Import sources from 2011-03-30 iso image

1 files changed, 104 insertions, 0 deletions

diff --git a/sys/src/cmd/astro/stars.c b/sys/src/cmd/astro/stars.c
new file mode 100755
index 000000000..4cee5ef10
--- /dev/null
+++ b/sys/src/cmd/astro/stars.c
@@ -0,0 +1,104 @@
+#include "astro.h"
+
+char*	startab = "/lib/sky/estartab";
+
+void
+stars(void)
+{
+	double lomoon, himoon, sd;
+	int wrap, f, i;
+	char *saop;
+	static char saoa[100];
+
+	sd = 1000*radsec;
+	lomoon = omoon.point[0].ra - sd;
+	if(lomoon < 0)
+		lomoon += pipi;
+	himoon = omoon.point[NPTS+1].ra + sd;
+	if(himoon > pipi)
+		himoon -= pipi;
+	lomoon *= 12/pi;
+	himoon *= 12/pi;
+	wrap = 0;
+	if(lomoon > himoon)
+		wrap++;
+
+	f = open(startab, OREAD);
+	if(f < 0) {
+		fprint(2, "%s?\n", startab);
+		return;
+	}
+	epoch = 1950.0;
+	epoch = (epoch-1900.0) * 365.24220 + 0.313;
+	saop = saoa;
+
+/*
+ *	read mean places of stars at epoch of star table
+ */
+
+loop:
+	if(rline(f)) {
+		close(f);
+		return;
+	}
+	rah = atof(line+17);
+	ram = atof(line+20);
+	ras = atof(line+23);
+
+	alpha = rah + ram/60 + ras/3600;
+	if(wrap == 0) {
+		if(alpha < lomoon || alpha > himoon)
+			goto loop;
+	} else
+		if(alpha < lomoon && alpha > himoon)
+			goto loop;
+
+	sao = atof(line+0);
+	sprint(saop, "%ld", sao);
+	da = atof(line+30);
+	dday = atof(line+37);
+	dmin = atof(line+41);
+	dsec = atof(line+44);
+	dd = atof(line+50);
+	px = atof(line+57);
+	mag = atof(line+61);
+
+/*
+ *	convert rt ascension and declination to internal format
+ */
+
+	delta = fabs(dday) + dmin/60 + dsec/3600;
+	if(dday < 0)
+		delta = -delta;
+
+	star();
+/*
+ *	if(fabs(beta) > 6.55*radian)
+ *		goto loop;
+ */
+	sd = .0896833e0*cos(beta)*sin(lambda-1.3820+.00092422117*eday)
+		 + 0.99597*sin(beta);
+	if(fabs(sd) > .0183)
+		goto loop;
+
+	for(i=0; i<=NPTS+1; i++)
+		setobj(&ostar.point[i]);
+
+	occult(&omoon, &ostar, 0);
+	if(occ.t1 >= 0 || occ.t5 >= 0) {
+		i = PTIME;
+		if(mag > 2)
+			i |= DARK;
+		if(mag < 5)
+			i |= SIGNIF;
+		if(occ.t1 >= 0 && occ.e1 >= 0)
+			event("Occultation of SAO %s begins at ",
+				saop, "", occ.t1, i);
+		if(occ.t5 >= 0 && occ.e5 >= 0)
+			event("Occultation of SAO %s ends at ",
+				saop, "", occ.t5, i);
+		while(*saop++)
+			;
+	}
+	goto loop;
+}