1 /* $OpenBSD: move.c,v 1.8 2016/01/07 14:37:51 mestre Exp $ */
2 /* $NetBSD: move.c,v 1.3 1995/04/22 10:59:12 cgd Exp $ */
3
4 /*
5 * Copyright (c) 1980, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <math.h>
34 #include <stdio.h>
35
36 #include "trek.h"
37
38 /*
39 ** Move Under Warp or Impulse Power
40 **
41 ** `Ramflag' is set if we are to be allowed to ram stars,
42 ** Klingons, etc. This is passed from warp(), which gets it from
43 ** either play() or ram(). Course is the course (0 -> 360) at
44 ** which we want to move. `Speed' is the speed we
45 ** want to go, and `time' is the expected time. It
46 ** can get cut short if a long range tractor beam is to occur. We
47 ** cut short the move so that the user doesn't get docked time and
48 ** energy for distance which he didn't travel.
49 **
50 ** We check the course through the current quadrant to see that he
51 ** doesn't run into anything. After that, though, space sort of
52 ** bends around him. Note that this puts us in the awkward posi-
53 ** tion of being able to be dropped into a sector which is com-
54 ** pletely surrounded by stars. Oh Well.
55 **
56 ** If the SINS (Space Inertial Navigation System) is out, we ran-
57 ** domize the course accordingly before ever starting to move.
58 ** We will still move in a straight line.
59 **
60 ** Note that if your computer is out, you ram things anyway. In
61 ** other words, if your computer and sins are both out, you're in
62 ** potentially very bad shape.
63 **
64 ** Klingons get a chance to zap you as you leave the quadrant.
65 ** By the way, they also try to follow you (heh heh).
66 **
67 ** Return value is the actual amount of time used.
68 */
69
70 double
move(int ramflag,int course,double time,double speed)71 move(int ramflag, int course, double time, double speed)
72 {
73 double angle;
74 double x, y, dx, dy;
75 int ix = 0, iy = 0;
76 double bigger;
77 int n, i;
78 double dist, sectsize, xn, evtime;
79
80 # ifdef xTRACE
81 if (Trace)
82 printf("move: ramflag %d course %d time %.2f speed %.2f\n",
83 ramflag, course, time, speed);
84 # endif
85 sectsize = NSECTS;
86 /* initialize delta factors for move */
87 angle = course * 0.0174532925;
88 if (damaged(SINS))
89 angle += Param.navigcrud[1] * (franf() - 0.5);
90 else
91 if (Ship.sinsbad)
92 angle += Param.navigcrud[0] * (franf() - 0.5);
93 dx = -cos(angle);
94 dy = sin(angle);
95 bigger = fabs(dx);
96 dist = fabs(dy);
97 if (dist > bigger)
98 bigger = dist;
99 dx /= bigger;
100 dy /= bigger;
101
102 /* check for long range tractor beams */
103 /**** TEMPORARY CODE == DEBUGGING ****/
104 evtime = Now.eventptr[E_LRTB]->date - Now.date;
105 # ifdef xTRACE
106 if (Trace)
107 printf("E.ep = %p, ->evcode = %d, ->date = %.2f, evtime = %.2f\n",
108 Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
109 Now.eventptr[E_LRTB]->date, evtime);
110 # endif
111 if (time > evtime && Etc.nkling < 3)
112 {
113 /* then we got a LRTB */
114 evtime += 0.005;
115 time = evtime;
116 }
117 else
118 evtime = -1.0e50;
119 dist = time * speed;
120
121 /* move within quadrant */
122 Sect[Ship.sectx][Ship.secty] = EMPTY;
123 x = Ship.sectx + 0.5;
124 y = Ship.secty + 0.5;
125 xn = NSECTS * dist * bigger;
126 n = xn + 0.5;
127 # ifdef xTRACE
128 if (Trace)
129 printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n", dx, dy, xn, n);
130 # endif
131 Move.free = 0;
132
133 for (i = 0; i < n; i++)
134 {
135 ix = (x += dx);
136 iy = (y += dy);
137 # ifdef xTRACE
138 if (Trace)
139 printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n", ix, x, iy, y);
140 # endif
141 if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize)
142 {
143 /* enter new quadrant */
144 dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
145 dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
146 if (dx < 0.0)
147 ix = -1;
148 else
149 ix = dx + 0.5;
150 if (dy < 0.0)
151 iy = -1;
152 else
153 iy = dy + 0.5;
154 # ifdef xTRACE
155 if (Trace)
156 printf("New quad: ix = %d, iy = %d\n", ix, iy);
157 # endif
158 Ship.sectx = x;
159 Ship.secty = y;
160 compkldist(0);
161 Move.newquad = 2;
162 attack(0);
163 checkcond();
164 Ship.quadx = ix / NSECTS;
165 Ship.quady = iy / NSECTS;
166 Ship.sectx = ix % NSECTS;
167 Ship.secty = iy % NSECTS;
168 if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 || Ship.quady >= NQUADS)
169 {
170 if (!damaged(COMPUTER))
171 dumpme(0);
172 else
173 lose(L_NEGENB);
174 }
175 initquad(0);
176 n = 0;
177 break;
178 }
179 if (Sect[ix][iy] != EMPTY)
180 {
181 /* we just hit something */
182 if (!damaged(COMPUTER) && ramflag <= 0)
183 {
184 ix = x - dx;
185 iy = y - dy;
186 printf("Computer reports navigation error; %s stopped at %d,%d\n",
187 Ship.shipname, ix, iy);
188 Ship.energy -= Param.stopengy * speed;
189 break;
190 }
191 /* test for a black hole */
192 if (Sect[ix][iy] == HOLE)
193 {
194 /* get dumped elsewhere in the galaxy */
195 dumpme(1);
196 initquad(0);
197 n = 0;
198 break;
199 }
200 ram(ix, iy);
201 break;
202 }
203 }
204 if (n > 0)
205 {
206 dx = Ship.sectx - ix;
207 dy = Ship.secty - iy;
208 dist = sqrt(dx * dx + dy * dy) / NSECTS;
209 time = dist / speed;
210 if (evtime > time)
211 time = evtime; /* spring the LRTB trap */
212 Ship.sectx = ix;
213 Ship.secty = iy;
214 }
215 Sect[Ship.sectx][Ship.secty] = Ship.ship;
216 compkldist(0);
217 return (time);
218 }
219