projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| f54f2bac WJ |
1 | /* |
| 2 | * Copyright (c) 1980 Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms, with or without | |
| 6 | * modification, are permitted provided that the following conditions | |
| 7 | * are met: | |
| 8 | * 1. Redistributions of source code must retain the above copyright | |
| 9 | * notice, this list of conditions and the following disclaimer. | |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 | * notice, this list of conditions and the following disclaimer in the | |
| 12 | * documentation and/or other materials provided with the distribution. | |
| 13 | * 3. All advertising materials mentioning features or use of this software | |
| 14 | * must display the following acknowledgement: | |
| 15 | * This product includes software developed by the University of | |
| 16 | * California, Berkeley and its contributors. | |
| 17 | * 4. Neither the name of the University nor the names of its contributors | |
| 18 | * may be used to endorse or promote products derived from this software | |
| 19 | * without specific prior written permission. | |
| 20 | * | |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 31 | * SUCH DAMAGE. | |
| 32 | */ | |
| 33 | ||
| 34 | #ifndef lint | |
| 35 | static char sccsid[] = "@(#)compkl.c 5.4 (Berkeley) 6/1/90"; | |
| 36 | #endif /* not lint */ | |
| 37 | ||
| 38 | # include "trek.h" | |
| 39 | ||
| 40 | /* | |
| 41 | ** compute klingon distances | |
| 42 | ** | |
| 43 | ** The klingon list has the distances for all klingons recomputed | |
| 44 | ** and sorted. The parameter is a Boolean flag which is set if | |
| 45 | ** we have just entered a new quadrant. | |
| 46 | ** | |
| 47 | ** This routine is used every time the Enterprise or the Klingons | |
| 48 | ** move. | |
| 49 | */ | |
| 50 | ||
| 51 | compkldist(f) | |
| 52 | int f; /* set if new quadrant */ | |
| 53 | { | |
| 54 | register int i, dx, dy; | |
| 55 | double d; | |
| 56 | double temp; | |
| 57 | ||
| 58 | if (Etc.nkling == 0) | |
| 59 | return; | |
| 60 | for (i = 0; i < Etc.nkling; i++) | |
| 61 | { | |
| 62 | /* compute distance to the Klingon */ | |
| 63 | dx = Ship.sectx - Etc.klingon[i].x; | |
| 64 | dy = Ship.secty - Etc.klingon[i].y; | |
| 65 | d = dx * dx + dy * dy; | |
| 66 | d = sqrt(d); | |
| 67 | ||
| 68 | /* compute average of new and old distances to Klingon */ | |
| 69 | if (!f) | |
| 70 | { | |
| 71 | temp = Etc.klingon[i].dist; | |
| 72 | Etc.klingon[i].avgdist = 0.5 * (temp + d); | |
| 73 | } | |
| 74 | else | |
| 75 | { | |
| 76 | /* new quadrant: average is current */ | |
| 77 | Etc.klingon[i].avgdist = d; | |
| 78 | } | |
| 79 | Etc.klingon[i].dist = d; | |
| 80 | } | |
| 81 | ||
| 82 | /* leave them sorted */ | |
| 83 | sortkl(); | |
| 84 | } | |
| 85 | ||
| 86 | ||
| 87 | /* | |
| 88 | ** sort klingons | |
| 89 | ** | |
| 90 | ** bubble sort on ascending distance | |
| 91 | */ | |
| 92 | ||
| 93 | sortkl() | |
| 94 | { | |
| 95 | struct kling t; | |
| 96 | register int f, i, m; | |
| 97 | ||
| 98 | m = Etc.nkling - 1; | |
| 99 | f = 1; | |
| 100 | while (f) | |
| 101 | { | |
| 102 | f = 0; | |
| 103 | for (i = 0; i < m; i++) | |
| 104 | if (Etc.klingon[i].dist > Etc.klingon[i+1].dist) | |
| 105 | { | |
| 106 | bmove(&Etc.klingon[i], &t, sizeof t); | |
| 107 | bmove(&Etc.klingon[i+1], &Etc.klingon[i], sizeof t); | |
| 108 | bmove(&t, &Etc.klingon[i+1], sizeof t); | |
| 109 | f = 1; | |
| 110 | } | |
| 111 | } | |
| 112 | } |