--- ray/src/util/glarendx.c	1991/04/17 08:21:41	1.2
+++ ray/src/util/glarendx.c	1992/04/28 09:11:00	2.2
@@ -5,10 +5,14 @@ static char SCCSid[] = "$SunId$ LBL";
 #endif
 
 /*
- * Compute Glare Index given by program name:
+ * Compute Glare Index given by program name or -t option:
  *
  *	guth_dgr -	Guth discomfort glare rating
  *	guth_vcp -	Guth visual comfort probability
+ *	cie_cgi -	CIE Glare Index (1983, due to Einhorn)
+ *	vert_dir -	Direct vertical illuminance
+ *	vert_ind -	Indirect vertical illuminance (from input)
+ *	vert_ill -	Total vertical illuminance
  *
  *		12 April 1991	Greg Ward	EPFL
  */
@@ -19,17 +23,21 @@ static char SCCSid[] = "$SunId$ LBL";
 extern double	erfc();
 
 double	posindex();
-int	headline();
 
-double	direct(), guth_dgr(), guth_vcp();
+double	direct(), guth_dgr(), guth_vcp(), cie_cgi(),
+	indirect(), total();
 
 struct named_func {
 	char	*name;
 	double	(*func)();
+	char	*descrip;
 } all_funcs[] = {
-	{"direct", direct},
-	{"guth_dgr", guth_dgr},
-	{"guth_vcp", guth_vcp},
+	{"guth_vcp", guth_vcp, "Guth Visual Comfort Probability"},
+	{"cie_cgi", cie_cgi, "CIE Glare Index (Einhorn)"},
+	{"guth_dgr", guth_dgr, "Guth Disability Glare Rating"},
+	{"vert_dir", direct, "Direct Vertical Illuminance"},
+	{"vert_ill", total, "Total Vertical Illuminance"},
+	{"vert_ind", indirect, "Indirect Vertical Illuminance"},
 	{NULL}
 };
 
@@ -53,7 +61,9 @@ int	print_header = 1;
 
 VIEW	midview = STDVIEW;
 
+int	wrongformat = 0;
 
+
 main(argc, argv)
 int	argc;
 char	*argv[];
@@ -88,30 +98,24 @@ char	*argv[];
 			perror(argv[i]);
 			exit(1);
 		}
-					/* read header */
-	getheader(stdin, headline);
-	if (print_header) {		/* add to header */
-		printargs(i, argv, stdout);
-		putchar('\n');
-	}
-					/* set view */
-	if (setview(&midview) != NULL) {
-		fprintf(stderr, "%s: bad view information in input\n");
-		exit(1);
-	}
-					/* get findglare data */
-	read_input();
-					/* find calculation */
+					/* find and run calculation */
 	for (funp = all_funcs; funp->name != NULL; funp++)
 		if (!strcmp(funp->name, progtail)) {
+			init();
+			read_input();
+			if (print_header) {
+				printargs(i, argv, stdout);
+				putchar('\n');
+			}
 			print_values(funp->func);
 			exit(0);		/* we're done */
 		}
 					/* invalid function */
-	fprintf(stderr, "%s: unknown function!\n", progtail);
-	exit(1);
 userr:
-	fprintf(stderr, "Usage: %s [-t type][-h] [input]\n", progname);
+	fprintf(stderr, "Usage: %s -t type [-h] [input]\n", progname);
+	fprintf(stderr, "\twhere 'type' is one of the following:\n");
+	for (funp = all_funcs; funp->name != NULL; funp++)
+		fprintf(stderr, "\t%12s\t%s\n", funp->name, funp->descrip);
 	exit(1);
 }
 
@@ -119,13 +123,36 @@ userr:
 headline(s)			/* get line from header */
 char	*s;
 {
+	char	fmt[32];
+
 	if (print_header)		/* copy to output */
 		fputs(s, stdout);
-	if (!strncmp(s, VIEWSTR, VIEWSTRL))
-		sscanview(&midview, s+VIEWSTRL);
+	if (isview(s))
+		sscanview(&midview, s);
+	else if (isformat(s)) {
+		formatval(fmt, s);
+		wrongformat = strcmp(fmt, "ascii");
+	}
 }
 
 
+init()				/* initialize calculation */
+{
+					/* read header */
+	getheader(stdin, headline, NULL);
+	if (wrongformat) {
+		fprintf(stderr, "%s: bad input format\n", progname);
+		exit(1);
+	}
+					/* set view */
+	if (setview(&midview) != NULL) {
+		fprintf(stderr, "%s: bad view information in input\n",
+				progname);
+		exit(1);
+	}
+}
+
+
 read_input()			/* read glare sources from stdin */
 {
 #define	S_SEARCH	0
@@ -198,7 +225,7 @@ double	(*funp)();
 
 
 double
-direct(gd)			/* compute direct illuminance */
+direct(gd)			/* compute direct vertical illuminance */
 struct glare_dir	*gd;
 {
 	FVECT	mydir;
@@ -216,6 +243,22 @@ struct glare_dir	*gd;
 }
 
 
+double
+indirect(gd)			/* return indirect vertical illuminance */
+struct glare_dir	*gd;
+{
+	return(gd->indirect);
+}
+
+
+double
+total(gd)			/* return total vertical illuminance */
+struct glare_dir	*gd;
+{
+	return(direct(gd)+gd->indirect);
+}
+
+
 /*
  * posindex -	compute glare position index from:
  *
@@ -226,6 +269,7 @@ struct glare_dir	*gd;
  * All vectors are assumed to be normalized.
  * This function is an implementation of the method proposed by
  * Robert Levin in his 1975 JIES article.
+ * This calculation presumes the view direction and up vectors perpendicular.
  * We return a value less than zero for improper positions.
  */
 
@@ -239,8 +283,14 @@ FVECT	sd, vd, vu;
 	d = DOT(sd,vd);
 	if (d <= 0.0)
 		return(-1.0);
+	if (d >= 1.0)
+		return(1.0);
 	sigma = acos(d) * (180./PI);
-	tau = acos(DOT(sd,vu)/sqrt(1.0-d*d)) * (180./PI);
+	d = DOT(sd,vu)/sqrt(1.0-d*d);
+	if (d >= 1.0)
+		tau = 0.0;
+	else
+		tau = acos(d) * (180./PI);
 	return( exp( sigma*( (35.2 - tau*.31889 - 1.22*exp(-.22222*tau))*1e-3
 			+ sigma*(21. + tau*(.26667 + tau*-.002963))*1e-5 )
 		) );
@@ -253,23 +303,27 @@ struct glare_dir	*gd;
 {
 #define q(w)	(20.4*w+1.52*pow(w,.2)-.075)
 	register struct glare_src	*gs;
+	FVECT	mydir;
 	double	p;
 	double	sum;
+	double	wtot, brsum;
 	int	n;
 
-	sum = 0.0; n = 0;
+	spinvector(mydir, midview.vdir, midview.vup, gd->ang);
+	sum = wtot = brsum = 0.0; n = 0;
 	for (gs = all_srcs; gs != NULL; gs = gs->next) {
-		p = posindex(gs->dir, midview.vdir, midview.vup);
+		p = posindex(gs->dir, mydir, midview.vup);
 		if (p <= FTINY)
 			continue;
 		sum += gs->lum * q(gs->dom) / p;
+		brsum += gs->lum * gs->dom;
+		wtot += gs->dom;
 		n++;
 	}
 	if (n == 0)
 		return(0.0);
-	else
-		return( pow(
-			.5*sum/pow(direct(gd)+gd->indirect,.44),
+
+	return( pow(.5*sum/pow((brsum+(5.-wtot)*gd->indirect/PI)/5.,.44),
 			pow((double)n, -.0914) ) );
 #undef q
 }
@@ -288,5 +342,35 @@ double
 guth_vcp(gd)		/* compute Guth visual comfort probability */
 struct glare_dir	*gd;
 {
-	return(100.*norm_integral(-6.374+1.3227*log(guth_dgr(gd))));
+	double	dgr;
+
+	dgr = guth_dgr(gd);
+	if (dgr <= FTINY)
+		return(100.0);
+	return(100.*norm_integral(6.374-1.3227*log(dgr)));
+}
+
+
+double
+cie_cgi(gd)		/* compute CIE Glare Index */
+struct glare_dir	*gd;
+{
+	register struct glare_src	*gs;
+	FVECT	mydir;
+	double	dillum;
+	double	p;
+	double	sum;
+
+	spinvector(mydir, midview.vdir, midview.vup, gd->ang);
+	sum = 0.0;
+	for (gs = all_srcs; gs != NULL; gs = gs->next) {
+		p = posindex(gs->dir, mydir, midview.vup);
+		if (p <= FTINY)
+			continue;
+		sum += gs->lum*gs->lum * gs->dom / (p*p);
+	}
+	if (sum <= FTINY)
+		return(0.0);
+	dillum = direct(gd);
+	return(8.*log10(2.*sum*(1.+dillum/500.)/(dillum+gd->indirect)));
 }