add rcsid
[bsdgames-darwin.git] / trek / compkl.c
1 /* $NetBSD: compkl.c,v 1.3 1995/04/22 10:58:38 cgd Exp $ */
2
3 /*
4 * Copyright (c) 1980, 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. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by the University of
18 * California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)compkl.c 8.1 (Berkeley) 5/31/93";
39 #else
40 static char rcsid[] = "$NetBSD: compkl.c,v 1.3 1995/04/22 10:58:38 cgd Exp $";
41 #endif
42 #endif /* not lint */
43
44 # include "trek.h"
45
46 /*
47 ** compute klingon distances
48 **
49 ** The klingon list has the distances for all klingons recomputed
50 ** and sorted. The parameter is a Boolean flag which is set if
51 ** we have just entered a new quadrant.
52 **
53 ** This routine is used every time the Enterprise or the Klingons
54 ** move.
55 */
56
57 compkldist(f)
58 int f; /* set if new quadrant */
59 {
60 register int i, dx, dy;
61 double d;
62 double temp;
63
64 if (Etc.nkling == 0)
65 return;
66 for (i = 0; i < Etc.nkling; i++)
67 {
68 /* compute distance to the Klingon */
69 dx = Ship.sectx - Etc.klingon[i].x;
70 dy = Ship.secty - Etc.klingon[i].y;
71 d = dx * dx + dy * dy;
72 d = sqrt(d);
73
74 /* compute average of new and old distances to Klingon */
75 if (!f)
76 {
77 temp = Etc.klingon[i].dist;
78 Etc.klingon[i].avgdist = 0.5 * (temp + d);
79 }
80 else
81 {
82 /* new quadrant: average is current */
83 Etc.klingon[i].avgdist = d;
84 }
85 Etc.klingon[i].dist = d;
86 }
87
88 /* leave them sorted */
89 sortkl();
90 }
91
92
93 /*
94 ** sort klingons
95 **
96 ** bubble sort on ascending distance
97 */
98
99 sortkl()
100 {
101 struct kling t;
102 register int f, i, m;
103
104 m = Etc.nkling - 1;
105 f = 1;
106 while (f)
107 {
108 f = 0;
109 for (i = 0; i < m; i++)
110 if (Etc.klingon[i].dist > Etc.klingon[i+1].dist)
111 {
112 bmove(&Etc.klingon[i], &t, sizeof t);
113 bmove(&Etc.klingon[i+1], &Etc.klingon[i], sizeof t);
114 bmove(&t, &Etc.klingon[i+1], sizeof t);
115 f = 1;
116 }
117 }
118 }