1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2000 Chiharu Shibata
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer
12 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33#include	<sys/param.h>
34#include	<sys/systm.h>
35#include	<sys/kernel.h>
36#include	<sys/module.h>
37#include	<sys/syslog.h>
38#include	<sys/consio.h>
39#include	<sys/fbio.h>
40
41#include	<sys/random.h>
42
43#include	<dev/fb/fbreg.h>
44#include	<dev/fb/splashreg.h>
45#include	<dev/syscons/syscons.h>
46
47#define SAVER_NAME	 "dragon_saver"
48
49static u_char	*vid;
50static int	blanked;
51
52#define	VIDEO_MODE	M_VGA_CG320
53#define	VIDEO_MODE_NAME	"M_VGA_CG320"
54#define	SCRW	320
55#define	SCRH	200
56#define	ORDER	13
57#define	CURVE	3
58#define	OUT	100
59
60static int	cur_x, cur_y;
61static int	curve;
62static u_char	dragon_pal[3*256];	/* zero-filled by the compiler */
63
64static __inline int
65gpset(int x, int y, int val)
66{
67	if (x < 0 || y < 0 || SCRW <= x || SCRH <= y) {
68		return 0;
69	}
70	vid[x + y * SCRW] = val;
71	return 1;
72}
73
74static int
75gdraw(int dx, int dy, int val)
76{
77	int	i;
78	int	set = 0;
79
80	if (dx != 0) {
81		i = cur_x;
82		cur_x += dx;
83		if (dx < 0) {
84			i += dx;
85			dx = -dx;
86		}
87		/* horizontal line */
88		for (; dx >= 0; --dx, ++i) {
89			set |= gpset(i, cur_y, val);
90		}
91	}
92	else {	/* dy != 0 */
93		i = cur_y;
94		cur_y += dy;
95		if (dy < 0) {
96			i += dy;
97			dy = -dy;
98		}
99		/* vertical line */
100		for (; dy >= 0; --dy, ++i) {
101			set |= gpset(cur_x, i, val);
102		}
103	}
104	return set;
105}
106
107static void
108dragon_update(video_adapter_t *adp)
109{
110	static int	i, p, q;
111	static int	order, mul, out;
112	static int	org_x, org_y;
113	static int	dx, dy;
114	static unsigned char	fold[1 << (ORDER - 3)];
115#define	GET_FOLD(x)	(fold[(x) >> 3]  &  (1 << ((x) & 7)))
116#define	SET_FOLD(x)	(fold[(x) >> 3] |=  (1 << ((x) & 7)))
117#define	CLR_FOLD(x)	(fold[(x) >> 3] &= ~(1 << ((x) & 7)))
118	int	tmp;
119
120	if (curve > CURVE) {
121		vidd_clear(adp);
122
123		/* set palette of each curves */
124		for (tmp = 0; tmp < 3*CURVE; ++tmp) {
125			dragon_pal[3+tmp] = (u_char)random();
126		}
127		vidd_load_palette(adp, dragon_pal);
128
129		mul = ((random() & 7) + 1) * (SCRW / 320);
130		org_x = random() % SCRW; org_y = random() % SCRH;
131
132		curve = 0;
133		order = ORDER;
134	}
135
136	if (order >= ORDER) {
137		++curve;
138
139		cur_x = org_x; cur_y = org_y;
140
141		switch (curve) {
142		case 1:
143			dx = 0; dy = mul;
144			break;
145		case 2:
146			dx = mul; dy = 0;
147			break;
148		case 3:
149			dx = 0; dy = -mul;
150			break;
151		}
152		(void)gdraw(dx, dy, curve); out = 0;
153
154		order = 0;
155		q = p = 0; i = q + 1;
156	}
157
158	if (i > q) {
159		SET_FOLD(p); q = p * 2;
160
161		++order;
162		i = p; p = q + 1;
163	}
164
165	if (GET_FOLD(q-i) != 0) {
166		CLR_FOLD(i);
167		tmp = dx; dx =  dy; dy = -tmp;	/* turn right */
168	}
169	else {
170		SET_FOLD(i);
171		tmp = dx; dx = -dy; dy =  tmp;	/* turn left */
172	}
173	if (gdraw(dx, dy, curve)) {
174		out = 0;
175	}
176	else {
177		if (++out > OUT) {
178			order = ORDER;	/* force to terminate this curve */
179		}
180	}
181	++i;
182}
183
184static int
185dragon_saver(video_adapter_t *adp, int blank)
186{
187	int pl;
188
189	if (blank) {
190		/* switch to graphics mode */
191		if (blanked <= 0) {
192			pl = splhigh();
193			vidd_set_mode(adp, VIDEO_MODE);
194			vid = (u_char *)adp->va_window;
195			curve = CURVE + 1;
196			++blanked;
197			splx(pl);
198		}
199
200		/* update display */
201		dragon_update(adp);
202	}
203	else {
204		blanked = 0;
205	}
206	return 0;
207}
208
209static int
210dragon_init(video_adapter_t *adp)
211{
212	video_info_t info;
213
214	/* check that the console is capable of running in 320x200x256 */
215	if (vidd_get_info(adp, VIDEO_MODE, &info)) {
216		log(LOG_NOTICE,
217		    "%s: the console does not support " VIDEO_MODE_NAME "\n",
218		    SAVER_NAME);
219		return ENODEV;
220	}
221
222	blanked = 0;
223	return 0;
224}
225
226static int
227dragon_term(video_adapter_t *adp)
228{
229	return 0;
230}
231
232static scrn_saver_t dragon_module = {
233	SAVER_NAME,
234	dragon_init,
235	dragon_term,
236	dragon_saver,
237	NULL,
238};
239
240SAVER_MODULE(dragon_saver, dragon_module);
241