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  * @(#)phaser.c 8.1 (Berkeley) 5/31/93
  34  * $FreeBSD: src/games/trek/phaser.c,v 1.5.2.1 2000/07/20 10:35:07 kris Exp $
  35  * $DragonFly: src/games/trek/phaser.c,v 1.3 2006/09/07 21:19:44 pavalos Exp $
  36  */
  37
  38 # include       "trek.h"
  39 # include       "getpar.h"
  40
  41 /* factors for phaser hits; see description below */
  42
  43 # define        ALPHA           3.0             /* spread */
  44 # define        BETA            3.0             /* franf() */
  45 # define        GAMMA           0.30            /* cos(angle) */
  46 # define        EPSILON         150.0           /* dist ** 2 */
  47 # define        OMEGA           10.596          /* overall scaling factor */
  48
  49 /* OMEGA ~= 100 * (ALPHA + 1) * (BETA + 1) / (EPSILON + 1) */
  50
  51 /*
  52 **  Phaser Control
  53 **
  54 **      There are up to NBANKS phaser banks which may be fired
  55 **      simultaneously.  There are two modes, "manual" and
  56 **      "automatic".  In manual mode, you specify exactly which
  57 **      direction you want each bank to be aimed, the number
  58 **      of units to fire, and the spread angle.  In automatic
  59 **      mode, you give only the total number of units to fire.
  60 **
  61 **      The spread is specified as a number between zero and
  62 **      one, with zero being minimum spread and one being maximum
  63 **      spread.  You  will normally want zero spread, unless your
  64 **      short range scanners are out, in which case you probably
  65 **      don't know exactly where the Klingons are.  In that case,
  66 **      you really don't have any choice except to specify a
  67 **      fairly large spread.
  68 **
  69 **      Phasers spread slightly, even if you specify zero spread.
  70 **
  71 **      Uses trace flag 30
  72 */
  73
  74 struct cvntab   Matab[] =
  75 {
  76         { "m",          "anual",        (void (*)(int))1,       0 },
  77         { "a",          "utomatic",     (void (*)(int))0,       0 },
  78         { NULL,         NULL,           NULL,                   0 }
  79 };
  80
  81 struct banks
  82 {
  83         int     units;
  84         double  angle;
  85         double  spread;
  86 };
  87
  88
  89 void
  90 phaser(__unused int unused)
  91 {
  92         int             i;
  93         int                     j;
  94         struct kling    *k;
  95         double                  dx, dy;
  96         double                  anglefactor, distfactor;
  97         struct banks    *b;
  98         int                     manual, flag, extra = 0;
  99         int                     hit;
 100         double                  tot;
 101         int                     n;
 102         int                     hitreqd[NBANKS];
 103         struct banks            bank[NBANKS];
 104         struct cvntab           *ptr;
 105
 106         if (Ship.cond == DOCKED) {
 107                 printf("Phasers cannot fire through starbase shields\n");
 108                 return;
 109         }
 110         if (damaged(PHASER)) {
 111                 out(PHASER);
 112                 return;
 113         }
 114         if (Ship.shldup) {
 115                 printf("Sulu: Captain, we cannot fire through shields.\n");
 116                 return;
 117         }
 118         if (Ship.cloaked)
 119         {
 120                 printf("Sulu: Captain, surely you must realize that we cannot fire\n");
 121                 printf("  phasers with the cloaking device up.\n");
 122                 return;
 123         }
 124
 125         /* decide if we want manual or automatic mode */
 126         manual = 0;
 127         if (testnl())
 128         {
 129                 if (damaged(COMPUTER))
 130                 {
 131                         printf("%s", Device[COMPUTER].name);
 132                         manual++;
 133                 }
 134                 else
 135                         if (damaged(SRSCAN))
 136                         {
 137                                 printf("%s", Device[SRSCAN].name);
 138                                 manual++;
 139                         }
 140                 if (manual)
 141                         printf(" damaged, manual mode selected\n");
 142         }
 143
 144         if (!manual)
 145         {
 146                 ptr = getcodpar("Manual or automatic", Matab);
 147                 manual = (long) ptr->value;
 148         }
 149         if (!manual && damaged(COMPUTER))
 150         {
 151                 printf("Computer damaged, manual selected\n");
 152                 skiptonl(0);
 153                 manual++;
 154         }
 155
 156         /* initialize the bank[] array */
 157         flag = 1;
 158         for (i = 0; i < NBANKS; i++)
 159                 bank[i].units = 0;
 160         if (manual)
 161         {
 162                 /* collect manual mode statistics */
 163                 while (flag)
 164                 {
 165                         printf("%d units available\n", Ship.energy);
 166                         extra = 0;
 167                         flag = 0;
 168                         for (i = 0; i < NBANKS; i++)
 169                         {
 170                                 b = &bank[i];
 171                                 printf("\nBank %d:\n", i);
 172                                 hit = getintpar("units");
 173                                 if (hit < 0)
 174                                         return;
 175                                 if (hit == 0)
 176                                         break;
 177                                 extra += hit;
 178                                 if (extra > Ship.energy)
 179                                 {
 180                                         printf("available energy exceeded.  ");
 181                                         skiptonl(0);
 182                                         flag++;
 183                                         break;
 184                                 }
 185                                 b->units = hit;
 186                                 hit = getintpar("course");
 187                                 if (hit < 0 || hit > 360)
 188                                         return;
 189                                 b->angle = hit * 0.0174532925;
 190                                 b->spread = getfltpar("spread");
 191                                 if (b->spread < 0 || b->spread > 1)
 192                                         return;
 193                         }
 194                         Ship.energy -= extra;
 195                 }
 196                 extra = 0;
 197         }
 198         else
 199         {
 200                 /* automatic distribution of power */
 201                 if (Etc.nkling <= 0) {
 202                         printf("Sulu: But there are no Klingons in this quadrant\n");
 203                         return;
 204                 }
 205                 printf("Phasers locked on target.  ");
 206                 while (flag)
 207                 {
 208                         printf("%d units available\n", Ship.energy);
 209                         hit = getintpar("Units to fire");
 210                         if (hit <= 0)
 211                                 return;
 212                         if (hit > Ship.energy)
 213                         {
 214                                 printf("available energy exceeded.  ");
 215                                 skiptonl(0);
 216                                 continue;
 217                         }
 218                         flag = 0;
 219                         Ship.energy -= hit;
 220                         extra = hit;
 221                         n = Etc.nkling;
 222                         if (n > NBANKS)
 223                                 n = NBANKS;
 224                         tot = n * (n + 1) / 2;
 225                         for (i = 0; i < n; i++)
 226                         {
 227                                 k = &Etc.klingon[i];
 228                                 b = &bank[i];
 229                                 distfactor = k->dist;
 230                                 anglefactor = ALPHA * BETA * OMEGA / (distfactor * distfactor + EPSILON);
 231                                 anglefactor *= GAMMA;
 232                                 distfactor = k->power;
 233                                 distfactor /= anglefactor;
 234                                 hitreqd[i] = distfactor + 0.5;
 235                                 dx = Ship.sectx - k->x;
 236                                 dy = k->y - Ship.secty;
 237                                 b->angle = atan2(dy, dx);
 238                                 b->spread = 0.0;
 239                                 b->units = ((n - i) / tot) * extra;
 240 #                               ifdef xTRACE
 241                                 if (Trace)
 242                                 {
 243                                         printf("b%d hr%d u%d df%.2f af%.2f\n",
 244                                                 i, hitreqd[i], b->units,
 245                                                 distfactor, anglefactor);
 246                                 }
 247 #                               endif
 248                                 extra -= b->units;
 249                                 hit = b->units - hitreqd[i];
 250                                 if (hit > 0)
 251                                 {
 252                                         extra += hit;
 253                                         b->units -= hit;
 254                                 }
 255                         }
 256
 257                         /* give out any extra energy we might have around */
 258                         if (extra > 0)
 259                         {
 260                                 for (i = 0; i < n; i++)
 261                                 {
 262                                         b = &bank[i];
 263                                         hit = hitreqd[i] - b->units;
 264                                         if (hit <= 0)
 265                                                 continue;
 266                                         if (hit >= extra)
 267                                         {
 268                                                 b->units += extra;
 269                                                 extra = 0;
 270                                                 break;
 271                                         }
 272                                         b->units = hitreqd[i];
 273                                         extra -= hit;
 274                                 }
 275                                 if (extra > 0)
 276                                         printf("%d units overkill\n", extra);
 277                         }
 278                 }
 279         }
 280
 281 #       ifdef xTRACE
 282         if (Trace)
 283         {
 284                 for (i = 0; i < NBANKS; i++)
 285                 {
 286                         b = &bank[i];
 287                         printf("b%d u%d", i, b->units);
 288                         if (b->units > 0)
 289                                 printf(" a%.2f s%.2f\n", b->angle, b->spread);
 290                         else
 291                                 printf("\n");
 292                 }
 293         }
 294 #       endif
 295
 296         /* actually fire the shots */
 297         Move.free = 0;
 298         for (i = 0; i < NBANKS; i++)
 299         {
 300                 b = &bank[i];
 301                 if (b->units <= 0)
 302                 {
 303                         continue;
 304                 }
 305                 printf("\nPhaser bank %d fires:\n", i);
 306                 n = Etc.nkling;
 307                 k = Etc.klingon;
 308                 for (j = 0; j < n; j++)
 309                 {
 310                         if (b->units <= 0)
 311                                 break;
 312                         /*
 313                         ** The formula for hit is as follows:
 314                         **
 315                         **  zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
 316                         **      / (dist ** 2 + EPSILON)]
 317                         **      * [cos(delta * sigma) + GAMMA]
 318                         **      * hit
 319                         **
 320                         ** where sigma is the spread factor,
 321                         ** rho is a random number (0 -> 1),
 322                         ** GAMMA is a crud factor for angle (essentially
 323                         **      cruds up the spread factor),
 324                         ** delta is the difference in radians between the
 325                         **      angle you are shooting at and the actual
 326                         **      angle of the klingon,
 327                         ** ALPHA scales down the significance of sigma,
 328                         ** BETA scales down the significance of rho,
 329                         ** OMEGA is the magic number which makes everything
 330                         **      up to "* hit" between zero and one,
 331                         ** dist is the distance to the klingon
 332                         ** hit is the number of units in the bank, and
 333                         ** zap is the amount of the actual hit.
 334                         **
 335                         ** Everything up through dist squared should maximize
 336                         ** at 1.0, so that the distance factor is never
 337                         ** greater than one.  Conveniently, cos() is
 338                         ** never greater than one, but the same restric-
 339                         ** tion applies.
 340                         */
 341                         distfactor = BETA + franf();
 342                         distfactor *= ALPHA + b->spread;
 343                         distfactor *= OMEGA;
 344                         anglefactor = k->dist;
 345                         distfactor /= anglefactor * anglefactor + EPSILON;
 346                         distfactor *= b->units;
 347                         dx = Ship.sectx - k->x;
 348                         dy = k->y - Ship.secty;
 349                         anglefactor = atan2(dy, dx) - b->angle;
 350                         anglefactor = cos((anglefactor * b->spread) + GAMMA);
 351                         if (anglefactor < 0.0)
 352                         {
 353                                 k++;
 354                                 continue;
 355                         }
 356                         hit = anglefactor * distfactor + 0.5;
 357                         k->power -= hit;
 358                         printf("%d unit hit on Klingon", hit);
 359                         if (!damaged(SRSCAN))
 360                                 printf(" at %d,%d", k->x, k->y);
 361                         printf("\n");
 362                         b->units -= hit;
 363                         if (k->power <= 0)
 364                         {
 365                                 killk(k->x, k->y);
 366                                 continue;
 367                         }
 368                         k++;
 369                 }
 370         }
 371
 372         /* compute overkill */
 373         for (i = 0; i < NBANKS; i++)
 374                 extra += bank[i].units;
 375         if (extra > 0)
 376                 printf("\n%d units expended on empty space\n", extra);
 377 }