1 /*
2 * Copyright (c) 1980, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 */
7
8 #ifndef lint
9 static char sccsid[] = "@(#)move.c 8.1 (Berkeley) 05/31/93";
10 #endif /* not lint */
11
12 # include "trek.h"
13
14 /*
15 ** Move Under Warp or Impulse Power
16 **
17 ** `Ramflag' is set if we are to be allowed to ram stars,
18 ** Klingons, etc. This is passed from warp(), which gets it from
19 ** either play() or ram(). Course is the course (0 -> 360) at
20 ** which we want to move. `Speed' is the speed we
21 ** want to go, and `time' is the expected time. It
22 ** can get cut short if a long range tractor beam is to occur. We
23 ** cut short the move so that the user doesn't get docked time and
24 ** energy for distance which he didn't travel.
25 **
26 ** We check the course through the current quadrant to see that he
27 ** doesn't run into anything. After that, though, space sort of
28 ** bends around him. Note that this puts us in the awkward posi-
29 ** tion of being able to be dropped into a sector which is com-
30 ** pletely surrounded by stars. Oh Well.
31 **
32 ** If the SINS (Space Inertial Navigation System) is out, we ran-
33 ** domize the course accordingly before ever starting to move.
34 ** We will still move in a straight line.
35 **
36 ** Note that if your computer is out, you ram things anyway. In
37 ** other words, if your computer and sins are both out, you're in
38 ** potentially very bad shape.
39 **
40 ** Klingons get a chance to zap you as you leave the quadrant.
41 ** By the way, they also try to follow you (heh heh).
42 **
43 ** Return value is the actual amount of time used.
44 **
45 **
46 ** Uses trace flag 4.
47 */
48
move(ramflag,course,time,speed)49 double move(ramflag, course, time, speed)
50 int ramflag;
51 int course;
52 double time;
53 double speed;
54 {
55 double angle;
56 double x, y, dx, dy;
57 register int ix, iy;
58 double bigger;
59 int n;
60 register int i;
61 double dist;
62 double sectsize;
63 double xn;
64 double evtime;
65
66 # ifdef xTRACE
67 if (Trace)
68 printf("move: ramflag %d course %d time %.2f speed %.2f\n",
69 ramflag, course, time, speed);
70 # endif
71 sectsize = NSECTS;
72 /* initialize delta factors for move */
73 angle = course * 0.0174532925;
74 if (damaged(SINS))
75 angle += Param.navigcrud[1] * (franf() - 0.5);
76 else
77 if (Ship.sinsbad)
78 angle += Param.navigcrud[0] * (franf() - 0.5);
79 dx = -cos(angle);
80 dy = sin(angle);
81 bigger = fabs(dx);
82 dist = fabs(dy);
83 if (dist > bigger)
84 bigger = dist;
85 dx /= bigger;
86 dy /= bigger;
87
88 /* check for long range tractor beams */
89 /**** TEMPORARY CODE == DEBUGGING ****/
90 evtime = Now.eventptr[E_LRTB]->date - Now.date;
91 # ifdef xTRACE
92 if (Trace)
93 printf("E.ep = %u, ->evcode = %d, ->date = %.2f, evtime = %.2f\n",
94 Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
95 Now.eventptr[E_LRTB]->date, evtime);
96 # endif
97 if (time > evtime && Etc.nkling < 3)
98 {
99 /* then we got a LRTB */
100 evtime += 0.005;
101 time = evtime;
102 }
103 else
104 evtime = -1.0e50;
105 dist = time * speed;
106
107 /* move within quadrant */
108 Sect[Ship.sectx][Ship.secty] = EMPTY;
109 x = Ship.sectx + 0.5;
110 y = Ship.secty + 0.5;
111 xn = NSECTS * dist * bigger;
112 n = xn + 0.5;
113 # ifdef xTRACE
114 if (Trace)
115 printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n", dx, dy, xn, n);
116 # endif
117 Move.free = 0;
118
119 for (i = 0; i < n; i++)
120 {
121 ix = (x += dx);
122 iy = (y += dy);
123 # ifdef xTRACE
124 if (Trace)
125 printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n", ix, x, iy, y);
126 # endif
127 if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize)
128 {
129 /* enter new quadrant */
130 dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
131 dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
132 if (dx < 0.0)
133 ix = -1;
134 else
135 ix = dx + 0.5;
136 if (dy < 0.0)
137 iy = -1;
138 else
139 iy = dy + 0.5;
140 # ifdef xTRACE
141 if (Trace)
142 printf("New quad: ix = %d, iy = %d\n", ix, iy);
143 # endif
144 Ship.sectx = x;
145 Ship.secty = y;
146 compkldist(0);
147 Move.newquad = 2;
148 attack(0);
149 checkcond();
150 Ship.quadx = ix / NSECTS;
151 Ship.quady = iy / NSECTS;
152 Ship.sectx = ix % NSECTS;
153 Ship.secty = iy % NSECTS;
154 if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 || Ship.quady >= NQUADS)
155 if (!damaged(COMPUTER))
156 {
157 dumpme(0);
158 }
159 else
160 lose(L_NEGENB);
161 initquad(0);
162 n = 0;
163 break;
164 }
165 if (Sect[ix][iy] != EMPTY)
166 {
167 /* we just hit something */
168 if (!damaged(COMPUTER) && ramflag <= 0)
169 {
170 ix = x - dx;
171 iy = y - dy;
172 printf("Computer reports navigation error; %s stopped at %d,%d\n",
173 Ship.shipname, ix, iy);
174 Ship.energy -= Param.stopengy * speed;
175 break;
176 }
177 /* test for a black hole */
178 if (Sect[ix][iy] == HOLE)
179 {
180 /* get dumped elsewhere in the galaxy */
181 dumpme(1);
182 initquad(0);
183 n = 0;
184 break;
185 }
186 ram(ix, iy);
187 break;
188 }
189 }
190 if (n > 0)
191 {
192 dx = Ship.sectx - ix;
193 dy = Ship.secty - iy;
194 dist = sqrt(dx * dx + dy * dy) / NSECTS;
195 time = dist / speed;
196 if (evtime > time)
197 time = evtime; /* spring the LRTB trap */
198 Ship.sectx = ix;
199 Ship.secty = iy;
200 }
201 Sect[Ship.sectx][Ship.secty] = Ship.ship;
202 compkldist(0);
203 return (time);
204 }
205