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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 $
41 /* factors for phaser hits; see description below */
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 */
49 /* OMEGA ~= 100 * (ALPHA + 1) * (BETA + 1) / (EPSILON + 1) */
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.
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.
69 ** Phasers spread slightly, even if you specify zero spread.
74 struct cvntab Matab[] =
76 "m", "anual", (int (*)())1, 0,
77 "a", "utomatic", 0, 0,
96 double anglefactor, distfactor;
98 int manual, flag, extra;
103 struct banks bank[NBANKS];
106 if (Ship.cond == DOCKED)
107 return(printf("Phasers cannot fire through starbase shields\n"));
109 return (out(PHASER));
111 return (printf("Sulu: Captain, we cannot fire through shields.\n"));
114 printf("Sulu: Captain, surely you must realize that we cannot fire\n");
115 printf(" phasers with the cloaking device up.\n");
119 /* decide if we want manual or automatic mode */
123 if (damaged(COMPUTER))
125 printf("%s", Device[COMPUTER].name);
131 printf("%s", Device[SRSCAN].name);
135 printf(" damaged, manual mode selected\n");
140 ptr = getcodpar("Manual or automatic", Matab);
141 manual = (long) ptr->value;
143 if (!manual && damaged(COMPUTER))
145 printf("Computer damaged, manual selected\n");
150 /* initialize the bank[] array */
152 for (i = 0; i < NBANKS; i++)
156 /* collect manual mode statistics */
159 printf("%d units available\n", Ship.energy);
162 for (i = 0; i < NBANKS; i++)
165 printf("\nBank %d:\n", i);
166 hit = getintpar("units");
172 if (extra > Ship.energy)
174 printf("available energy exceeded. ");
180 hit = getintpar("course");
181 if (hit < 0 || hit > 360)
183 b->angle = hit * 0.0174532925;
184 b->spread = getfltpar("spread");
185 if (b->spread < 0 || b->spread > 1)
188 Ship.energy -= extra;
194 /* automatic distribution of power */
196 return (printf("Sulu: But there are no Klingons in this quadrant\n"));
197 printf("Phasers locked on target. ");
200 printf("%d units available\n", Ship.energy);
201 hit = getintpar("Units to fire");
204 if (hit > Ship.energy)
206 printf("available energy exceeded. ");
216 tot = n * (n + 1) / 2;
217 for (i = 0; i < n; 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);
231 b->units = ((n - i) / tot) * extra;
235 printf("b%d hr%d u%d df%.2f af%.2f\n",
236 i, hitreqd[i], b->units,
237 distfactor, anglefactor);
241 hit = b->units - hitreqd[i];
249 /* give out any extra energy we might have around */
252 for (i = 0; i < n; i++)
255 hit = hitreqd[i] - b->units;
264 b->units = hitreqd[i];
268 printf("%d units overkill\n", extra);
276 for (i = 0; i < NBANKS; i++)
279 printf("b%d u%d", i, b->units);
281 printf(" a%.2f s%.2f\n", b->angle, b->spread);
288 /* actually fire the shots */
290 for (i = 0; i < NBANKS; i++)
297 printf("\nPhaser bank %d fires:\n", i);
300 for (j = 0; j < n; j++)
305 ** The formula for hit is as follows:
307 ** zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
308 ** / (dist ** 2 + EPSILON)]
309 ** * [cos(delta * sigma) + GAMMA]
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.
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-
333 distfactor = BETA + franf();
334 distfactor *= ALPHA + b->spread;
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)
348 hit = anglefactor * distfactor + 0.5;
350 printf("%d unit hit on Klingon", hit);
351 if (!damaged(SRSCAN))
352 printf(" at %d,%d", k->x, k->y);
364 /* compute overkill */
365 for (i = 0; i < NBANKS; i++)
366 extra += bank[i].units;
368 printf("\n%d units expended on empty space\n", extra);