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. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)phaser.c 8.1 (Berkeley) 5/31/93
  30  * $FreeBSD: src/games/trek/phaser.c,v 1.5.2.1 2000/07/20 10:35:07 kris Exp $
  31  * $DragonFly: src/games/trek/phaser.c,v 1.3 2006/09/07 21:19:44 pavalos Exp $
  32  */
  33
  34 #include "trek.h"
  35 #include "getpar.h"
  36
  37 /* factors for phaser hits; see description below */
  38
  39 #define ALPHA           3.0             /* spread */
  40 #define BETA            3.0             /* franf() */
  41 #define GAMMA           0.30            /* cos(angle) */
  42 #define EPSILON         150.0           /* dist ** 2 */
  43 #define OMEGA           10.596          /* overall scaling factor */
  44
  45 /* OMEGA ~= 100 * (ALPHA + 1) * (BETA + 1) / (EPSILON + 1) */
  46
  47 /*
  48 **  Phaser Control
  49 **
  50 **      There are up to NBANKS phaser banks which may be fired
  51 **      simultaneously.  There are two modes, "manual" and
  52 **      "automatic".  In manual mode, you specify exactly which
  53 **      direction you want each bank to be aimed, the number
  54 **      of units to fire, and the spread angle.  In automatic
  55 **      mode, you give only the total number of units to fire.
  56 **
  57 **      The spread is specified as a number between zero and
  58 **      one, with zero being minimum spread and one being maximum
  59 **      spread.  You  will normally want zero spread, unless your
  60 **      short range scanners are out, in which case you probably
  61 **      don't know exactly where the Klingons are.  In that case,
  62 **      you really don't have any choice except to specify a
  63 **      fairly large spread.
  64 **
  65 **      Phasers spread slightly, even if you specify zero spread.
  66 **
  67 **      Uses trace flag 30
  68 */
  69
  70 struct cvntab Matab[] = {
  71         { "m",          "anual",        (cmdfun)1,      0 },
  72         { "a",          "utomatic",     (cmdfun)0,      0 },
  73         { NULL,         NULL,           NULL,           0 }
  74 };
  75
  76 struct banks {
  77         int     units;
  78         double  angle;
  79         double  spread;
  80 };
  81
  82
  83 void
  84 phaser(int v __unused)
  85 {
  86         int             i;
  87         int             j;
  88         struct kling    *k;
  89         double          dx, dy;
  90         double          anglefactor, distfactor;
  91         struct banks    *b;
  92         int             manual, flag, extra = 0;
  93         int             hit;
  94         double          tot;
  95         int             n;
  96         int             hitreqd[NBANKS];
  97         struct banks    bank[NBANKS];
  98         struct cvntab   *ptr;
  99
 100         if (Ship.cond == DOCKED) {
 101                 printf("Phasers cannot fire through starbase shields\n");
 102                 return;
 103         }
 104         if (damaged(PHASER)) {
 105                 out(PHASER);
 106                 return;
 107         }
 108         if (Ship.shldup) {
 109                 printf("Sulu: Captain, we cannot fire through shields.\n");
 110                 return;
 111         }
 112         if (Ship.cloaked) {
 113                 printf("Sulu: Captain, surely you must realize that we cannot fire\n");
 114                 printf("  phasers with the cloaking device up.\n");
 115                 return;
 116         }
 117
 118         /* decide if we want manual or automatic mode */
 119         manual = 0;
 120         if (testnl()) {
 121                 if (damaged(COMPUTER)) {
 122                         printf("%s", Device[COMPUTER].name);
 123                         manual++;
 124                 } else if (damaged(SRSCAN)) {
 125                         printf("%s", Device[SRSCAN].name);
 126                         manual++;
 127                 }
 128                 if (manual)
 129                         printf(" damaged, manual mode selected\n");
 130         }
 131
 132         if (!manual) {
 133                 ptr = getcodpar("Manual or automatic", Matab);
 134                 manual = (long) ptr->value;
 135         }
 136         if (!manual && damaged(COMPUTER)) {
 137                 printf("Computer damaged, manual selected\n");
 138                 skiptonl(0);
 139                 manual++;
 140         }
 141
 142         /* initialize the bank[] array */
 143         flag = 1;
 144         for (i = 0; i < NBANKS; i++)
 145                 bank[i].units = 0;
 146         if (manual) {
 147                 /* collect manual mode statistics */
 148                 while (flag) {
 149                         printf("%d units available\n", Ship.energy);
 150                         extra = 0;
 151                         flag = 0;
 152                         for (i = 0; i < NBANKS; i++) {
 153                                 b = &bank[i];
 154                                 printf("\nBank %d:\n", i);
 155                                 hit = getintpar("units");
 156                                 if (hit < 0)
 157                                         return;
 158                                 if (hit == 0)
 159                                         break;
 160                                 extra += hit;
 161                                 if (extra > Ship.energy) {
 162                                         printf("available energy exceeded.  ");
 163                                         skiptonl(0);
 164                                         flag++;
 165                                         break;
 166                                 }
 167                                 b->units = hit;
 168                                 hit = getintpar("course");
 169                                 if (hit < 0 || hit > 360)
 170                                         return;
 171                                 b->angle = hit * 0.0174532925;
 172                                 b->spread = getfltpar("spread");
 173                                 if (b->spread < 0 || b->spread > 1)
 174                                         return;
 175                         }
 176                         Ship.energy -= extra;
 177                 }
 178                 extra = 0;
 179         } else {
 180                 /* automatic distribution of power */
 181                 if (Etc.nkling <= 0) {
 182                         printf("Sulu: But there are no Klingons in this quadrant\n");
 183                         return;
 184                 }
 185                 printf("Phasers locked on target.  ");
 186                 while (flag) {
 187                         printf("%d units available\n", Ship.energy);
 188                         hit = getintpar("Units to fire");
 189                         if (hit <= 0)
 190                                 return;
 191                         if (hit > Ship.energy) {
 192                                 printf("available energy exceeded.  ");
 193                                 skiptonl(0);
 194                                 continue;
 195                         }
 196                         flag = 0;
 197                         Ship.energy -= hit;
 198                         extra = hit;
 199                         n = Etc.nkling;
 200                         if (n > NBANKS)
 201                                 n = NBANKS;
 202                         tot = n * (n + 1) / 2;
 203                         for (i = 0; i < n; i++) {
 204                                 k = &Etc.klingon[i];
 205                                 b = &bank[i];
 206                                 distfactor = k->dist;
 207                                 anglefactor = ALPHA * BETA * OMEGA / (distfactor * distfactor + EPSILON);
 208                                 anglefactor *= GAMMA;
 209                                 distfactor = k->power;
 210                                 distfactor /= anglefactor;
 211                                 hitreqd[i] = distfactor + 0.5;
 212                                 dx = Ship.sectx - k->x;
 213                                 dy = k->y - Ship.secty;
 214                                 b->angle = atan2(dy, dx);
 215                                 b->spread = 0.0;
 216                                 b->units = ((n - i) / tot) * extra;
 217 #ifdef xTRACE
 218                                 if (Trace) {
 219                                         printf("b%d hr%d u%d df%.2f af%.2f\n",
 220                                                 i, hitreqd[i], b->units,
 221                                                 distfactor, anglefactor);
 222                                 }
 223 #endif
 224                                 extra -= b->units;
 225                                 hit = b->units - hitreqd[i];
 226                                 if (hit > 0) {
 227                                         extra += hit;
 228                                         b->units -= hit;
 229                                 }
 230                         }
 231
 232                         /* give out any extra energy we might have around */
 233                         if (extra > 0) {
 234                                 for (i = 0; i < n; i++) {
 235                                         b = &bank[i];
 236                                         hit = hitreqd[i] - b->units;
 237                                         if (hit <= 0)
 238                                                 continue;
 239                                         if (hit >= extra) {
 240                                                 b->units += extra;
 241                                                 extra = 0;
 242                                                 break;
 243                                         }
 244                                         b->units = hitreqd[i];
 245                                         extra -= hit;
 246                                 }
 247                                 if (extra > 0)
 248                                         printf("%d units overkill\n", extra);
 249                         }
 250                 }
 251         }
 252
 253 #ifdef xTRACE
 254         if (Trace) {
 255                 for (i = 0; i < NBANKS; i++) {
 256                         b = &bank[i];
 257                         printf("b%d u%d", i, b->units);
 258                         if (b->units > 0)
 259                                 printf(" a%.2f s%.2f\n", b->angle, b->spread);
 260                         else
 261                                 printf("\n");
 262                 }
 263         }
 264 #endif
 265
 266         /* actually fire the shots */
 267         Move.free = 0;
 268         for (i = 0; i < NBANKS; i++) {
 269                 b = &bank[i];
 270                 if (b->units <= 0) {
 271                         continue;
 272                 }
 273                 printf("\nPhaser bank %d fires:\n", i);
 274                 n = Etc.nkling;
 275                 k = Etc.klingon;
 276                 for (j = 0; j < n; j++) {
 277                         if (b->units <= 0)
 278                                 break;
 279                         /*
 280                         ** The formula for hit is as follows:
 281                         **
 282                         **  zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
 283                         **      / (dist ** 2 + EPSILON)]
 284                         **      * [cos(delta * sigma) + GAMMA]
 285                         **      * hit
 286                         **
 287                         ** where sigma is the spread factor,
 288                         ** rho is a random number (0 -> 1),
 289                         ** GAMMA is a crud factor for angle (essentially
 290                         **      cruds up the spread factor),
 291                         ** delta is the difference in radians between the
 292                         **      angle you are shooting at and the actual
 293                         **      angle of the klingon,
 294                         ** ALPHA scales down the significance of sigma,
 295                         ** BETA scales down the significance of rho,
 296                         ** OMEGA is the magic number which makes everything
 297                         **      up to "* hit" between zero and one,
 298                         ** dist is the distance to the klingon
 299                         ** hit is the number of units in the bank, and
 300                         ** zap is the amount of the actual hit.
 301                         **
 302                         ** Everything up through dist squared should maximize
 303                         ** at 1.0, so that the distance factor is never
 304                         ** greater than one.  Conveniently, cos() is
 305                         ** never greater than one, but the same restric-
 306                         ** tion applies.
 307                         */
 308                         distfactor = BETA + franf();
 309                         distfactor *= ALPHA + b->spread;
 310                         distfactor *= OMEGA;
 311                         anglefactor = k->dist;
 312                         distfactor /= anglefactor * anglefactor + EPSILON;
 313                         distfactor *= b->units;
 314                         dx = Ship.sectx - k->x;
 315                         dy = k->y - Ship.secty;
 316                         anglefactor = atan2(dy, dx) - b->angle;
 317                         anglefactor = cos((anglefactor * b->spread) + GAMMA);
 318                         if (anglefactor < 0.0) {
 319                                 k++;
 320                                 continue;
 321                         }
 322                         hit = anglefactor * distfactor + 0.5;
 323                         k->power -= hit;
 324                         printf("%d unit hit on Klingon", hit);
 325                         if (!damaged(SRSCAN))
 326                                 printf(" at %d,%d", k->x, k->y);
 327                         printf("\n");
 328                         b->units -= hit;
 329                         if (k->power <= 0) {
 330                                 killk(k->x, k->y);
 331                                 continue;
 332                         }
 333                         k++;
 334                 }
 335         }
 336
 337         /* compute overkill */
 338         for (i = 0; i < NBANKS; i++)
 339                 extra += bank[i].units;
 340         if (extra > 0)
 341                 printf("\n%d units expended on empty space\n", extra);
 342 }