snake_saver.c revision 24673 
1/*-
2 * Copyright (c) 1995 S�ren Schmidt
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer
10 *    in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 *    derived from this software withough specific prior written permission
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 *	$Id: snake_saver.c,v 1.13 1997/02/22 12:49:19 peter Exp $
29 */
30
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/conf.h>
34#include <sys/exec.h>
35#include <sys/sysent.h>
36#include <sys/lkm.h>
37#include <sys/errno.h>
38
39#include <machine/md_var.h>
40
41#include "saver.h"
42
43MOD_MISC(snake_saver);
44
45void (*current_saver)(int blank);
46void (*old_saver)(int blank);
47
48static void
49snake_saver(int blank)
50{
51	const char	saves[] = {"FreeBSD-3.0-CURRENT"};
52	static u_char	*savs[sizeof(saves)-1];
53	static int	dirx, diry;
54	int		f;
55	scr_stat	*scp = cur_console;
56
57	if (blank) {
58		if (!scrn_blanked) {
59			fillw((FG_LIGHTGREY|BG_BLACK)<<8 | scr_map[0x20],
60			      Crtat, scp->xsize * scp->ysize);
61			set_border(0);
62			dirx = (scp->xpos ? 1 : -1);
63			diry = (scp->ypos ?
64				scp->xsize : -scp->xsize);
65			for (f=0; f< sizeof(saves)-1; f++)
66				savs[f] = (u_char *)Crtat + 2 *
67					  (scp->xpos+scp->ypos*scp->xsize);
68			*(savs[0]) = scr_map[*saves];
69			f = scp->ysize * scp->xsize + 5;
70			outb(crtc_addr, 14);
71			outb(crtc_addr+1, f >> 8);
72			outb(crtc_addr, 15);
73			outb(crtc_addr+1, f & 0xff);
74			scrn_blanked = 1;
75		}
76		if (scrn_blanked++ < 4)
77			return;
78		scrn_blanked = 1;
79		*(savs[sizeof(saves)-2]) = scr_map[0x20];
80		for (f=sizeof(saves)-2; f > 0; f--)
81			savs[f] = savs[f-1];
82		f = (savs[0] - (u_char *)Crtat) / 2;
83		if ((f % scp->xsize) == 0 ||
84		    (f % scp->xsize) == scp->xsize - 1 ||
85		    (random() % 50) == 0)
86			dirx = -dirx;
87		if ((f / scp->xsize) == 0 ||
88		    (f / scp->xsize) == scp->ysize - 1 ||
89		    (random() % 20) == 0)
90			diry = -diry;
91		savs[0] += 2*dirx + 2*diry;
92		for (f=sizeof(saves)-2; f>=0; f--)
93			*(savs[f]) = scr_map[saves[f]];
94	}
95	else {
96		if (scrn_blanked) {
97			set_border(scp->border);
98			scrn_blanked = 0;
99			scp->start = 0;
100			scp->end = scp->xsize * scp->ysize;
101		}
102	}
103}
104
105static int
106snake_saver_load(struct lkm_table *lkmtp, int cmd)
107{
108	(*current_saver)(0);
109	old_saver = current_saver;
110	current_saver = snake_saver;
111	return 0;
112}
113
114static int
115snake_saver_unload(struct lkm_table *lkmtp, int cmd)
116{
117	(*current_saver)(0);
118	current_saver = old_saver;
119	return 0;
120}
121
122int
123snake_saver_mod(struct lkm_table *lkmtp, int cmd, int ver)
124{
125	MOD_DISPATCH(snake_saver, lkmtp, cmd, ver,
126		snake_saver_load, snake_saver_unload, lkm_nullcmd);
127}
128