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BSD 4_4 release
[unix-history] / usr / src / games / trek / phaser.c
/*
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char sccsid[] = "@(#)phaser.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
# include "trek.h"
# include "getpar.h"
/* factors for phaser hits; see description below */
# define ALPHA 3.0 /* spread */
# define BETA 3.0 /* franf() */
# define GAMMA 0.30 /* cos(angle) */
# define EPSILON 150.0 /* dist ** 2 */
# define OMEGA 10.596 /* overall scaling factor */
/* OMEGA ~= 100 * (ALPHA + 1) * (BETA + 1) / (EPSILON + 1) */
/*
** Phaser Control
**
** There are up to NBANKS phaser banks which may be fired
** simultaneously. There are two modes, "manual" and
** "automatic". In manual mode, you specify exactly which
** direction you want each bank to be aimed, the number
** of units to fire, and the spread angle. In automatic
** mode, you give only the total number of units to fire.
**
** The spread is specified as a number between zero and
** one, with zero being minimum spread and one being maximum
** spread. You will normally want zero spread, unless your
** short range scanners are out, in which case you probably
** don't know exactly where the Klingons are. In that case,
** you really don't have any choice except to specify a
** fairly large spread.
**
** Phasers spread slightly, even if you specify zero spread.
**
** Uses trace flag 30
*/
struct cvntab Matab[] =
{
"m", "anual", (int (*)())1, 0,
"a", "utomatic", 0, 0,
0
};
struct banks
{
int units;
double angle;
double spread;
};
phaser()
{
register int i;
int j;
register struct kling *k;
double dx, dy;
double anglefactor, distfactor;
register struct banks *b;
int manual, flag, extra;
int hit;
double tot;
int n;
int hitreqd[NBANKS];
struct banks bank[NBANKS];
struct cvntab *ptr;
if (Ship.cond == DOCKED)
return(printf("Phasers cannot fire through starbase shields\n"));
if (damaged(PHASER))
return (out(PHASER));
if (Ship.shldup)
return (printf("Sulu: Captain, we cannot fire through shields.\n"));
if (Ship.cloaked)
{
printf("Sulu: Captain, surely you must realize that we cannot fire\n");
printf(" phasers with the cloaking device up.\n");
return;
}
/* decide if we want manual or automatic mode */
manual = 0;
if (testnl())
{
if (damaged(COMPUTER))
{
printf(Device[COMPUTER].name);
manual++;
}
else
if (damaged(SRSCAN))
{
printf(Device[SRSCAN].name);
manual++;
}
if (manual)
printf(" damaged, manual mode selected\n");
}
if (!manual)
{
ptr = getcodpar("Manual or automatic", Matab);
manual = (int) ptr->value;
}
if (!manual && damaged(COMPUTER))
{
printf("Computer damaged, manual selected\n");
skiptonl(0);
manual++;
}
/* initialize the bank[] array */
flag = 1;
for (i = 0; i < NBANKS; i++)
bank[i].units = 0;
if (manual)
{
/* collect manual mode statistics */
while (flag)
{
printf("%d units available\n", Ship.energy);
extra = 0;
flag = 0;
for (i = 0; i < NBANKS; i++)
{
b = &bank[i];
printf("\nBank %d:\n", i);
hit = getintpar("units");
if (hit < 0)
return;
if (hit == 0)
break;
extra += hit;
if (extra > Ship.energy)
{
printf("available energy exceeded. ");
skiptonl(0);
flag++;
break;
}
b->units = hit;
hit = getintpar("course");
if (hit < 0 || hit > 360)
return;
b->angle = hit * 0.0174532925;
b->spread = getfltpar("spread");
if (b->spread < 0 || b->spread > 1)
return;
}
Ship.energy -= extra;
}
extra = 0;
}
else
{
/* automatic distribution of power */
if (Etc.nkling <= 0)
return (printf("Sulu: But there are no Klingons in this quadrant\n"));
printf("Phasers locked on target. ");
while (flag)
{
printf("%d units available\n", Ship.energy);
hit = getintpar("Units to fire");
if (hit <= 0)
return;
if (hit > Ship.energy)
{
printf("available energy exceeded. ");
skiptonl(0);
continue;
}
flag = 0;
Ship.energy -= hit;
extra = hit;
n = Etc.nkling;
if (n > NBANKS)
n = NBANKS;
tot = n * (n + 1) / 2;
for (i = 0; i < n; i++)
{
k = &Etc.klingon[i];
b = &bank[i];
distfactor = k->dist;
anglefactor = ALPHA * BETA * OMEGA / (distfactor * distfactor + EPSILON);
anglefactor *= GAMMA;
distfactor = k->power;
distfactor /= anglefactor;
hitreqd[i] = distfactor + 0.5;
dx = Ship.sectx - k->x;
dy = k->y - Ship.secty;
b->angle = atan2(dy, dx);
b->spread = 0.0;
b->units = ((n - i) / tot) * extra;
# ifdef xTRACE
if (Trace)
{
printf("b%d hr%d u%d df%.2f af%.2f\n",
i, hitreqd[i], b->units,
distfactor, anglefactor);
}
# endif
extra -= b->units;
hit = b->units - hitreqd[i];
if (hit > 0)
{
extra += hit;
b->units -= hit;
}
}
/* give out any extra energy we might have around */
if (extra > 0)
{
for (i = 0; i < n; i++)
{
b = &bank[i];
hit = hitreqd[i] - b->units;
if (hit <= 0)
continue;
if (hit >= extra)
{
b->units += extra;
extra = 0;
break;
}
b->units = hitreqd[i];
extra -= hit;
}
if (extra > 0)
printf("%d units overkill\n", extra);
}
}
}
# ifdef xTRACE
if (Trace)
{
for (i = 0; i < NBANKS; i++)
{
b = &bank[i];
printf("b%d u%d", i, b->units);
if (b->units > 0)
printf(" a%.2f s%.2f\n", b->angle, b->spread);
else
printf("\n");
}
}
# endif
/* actually fire the shots */
Move.free = 0;
for (i = 0; i < NBANKS; i++)
{
b = &bank[i];
if (b->units <= 0)
{
continue;
}
printf("\nPhaser bank %d fires:\n", i);
n = Etc.nkling;
k = Etc.klingon;
for (j = 0; j < n; j++)
{
if (b->units <= 0)
break;
/*
** The formula for hit is as follows:
**
** zap = OMEGA * [(sigma + ALPHA) * (rho + BETA)]
** / (dist ** 2 + EPSILON)]
** * [cos(delta * sigma) + GAMMA]
** * hit
**
** where sigma is the spread factor,
** rho is a random number (0 -> 1),
** GAMMA is a crud factor for angle (essentially
** cruds up the spread factor),
** delta is the difference in radians between the
** angle you are shooting at and the actual
** angle of the klingon,
** ALPHA scales down the significance of sigma,
** BETA scales down the significance of rho,
** OMEGA is the magic number which makes everything
** up to "* hit" between zero and one,
** dist is the distance to the klingon
** hit is the number of units in the bank, and
** zap is the amount of the actual hit.
**
** Everything up through dist squared should maximize
** at 1.0, so that the distance factor is never
** greater than one. Conveniently, cos() is
** never greater than one, but the same restric-
** tion applies.
*/
distfactor = BETA + franf();
distfactor *= ALPHA + b->spread;
distfactor *= OMEGA;
anglefactor = k->dist;
distfactor /= anglefactor * anglefactor + EPSILON;
distfactor *= b->units;
dx = Ship.sectx - k->x;
dy = k->y - Ship.secty;
anglefactor = atan2(dy, dx) - b->angle;
anglefactor = cos((anglefactor * b->spread) + GAMMA);
if (anglefactor < 0.0)
{
k++;
continue;
}
hit = anglefactor * distfactor + 0.5;
k->power -= hit;
printf("%d unit hit on Klingon", hit);
if (!damaged(SRSCAN))
printf(" at %d,%d", k->x, k->y);
printf("\n");
b->units -= hit;
if (k->power <= 0)
{
killk(k->x, k->y);
continue;
}
k++;
}
}
/* compute overkill */
for (i = 0; i < NBANKS; i++)
extra += bank[i].units;
if (extra > 0)
printf("\n%d units expended on empty space\n", extra);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.