games/trek/phaser.c

   1 /*      $NetBSD: phaser.c,v 1.14 2009/05/24 22:55:03 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[] = "@(#)phaser.c    8.1 (Berkeley) 5/31/93";
  36 #else
  37 __RCSID("$NetBSD: phaser.c,v 1.14 2009/05/24 22:55:03 dholland Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <stdio.h>
  42 #include <math.h>
  43 #include "trek.h"
  44 #include "getpar.h"
  45
  46 /* factors for phaser hits; see description below */
  47
  48 #define ALPHA           3.0             /* spread */
  49 #define BETA            3.0             /* franf() */
  50 #define GAMMA           0.30            /* cos(angle) */
  51 #define EPSILON         150.0           /* dist ** 2 */
  52 #define OMEGA           10.596          /* overall scaling factor */
  53
  54 /* OMEGA ~= 100 * (ALPHA + 1) * (BETA + 1) / (EPSILON + 1) */
  55
  56 /*
  57 **  Phaser Control
  58 **
  59 **      There are up to NBANKS phaser banks which may be fired
  60 **      simultaneously.  There are two modes, "manual" and
  61 **      "automatic".  In manual mode, you specify exactly which
  62 **      direction you want each bank to be aimed, the number
  63 **      of units to fire, and the spread angle.  In automatic
  64 **      mode, you give only the total number of units to fire.
  65 **
  66 **      The spread is specified as a number between zero and
  67 **      one, with zero being minimum spread and one being maximum
  68 **      spread.  You  will normally want zero spread, unless your
  69 **      short range scanners are out, in which case you probably
  70 **      don't know exactly where the Klingons are.  In that case,
  71 **      you really don't have any choice except to specify a
  72 **      fairly large spread.
  73 **
  74 **      Phasers spread slightly, even if you specify zero spread.
  75 **
  76 **      Uses trace flag 30
  77 */
  78
  79 static struct cvntab Matab[] = {
  80         { "m",          "anual",        (cmdfun) 1,     0 },
  81         { "a",          "utomatic",     (cmdfun) 0,     0 },
  82         { NULL,         NULL,           NULL,           0 }
  83 };
  84
  85 struct banks {
  86         int     units;
  87         double  angle;
  88         double  spread;
  89 };
  90
  91
  92
  93 /*ARGSUSED*/
  94 void
  95 phaser(int v __unused)
  96 {
  97         int             i;
  98         int             j;
  99         struct kling    *k;
 100         double          dx, dy;
 101         double          anglefactor, distfactor;
 102         struct banks    *b;
 103         int             manual, flag, extra = 0;
 104         int             hit;
 105         double          tot;
 106         int             n;
 107         int             hitreqd[NBANKS];
 108         struct banks    bank[NBANKS];
 109         const struct cvntab     *ptr;
 110
 111         if (Ship.cond == DOCKED) {
 112                 printf("Phasers cannot fire through starbase shields\n");
 113                 return;
 114         }
 115         if (damaged(PHASER)) {
 116                 out(PHASER);
 117                 return;
 118         }
 119         if (Ship.shldup) {
 120                 printf("Sulu: Captain, we cannot fire through shields.\n");
 121                 return;
 122         }
 123         if (Ship.cloaked) {
 124                 printf("Sulu: Captain, surely you must realize that we cannot "
 125                        "fire\n");
 126                 printf("  phasers with the cloaking device up.\n");
 127                 return;
 128         }
 129
 130         /* decide if we want manual or automatic mode */
 131         manual = 0;
 132         if (testnl()) {
 133                 if (damaged(COMPUTER)) {
 134                         printf("%s", Device[COMPUTER].name);
 135                         manual++;
 136                 } else if (damaged(SRSCAN)) {
 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                 ptr = getcodpar("Manual or automatic", Matab);
 146                 manual = (long) ptr->value;
 147         }
 148         if (!manual && damaged(COMPUTER)) {
 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                 /* collect manual mode statistics */
 160                 while (flag) {
 161                         printf("%d units available\n", Ship.energy);
 162                         extra = 0;
 163                         flag = 0;
 164                         for (i = 0; i < NBANKS; i++) {
 165                                 b = &bank[i];
 166                                 printf("\nBank %d:\n", i);
 167                                 hit = getintpar("units");
 168                                 if (hit < 0)
 169                                         return;
 170                                 if (hit == 0)
 171                                         break;
 172                                 extra += hit;
 173                                 if (extra > Ship.energy) {
 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         } else {
 192                 /* automatic distribution of power */
 193                 if (Etc.nkling <= 0) {
 194                         printf("Sulu: But there are no Klingons in this "
 195                                "quadrant\n");
 196                         return;
 197                 }
 198                 printf("Phasers locked on target.  ");
 199                 while (flag) {
 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                                 printf("available energy exceeded.  ");
 206                                 skiptonl(0);
 207                                 continue;
 208                         }
 209                         flag = 0;
 210                         Ship.energy -= hit;
 211                         extra = hit;
 212                         n = Etc.nkling;
 213                         if (n > NBANKS)
 214                                 n = NBANKS;
 215                         tot = n * (n + 1) / 2;
 216                         for (i = 0; i < n; i++) {
 217                                 k = &Etc.klingon[i];
 218                                 b = &bank[i];
 219                                 distfactor = k->dist;
 220                                 anglefactor = ALPHA * BETA * OMEGA /
 221                                         (distfactor * distfactor + EPSILON);
 222                                 anglefactor *= GAMMA;
 223                                 distfactor = k->power;
 224                                 distfactor /= anglefactor;
 225                                 hitreqd[i] = distfactor + 0.5;
 226                                 dx = Ship.sectx - k->x;
 227                                 dy = k->y - Ship.secty;
 228                                 b->angle = atan2(dy, dx);
 229                                 b->spread = 0.0;
 230                                 b->units = ((n - i) / tot) * extra;
 231 #ifdef xTRACE
 232                                 if (Trace) {
 233                                         printf("b%d hr%d u%d df%.2f af%.2f\n",
 234                                                 i, hitreqd[i], b->units,
 235                                                 distfactor, anglefactor);
 236                                 }
 237 #endif
 238                                 extra -= b->units;
 239                                 hit = b->units - hitreqd[i];
 240                                 if (hit > 0) {
 241                                         extra += hit;
 242                                         b->units -= hit;
 243                                 }
 244                         }
 245
 246                         /* give out any extra energy we might have around */
 247                         if (extra > 0) {
 248                                 for (i = 0; i < n; i++) {
 249                                         b = &bank[i];
 250                                         hit = hitreqd[i] - b->units;
 251                                         if (hit <= 0)
 252                                                 continue;
 253                                         if (hit >= extra) {
 254                                                 b->units += extra;
 255                                                 extra = 0;
 256                                                 break;
 257                                         }
 258                                         b->units = hitreqd[i];
 259                                         extra -= hit;
 260                                 }
 261                                 if (extra > 0)
 262                                         printf("%d units overkill\n", extra);
 263                         }
 264                 }
 265         }
 266
 267 #ifdef xTRACE
 268         if (Trace) {
 269                 for (i = 0; i < NBANKS; i++) {
 270                         b = &bank[i];
 271                         printf("b%d u%d", i, b->units);
 272                         if (b->units > 0)
 273                                 printf(" a%.2f s%.2f\n", b->angle, b->spread);
 274                         else
 275                                 printf("\n");
 276                 }
 277         }
 278 #endif
 279
 280         /* actually fire the shots */
 281         Move.free = 0;
 282         for (i = 0; i < NBANKS; i++) {
 283                 b = &bank[i];
 284                 if (b->units <= 0) {
 285                         continue;
 286                 }
 287                 printf("\nPhaser bank %d fires:\n", i);
 288                 n = Etc.nkling;
 289                 k = Etc.klingon;
 290                 for (j = 0; j < n; j++) {
 291                         if (b->units <= 0)
 292                                 break;
 293                         /*
 294                         ** The formula for hit is as follows:
 295                         **
 296                         **  zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
 297                         **      / (dist ** 2 + EPSILON)]
 298                         **      * [cos(delta * sigma) + GAMMA]
 299                         **      * hit
 300                         **
 301                         ** where sigma is the spread factor,
 302                         ** rho is a random number (0 -> 1),
 303                         ** GAMMA is a crud factor for angle (essentially
 304                         **      cruds up the spread factor),
 305                         ** delta is the difference in radians between the
 306                         **      angle you are shooting at and the actual
 307                         **      angle of the klingon,
 308                         ** ALPHA scales down the significance of sigma,
 309                         ** BETA scales down the significance of rho,
 310                         ** OMEGA is the magic number which makes everything
 311                         **      up to "* hit" between zero and one,
 312                         ** dist is the distance to the klingon
 313                         ** hit is the number of units in the bank, and
 314                         ** zap is the amount of the actual hit.
 315                         **
 316                         ** Everything up through dist squared should maximize
 317                         ** at 1.0, so that the distance factor is never
 318                         ** greater than one.  Conveniently, cos() is
 319                         ** never greater than one, but the same restric-
 320                         ** tion applies.
 321                         */
 322                         distfactor = BETA + franf();
 323                         distfactor *= ALPHA + b->spread;
 324                         distfactor *= OMEGA;
 325                         anglefactor = k->dist;
 326                         distfactor /= anglefactor * anglefactor + EPSILON;
 327                         distfactor *= b->units;
 328                         dx = Ship.sectx - k->x;
 329                         dy = k->y - Ship.secty;
 330                         anglefactor = atan2(dy, dx) - b->angle;
 331                         anglefactor = cos((anglefactor * b->spread) + GAMMA);
 332                         if (anglefactor < 0.0) {
 333                                 k++;
 334                                 continue;
 335                         }
 336                         hit = anglefactor * distfactor + 0.5;
 337                         k->power -= hit;
 338                         printf("%d unit hit on Klingon", hit);
 339                         if (!damaged(SRSCAN))
 340                                 printf(" at %d,%d", k->x, k->y);
 341                         printf("\n");
 342                         b->units -= hit;
 343                         if (k->power <= 0) {
 344                                 killk(k->x, k->y);
 345                                 continue;
 346                         }
 347                         k++;
 348                 }
 349         }
 350
 351         /* compute overkill */
 352         for (i = 0; i < NBANKS; i++)
 353                 extra += bank[i].units;
 354         if (extra > 0)
 355                 printf("\n%d units expended on empty space\n", extra);
 356 }