1/*	$NetBSD: misc.c,v 1.17 2009/03/14 18:41:21 dholland Exp $	*/
2
3/*
4 * Copyright (c) 1983, 1993
5 *	The Regents of the University of California.  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 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34#if 0
35static char sccsid[] = "@(#)misc.c	8.2 (Berkeley) 4/28/95";
36#else
37__RCSID("$NetBSD: misc.c,v 1.17 2009/03/14 18:41:21 dholland Exp $");
38#endif
39#endif /* not lint */
40
41#include <ctype.h>
42#include <stdio.h>
43#include <unistd.h>
44#include <stdlib.h>
45#include <string.h>
46#include "extern.h"
47#include "pathnames.h"
48
49#define distance(x,y) \
50	(abs(x) >= abs(y) ? abs(x) + abs(y)/2 : abs(y) + abs(x)/2)
51
52static int angle(int, int);
53
54/* XXX */
55int
56range(struct ship *from, struct ship *to)
57{
58	int bow1r, bow1c, bow2r, bow2c;
59	int stern1r, stern1c, stern2c, stern2r;
60	int bb, bs, sb, ss, result;
61
62	if (!to->file->dir)
63		return -1;
64	stern1r = bow1r = from->file->row;
65	stern1c = bow1c = from->file->col;
66	stern2r = bow2r = to->file->row;
67	stern2c = bow2c = to->file->col;
68	result = bb = distance(bow2r - bow1r, bow2c - bow1c);
69	if (bb < 5) {
70		stern2r += dr[to->file->dir];
71		stern2c += dc[to->file->dir];
72		stern1r += dr[from->file->dir];
73		stern1c += dc[from->file->dir];
74		bs = distance((bow2r - stern1r), (bow2c - stern1c));
75		sb = distance((bow1r - stern2r), (bow1c - stern2c));
76		ss = distance((stern2r - stern1r) ,(stern2c - stern1c));
77		result = min(bb, min(bs, min(sb, ss)));
78	}
79	return result;
80}
81
82struct ship *
83closestenemy(struct ship *from, int side, int anyship)
84{
85	struct ship *sp;
86	char a;
87	int olddist = 30000, dist;
88	struct ship *closest = 0;
89
90	a = capship(from)->nationality;
91	foreachship(sp) {
92		if (sp == from)
93			continue;
94		if (sp->file->dir == 0)
95			continue;
96		if (a == capship(sp)->nationality && !anyship)
97			continue;
98		if (side && gunsbear(from, sp) != side)
99			continue;
100		dist = range(from, sp);
101		if (dist < olddist) {
102			closest = sp;
103			olddist = dist;
104		}
105	}
106	return closest;
107}
108
109static int
110angle(int Dr, int Dc)
111{
112	int i;
113
114	if (Dc >= 0 && Dr > 0)
115		i = 0;
116	else if (Dr <= 0 && Dc > 0)
117		i = 2;
118	else if (Dc <= 0 && Dr < 0)
119		i = 4;
120	else
121		i = 6;
122	Dr = abs(Dr);
123	Dc = abs(Dc);
124	if ((i == 0 || i == 4) && Dc * 2.4 > Dr) {
125		i++;
126		if (Dc > Dr * 2.4)
127			i++;
128	} else if ((i == 2 || i == 6) && Dr * 2.4 > Dc) {
129		i++;
130		if (Dr > Dc * 2.4)
131			i++;
132	}
133	return i % 8 + 1;
134}
135
136/* checks for target bow or stern */
137int
138gunsbear(struct ship *from, struct ship *to)
139{
140	int Dr, Dc, i;
141	int ang;
142
143	Dr = from->file->row - to->file->row;
144	Dc = to->file->col - from->file->col;
145	for (i = 2; i; i--) {
146		if ((ang = angle(Dr, Dc) - from->file->dir + 1) < 1)
147			ang += 8;
148		if (ang >= 2 && ang <= 4)
149			return 'r';
150		if (ang >= 6 && ang <= 7)
151			return 'l';
152		Dr += dr[to->file->dir];
153		Dc += dc[to->file->dir];
154	}
155	return 0;
156}
157
158/* returns true if fromship is shooting at onship's starboard side */
159int
160portside(struct ship *from, struct ship *on, int quick)
161{
162	int ang;
163	int Dr, Dc;
164
165	Dr = from->file->row - on->file->row;
166	Dc = on->file->col - from->file->col;
167	if (quick == -1) {
168		Dr += dr[on->file->dir];
169		Dc += dc[on->file->dir];
170	}
171	ang = angle(Dr, Dc);
172	if (quick != 0)
173		return ang;
174	ang = (ang + 4 - on->file->dir - 1) % 8 + 1;
175	return ang < 5;
176}
177
178int
179colours(struct ship *sp)
180{
181	char flag = '\0';
182
183	if (sp->file->struck)
184		flag = '!';
185	if (sp->file->explode)
186		flag = '#';
187	if (sp->file->sink)
188		flag = '~';
189	if (sp->file->struck)
190		return flag;
191	flag = *countryname[capship(sp)->nationality];
192	return sp->file->FS ? flag : tolower((unsigned char)flag);
193}
194
195void
196logger(struct ship *s)
197{
198	FILE *fp;
199	int persons;
200	int n;
201	struct logs log[NLOG];
202	float net;
203	struct logs *lp;
204
205	setegid(egid);
206	if ((fp = fopen(_PATH_LOGFILE, "r+")) == NULL) {
207		setegid(gid);
208		return;
209	}
210	setegid(gid);
211#ifdef LOCK_EX
212	if (flock(fileno(fp), LOCK_EX) < 0)
213		return;
214#endif
215	net = (float)s->file->points / s->specs->pts;
216	persons = getw(fp);
217	n = fread(log, sizeof(struct logs), NLOG, fp);
218	for (lp = &log[n]; lp < &log[NLOG]; lp++)
219		lp->l_name[0] = lp->l_uid = lp->l_shipnum
220			= lp->l_gamenum = lp->l_netpoints = 0;
221	rewind(fp);
222	if (persons < 0)
223		putw(1, fp);
224	else
225		putw(persons + 1, fp);
226	for (lp = log; lp < &log[NLOG]; lp++)
227		if (net > (float)lp->l_netpoints
228		    / scene[lp->l_gamenum].ship[lp->l_shipnum].specs->pts) {
229			fwrite(log, sizeof (struct logs), lp - log, fp);
230			strcpy(log[NLOG-1].l_name, s->file->captain);
231			log[NLOG-1].l_uid = getuid();
232			log[NLOG-1].l_shipnum = s->file->index;
233			log[NLOG-1].l_gamenum = game;
234			log[NLOG-1].l_netpoints = s->file->points;
235			fwrite(&log[NLOG-1], sizeof (struct logs), 1, fp);
236			fwrite(lp, sizeof (struct logs), &log[NLOG-1] - lp, fp);
237			break;
238		}
239#ifdef LOCK_EX
240	flock(fileno(fp), LOCK_UN);
241#endif
242	fclose(fp);
243}
244