xref: /dragonfly/games/trek/klmove.c (revision fcf53d9b)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)klmove.c	8.1 (Berkeley) 5/31/93
30  * $FreeBSD: src/games/trek/klmove.c,v 1.4 1999/11/30 03:49:49 billf Exp $
31  * $DragonFly: src/games/trek/klmove.c,v 1.4 2006/10/08 17:11:30 pavalos Exp $
32  */
33 
34 #include "trek.h"
35 
36 /*
37 **  Move Klingons Around
38 **
39 **	This is a largely incomprehensible block of code that moves
40 **	Klingons around in a quadrant.  It was written in a very
41 **	"program as you go" fashion, and is a prime candidate for
42 **	rewriting.
43 **
44 **	The flag `fl' is zero before an attack, one after an attack,
45 **	and two if you are leaving a quadrant.  This serves to
46 **	change the probability and distance that it moves.
47 **
48 **	Basically, what it will try to do is to move a certain number
49 **	of steps either toward you or away from you.  It will avoid
50 **	stars whenever possible.  Nextx and nexty are the next
51 **	sector to move to on a per-Klingon basis; they are roughly
52 **	equivalent to Ship.sectx and Ship.secty for the starship.  Lookx and
53 **	looky are the sector that you are going to look at to see
54 **	if you can move their.  Dx and dy are the increment.  Fudgex
55 **	and fudgey are the things you change around to change your
56 **	course around stars.
57 */
58 
59 void
60 klmove(int fl)
61 {
62 	int			n;
63 	struct kling	*k;
64 	double			dx, dy;
65 	int			nextx, nexty;
66 	int		lookx, looky;
67 	int			motion;
68 	int			fudgex, fudgey;
69 	int			qx, qy;
70 	double			bigger;
71 	int			i;
72 
73 #ifdef xTRACE
74 	if (Trace)
75 		printf("klmove: fl = %d, Etc.nkling = %d\n", fl, Etc.nkling);
76 #endif
77 	for (n = 0; n < Etc.nkling; n++) {
78 		k = &Etc.klingon[n];
79 		i = 100;
80 		if (fl)
81 			i = 100.0 * k->power / Param.klingpwr;
82 		if (ranf(i) >= Param.moveprob[2 * Move.newquad + fl])
83 			continue;
84 		/* compute distance to move */
85 		motion = ranf(75) - 25;
86 		motion *= k->avgdist * Param.movefac[2 * Move.newquad + fl];
87 		/* compute direction */
88 		dx = Ship.sectx - k->x + ranf(3) - 1;
89 		dy = Ship.secty - k->y + ranf(3) - 1;
90 		bigger = dx;
91 		if (dy > bigger)
92 			bigger = dy;
93 		if (bigger == 0.0)
94 			bigger = 1.0;
95 		dx = dx / bigger + 0.5;
96 		dy = dy / bigger + 0.5;
97 		if (motion < 0) {
98 			motion = -motion;
99 			dx = -dx;
100 			dy = -dy;
101 		}
102 		fudgex = fudgey = 1;
103 		/* try to move the klingon */
104 		nextx = k->x;
105 		nexty = k->y;
106 		for (; motion > 0; motion--) {
107 			lookx = nextx + dx;
108 			looky = nexty + dy;
109 			if (lookx < 0 || lookx >= NSECTS ||
110 			    looky < 0 || looky >= NSECTS) {
111 				/* new quadrant */
112 				qx = Ship.quadx;
113 				qy = Ship.quady;
114 				if (lookx < 0)
115 					qx -= 1;
116 				else
117 					if (lookx >= NSECTS)
118 						qx += 1;
119 				if (looky < 0)
120 					qy -= 1;
121 				else
122 					if (looky >= NSECTS)
123 						qy += 1;
124 				if (qx < 0 || qx >= NQUADS ||
125 				    qy < 0 || qy >= NQUADS ||
126 				    Quad[qx][qy].stars < 0 ||
127 				    Quad[qx][qy].klings > MAXKLQUAD - 1)
128 					break;
129 				if (!damaged(SRSCAN)) {
130 					printf("Klingon at %d,%d escapes to quadrant %d,%d\n",
131 						k->x, k->y, qx, qy);
132 					motion = Quad[qx][qy].scanned;
133 					if (motion >= 0 && motion < 1000)
134 						Quad[qx][qy].scanned += 100;
135 					motion = Quad[Ship.quadx][Ship.quady].scanned;
136 					if (motion >= 0 && motion < 1000)
137 						Quad[Ship.quadx][Ship.quady].scanned -= 100;
138 				}
139 				Sect[k->x][k->y] = EMPTY;
140 				Quad[qx][qy].klings += 1;
141 				Etc.nkling -= 1;
142 				bmove(&Etc.klingon[Etc.nkling], k, sizeof *k);
143 				Quad[Ship.quadx][Ship.quady].klings -= 1;
144 				k = 0;
145 				break;
146 			}
147 			if (Sect[lookx][looky] != EMPTY) {
148 				lookx = nextx + fudgex;
149 				if (lookx < 0 || lookx >= NSECTS)
150 					lookx = nextx + dx;
151 				if (Sect[lookx][looky] != EMPTY) {
152 					fudgex = -fudgex;
153 					looky = nexty + fudgey;
154 					if (looky < 0 || looky >= NSECTS ||
155 					    Sect[lookx][looky] != EMPTY) {
156 						fudgey = -fudgey;
157 						break;
158 					}
159 				}
160 			}
161 			nextx = lookx;
162 			nexty = looky;
163 		}
164 		if (k && (k->x != nextx || k->y != nexty)) {
165 			if (!damaged(SRSCAN))
166 				printf("Klingon at %d,%d moves to %d,%d\n",
167 					k->x, k->y, nextx, nexty);
168 			Sect[k->x][k->y] = EMPTY;
169 			Sect[k->x = nextx][k->y = nexty] = KLINGON;
170 		}
171 	}
172 	compkldist(0);
173 }
174