1 /* 2 * Copyright (c) 1980, 1993 3 * The Regents of the University of California. 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 * @(#)compkl.c 8.1 (Berkeley) 5/31/93 34 * $FreeBSD: src/games/trek/compkl.c,v 1.4 1999/11/30 03:49:44 billf Exp $ 35 * $DragonFly: src/games/trek/compkl.c,v 1.2 2003/06/17 04:25:25 dillon Exp $ 36 */ 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 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 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 } 113