harvey/sys/src/cmd/astro/init.c

/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */

#include "astro.h"

Obj2*	objlst[] =
{
	&osun,
	&omoon,
	&oshad,
	&omerc,
	&ovenus,
	&omars,
	&ojup,
	&osat,
	&ouran,
	&onept,
	&oplut,
	&ocomet,
	0,
};

struct	idata
{
	char*	name;
	char*	name1;
	void	(*obj)(void);
} idata[] =
{
	"The sun",	"sun",		fsun,
	"The moon",	"moon",		moon,
	"The shadow",	"shadow",	shad,
	"Mercury",	"mercury",	merc,
	"Venus",	"venus",	venus,
	"Mars",		"mars",		mars,
	"Jupiter",	"jupiter",	jup,
	"Saturn",	"saturn",	sat,
	"Uranus",	"uranus",	uran,
	"Neptune",	"neptune",	nept,
	"Pluto",	"pluto",	plut,
	"Comet",	"comet",	comet,
};

void
init(void)
{
	Obj2 *q;
	int i;

	glat = nlat - (692.74*radsec)*sin(2.*nlat)
		 + (1.16*radsec)*sin(4.*nlat);
	erad = .99832707e0 + .00167644e0*cos(2.*nlat)
		 - 0.352e-5*cos(4.*nlat)
		 + 0.001e-5*cos(6.*nlat)
		 + 0.1568e-6*elev;

	for(i=0; q=objlst[i]; i++) {
		q->name = idata[i].name;
		q->name1 = idata[i].name1;
		q->obj = idata[i].obj;
	}
	ostar.obj = fstar;
	ostar.name = "star";
}

void
setime(double d)
{
	double x, xm, ym, zm;

	eday = d + deltat/86400.;
	wlong = awlong + 15.*deltat*radsec;

	capt = eday/36524.220e0;
	capt2 = capt*capt;
	capt3 = capt*capt2;
	nutate();
	eday += .1;
	sun();
	srad = rad;
	xm = rad*cos(beta)*cos(lambda);
	ym = rad*cos(beta)*sin(lambda);
	zm = rad*sin(beta);
	eday -= .1;
	sun();
	xms = rad*cos(beta)*cos(lambda);
	yms = rad*cos(beta)*sin(lambda);
	zms = rad*sin(beta);
	x = .057756;
	xdot = x*(xm-xms);
	ydot = x*(ym-yms);
	zdot = x*(zm-zms);
}

void
setobj(Obj1 *op)
{
	Obj1 *p;

	p = op;
	p->ra = ra;
	p->decl2 = decl2;
	p->semi2 = semi2;
	p->az = az;
	p->el = el;
	p->mag = mag;
}

int32_t	starsao = 0;

void
fstar(void)
{

	ra = ostar.point[0].ra;
	decl2 = ostar.point[0].decl2;
	semi2 = ostar.point[0].semi2;
	az = ostar.point[0].az;
	el = ostar.point[0].el;
	mag = ostar.point[0].mag;
}

void
fsun(void)
{

	beta = 0;
	rad = 0;
	lambda = 0;
	motion = 0;
	helio();
	geo();
	seday = eday;
	salph = alpha;
	sdelt = delta;
	mag = lmb2;
}

void
shad(void)
{

	if(seday != eday)
		fsun();
	if(meday != eday)
		moon();
	alpha = fmod(salph+pi, pipi);
	delta = -sdelt;
	hp = mhp;
	semi = 1.0183*mhp/radsec - 969.85/srad;
	geo();
}