games/trek/move.c

   1 /*      $NetBSD: move.c,v 1.9 2009/05/24 21:44:56 dholland 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 1.9 2009/05/24 21:44:56 dholland Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <stdio.h>
  42 #include <math.h>
  43 #include "trek.h"
  44
  45 /*
  46 **  Move Under Warp or Impulse Power
  47 **
  48 **      `Ramflag' is set if we are to be allowed to ram stars,
  49 **      Klingons, etc.  This is passed from warp(), which gets it from
  50 **      either play() or ram().  Course is the course (0 -> 360) at
  51 **      which we want to move.  `Speed' is the speed we
  52 **      want to go, and `time' is the expected time.  It
  53 **      can get cut short if a long range tractor beam is to occur.  We
  54 **      cut short the move so that the user doesn't get docked time and
  55 **      energy for distance which he didn't travel.
  56 **
  57 **      We check the course through the current quadrant to see that he
  58 **      doesn't run into anything.  After that, though, space sort of
  59 **      bends around him.  Note that this puts us in the awkward posi-
  60 **      tion of being able to be dropped into a sector which is com-
  61 **      pletely surrounded by stars.  Oh Well.
  62 **
  63 **      If the SINS (Space Inertial Navigation System) is out, we ran-
  64 **      domize the course accordingly before ever starting to move.
  65 **      We will still move in a straight line.
  66 **
  67 **      Note that if your computer is out, you ram things anyway.  In
  68 **      other words, if your computer and sins are both out, you're in
  69 **      potentially very bad shape.
  70 **
  71 **      Klingons get a chance to zap you as you leave the quadrant.
  72 **      By the way, they also try to follow you (heh heh).
  73 **
  74 **      Return value is the actual amount of time used.
  75 **
  76 **
  77 **      Uses trace flag 4.
  78 */
  79
  80 double
  81 move(int ramflag, int course, double time, double speed)
  82 {
  83         double                  angle;
  84         double                  x, y, dx, dy;
  85         int             ix = 0, iy = 0;
  86         double                  bigger;
  87         int                     n;
  88         int             i;
  89         double                  dist;
  90         double                  sectsize;
  91         double                  xn;
  92         double                  evtime;
  93
  94 #ifdef xTRACE
  95         if (Trace)
  96                 printf("move: ramflag %d course %d time %.2f speed %.2f\n",
  97                         ramflag, course, time, speed);
  98 #endif
  99         sectsize = NSECTS;
 100         /* initialize delta factors for move */
 101         angle = course * 0.0174532925;
 102         if (damaged(SINS))
 103                 angle += Param.navigcrud[1] * (franf() - 0.5);
 104         else
 105                 if (Ship.sinsbad)
 106                         angle += Param.navigcrud[0] * (franf() - 0.5);
 107         dx = -cos(angle);
 108         dy = sin(angle);
 109         bigger = fabs(dx);
 110         dist = fabs(dy);
 111         if (dist > bigger)
 112                 bigger = dist;
 113         dx /= bigger;
 114         dy /= bigger;
 115
 116         /* check for long range tractor beams */
 117         /****  TEMPORARY CODE == DEBUGGING  ****/
 118         evtime = Now.eventptr[E_LRTB]->date - Now.date;
 119 #ifdef xTRACE
 120         if (Trace)
 121                 printf("E.ep = %p, ->evcode = %d, ->date = %.2f, "
 122                        "evtime = %.2f\n",
 123                         Now.eventptr[E_LRTB], Now.eventptr[E_LRTB]->evcode,
 124                         Now.eventptr[E_LRTB]->date, evtime);
 125 #endif
 126         if (time > evtime && Etc.nkling < 3) {
 127                 /* then we got a LRTB */
 128                 evtime += 0.005;
 129                 time = evtime;
 130         } else
 131                 evtime = -1.0e50;
 132         dist = time * speed;
 133
 134         /* move within quadrant */
 135         Sect[Ship.sectx][Ship.secty] = EMPTY;
 136         x = Ship.sectx + 0.5;
 137         y = Ship.secty + 0.5;
 138         xn = NSECTS * dist * bigger;
 139         n = xn + 0.5;
 140 #ifdef xTRACE
 141         if (Trace)
 142                 printf("dx = %.2f, dy = %.2f, xn = %.2f, n = %d\n",
 143                         dx, dy, xn, n);
 144 #endif
 145         Move.free = 0;
 146
 147         for (i = 0; i < n; i++) {
 148                 ix = (x += dx);
 149                 iy = (y += dy);
 150 #ifdef xTRACE
 151                 if (Trace)
 152                         printf("ix = %d, x = %.2f, iy = %d, y = %.2f\n",
 153                                 ix, x, iy, y);
 154 #endif
 155                 if (x < 0.0 || y < 0.0 || x >= sectsize || y >= sectsize) {
 156                         /* enter new quadrant */
 157                         dx = Ship.quadx * NSECTS + Ship.sectx + dx * xn;
 158                         dy = Ship.quady * NSECTS + Ship.secty + dy * xn;
 159                         if (dx < 0.0)
 160                                 ix = -1;
 161                         else
 162                                 ix = dx + 0.5;
 163                         if (dy < 0.0)
 164                                 iy = -1;
 165                         else
 166                                 iy = dy + 0.5;
 167 #ifdef xTRACE
 168                         if (Trace)
 169                                 printf("New quad: ix = %d, iy = %d\n", ix, iy);
 170 #endif
 171                         Ship.sectx = x;
 172                         Ship.secty = y;
 173                         compkldist(0);
 174                         Move.newquad = 2;
 175                         attack(0);
 176                         checkcond();
 177                         Ship.quadx = ix / NSECTS;
 178                         Ship.quady = iy / NSECTS;
 179                         Ship.sectx = ix % NSECTS;
 180                         Ship.secty = iy % NSECTS;
 181                         if (ix < 0 || Ship.quadx >= NQUADS || iy < 0 ||
 182                             Ship.quady >= NQUADS) {
 183                                 if (!damaged(COMPUTER)) {
 184                                         dumpme(0);
 185                                 } else
 186                                         lose(L_NEGENB);
 187                         }
 188                         initquad(0);
 189                         n = 0;
 190                         break;
 191                 }
 192                 if (Sect[ix][iy] != EMPTY) {
 193                         /* we just hit something */
 194                         if (!damaged(COMPUTER) && ramflag <= 0) {
 195                                 ix = x - dx;
 196                                 iy = y - dy;
 197                                 printf("Computer reports navigation error; "
 198                                        "%s stopped at %d,%d\n",
 199                                         Ship.shipname, ix, iy);
 200                                 Ship.energy -= Param.stopengy * speed;
 201                                 break;
 202                         }
 203                         /* test for a black hole */
 204                         if (Sect[ix][iy] == HOLE) {
 205                                 /* get dumped elsewhere in the galaxy */
 206                                 dumpme(1);
 207                                 initquad(0);
 208                                 n = 0;
 209                                 break;
 210                         }
 211                         ram(ix, iy);
 212                         break;
 213                 }
 214         }
 215         if (n > 0) {
 216                 dx = Ship.sectx - ix;
 217                 dy = Ship.secty - iy;
 218                 dist = sqrt(dx * dx + dy * dy) / NSECTS;
 219                 time = dist / speed;
 220                 if (evtime > time) {
 221                         /* spring the LRTB trap */
 222                         time = evtime;
 223                 }
 224                 Ship.sectx = ix;
 225                 Ship.secty = iy;
 226         }
 227         Sect[Ship.sectx][Ship.secty] = Ship.ship;
 228         compkldist(0);
 229         return (time);
 230 }