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
31#include	<sys/param.h>
32#include	<sys/systm.h>
33#include	<sys/kernel.h>
34#include	<sys/module.h>
35#include	<sys/syslog.h>
36#include	<sys/consio.h>
37#include	<sys/fbio.h>
38
39#include	<sys/random.h>
40
41#include	<dev/fb/fbreg.h>
42#include	<dev/fb/splashreg.h>
43#include	<dev/syscons/syscons.h>
44
45#define SAVER_NAME	 "dragon_saver"
46
47static u_char	*vid;
48static int	blanked;
49
50#define	VIDEO_MODE	M_VGA_CG320
51#define	VIDEO_MODE_NAME	"M_VGA_CG320"
52#define	SCRW	320
53#define	SCRH	200
54#define	ORDER	13
55#define	CURVE	3
56#define	OUT	100
57
58static int	cur_x, cur_y;
59static int	curve;
60static u_char	dragon_pal[3*256];	/* zero-filled by the compiler */
61
62static __inline int
63gpset(int x, int y, int val)
64{
65	if (x < 0 || y < 0 || SCRW <= x || SCRH <= y) {
66		return 0;
67	}
68	vid[x + y * SCRW] = val;
69	return 1;
70}
71
72static int
73gdraw(int dx, int dy, int val)
74{
75	int	i;
76	int	set = 0;
77
78	if (dx != 0) {
79		i = cur_x;
80		cur_x += dx;
81		if (dx < 0) {
82			i += dx;
83			dx = -dx;
84		}
85		/* horizontal line */
86		for (; dx >= 0; --dx, ++i) {
87			set |= gpset(i, cur_y, val);
88		}
89	}
90	else {	/* dy != 0 */
91		i = cur_y;
92		cur_y += dy;
93		if (dy < 0) {
94			i += dy;
95			dy = -dy;
96		}
97		/* vertical line */
98		for (; dy >= 0; --dy, ++i) {
99			set |= gpset(cur_x, i, val);
100		}
101	}
102	return set;
103}
104
105static void
106dragon_update(video_adapter_t *adp)
107{
108	static int	i, p, q;
109	static int	order, mul, out;
110	static int	org_x, org_y;
111	static int	dx, dy;
112	static unsigned char	fold[1 << (ORDER - 3)];
113#define	GET_FOLD(x)	(fold[(x) >> 3]  &  (1 << ((x) & 7)))
114#define	SET_FOLD(x)	(fold[(x) >> 3] |=  (1 << ((x) & 7)))
115#define	CLR_FOLD(x)	(fold[(x) >> 3] &= ~(1 << ((x) & 7)))
116	int	tmp;
117
118	if (curve > CURVE) {
119		vidd_clear(adp);
120
121		/* set palette of each curves */
122		for (tmp = 0; tmp < 3*CURVE; ++tmp) {
123			dragon_pal[3+tmp] = (u_char)random();
124		}
125		vidd_load_palette(adp, dragon_pal);
126
127		mul = ((random() & 7) + 1) * (SCRW / 320);
128		org_x = random() % SCRW; org_y = random() % SCRH;
129
130		curve = 0;
131		order = ORDER;
132	}
133
134	if (order >= ORDER) {
135		++curve;
136
137		cur_x = org_x; cur_y = org_y;
138
139		switch (curve) {
140		case 1:
141			dx = 0; dy = mul;
142			break;
143		case 2:
144			dx = mul; dy = 0;
145			break;
146		case 3:
147			dx = 0; dy = -mul;
148			break;
149		}
150		(void)gdraw(dx, dy, curve); out = 0;
151
152		order = 0;
153		q = p = 0; i = q + 1;
154	}
155
156	if (i > q) {
157		SET_FOLD(p); q = p * 2;
158
159		++order;
160		i = p; p = q + 1;
161	}
162
163	if (GET_FOLD(q-i) != 0) {
164		CLR_FOLD(i);
165		tmp = dx; dx =  dy; dy = -tmp;	/* turn right */
166	}
167	else {
168		SET_FOLD(i);
169		tmp = dx; dx = -dy; dy =  tmp;	/* turn left */
170	}
171	if (gdraw(dx, dy, curve)) {
172		out = 0;
173	}
174	else {
175		if (++out > OUT) {
176			order = ORDER;	/* force to terminate this curve */
177		}
178	}
179	++i;
180}
181
182static int
183dragon_saver(video_adapter_t *adp, int blank)
184{
185	int pl;
186
187	if (blank) {
188		/* switch to graphics mode */
189		if (blanked <= 0) {
190			pl = splhigh();
191			vidd_set_mode(adp, VIDEO_MODE);
192			vid = (u_char *)adp->va_window;
193			curve = CURVE + 1;
194			++blanked;
195			splx(pl);
196		}
197
198		/* update display */
199		dragon_update(adp);
200	}
201	else {
202		blanked = 0;
203	}
204	return 0;
205}
206
207static int
208dragon_init(video_adapter_t *adp)
209{
210	video_info_t info;
211
212	/* check that the console is capable of running in 320x200x256 */
213	if (vidd_get_info(adp, VIDEO_MODE, &info)) {
214		log(LOG_NOTICE,
215		    "%s: the console does not support " VIDEO_MODE_NAME "\n",
216		    SAVER_NAME);
217		return ENODEV;
218	}
219
220	blanked = 0;
221	return 0;
222}
223
224static int
225dragon_term(video_adapter_t *adp)
226{
227	return 0;
228}
229
230static scrn_saver_t dragon_module = {
231	SAVER_NAME,
232	dragon_init,
233	dragon_term,
234	dragon_saver,
235	NULL,
236};
237
238SAVER_MODULE(dragon_saver, dragon_module);
239