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b6f0a7e4 | 1 | /* |
82daddb0 KB |
2 | * Copyright (c) 1980, 1993 |
3 | * The Regents of the University of California. All rights reserved. | |
e9fb6bea | 4 | * |
b2e7427f | 5 | * %sccs.include.redist.c% |
b6f0a7e4 DF |
6 | */ |
7 | ||
f67257fc | 8 | #ifndef lint |
82daddb0 | 9 | static char sccsid[] = "@(#)compkl.c 8.1 (Berkeley) %G%"; |
e9fb6bea | 10 | #endif /* not lint */ |
f67257fc KM |
11 | |
12 | # include "trek.h" | |
13 | ||
14 | /* | |
15 | ** compute klingon distances | |
16 | ** | |
17 | ** The klingon list has the distances for all klingons recomputed | |
18 | ** and sorted. The parameter is a Boolean flag which is set if | |
19 | ** we have just entered a new quadrant. | |
20 | ** | |
21 | ** This routine is used every time the Enterprise or the Klingons | |
22 | ** move. | |
23 | */ | |
24 | ||
25 | compkldist(f) | |
26 | int f; /* set if new quadrant */ | |
27 | { | |
28 | register int i, dx, dy; | |
29 | double d; | |
30 | double temp; | |
31 | ||
32 | if (Etc.nkling == 0) | |
33 | return; | |
34 | for (i = 0; i < Etc.nkling; i++) | |
35 | { | |
36 | /* compute distance to the Klingon */ | |
37 | dx = Ship.sectx - Etc.klingon[i].x; | |
38 | dy = Ship.secty - Etc.klingon[i].y; | |
39 | d = dx * dx + dy * dy; | |
40 | d = sqrt(d); | |
41 | ||
42 | /* compute average of new and old distances to Klingon */ | |
43 | if (!f) | |
44 | { | |
45 | temp = Etc.klingon[i].dist; | |
46 | Etc.klingon[i].avgdist = 0.5 * (temp + d); | |
47 | } | |
48 | else | |
49 | { | |
50 | /* new quadrant: average is current */ | |
51 | Etc.klingon[i].avgdist = d; | |
52 | } | |
53 | Etc.klingon[i].dist = d; | |
54 | } | |
55 | ||
56 | /* leave them sorted */ | |
57 | sortkl(); | |
58 | } | |
59 | ||
60 | ||
61 | /* | |
62 | ** sort klingons | |
63 | ** | |
64 | ** bubble sort on ascending distance | |
65 | */ | |
66 | ||
67 | sortkl() | |
68 | { | |
69 | struct kling t; | |
70 | register int f, i, m; | |
71 | ||
72 | m = Etc.nkling - 1; | |
73 | f = 1; | |
74 | while (f) | |
75 | { | |
76 | f = 0; | |
77 | for (i = 0; i < m; i++) | |
78 | if (Etc.klingon[i].dist > Etc.klingon[i+1].dist) | |
79 | { | |
80 | bmove(&Etc.klingon[i], &t, sizeof t); | |
81 | bmove(&Etc.klingon[i+1], &Etc.klingon[i], sizeof t); | |
82 | bmove(&t, &Etc.klingon[i+1], sizeof t); | |
83 | f = 1; | |
84 | } | |
85 | } | |
f67257fc | 86 | } |