games/trek/phaser.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #ifndef lint
  35 #if 0
  36 static char sccsid[] = "@(#)phaser.c    8.1 (Berkeley) 5/31/93";
  37 #endif
  38 static const char rcsid[] =
  39  "$FreeBSD$";
  40 #endif /* not lint */
  41
  42 # include       "trek.h"
  43 # include       "getpar.h"
  44
  45 /* factors for phaser hits; see description below */
  46
  47 # define        ALPHA           3.0             /* spread */
  48 # define        BETA            3.0             /* franf() */
  49 # define        GAMMA           0.30            /* cos(angle) */
  50 # define        EPSILON         150.0           /* dist ** 2 */
  51 # define        OMEGA           10.596          /* overall scaling factor */
  52
  53 /* OMEGA ~= 100 * (ALPHA + 1) * (BETA + 1) / (EPSILON + 1) */
  54
  55 /*
  56 **  Phaser Control
  57 **
  58 **      There are up to NBANKS phaser banks which may be fired
  59 **      simultaneously.  There are two modes, "manual" and
  60 **      "automatic".  In manual mode, you specify exactly which
  61 **      direction you want each bank to be aimed, the number
  62 **      of units to fire, and the spread angle.  In automatic
  63 **      mode, you give only the total number of units to fire.
  64 **
  65 **      The spread is specified as a number between zero and
  66 **      one, with zero being minimum spread and one being maximum
  67 **      spread.  You  will normally want zero spread, unless your
  68 **      short range scanners are out, in which case you probably
  69 **      don't know exactly where the Klingons are.  In that case,
  70 **      you really don't have any choice except to specify a
  71 **      fairly large spread.
  72 **
  73 **      Phasers spread slightly, even if you specify zero spread.
  74 **
  75 **      Uses trace flag 30
  76 */
  77
  78 struct cvntab   Matab[] =
  79 {
  80         "m",            "anual",                (int (*)())1,           0,
  81         "a",            "utomatic",             0,              0,
  82         0
  83 };
  84
  85 struct banks
  86 {
  87         int     units;
  88         double  angle;
  89         double  spread;
  90 };
  91
  92
  93
  94 phaser()
  95 {
  96         int             i;
  97         int                     j;
  98         struct kling    *k;
  99         double                  dx, dy;
 100         double                  anglefactor, distfactor;
 101         struct banks    *b;
 102         int                     manual, flag, extra;
 103         int                     hit;
 104         double                  tot;
 105         int                     n;
 106         int                     hitreqd[NBANKS];
 107         struct banks            bank[NBANKS];
 108         struct cvntab           *ptr;
 109
 110         if (Ship.cond == DOCKED)
 111                 return(printf("Phasers cannot fire through starbase shields\n"));
 112         if (damaged(PHASER))
 113                 return (out(PHASER));
 114         if (Ship.shldup)
 115                 return (printf("Sulu: Captain, we cannot fire through shields.\n"));
 116         if (Ship.cloaked)
 117         {
 118                 printf("Sulu: Captain, surely you must realize that we cannot fire\n");
 119                 printf("  phasers with the cloaking device up.\n");
 120                 return;
 121         }
 122
 123         /* decide if we want manual or automatic mode */
 124         manual = 0;
 125         if (testnl())
 126         {
 127                 if (damaged(COMPUTER))
 128                 {
 129                         printf("%s", Device[COMPUTER].name);
 130                         manual++;
 131                 }
 132                 else
 133                         if (damaged(SRSCAN))
 134                         {
 135                                 printf("%s", Device[SRSCAN].name);
 136                                 manual++;
 137                         }
 138                 if (manual)
 139                         printf(" damaged, manual mode selected\n");
 140         }
 141
 142         if (!manual)
 143         {
 144                 ptr = getcodpar("Manual or automatic", Matab);
 145                 manual = (long) ptr->value;
 146         }
 147         if (!manual && damaged(COMPUTER))
 148         {
 149                 printf("Computer damaged, manual selected\n");
 150                 skiptonl(0);
 151                 manual++;
 152         }
 153
 154         /* initialize the bank[] array */
 155         flag = 1;
 156         for (i = 0; i < NBANKS; i++)
 157                 bank[i].units = 0;
 158         if (manual)
 159         {
 160                 /* collect manual mode statistics */
 161                 while (flag)
 162                 {
 163                         printf("%d units available\n", Ship.energy);
 164                         extra = 0;
 165                         flag = 0;
 166                         for (i = 0; i < NBANKS; i++)
 167                         {
 168                                 b = &bank[i];
 169                                 printf("\nBank %d:\n", i);
 170                                 hit = getintpar("units");
 171                                 if (hit < 0)
 172                                         return;
 173                                 if (hit == 0)
 174                                         break;
 175                                 extra += hit;
 176                                 if (extra > Ship.energy)
 177                                 {
 178                                         printf("available energy exceeded.  ");
 179                                         skiptonl(0);
 180                                         flag++;
 181                                         break;
 182                                 }
 183                                 b->units = hit;
 184                                 hit = getintpar("course");
 185                                 if (hit < 0 || hit > 360)
 186                                         return;
 187                                 b->angle = hit * 0.0174532925;
 188                                 b->spread = getfltpar("spread");
 189                                 if (b->spread < 0 || b->spread > 1)
 190                                         return;
 191                         }
 192                         Ship.energy -= extra;
 193                 }
 194                 extra = 0;
 195         }
 196         else
 197         {
 198                 /* automatic distribution of power */
 199                 if (Etc.nkling <= 0)
 200                         return (printf("Sulu: But there are no Klingons in this quadrant\n"));
 201                 printf("Phasers locked on target.  ");
 202                 while (flag)
 203                 {
 204                         printf("%d units available\n", Ship.energy);
 205                         hit = getintpar("Units to fire");
 206                         if (hit <= 0)
 207                                 return;
 208                         if (hit > Ship.energy)
 209                         {
 210                                 printf("available energy exceeded.  ");
 211                                 skiptonl(0);
 212                                 continue;
 213                         }
 214                         flag = 0;
 215                         Ship.energy -= hit;
 216                         extra = hit;
 217                         n = Etc.nkling;
 218                         if (n > NBANKS)
 219                                 n = NBANKS;
 220                         tot = n * (n + 1) / 2;
 221                         for (i = 0; i < n; i++)
 222                         {
 223                                 k = &Etc.klingon[i];
 224                                 b = &bank[i];
 225                                 distfactor = k->dist;
 226                                 anglefactor = ALPHA * BETA * OMEGA / (distfactor * distfactor + EPSILON);
 227                                 anglefactor *= GAMMA;
 228                                 distfactor = k->power;
 229                                 distfactor /= anglefactor;
 230                                 hitreqd[i] = distfactor + 0.5;
 231                                 dx = Ship.sectx - k->x;
 232                                 dy = k->y - Ship.secty;
 233                                 b->angle = atan2(dy, dx);
 234                                 b->spread = 0.0;
 235                                 b->units = ((n - i) / tot) * extra;
 236 #                               ifdef xTRACE
 237                                 if (Trace)
 238                                 {
 239                                         printf("b%d hr%d u%d df%.2f af%.2f\n",
 240                                                 i, hitreqd[i], b->units,
 241                                                 distfactor, anglefactor);
 242                                 }
 243 #                               endif
 244                                 extra -= b->units;
 245                                 hit = b->units - hitreqd[i];
 246                                 if (hit > 0)
 247                                 {
 248                                         extra += hit;
 249                                         b->units -= hit;
 250                                 }
 251                         }
 252
 253                         /* give out any extra energy we might have around */
 254                         if (extra > 0)
 255                         {
 256                                 for (i = 0; i < n; i++)
 257                                 {
 258                                         b = &bank[i];
 259                                         hit = hitreqd[i] - b->units;
 260                                         if (hit <= 0)
 261                                                 continue;
 262                                         if (hit >= extra)
 263                                         {
 264                                                 b->units += extra;
 265                                                 extra = 0;
 266                                                 break;
 267                                         }
 268                                         b->units = hitreqd[i];
 269                                         extra -= hit;
 270                                 }
 271                                 if (extra > 0)
 272                                         printf("%d units overkill\n", extra);
 273                         }
 274                 }
 275         }
 276
 277 #       ifdef xTRACE
 278         if (Trace)
 279         {
 280                 for (i = 0; i < NBANKS; i++)
 281                 {
 282                         b = &bank[i];
 283                         printf("b%d u%d", i, b->units);
 284                         if (b->units > 0)
 285                                 printf(" a%.2f s%.2f\n", b->angle, b->spread);
 286                         else
 287                                 printf("\n");
 288                 }
 289         }
 290 #       endif
 291
 292         /* actually fire the shots */
 293         Move.free = 0;
 294         for (i = 0; i < NBANKS; i++)
 295         {
 296                 b = &bank[i];
 297                 if (b->units <= 0)
 298                 {
 299                         continue;
 300                 }
 301                 printf("\nPhaser bank %d fires:\n", i);
 302                 n = Etc.nkling;
 303                 k = Etc.klingon;
 304                 for (j = 0; j < n; j++)
 305                 {
 306                         if (b->units <= 0)
 307                                 break;
 308                         /*
 309                         ** The formula for hit is as follows:
 310                         **
 311                         **  zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
 312                         **      / (dist ** 2 + EPSILON)]
 313                         **      * [cos(delta * sigma) + GAMMA]
 314                         **      * hit
 315                         **
 316                         ** where sigma is the spread factor,
 317                         ** rho is a random number (0 -> 1),
 318                         ** GAMMA is a crud factor for angle (essentially
 319                         **      cruds up the spread factor),
 320                         ** delta is the difference in radians between the
 321                         **      angle you are shooting at and the actual
 322                         **      angle of the klingon,
 323                         ** ALPHA scales down the significance of sigma,
 324                         ** BETA scales down the significance of rho,
 325                         ** OMEGA is the magic number which makes everything
 326                         **      up to "* hit" between zero and one,
 327                         ** dist is the distance to the klingon
 328                         ** hit is the number of units in the bank, and
 329                         ** zap is the amount of the actual hit.
 330                         **
 331                         ** Everything up through dist squared should maximize
 332                         ** at 1.0, so that the distance factor is never
 333                         ** greater than one.  Conveniently, cos() is
 334                         ** never greater than one, but the same restric-
 335                         ** tion applies.
 336                         */
 337                         distfactor = BETA + franf();
 338                         distfactor *= ALPHA + b->spread;
 339                         distfactor *= OMEGA;
 340                         anglefactor = k->dist;
 341                         distfactor /= anglefactor * anglefactor + EPSILON;
 342                         distfactor *= b->units;
 343                         dx = Ship.sectx - k->x;
 344                         dy = k->y - Ship.secty;
 345                         anglefactor = atan2(dy, dx) - b->angle;
 346                         anglefactor = cos((anglefactor * b->spread) + GAMMA);
 347                         if (anglefactor < 0.0)
 348                         {
 349                                 k++;
 350                                 continue;
 351                         }
 352                         hit = anglefactor * distfactor + 0.5;
 353                         k->power -= hit;
 354                         printf("%d unit hit on Klingon", hit);
 355                         if (!damaged(SRSCAN))
 356                                 printf(" at %d,%d", k->x, k->y);
 357                         printf("\n");
 358                         b->units -= hit;
 359                         if (k->power <= 0)
 360                         {
 361                                 killk(k->x, k->y);
 362                                 continue;
 363                         }
 364                         k++;
 365                 }
 366         }
 367
 368         /* compute overkill */
 369         for (i = 0; i < NBANKS; i++)
 370                 extra += bank[i].units;
 371         if (extra > 0)
 372                 printf("\n%d units expended on empty space\n", extra);
 373 }