/* * Copyright (c) 1980 Regents of the University of California. * All rights reserved. The Berkeley software License Agreement * specifies the terms and conditions for redistribution. */ #ifndef lint static char sccsid[] = "@(#)compkl.c 5.1 (Berkeley) 5/30/85"; #endif not lint # include "trek.h" /* ** compute klingon distances ** ** The klingon list has the distances for all klingons recomputed ** and sorted. The parameter is a Boolean flag which is set if ** we have just entered a new quadrant. ** ** This routine is used every time the Enterprise or the Klingons ** move. */ compkldist(f) int f; /* set if new quadrant */ { register int i, dx, dy; double d; double temp; if (Etc.nkling == 0) return; for (i = 0; i < Etc.nkling; i++) { /* compute distance to the Klingon */ dx = Ship.sectx - Etc.klingon[i].x; dy = Ship.secty - Etc.klingon[i].y; d = dx * dx + dy * dy; d = sqrt(d); /* compute average of new and old distances to Klingon */ if (!f) { temp = Etc.klingon[i].dist; Etc.klingon[i].avgdist = 0.5 * (temp + d); } else { /* new quadrant: average is current */ Etc.klingon[i].avgdist = d; } Etc.klingon[i].dist = d; } /* leave them sorted */ sortkl(); } /* ** sort klingons ** ** bubble sort on ascending distance */ sortkl() { struct kling t; register int f, i, m; m = Etc.nkling - 1; f = 1; while (f) { f = 0; for (i = 0; i < m; i++) if (Etc.klingon[i].dist > Etc.klingon[i+1].dist) { bmove(&Etc.klingon[i], &t, sizeof t); bmove(&Etc.klingon[i+1], &Etc.klingon[i], sizeof t); bmove(&t, &Etc.klingon[i+1], sizeof t); f = 1; } } }