freebsd-dev/games/pom/pom.c
Jordan K. Hubbard 554eb505f8 Bring in the 4.4 Lite games directory, modulo man page changes and segregation
of the x11 based games.  I'm not going to tag the originals with bsd_44_lite
and do this in two stages since it's just not worth it for this collection,
and I've got directory renames to deal with that way.  Bleah.
Submitted by:	jkh
1994-09-04 04:03:31 +00:00

179 lines
5.4 KiB
C

/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software posted to USENET.
*
* 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 copyright[] =
"@(#) Copyright (c) 1989, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)pom.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
/*
* Phase of the Moon. Calculates the current phase of the moon.
* Based on routines from `Practical Astronomy with Your Calculator',
* by Duffett-Smith. Comments give the section from the book that
* particular piece of code was adapted from.
*
* -- Keith E. Brandt VIII 1984
*
*/
#include <sys/time.h>
#include <stdio.h>
#include <tzfile.h>
#include <math.h>
#define PI 3.141592654
#define EPOCH 85
#define EPSILONg 279.611371 /* solar ecliptic long at EPOCH */
#define RHOg 282.680403 /* solar ecliptic long of perigee at EPOCH */
#define ECCEN 0.01671542 /* solar orbit eccentricity */
#define lzero 18.251907 /* lunar mean long at EPOCH */
#define Pzero 192.917585 /* lunar mean long of perigee at EPOCH */
#define Nzero 55.204723 /* lunar mean long of node at EPOCH */
double dtor(), potm(), adj360();
main()
{
extern int errno;
struct timeval tp;
struct timezone tzp;
struct tm *GMT, *gmtime();
double days, today, tomorrow;
int cnt;
char *strerror();
if (gettimeofday(&tp,&tzp)) {
(void)fprintf(stderr, "pom: %s\n", strerror(errno));
exit(1);
}
GMT = gmtime(&tp.tv_sec);
days = (GMT->tm_yday + 1) + ((GMT->tm_hour +
(GMT->tm_min / 60.0) + (GMT->tm_sec / 3600.0)) / 24.0);
for (cnt = EPOCH; cnt < GMT->tm_year; ++cnt)
days += isleap(cnt) ? 366 : 365;
today = potm(days) + .5;
(void)printf("The Moon is ");
if ((int)today == 100)
(void)printf("Full\n");
else if (!(int)today)
(void)printf("New\n");
else {
tomorrow = potm(days + 1);
if ((int)today == 50)
(void)printf("%s\n", tomorrow > today ?
"at the First Quarter" : "at the Last Quarter");
else {
(void)printf("%s ", tomorrow > today ?
"Waxing" : "Waning");
if (today > 50)
(void)printf("Gibbous (%1.0f%% of Full)\n",
today);
else if (today < 50)
(void)printf("Crescent (%1.0f%% of Full)\n",
today);
}
}
}
/*
* potm --
* return phase of the moon
*/
double
potm(days)
double days;
{
double N, Msol, Ec, LambdaSol, l, Mm, Ev, Ac, A3, Mmprime;
double A4, lprime, V, ldprime, D, Nm;
N = 360 * days / 365.2422; /* sec 42 #3 */
adj360(&N);
Msol = N + EPSILONg - RHOg; /* sec 42 #4 */
adj360(&Msol);
Ec = 360 / PI * ECCEN * sin(dtor(Msol)); /* sec 42 #5 */
LambdaSol = N + Ec + EPSILONg; /* sec 42 #6 */
adj360(&LambdaSol);
l = 13.1763966 * days + lzero; /* sec 61 #4 */
adj360(&l);
Mm = l - (0.1114041 * days) - Pzero; /* sec 61 #5 */
adj360(&Mm);
Nm = Nzero - (0.0529539 * days); /* sec 61 #6 */
adj360(&Nm);
Ev = 1.2739 * sin(dtor(2*(l - LambdaSol) - Mm)); /* sec 61 #7 */
Ac = 0.1858 * sin(dtor(Msol)); /* sec 61 #8 */
A3 = 0.37 * sin(dtor(Msol));
Mmprime = Mm + Ev - Ac - A3; /* sec 61 #9 */
Ec = 6.2886 * sin(dtor(Mmprime)); /* sec 61 #10 */
A4 = 0.214 * sin(dtor(2 * Mmprime)); /* sec 61 #11 */
lprime = l + Ev + Ec - Ac + A4; /* sec 61 #12 */
V = 0.6583 * sin(dtor(2 * (lprime - LambdaSol))); /* sec 61 #13 */
ldprime = lprime + V; /* sec 61 #14 */
D = ldprime - LambdaSol; /* sec 63 #2 */
return(50 * (1 - cos(dtor(D)))); /* sec 63 #3 */
}
/*
* dtor --
* convert degrees to radians
*/
double
dtor(deg)
double deg;
{
return(deg * PI / 180);
}
/*
* adj360 --
* adjust value so 0 <= deg <= 360
*/
double
adj360(deg)
double *deg;
{
for (;;)
if (*deg < 0)
*deg += 360;
else if (*deg > 360)
*deg -= 360;
else
break;
}