trek/move.c

   1 /*      $NetBSD: move.c,v 1.4 1997/10/12 21:25:02 christos 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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #ifndef lint
  38 #if 0
  39 static char sccsid[] = "@(#)move.c      8.1 (Berkeley) 5/31/93";
  40 #else
  41 __RCSID("$NetBSD: move.c,v 1.4 1997/10/12 21:25:02 christos Exp $");
  42 #endif
  43 #endif /* not lint */
  44
  45 #include <stdio.h>
  46 #include <math.h>
  47 #include "trek.h"
  48
  49 /*
  50 **  Move Under Warp or Impulse Power
  51 **
  52 **      `Ramflag' is set if we are to be allowed to ram stars,
  53 **      Klingons, etc.  This is passed from warp(), which gets it from
  54 **      either play() or ram().  Course is the course (0 -> 360) at
  55 **      which we want to move.  `Speed' is the speed we
  56 **      want to go, and `time' is the expected time.  It
  57 **      can get cut short if a long range tractor beam is to occur.  We
  58 **      cut short the move so that the user doesn't get docked time and
  59 **      energy for distance which he didn't travel.
  60 **
  61 **      We check the course through the current quadrant to see that he
  62 **      doesn't run into anything.  After that, though, space sort of
  63 **      bends around him.  Note that this puts us in the awkward posi-
  64 **      tion of being able to be dropped into a sector which is com-
  65 **      pletely surrounded by stars.  Oh Well.
  66 **
  67 **      If the SINS (Space Inertial Navigation System) is out, we ran-
  68 **      domize the course accordingly before ever starting to move.
  69 **      We will still move in a straight line.
  70 **
  71 **      Note that if your computer is out, you ram things anyway.  In
  72 **      other words, if your computer and sins are both out, you're in
  73 **      potentially very bad shape.
  74 **
  75 **      Klingons get a chance to zap you as you leave the quadrant.
  76 **      By the way, they also try to follow you (heh heh).
  77 **
  78 **      Return value is the actual amount of time used.
  79 **
  80 **
  81 **      Uses trace flag 4.
  82 */
  83
  84 double move(ramflag, course, time, speed)
  85 int     ramflag;
  86 int     course;
  87 double  time;
  88 double  speed;
  89 {
  90         double                  angle;
  91         double                  x, y, dx, dy;
  92         int             ix = 0, iy = 0;
  93         double                  bigger;
  94         int                     n;
  95         int             i;
  96         double                  dist;
  97         double                  sectsize;
  98         double                  xn;
  99         double                  evtime;
 100
 101 #       ifdef xTRACE
 102         if (Trace)
 103                 printf("move: ramflag %d course %d time %.2f speed %.2f\n",
 104                         ramflag, course, time, speed);
 105 #       endif
 106         sectsize = NSECTS;
 107         /* initialize delta factors for move */
 108         angle = course * 0.0174532925;
 109         if (damaged(SINS))
 110                 angle += Param.navigcrud[1] * (franf() - 0.5);
 111         else
 112                 if (Ship.sinsbad)
 113                         angle += Param.navigcrud[0] * (franf() - 0.5);
 114         dx = -cos(angle);
 115         dy = sin(angle);
 116         bigger = fabs(dx);
 117         dist = fabs(dy);
 118         if (dist > bigger)
 119                 bigger = dist;
 120         dx /= bigger;
 121         dy /= bigger;
 122
 123         /* check for long range tractor beams */
 124         /****  TEMPORARY CODE == DEBUGGING  ****/
 125         evtime = Now.eventptr[E_LRTB]->date - Now.date;
 126 #       ifdef xTRACE
 127         if (Trace)
 128                 printf("E.ep = %p, ->evcode = %d, ->date = %.2f, evtime = %.2f\n",
 129                         Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
 130                         Now.eventptr[E_LRTB]->date, evtime);
 131 #       endif
 132         if (time > evtime && Etc.nkling < 3)
 133         {
 134                 /* then we got a LRTB */
 135                 evtime += 0.005;
 136                 time = evtime;
 137         }
 138         else
 139                 evtime = -1.0e50;
 140         dist = time * speed;
 141
 142         /* move within quadrant */
 143         Sect[Ship.sectx][Ship.secty] = EMPTY;
 144         x = Ship.sectx + 0.5;
 145         y = Ship.secty + 0.5;
 146         xn = NSECTS * dist * bigger;
 147         n = xn + 0.5;
 148 #       ifdef xTRACE
 149         if (Trace)
 150                 printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n", dx, dy, xn, n);
 151 #       endif
 152         Move.free = 0;
 153
 154         for (i = 0; i < n; i++)
 155         {
 156                 ix = (x += dx);
 157                 iy = (y += dy);
 158 #               ifdef xTRACE
 159                 if (Trace)
 160                         printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n", ix, x, iy, y);
 161 #               endif
 162                 if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize)
 163                 {
 164                         /* enter new quadrant */
 165                         dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
 166                         dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
 167                         if (dx < 0.0)
 168                                 ix = -1;
 169                         else
 170                                 ix = dx + 0.5;
 171                         if (dy < 0.0)
 172                                 iy = -1;
 173                         else
 174                                 iy = dy + 0.5;
 175 #                       ifdef xTRACE
 176                         if (Trace)
 177                                 printf("New quad: ix = %d, iy = %d\n", ix, iy);
 178 #                       endif
 179                         Ship.sectx = x;
 180                         Ship.secty = y;
 181                         compkldist(0);
 182                         Move.newquad = 2;
 183                         attack(0);
 184                         checkcond();
 185                         Ship.quadx = ix / NSECTS;
 186                         Ship.quady = iy / NSECTS;
 187                         Ship.sectx = ix % NSECTS;
 188                         Ship.secty = iy % NSECTS;
 189                         if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 || Ship.quady >= NQUADS)
 190                                 if (!damaged(COMPUTER))
 191                                 {
 192                                         dumpme(0);
 193                                 }
 194                                 else
 195                                         lose(L_NEGENB);
 196                         initquad(0);
 197                         n = 0;
 198                         break;
 199                 }
 200                 if (Sect[ix][iy] != EMPTY)
 201                 {
 202                         /* we just hit something */
 203                         if (!damaged(COMPUTER) && ramflag <= 0)
 204                         {
 205                                 ix = x - dx;
 206                                 iy = y - dy;
 207                                 printf("Computer reports navigation error; %s stopped at %d,%d\n",
 208                                         Ship.shipname, ix, iy);
 209                                 Ship.energy -= Param.stopengy * speed;
 210                                 break;
 211                         }
 212                         /* test for a black hole */
 213                         if (Sect[ix][iy] == HOLE)
 214                         {
 215                                 /* get dumped elsewhere in the galaxy */
 216                                 dumpme(1);
 217                                 initquad(0);
 218                                 n = 0;
 219                                 break;
 220                         }
 221                         ram(ix, iy);
 222                         break;
 223                 }
 224         }
 225         if (n > 0)
 226         {
 227                 dx = Ship.sectx - ix;
 228                 dy = Ship.secty - iy;
 229                 dist = sqrt(dx * dx + dy * dy) / NSECTS;
 230                 time = dist / speed;
 231                 if (evtime > time)
 232                         time = evtime;          /* spring the LRTB trap */
 233                 Ship.sectx = ix;
 234                 Ship.secty = iy;
 235         }
 236         Sect[Ship.sectx][Ship.secty] = Ship.ship;
 237         compkldist(0);
 238         return (time);
 239 }