--- ray/src/gen/gensky.c	1996/06/25 20:48:17	2.16
+++ ray/src/gen/gensky.c	2003/11/16 10:29:38	2.22
@@ -1,9 +1,6 @@
-/* Copyright (c) 1992 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: gensky.c,v 2.22 2003/11/16 10:29:38 schorsch Exp $";
 #endif
-
 /*
  *  gensky.c - program to generate sky functions.
  *		Our zenith is along the Z-axis, the X-axis
@@ -14,15 +11,22 @@ static char SCCSid[] = "$SunId$ LBL";
  */
 
 #include  <stdio.h>
-
+#include  <stdlib.h>
+#include  <string.h>
 #include  <math.h>
+#include  <ctype.h>
 
 #include  "color.h"
 
-extern char  *strcpy(), *strcat(), *malloc();
-extern double  stadj(), sdec(), sazi(), salt();
+extern int jdate(int month, int day);
+extern double stadj(int  jd);
+extern double sdec(int  jd);
+extern double salt(double sd, double st);
+extern double sazi(double sd, double st);
 
-#define  PI		3.141592654
+#ifndef  PI
+#define  PI		3.14159265358979323846
+#endif
 
 #define  DOT(v1,v2)	(v1[0]*v2[0]+v1[1]*v2[1]+v1[2]*v2[2])
 
@@ -31,13 +35,39 @@ extern double  stadj(), sdec(), sazi(), salt();
 #define  S_UNIF		3
 #define  S_INTER	4
 
-#define  overcast	(skytype==S_OVER|skytype==S_UNIF)
+#define  overcast	((skytype==S_OVER)|(skytype==S_UNIF))
 
 double  normsc();
 					/* sun calculation constants */
 extern double  s_latitude;
 extern double  s_longitude;
 extern double  s_meridian;
+
+#undef  toupper
+#define  toupper(c)	((c) & ~0x20)	/* ASCII trick to convert case */
+
+					/* European and North American zones */
+struct {
+	char	zname[8];	/* time zone name (all caps) */
+	float	zmer;		/* standard meridian */
+} tzone[] = {
+	{"YST", 135}, {"YDT", 120},
+	{"PST", 120}, {"PDT", 105},
+	{"MST", 105}, {"MDT", 90},
+	{"CST", 90}, {"CDT", 75},
+	{"EST", 75}, {"EDT", 60},
+	{"AST", 60}, {"ADT", 45},
+	{"NST", 52.5}, {"NDT", 37.5},
+	{"GMT", 0}, {"BST", -15},
+	{"CET", -15}, {"CEST", -30},
+	{"EET", -30}, {"EEST", -45},
+	{"AST", -45}, {"ADT", -60},
+	{"GST", -60}, {"GDT", -75},
+	{"IST", -82.5}, {"IDT", -97.5},
+	{"JST", -135}, {"NDT", -150},
+	{"NZST", -180}, {"NZDT", -195},
+	{"", 0}
+};
 					/* required values */
 int  month, day;				/* date */
 double  hour;					/* time */
@@ -60,7 +90,16 @@ int	u_solar = 0;				/* -1=irradiance, 1=radiance */
 char  *progname;
 char  errmsg[128];
 
+void computesky(void);
+void printsky(void);
+void printdefaults(void);
+void userror(char  *msg);
+double normsc(void);
+void cvthour(char  *hs);
+void printhead(register int  ac, register char  **av);
 
+
+int
 main(argc, argv)
 int  argc;
 char  *argv[];
@@ -136,7 +175,7 @@ char  *argv[];
 		else
 			userror("bad option");
 
-	if (fabs(s_meridian-s_longitude) > 30*PI/180)
+	if (fabs(s_meridian-s_longitude) > 45*PI/180)
 		fprintf(stderr,
 	"%s: warning: %.1f hours btwn. standard meridian and longitude\n",
 			progname, (s_longitude-s_meridian)*12/PI);
@@ -150,7 +189,8 @@ char  *argv[];
 }
 
 
-computesky()			/* compute sky parameters */
+void
+computesky(void)			/* compute sky parameters */
 {
 	double	normfactor;
 					/* compute solar direction */
@@ -166,6 +206,7 @@ computesky()			/* compute sky parameters */
 			st = hour + stadj(jd);
 		altitude = salt(sd, st);
 		azimuth = sazi(sd, st);
+		printf("# Local solar time: %.2f\n", st);
 		printf("# Solar altitude and azimuth: %.1f %.1f\n",
 				180./PI*altitude, 180./PI*azimuth);
 	}
@@ -234,7 +275,8 @@ computesky()			/* compute sky parameters */
 }
 
 
-printsky()			/* print out sky */
+void
+printsky(void)			/* print out sky */
 {
 	if (dosun) {
 		printf("\nvoid light solar\n");
@@ -257,7 +299,8 @@ printsky()			/* print out sky */
 }
 
 
-printdefaults()			/* print default values */
+void
+printdefaults(void)			/* print default values */
 {
 	switch (skytype) {
 	case S_OVER:
@@ -290,8 +333,10 @@ printdefaults()			/* print default values */
 }
 
 
-userror(msg)			/* print usage error and quit */
-char  *msg;
+void
+userror(			/* print usage error and quit */
+	char  *msg
+)
 {
 	if (msg != NULL)
 		fprintf(stderr, "%s: Use error - %s\n", progname, msg);
@@ -303,7 +348,7 @@ char  *msg;
 
 
 double
-normsc()			/* compute normalization factor (E0*F2/L0) */
+normsc(void)			/* compute normalization factor (E0*F2/L0) */
 {
 	static double  nfc[2][5] = {
 				/* clear sky approx. */
@@ -325,24 +370,54 @@ normsc()			/* compute normalization factor (E0*F2/L0) 
 }
 
 
-cvthour(hs)			/* convert hour string */
-char  *hs;
+void
+cvthour(			/* convert hour string */
+	char  *hs
+)
 {
 	register char  *cp = hs;
+	register int	i, j;
 
-	while (*cp && *cp++ != ':')
-		;
-	if (*cp)
-		hour = atoi(hs) + atoi(cp)/60.0;
-	else
+	if ( (tsolar = *cp == '+') ) cp++;		/* solar time? */
+	while (isdigit(*cp)) cp++;
+	if (*cp == ':')
+		hour = atoi(hs) + atoi(++cp)/60.0;
+	else {
 		hour = atof(hs);
-	tsolar = *hs == '+';
+		if (*cp == '.') cp++;
+	}
+	while (isdigit(*cp)) cp++;
+	if (!*cp)
+		return;
+	if (tsolar || !isalpha(*cp)) {
+		fprintf(stderr, "%s: bad time format: %s\n", progname, hs);
+		exit(1);
+	}
+	i = 0;
+	do {
+		for (j = 0; cp[j]; j++)
+			if (toupper(cp[j]) != tzone[i].zname[j])
+				break;
+		if (!cp[j] && !tzone[i].zname[j]) {
+			s_meridian = tzone[i].zmer * (PI/180);
+			return;
+		}
+	} while (tzone[i++].zname[0]);
+
+	fprintf(stderr, "%s: unknown time zone: %s\n", progname, cp);
+	fprintf(stderr, "Known time zones:\n\t%s", tzone[0].zname);
+	for (i = 1; tzone[i].zname[0]; i++)
+		fprintf(stderr, " %s", tzone[i].zname);
+	putc('\n', stderr);
+	exit(1);
 }
 
 
-printhead(ac, av)		/* print command header */
-register int  ac;
-register char  **av;
+void
+printhead(		/* print command header */
+	register int  ac,
+	register char  **av
+)
 {
 	putchar('#');
 	while (ac--) {