1 /* @(#)move.c 8.1 (Berkeley) 5/31/93 */ 2 /* $NetBSD: move.c,v 1.11 2011/07/03 06:44:01 mrg 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 <stdio.h> 34 #include <math.h> 35 #include <float.h> 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 ** Uses trace flag 4. 71 */ 72 73 double 74 move(int ramflag, int course, double time, double speed) 75 { 76 double angle; 77 double x, y, dx, dy; 78 int ix = 0, iy = 0; 79 double bigger; 80 int n; 81 int i; 82 double dist; 83 double sectsize; 84 double xn; 85 double evtime; 86 87 #ifdef xTRACE 88 if (Trace) 89 printf("move: ramflag %d course %d time %.2f speed %.2f\n", 90 ramflag, course, time, speed); 91 #endif 92 sectsize = NSECTS; 93 /* initialize delta factors for move */ 94 angle = course * 0.0174532925; 95 if (damaged(SINS)) 96 angle += Param.navigcrud[1] * (franf() - 0.5); 97 else 98 if (Ship.sinsbad) 99 angle += Param.navigcrud[0] * (franf() - 0.5); 100 dx = -cos(angle); 101 dy = sin(angle); 102 bigger = fabs(dx); 103 dist = fabs(dy); 104 if (dist > bigger) 105 bigger = dist; 106 dx /= bigger; 107 dy /= bigger; 108 109 /* check for long range tractor beams */ 110 /**** TEMPORARY CODE == DEBUGGING ****/ 111 evtime = Now.eventptr[E_LRTB]->date - Now.date; 112 #ifdef xTRACE 113 if (Trace) 114 printf("E.ep = %p, ->evcode = %d, ->date = %.2f, " 115 "evtime = %.2f\n", 116 Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode, 117 Now.eventptr[E_LRTB]->date, evtime); 118 #endif 119 if (time > evtime && Etc.nkling < 3) { 120 /* then we got a LRTB */ 121 evtime += 0.005; 122 time = evtime; 123 } else 124 evtime = DBL_MIN; 125 dist = time * speed; 126 127 /* move within quadrant */ 128 Sect[Ship.sectx][Ship.secty] = EMPTY; 129 x = Ship.sectx + 0.5; 130 y = Ship.secty + 0.5; 131 xn = NSECTS * dist * bigger; 132 n = xn + 0.5; 133 #ifdef xTRACE 134 if (Trace) 135 printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n", 136 dx, dy, xn, n); 137 #endif 138 Move.free = 0; 139 140 for (i = 0; i < n; i++) { 141 ix = (x += dx); 142 iy = (y += dy); 143 #ifdef xTRACE 144 if (Trace) 145 printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n", 146 ix, x, iy, y); 147 #endif 148 if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize) { 149 /* enter new quadrant */ 150 dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn; 151 dy = Ship.quady * NSECTS + Ship.secty + dy * xn; 152 if (dx < 0.0) 153 ix = -1; 154 else 155 ix = dx + 0.5; 156 if (dy < 0.0) 157 iy = -1; 158 else 159 iy = dy + 0.5; 160 #ifdef xTRACE 161 if (Trace) 162 printf("New quad: ix = %d, iy = %d\n", ix, iy); 163 #endif 164 Ship.sectx = x; 165 Ship.secty = y; 166 compkldist(0); 167 Move.newquad = 2; 168 attack(0); 169 checkcond(); 170 Ship.quadx = ix / NSECTS; 171 Ship.quady = iy / NSECTS; 172 Ship.sectx = ix % NSECTS; 173 Ship.secty = iy % NSECTS; 174 if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 || 175 Ship.quady >= NQUADS) { 176 if (!damaged(COMPUTER)) { 177 dumpme(0); 178 } else 179 lose(L_NEGENB); 180 } 181 initquad(0); 182 n = 0; 183 break; 184 } 185 if (Sect[ix][iy] != EMPTY) { 186 /* we just hit something */ 187 if (!damaged(COMPUTER) && ramflag <= 0) { 188 ix = x - dx; 189 iy = y - dy; 190 printf("Computer reports navigation error; " 191 "%s stopped at %d,%d\n", 192 Ship.shipname, ix, iy); 193 Ship.energy -= Param.stopengy * speed; 194 break; 195 } 196 /* test for a black hole */ 197 if (Sect[ix][iy] == HOLE) { 198 /* get dumped elsewhere in the galaxy */ 199 dumpme(1); 200 initquad(0); 201 n = 0; 202 break; 203 } 204 ram(ix, iy); 205 break; 206 } 207 } 208 if (n > 0) { 209 dx = Ship.sectx - ix; 210 dy = Ship.secty - iy; 211 dist = sqrt(dx * dx + dy * dy) / NSECTS; 212 time = dist / speed; 213 if (evtime > time) { 214 /* spring the LRTB trap */ 215 time = evtime; 216 } 217 Ship.sectx = ix; 218 Ship.secty = iy; 219 } 220 Sect[Ship.sectx][Ship.secty] = Ship.ship; 221 compkldist(0); 222 return (time); 223 } 224