--- ray/src/cv/lampcolor.c	1991/09/12 13:26:16	1.5
+++ ray/src/cv/lampcolor.c	2003/06/21 15:05:01	2.8
@@ -1,21 +1,17 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: lampcolor.c,v 2.8 2003/06/21 15:05:01 greg Exp $";
 #endif
-
 /*
  * Program to convert lamp color from table and compute radiance.
  */
 
 #include <stdio.h>
+#include <string.h>
+#include <math.h>
 
-#define PI	3.14159265358979323846
+#include "standard.h"
+#include "color.h"
 
-extern char	*gets(), *strcpy();
-extern double	atof();
-extern float	*matchlamp();
-
 				/* lamp parameters */
 #define LTYPE		0
 #define LUNIT		1
@@ -23,11 +19,17 @@ extern float	*matchlamp();
 #define LOUTP		3
 #define NPARAMS		4
 
-int	typecheck(), unitcheck(), geomcheck(), outpcheck();
+static int typecheck(char *s);
+static int unitcheck(char *s);
+static int geomcheck(char *s);
+static int outpcheck(char *s);
+static void compute(void);
+static int getpolygon(void), getsphere(void), getcylinder(void), getring(void);
 
+
 float	*lampcolor;		/* the lamp color (RGB) */
 double	unit2meter;		/* conversion from units to meters */
-double	projarea;		/* projected area for this geometry */
+double	area;			/* radiating area for this geometry */
 double	lumens;			/* total lamp lumens */
 
 struct {
@@ -36,9 +38,9 @@ struct {
 	int	(*check)();
 	char	*help;
 } param[NPARAMS] = {
-	{ "lamp type", "white", typecheck,
+	{ "lamp type", "WHITE", typecheck,
 "The lamp type is a string which corresponds to one of the types registered\n\
-in the lamp table file.  A value of \"white\" means an uncolored source,\n\
+in the lamp table file.  A value of \"WHITE\" means an uncolored source,\n\
 which may be preferable because it results in a color balanced image." },
 	{ "length unit", "meter", unitcheck,
 "Unit must be one of:  \"meter\", \"centimeter\", \"foot\", or \"inch\".\n\
@@ -93,16 +95,20 @@ char	*argv[];
 }
 
 
-typecheck(s)			/* check lamp type */
-char	*s;
+static int
+typecheck(			/* check lamp type */
+char	*s
+)
 {
 	lampcolor = matchlamp(s);
 	return(lampcolor != NULL);
 }
 
 
-unitcheck(s)			/* compute conversion to meters */
-char	*s;
+static int
+unitcheck(			/* compute conversion to meters */
+char	*s
+)
 {
 	int	len = strlen(s);
 
@@ -132,8 +138,10 @@ char	*s;
 }
 
 
-geomcheck(s)			/* check/set lamp geometry */
-char	*s;
+static int
+geomcheck(			/* check/set lamp geometry */
+char	*s
+)
 {
 	int	len = strlen(s);
 
@@ -159,8 +167,10 @@ char	*s;
 }
 
 
-outpcheck(s)			/* check lumen output value */
-register char	*s;
+static int
+outpcheck(			/* check lumen output value */
+register char	*s
+)
 {
 	if ((*s < '0' || *s > '9') && *s != '.')
 		return(0);
@@ -169,11 +179,12 @@ register char	*s;
 }
 
 
-compute()			/* compute lamp radiance */
+static void
+compute(void)			/* compute lamp radiance */
 {
 	double	whiteval;
 
-	whiteval = lumens/470./projarea;
+	whiteval = lumens/area/(WHTEFFICACY*PI);
 
 	printf("Lamp color (RGB) = %f %f %f\n",
 			lampcolor[0]*whiteval,
@@ -182,13 +193,20 @@ compute()			/* compute lamp radiance */
 }
 
 
-getd(dp)			/* get a positive double from stdin */
+getd(name, dp, help)		/* get a positive double from stdin */
+char	*name;
 double	*dp;
+char	*help;
 {
 	char	buf[32];
-
+again:
+	printf("%s [%g]: ", name, *dp);
 	if (gets(buf) == NULL)
 		return(0);
+	if (buf[0] == '?') {
+		puts(help);
+		goto again;
+	}
 	if ((buf[0] < '0' || buf[0] > '9') && buf[0] != '.')
 		return(0);
 	*dp = atof(buf);
@@ -196,47 +214,52 @@ double	*dp;
 }
 
 
-getpolygon()			/* get projected area for a polygon */
+static int
+getpolygon(void)			/* get projected area for a polygon */
 {
-	static double	area = 1.0;
+	static double	parea = 1.0;
 
-	printf("Polygon area [%g]: ", area);
-	getd(&area);
-	projarea = PI*unit2meter*unit2meter * area;
+	getd("Polygon area", &parea,
+		"Enter the total radiating area of the polygon.");
+	area = unit2meter*unit2meter * parea;
 	return(1);
 }
 
 
-getsphere()			/* get projected area for a sphere */
+static int
+getsphere(void)			/* get projected area for a sphere */
 {
 	static double	radius = 1.0;
 
-	printf("Sphere radius [%g]: ", radius);
-	getd(&radius);
-	projarea = 4.*PI*PI*unit2meter*unit2meter * radius*radius;
+	getd("Sphere radius", &radius,
+		"Enter the distance from the sphere's center to its surface.");
+	area = 4.*PI*unit2meter*unit2meter * radius*radius;
 	return(1);
 }
 
 
-getcylinder()			/* get projected area for a cylinder */
+static int
+getcylinder(void)			/* get projected area for a cylinder */
 {
 	static double	length = 1.0, radius = 0.1;
 
-	printf("Cylinder length [%g]: ", length);
-	getd(&length);
-	printf("Cylinder radius [%g]: ", radius);
-	getd(&radius);
-	projarea = PI*PI*2.*PI*unit2meter*unit2meter * radius*length;
+	getd("Cylinder length", &length,
+		"Enter the length of the cylinder.");
+	getd("Cylinder radius", &radius,
+		"Enter the distance from the cylinder's axis to its surface.");
+	area = 2.*PI*unit2meter*unit2meter * radius*length;
 	return(1);
 }
 
 
-getring()			/* get projected area for a ring */
+static int
+getring(void)			/* get projected area for a ring */
 {
 	static double	radius = 1.0;
 
-	printf("Disk radius [%g]: ", radius);
-	getd(&radius);
-	projarea = PI*PI*unit2meter*unit2meter * radius*radius;
+	getd("Disk radius", &radius,
+"Enter the distance from the ring's center to its outer edge.\n\
+The inner radius must be zero.");
+	area = PI*unit2meter*unit2meter * radius*radius;
 	return(1);
 }