xref: /original-bsd/games/atc/update.c (revision 48d2e7c6)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * Ed James.
7  *
8  * %sccs.include.redist.c%
9  */
10 
11 /*
12  * Copyright (c) 1987 by Ed James, UC Berkeley.  All rights reserved.
13  *
14  * Copy permission is hereby granted provided that this notice is
15  * retained on all partial or complete copies.
16  *
17  * For more info on this and all of my stuff, mail edjames@berkeley.edu.
18  */
19 
20 #ifndef lint
21 static char sccsid[] = "@(#)update.c	8.1 (Berkeley) 05/31/93";
22 #endif not lint
23 
24 #include "include.h"
25 
update()26 update()
27 {
28 	int	i, dir_diff, mask, unclean;
29 	PLANE	*pp, *p1, *p2, *p;
30 
31 #ifdef BSD
32 	mask = sigblock(sigmask(SIGINT));
33 #endif
34 #ifdef SYSV
35 	alarm(0);
36 	signal(SIGALRM, update);
37 #endif
38 
39 	clck++;
40 
41 	erase_all();
42 
43 	/* put some planes in the air */
44 	do {
45 		unclean = 0;
46 		for (pp = ground.head; pp != NULL; pp = pp->next) {
47 			if (pp->new_altitude > 0) {
48 				delete(&ground, pp);
49 				append(&air, pp);
50 				unclean = 1;
51 				break;
52 			}
53 		}
54 	} while (unclean);
55 
56 	/* do altitude change and basic movement */
57 	for (pp = air.head; pp != NULL; pp = pp->next) {
58 		/* type 0 only move every other turn */
59 		if (pp->plane_type == 0 && clck & 1)
60 			continue;
61 
62 		pp->fuel--;
63 		if (pp->fuel < 0)
64 			loser(pp, "ran out of fuel.");
65 
66 		pp->altitude += SGN(pp->new_altitude - pp->altitude);
67 
68 		if (!pp->delayd) {
69 			dir_diff = pp->new_dir - pp->dir;
70 			/*
71 			 * Allow for circle commands
72 			 */
73 			if (pp->new_dir >= 0 && pp->new_dir < MAXDIR) {
74 				if (dir_diff > MAXDIR/2)
75 					dir_diff -= MAXDIR;
76 				else if (dir_diff < -(MAXDIR/2))
77 					dir_diff += MAXDIR;
78 			}
79 			if (dir_diff > 2)
80 				dir_diff = 2;
81 			else if (dir_diff < -2)
82 				dir_diff = -2;
83 			pp->dir += dir_diff;
84 			if (pp->dir >= MAXDIR)
85 				pp->dir -= MAXDIR;
86 			else if (pp->dir < 0)
87 				pp->dir += MAXDIR;
88 		}
89 		pp->xpos += displacement[pp->dir].dx;
90 		pp->ypos += displacement[pp->dir].dy;
91 
92 		if (pp->delayd && pp->xpos == sp->beacon[pp->delayd_no].x &&
93 		    pp->ypos == sp->beacon[pp->delayd_no].y) {
94 			pp->delayd = 0;
95 			if (pp->status == S_UNMARKED)
96 				pp->status = S_MARKED;
97 		}
98 
99 		switch (pp->dest_type) {
100 		case T_AIRPORT:
101 			if (pp->xpos == sp->airport[pp->dest_no].x &&
102 			    pp->ypos == sp->airport[pp->dest_no].y &&
103 			    pp->altitude == 0) {
104 				if (pp->dir != sp->airport[pp->dest_no].dir)
105 				    loser(pp, "landed in the wrong direction.");
106 				else {
107 				    pp->status = S_GONE;
108 				    continue;
109 				}
110 			}
111 			break;
112 		case T_EXIT:
113 			if (pp->xpos == sp->exit[pp->dest_no].x &&
114 			    pp->ypos == sp->exit[pp->dest_no].y) {
115 			    	if (pp->altitude != 9)
116 				    loser(pp, "exited at the wrong altitude.");
117 				else {
118 				    pp->status = S_GONE;
119 				    continue;
120 				}
121 			}
122 			break;
123 		default:
124 			loser(pp, "has a bizarre destination, get help!");
125 		}
126 		if (pp->altitude > 9)
127 			/* "this is impossible" */
128 			loser(pp, "exceded flight ceiling.");
129 		if (pp->altitude <= 0) {
130 			for (i = 0; i < sp->num_airports; i++)
131 				if (pp->xpos == sp->airport[i].x &&
132 				    pp->ypos == sp->airport[i].y) {
133 					if (pp->dest_type == T_AIRPORT)
134 					    loser(pp,
135 						"landed at the wrong airport.");
136 					else
137 					    loser(pp,
138 						"landed instead of exited.");
139 				}
140 			loser(pp, "crashed on the ground.");
141 		}
142 		if (pp->xpos < 1 || pp->xpos >= sp->width - 1 ||
143 		    pp->ypos < 1 || pp->ypos >= sp->height - 1) {
144 			for (i = 0; i < sp->num_exits; i++)
145 				if (pp->xpos == sp->exit[i].x &&
146 				    pp->ypos == sp->exit[i].y) {
147 					if (pp->dest_type == T_EXIT)
148 					    loser(pp,
149 						"exited via the wrong exit.");
150 					else
151 					    loser(pp,
152 						"exited instead of landed.");
153 				}
154 			loser(pp, "illegally left the flight arena.");
155 		}
156 	}
157 
158 	/*
159 	 * Traverse the list once, deleting the planes that are gone.
160 	 */
161 	for (pp = air.head; pp != NULL; pp = p2) {
162 		p2 = pp->next;
163 		if (pp->status == S_GONE) {
164 			safe_planes++;
165 			delete(&air, pp);
166 		}
167 	}
168 
169 	draw_all();
170 
171 	for (p1 = air.head; p1 != NULL; p1 = p1->next)
172 		for (p2 = p1->next; p2 != NULL; p2 = p2->next)
173 			if (too_close(p1, p2, 1)) {
174 				static char	buf[80];
175 
176 				(void)sprintf(buf, "collided with plane '%c'.",
177 					name(p2));
178 				loser(p1, buf);
179 			}
180 	/*
181 	 * Check every other update.  Actually, only add on even updates.
182 	 * Otherwise, prop jobs show up *on* entrance.  Remember that
183 	 * we don't update props on odd updates.
184 	 */
185 	if ((rand() % sp->newplane_time) == 0)
186 		addplane();
187 
188 #ifdef BSD
189 	sigsetmask(mask);
190 #endif
191 #ifdef SYSV
192 	alarm(sp->update_secs);
193 #endif
194 }
195 
196 char *
command(pp)197 command(pp)
198 	PLANE	*pp;
199 {
200 	static char	buf[50], *bp, *comm_start;
201 	char	*index();
202 
203 	buf[0] = '\0';
204 	bp = buf;
205 	(void)sprintf(bp, "%c%d%c%c%d: ", name(pp), pp->altitude,
206 		(pp->fuel < LOWFUEL) ? '*' : ' ',
207 		(pp->dest_type == T_AIRPORT) ? 'A' : 'E', pp->dest_no);
208 
209 	comm_start = bp = index(buf, '\0');
210 	if (pp->altitude == 0)
211 		(void)sprintf(bp, "Holding @ A%d", pp->orig_no);
212 	else if (pp->new_dir >= MAXDIR || pp->new_dir < 0)
213 		strcpy(bp, "Circle");
214 	else if (pp->new_dir != pp->dir)
215 		(void)sprintf(bp, "%d", dir_deg(pp->new_dir));
216 
217 	bp = index(buf, '\0');
218 	if (pp->delayd)
219 		(void)sprintf(bp, " @ B%d", pp->delayd_no);
220 
221 	bp = index(buf, '\0');
222 	if (*comm_start == '\0' &&
223 	    (pp->status == S_UNMARKED || pp->status == S_IGNORED))
224 		strcpy(bp, "---------");
225 	return (buf);
226 }
227 
228 /* char */
name(p)229 name(p)
230 	PLANE	*p;
231 {
232 	if (p->plane_type == 0)
233 		return ('A' + p->plane_no);
234 	else
235 		return ('a' + p->plane_no);
236 }
237 
number(l)238 number(l)
239 {
240 	if (l < 'a' && l > 'z' && l < 'A' && l > 'Z')
241 		return (-1);
242 	else if (l >= 'a' && l <= 'z')
243 		return (l - 'a');
244 	else
245 		return (l - 'A');
246 }
247 
next_plane()248 next_plane()
249 {
250 	static int	last_plane = -1;
251 	PLANE		*pp;
252 	int		found, start_plane = last_plane;
253 
254 	do {
255 		found = 0;
256 		last_plane++;
257 		if (last_plane >= 26)
258 			last_plane = 0;
259 		for (pp = air.head; pp != NULL; pp = pp->next)
260 			if (pp->plane_no == last_plane) {
261 				found++;
262 				break;
263 			}
264 		if (!found)
265 			for (pp = ground.head; pp != NULL; pp = pp->next)
266 				if (pp->plane_no == last_plane) {
267 					found++;
268 					break;
269 				}
270 	} while (found && last_plane != start_plane);
271 	if (last_plane == start_plane)
272 		return (-1);
273 	return (last_plane);
274 }
275 
addplane()276 addplane()
277 {
278 	PLANE	p, *pp, *p1;
279 	int	i, num_starts, close, rnd, rnd2, pnum;
280 
281 	bzero(&p, sizeof (p));
282 
283 	p.status = S_MARKED;
284 	p.plane_type = random() % 2;
285 
286 	num_starts = sp->num_exits + sp->num_airports;
287 	rnd = random() % num_starts;
288 
289 	if (rnd < sp->num_exits) {
290 		p.dest_type = T_EXIT;
291 		p.dest_no = rnd;
292 	} else {
293 		p.dest_type = T_AIRPORT;
294 		p.dest_no = rnd - sp->num_exits;
295 	}
296 
297 	/* loop until we get a plane not near another */
298 	for (i = 0; i < num_starts; i++) {
299 		/* loop till we get a different start point */
300 		while ((rnd2 = random() % num_starts) == rnd)
301 			;
302 		if (rnd2 < sp->num_exits) {
303 			p.orig_type = T_EXIT;
304 			p.orig_no = rnd2;
305 			p.xpos = sp->exit[rnd2].x;
306 			p.ypos = sp->exit[rnd2].y;
307 			p.new_dir = p.dir = sp->exit[rnd2].dir;
308 			p.altitude = p.new_altitude = 7;
309 			close = 0;
310 			for (p1 = air.head; p1 != NULL; p1 = p1->next)
311 				if (too_close(p1, &p, 4)) {
312 					close++;
313 					break;
314 				}
315 			if (close)
316 				continue;
317 		} else {
318 			p.orig_type = T_AIRPORT;
319 			p.orig_no = rnd2 - sp->num_exits;
320 			p.xpos = sp->airport[p.orig_no].x;
321 			p.ypos = sp->airport[p.orig_no].y;
322 			p.new_dir = p.dir = sp->airport[p.orig_no].dir;
323 			p.altitude = p.new_altitude = 0;
324 		}
325 		p.fuel = sp->width + sp->height;
326 		break;
327 	}
328 	if (i >= num_starts)
329 		return (-1);
330 	pnum = next_plane();
331 	if (pnum < 0)
332 		return (-1);
333 	p.plane_no = pnum;
334 
335 	pp = newplane();
336 	bcopy(&p, pp, sizeof (p));
337 
338 	if (pp->orig_type == T_AIRPORT)
339 		append(&ground, pp);
340 	else
341 		append(&air, pp);
342 
343 	return (pp->dest_type);
344 }
345 
346 PLANE	*
findplane(n)347 findplane(n)
348 {
349 	PLANE	*pp;
350 
351 	for (pp = air.head; pp != NULL; pp = pp->next)
352 		if (pp->plane_no == n)
353 			return (pp);
354 	for (pp = ground.head; pp != NULL; pp = pp->next)
355 		if (pp->plane_no == n)
356 			return (pp);
357 	return (NULL);
358 }
359 
too_close(p1,p2,dist)360 too_close(p1, p2, dist)
361 	PLANE	*p1, *p2;
362 {
363 	if (ABS(p1->altitude - p2->altitude) <= dist &&
364 	    ABS(p1->xpos - p2->xpos) <= dist && ABS(p1->ypos - p2->ypos) <= dist)
365 		return (1);
366 	else
367 		return (0);
368 }
369 
dir_deg(d)370 dir_deg(d)
371 {
372 	switch (d) {
373 	case 0: return (0);
374 	case 1: return (45);
375 	case 2: return (90);
376 	case 3: return (135);
377 	case 4: return (180);
378 	case 5: return (225);
379 	case 6: return (270);
380 	case 7: return (315);
381 	default:
382 		return (-1);
383 	}
384 }
385