
38 		q = p + 1;
39 		for (i = w->ww_b.r - col; --i > 0;)
40 			*p++ = *q++;
41 		p->c_w = ' ';
42 	}
43 
44 	/*
45 	 * If can't see it, just return.
46 	 */
47 	if (row < w->ww_i.t || row >= w->ww_i.b
48 	    || w->ww_i.r <= 0 || w->ww_i.r <= col)
49 		return;
50 
51 	if (col < w->ww_i.l)
52 		col = w->ww_i.l;
53 
54 	/*
55 	 * Now find out how much is actually changed, and fix wwns.
56 	 */
57 	{
58 		register union ww_char *buf;
59 		register char *win;
60 		register union ww_char *ns;
61 		register char *smap;
62 		char touched;
63 
64 		nvis = 0;
65 		smap = &wwsmap[row][col];
66 		for (i = col; i < w->ww_i.r && *smap++ != w->ww_index; i++)
67 			;
68 		if (i >= w->ww_i.r)
69 			return;
70 		col = i;
71 		buf = w->ww_buf[row];
72 		win = w->ww_win[row];
73 		ns = wwns[row];
74 		smap = &wwsmap[row][i];
75 		touched = wwtouched[row];
76 		for (; i < w->ww_i.r; i++) {
77 			if (*smap++ != w->ww_index)
78 				continue;
79 			touched |= WWU_TOUCHED;
80 			if (win[i])
81 				ns[i].c_w =
82 					buf[i].c_w ^ win[i] << WWC_MSHIFT;
83 			else {
84 				nvis++;
85 				ns[i] = buf[i];
86 			}
87 		}
88 		wwtouched[row] = touched;
89 	}
90 
91 	/*
92 	 * Can/Should we use delete character?
93 	 */
94 	if (tt.tt_delchar != 0 && nvis > (wwncol - col) / 2) {
95 		register union ww_char *p, *q;
96 
97 		(*tt.tt_move)(row, col);
98 		(*tt.tt_delchar)();
99 
100 		p = &wwos[row][col];
101 		q = p + 1;
102 		for (i = wwncol - col; --i > 0;)
103 			*p++ = *q++;
104 		p->c_w = ' ';
105 	}
106 }
107