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 1.2 2003/06/17 04:25:25 dillon 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",                (int (*)())1,           0,
  77         "a",            "utomatic",             0,              0,
  78         0
  79 };
  80
  81 struct banks
  82 {
  83         int     units;
  84         double  angle;
  85         double  spread;
  86 };
  87
  88
  89
  90 phaser()
  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;
  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                 return(printf("Phasers cannot fire through starbase shields\n"));
 108         if (damaged(PHASER))
 109                 return (out(PHASER));
 110         if (Ship.shldup)
 111                 return (printf("Sulu: Captain, we cannot fire through shields.\n"));
 112         if (Ship.cloaked)
 113         {
 114                 printf("Sulu: Captain, surely you must realize that we cannot fire\n");
 115                 printf("  phasers with the cloaking device up.\n");
 116                 return;
 117         }
 118
 119         /* decide if we want manual or automatic mode */
 120         manual = 0;
 121         if (testnl())
 122         {
 123                 if (damaged(COMPUTER))
 124                 {
 125                         printf("%s", Device[COMPUTER].name);
 126                         manual++;
 127                 }
 128                 else
 129                         if (damaged(SRSCAN))
 130                         {
 131                                 printf("%s", Device[SRSCAN].name);
 132                                 manual++;
 133                         }
 134                 if (manual)
 135                         printf(" damaged, manual mode selected\n");
 136         }
 137
 138         if (!manual)
 139         {
 140                 ptr = getcodpar("Manual or automatic", Matab);
 141                 manual = (long) ptr->value;
 142         }
 143         if (!manual && damaged(COMPUTER))
 144         {
 145                 printf("Computer damaged, manual selected\n");
 146                 skiptonl(0);
 147                 manual++;
 148         }
 149
 150         /* initialize the bank[] array */
 151         flag = 1;
 152         for (i = 0; i < NBANKS; i++)
 153                 bank[i].units = 0;
 154         if (manual)
 155         {
 156                 /* collect manual mode statistics */
 157                 while (flag)
 158                 {
 159                         printf("%d units available\n", Ship.energy);
 160                         extra = 0;
 161                         flag = 0;
 162                         for (i = 0; i < NBANKS; i++)
 163                         {
 164                                 b = &bank[i];
 165                                 printf("\nBank %d:\n", i);
 166                                 hit = getintpar("units");
 167                                 if (hit < 0)
 168                                         return;
 169                                 if (hit == 0)
 170                                         break;
 171                                 extra += hit;
 172                                 if (extra > Ship.energy)
 173                                 {
 174                                         printf("available energy exceeded.  ");
 175                                         skiptonl(0);
 176                                         flag++;
 177                                         break;
 178                                 }
 179                                 b->units = hit;
 180                                 hit = getintpar("course");
 181                                 if (hit < 0 || hit > 360)
 182                                         return;
 183                                 b->angle = hit * 0.0174532925;
 184                                 b->spread = getfltpar("spread");
 185                                 if (b->spread < 0 || b->spread > 1)
 186                                         return;
 187                         }
 188                         Ship.energy -= extra;
 189                 }
 190                 extra = 0;
 191         }
 192         else
 193         {
 194                 /* automatic distribution of power */
 195                 if (Etc.nkling <= 0)
 196                         return (printf("Sulu: But there are no Klingons in this quadrant\n"));
 197                 printf("Phasers locked on target.  ");
 198                 while (flag)
 199                 {
 200                         printf("%d units available\n", Ship.energy);
 201                         hit = getintpar("Units to fire");
 202                         if (hit <= 0)
 203                                 return;
 204                         if (hit > Ship.energy)
 205                         {
 206                                 printf("available energy exceeded.  ");
 207                                 skiptonl(0);
 208                                 continue;
 209                         }
 210                         flag = 0;
 211                         Ship.energy -= hit;
 212                         extra = hit;
 213                         n = Etc.nkling;
 214                         if (n > NBANKS)
 215                                 n = NBANKS;
 216                         tot = n * (n + 1) / 2;
 217                         for (i = 0; i < n; i++)
 218                         {
 219                                 k = &Etc.klingon[i];
 220                                 b = &bank[i];
 221                                 distfactor = k->dist;
 222                                 anglefactor = ALPHA * BETA * OMEGA / (distfactor * distfactor + EPSILON);
 223                                 anglefactor *= GAMMA;
 224                                 distfactor = k->power;
 225                                 distfactor /= anglefactor;
 226                                 hitreqd[i] = distfactor + 0.5;
 227                                 dx = Ship.sectx - k->x;
 228                                 dy = k->y - Ship.secty;
 229                                 b->angle = atan2(dy, dx);
 230                                 b->spread = 0.0;
 231                                 b->units = ((n - i) / tot) * extra;
 232 #                               ifdef xTRACE
 233                                 if (Trace)
 234                                 {
 235                                         printf("b%d hr%d u%d df%.2f af%.2f\n",
 236                                                 i, hitreqd[i], b->units,
 237                                                 distfactor, anglefactor);
 238                                 }
 239 #                               endif
 240                                 extra -= b->units;
 241                                 hit = b->units - hitreqd[i];
 242                                 if (hit > 0)
 243                                 {
 244                                         extra += hit;
 245                                         b->units -= hit;
 246                                 }
 247                         }
 248
 249                         /* give out any extra energy we might have around */
 250                         if (extra > 0)
 251                         {
 252                                 for (i = 0; i < n; i++)
 253                                 {
 254                                         b = &bank[i];
 255                                         hit = hitreqd[i] - b->units;
 256                                         if (hit <= 0)
 257                                                 continue;
 258                                         if (hit >= extra)
 259                                         {
 260                                                 b->units += extra;
 261                                                 extra = 0;
 262                                                 break;
 263                                         }
 264                                         b->units = hitreqd[i];
 265                                         extra -= hit;
 266                                 }
 267                                 if (extra > 0)
 268                                         printf("%d units overkill\n", extra);
 269                         }
 270                 }
 271         }
 272
 273 #       ifdef xTRACE
 274         if (Trace)
 275         {
 276                 for (i = 0; i < NBANKS; i++)
 277                 {
 278                         b = &bank[i];
 279                         printf("b%d u%d", i, b->units);
 280                         if (b->units > 0)
 281                                 printf(" a%.2f s%.2f\n", b->angle, b->spread);
 282                         else
 283                                 printf("\n");
 284                 }
 285         }
 286 #       endif
 287
 288         /* actually fire the shots */
 289         Move.free = 0;
 290         for (i = 0; i < NBANKS; i++)
 291         {
 292                 b = &bank[i];
 293                 if (b->units <= 0)
 294                 {
 295                         continue;
 296                 }
 297                 printf("\nPhaser bank %d fires:\n", i);
 298                 n = Etc.nkling;
 299                 k = Etc.klingon;
 300                 for (j = 0; j < n; j++)
 301                 {
 302                         if (b->units <= 0)
 303                                 break;
 304                         /*
 305                         ** The formula for hit is as follows:
 306                         **
 307                         **  zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
 308                         **      / (dist ** 2 + EPSILON)]
 309                         **      * [cos(delta * sigma) + GAMMA]
 310                         **      * hit
 311                         **
 312                         ** where sigma is the spread factor,
 313                         ** rho is a random number (0 -> 1),
 314                         ** GAMMA is a crud factor for angle (essentially
 315                         **      cruds up the spread factor),
 316                         ** delta is the difference in radians between the
 317                         **      angle you are shooting at and the actual
 318                         **      angle of the klingon,
 319                         ** ALPHA scales down the significance of sigma,
 320                         ** BETA scales down the significance of rho,
 321                         ** OMEGA is the magic number which makes everything
 322                         **      up to "* hit" between zero and one,
 323                         ** dist is the distance to the klingon
 324                         ** hit is the number of units in the bank, and
 325                         ** zap is the amount of the actual hit.
 326                         **
 327                         ** Everything up through dist squared should maximize
 328                         ** at 1.0, so that the distance factor is never
 329                         ** greater than one.  Conveniently, cos() is
 330                         ** never greater than one, but the same restric-
 331                         ** tion applies.
 332                         */
 333                         distfactor = BETA + franf();
 334                         distfactor *= ALPHA + b->spread;
 335                         distfactor *= OMEGA;
 336                         anglefactor = k->dist;
 337                         distfactor /= anglefactor * anglefactor + EPSILON;
 338                         distfactor *= b->units;
 339                         dx = Ship.sectx - k->x;
 340                         dy = k->y - Ship.secty;
 341                         anglefactor = atan2(dy, dx) - b->angle;
 342                         anglefactor = cos((anglefactor * b->spread) + GAMMA);
 343                         if (anglefactor < 0.0)
 344                         {
 345                                 k++;
 346                                 continue;
 347                         }
 348                         hit = anglefactor * distfactor + 0.5;
 349                         k->power -= hit;
 350                         printf("%d unit hit on Klingon", hit);
 351                         if (!damaged(SRSCAN))
 352                                 printf(" at %d,%d", k->x, k->y);
 353                         printf("\n");
 354                         b->units -= hit;
 355                         if (k->power <= 0)
 356                         {
 357                                 killk(k->x, k->y);
 358                                 continue;
 359                         }
 360                         k++;
 361                 }
 362         }
 363
 364         /* compute overkill */
 365         for (i = 0; i < NBANKS; i++)
 366                 extra += bank[i].units;
 367         if (extra > 0)
 368                 printf("\n%d units expended on empty space\n", extra);
 369 }