1 /* $NetBSD: move.c,v 1.11 2011/07/03 06:44:01 mrg Exp $ */
2
3 /*
4 * Copyright (c) 1980, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)move.c 8.1 (Berkeley) 5/31/93";
36 #else
37 __RCSID("$NetBSD: move.c,v 1.11 2011/07/03 06:44:01 mrg Exp $");
38 #endif
39 #endif /* not lint */
40
41 #include <stdio.h>
42 #include <math.h>
43 #include <float.h>
44 #include "trek.h"
45
46 /*
47 ** Move Under Warp or Impulse Power
48 **
49 ** `Ramflag' is set if we are to be allowed to ram stars,
50 ** Klingons, etc. This is passed from warp(), which gets it from
51 ** either play() or ram(). Course is the course (0 -> 360) at
52 ** which we want to move. `Speed' is the speed we
53 ** want to go, and `time' is the expected time. It
54 ** can get cut short if a long range tractor beam is to occur. We
55 ** cut short the move so that the user doesn't get docked time and
56 ** energy for distance which he didn't travel.
57 **
58 ** We check the course through the current quadrant to see that he
59 ** doesn't run into anything. After that, though, space sort of
60 ** bends around him. Note that this puts us in the awkward posi-
61 ** tion of being able to be dropped into a sector which is com-
62 ** pletely surrounded by stars. Oh Well.
63 **
64 ** If the SINS (Space Inertial Navigation System) is out, we ran-
65 ** domize the course accordingly before ever starting to move.
66 ** We will still move in a straight line.
67 **
68 ** Note that if your computer is out, you ram things anyway. In
69 ** other words, if your computer and sins are both out, you're in
70 ** potentially very bad shape.
71 **
72 ** Klingons get a chance to zap you as you leave the quadrant.
73 ** By the way, they also try to follow you (heh heh).
74 **
75 ** Return value is the actual amount of time used.
76 **
77 **
78 ** Uses trace flag 4.
79 */
80
81 double
move(int ramflag,int course,double time,double speed)82 move(int ramflag, int course, double time, double speed)
83 {
84 double angle;
85 double x, y, dx, dy;
86 int ix = 0, iy = 0;
87 double bigger;
88 int n;
89 int i;
90 double dist;
91 double sectsize;
92 double xn;
93 double evtime;
94
95 #ifdef xTRACE
96 if (Trace)
97 printf("move: ramflag %d course %d time %.2f speed %.2f\n",
98 ramflag, course, time, speed);
99 #endif
100 sectsize = NSECTS;
101 /* initialize delta factors for move */
102 angle = course * 0.0174532925;
103 if (damaged(SINS))
104 angle += Param.navigcrud[1] * (franf() - 0.5);
105 else
106 if (Ship.sinsbad)
107 angle += Param.navigcrud[0] * (franf() - 0.5);
108 dx = -cos(angle);
109 dy = sin(angle);
110 bigger = fabs(dx);
111 dist = fabs(dy);
112 if (dist > bigger)
113 bigger = dist;
114 dx /= bigger;
115 dy /= bigger;
116
117 /* check for long range tractor beams */
118 /**** TEMPORARY CODE == DEBUGGING ****/
119 evtime = Now.eventptr[E_LRTB]->date - Now.date;
120 #ifdef xTRACE
121 if (Trace)
122 printf("E.ep = %p, ->evcode = %d, ->date = %.2f, "
123 "evtime = %.2f\n",
124 Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
125 Now.eventptr[E_LRTB]->date, evtime);
126 #endif
127 if (time > evtime && Etc.nkling < 3) {
128 /* then we got a LRTB */
129 evtime += 0.005;
130 time = evtime;
131 } else
132 evtime = DBL_MIN;
133 dist = time * speed;
134
135 /* move within quadrant */
136 Sect[Ship.sectx][Ship.secty] = EMPTY;
137 x = Ship.sectx + 0.5;
138 y = Ship.secty + 0.5;
139 xn = NSECTS * dist * bigger;
140 n = xn + 0.5;
141 #ifdef xTRACE
142 if (Trace)
143 printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n",
144 dx, dy, xn, n);
145 #endif
146 Move.free = 0;
147
148 for (i = 0; i < n; i++) {
149 ix = (x += dx);
150 iy = (y += dy);
151 #ifdef xTRACE
152 if (Trace)
153 printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n",
154 ix, x, iy, y);
155 #endif
156 if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize) {
157 /* enter new quadrant */
158 dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
159 dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
160 if (dx < 0.0)
161 ix = -1;
162 else
163 ix = dx + 0.5;
164 if (dy < 0.0)
165 iy = -1;
166 else
167 iy = dy + 0.5;
168 #ifdef xTRACE
169 if (Trace)
170 printf("New quad: ix = %d, iy = %d\n", ix, iy);
171 #endif
172 Ship.sectx = x;
173 Ship.secty = y;
174 compkldist(0);
175 Move.newquad = 2;
176 attack(0);
177 checkcond();
178 Ship.quadx = ix / NSECTS;
179 Ship.quady = iy / NSECTS;
180 Ship.sectx = ix % NSECTS;
181 Ship.secty = iy % NSECTS;
182 if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 ||
183 Ship.quady >= NQUADS) {
184 if (!damaged(COMPUTER)) {
185 dumpme(0);
186 } else
187 lose(L_NEGENB);
188 }
189 initquad(0);
190 n = 0;
191 break;
192 }
193 if (Sect[ix][iy] != EMPTY) {
194 /* we just hit something */
195 if (!damaged(COMPUTER) && ramflag <= 0) {
196 ix = x - dx;
197 iy = y - dy;
198 printf("Computer reports navigation error; "
199 "%s stopped at %d,%d\n",
200 Ship.shipname, ix, iy);
201 Ship.energy -= Param.stopengy * speed;
202 break;
203 }
204 /* test for a black hole */
205 if (Sect[ix][iy] == HOLE) {
206 /* get dumped elsewhere in the galaxy */
207 dumpme(1);
208 initquad(0);
209 n = 0;
210 break;
211 }
212 ram(ix, iy);
213 break;
214 }
215 }
216 if (n > 0) {
217 dx = Ship.sectx - ix;
218 dy = Ship.secty - iy;
219 dist = sqrt(dx * dx + dy * dy) / NSECTS;
220 time = dist / speed;
221 if (evtime > time) {
222 /* spring the LRTB trap */
223 time = evtime;
224 }
225 Ship.sectx = ix;
226 Ship.secty = iy;
227 }
228 Sect[Ship.sectx][Ship.secty] = Ship.ship;
229 compkldist(0);
230 return (time);
231 }
232