src/cv/lampcolor.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 * Program to convert lamp color from table and compute radiance.
 */

#include <stdio.h>

#include "color.h"

#define PI      3.14159265358979323846

extern char     *gets(), *strcpy();
extern double   atof();
extern float    *matchlamp();

                                /* lamp parameters */
#define LTYPE           0
#define LUNIT           1
#define LGEOM           2
#define LOUTP           3
#define NPARAMS         4

int     typecheck(), unitcheck(), geomcheck(), outpcheck();

float   *lampcolor;             /* the lamp color (RGB) */
double  unit2meter;             /* conversion from units to meters */
double  area;                   /* radiating area for this geometry */
double  lumens;                 /* total lamp lumens */

struct {
        char    *name;
        char    value[64];
        int     (*check)();
        char    *help;
} param[NPARAMS] = {
        { "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\
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\
These may be abbreviated as a single letter." },
        { "lamp geometry", "polygon", geomcheck,
"The lamp geometry must be one of:  \"polygon\", \"sphere\", \"cylinder\"\n\
or \"ring\".  These may be abbreviated as a single letter." },
        { "total lamp lumens", "0", outpcheck,
"This is the overall light output of the lamp and its fixture.  If you do\n\
not know this value explicitly, you can compute the approximate lumens\n\
by multiplying the input wattage by 14 for incandescent fixtures or 70\n\
for fluorescent fixtures." },
};


main(argc, argv)
int     argc;
char    *argv[];
{
        char    *lamptab = "lamp.tab";
        char    buf[64];
        int     i;

        if (argc > 1) lamptab = argv[1];
        if (loadlamps(lamptab) == 0) {
                fprintf(stderr, "%s: no such lamp table\n", lamptab);
                exit(1);
        }
        printf("Program to compute lamp radiance.  Enter '?' for help.\n");
        for ( ; ; ) {
                i = 0;
                while (i < NPARAMS) {
                        printf("Enter %s [%s]: ", param[i].name,
                                        param[i].value);
                        if (gets(buf) == NULL)
                                exit(0);
                        if (buf[0] == '?') {
                                puts(param[i].help);
                                continue;
                        }
                        if (buf[0])
                                strcpy(param[i].value, buf);
                        if (!(*param[i].check)(param[i].value)) {
                                fprintf(stderr, "%s: bad value for %s\n",
                                                param[i].value, param[i].name);
                                continue;
                        }
                        i++;
                }
                compute();
        }
}


typecheck(s)                    /* check lamp type */
char    *s;
{
        lampcolor = matchlamp(s);
        return(lampcolor != NULL);
}


unitcheck(s)                    /* compute conversion to meters */
char    *s;
{
        int     len = strlen(s);

        switch (*s) {
        case 'm':
                if (strncmp(s, "meters", len))
                        return(0);
                unit2meter = 1.0;
                return(1);
        case 'c':
                if (strncmp(s, "centimeters", len) && strncmp(s, "cms", len))
                        return(0);
                unit2meter = 0.01;
                return(1);
        case 'f':
                if (strncmp(s, "foot", len) && strncmp(s, "feet", len))
                        return(0);
                unit2meter = 0.3048;
                return(1);
        case 'i':
                if (strncmp(s, "inches", len))
                        return(0);
                unit2meter = 0.0254;
                return(1);
        }
        return(0);
}


geomcheck(s)                    /* check/set lamp geometry */
char    *s;
{
        int     len = strlen(s);

        switch (*s) {
        case 'p':
                if (strncmp(s, "polygonal", len))
                        return(0);
                return(getpolygon());
        case 's':
                if (strncmp(s, "sphere", len) && strncmp(s, "spherical", len))
                        return(0);
                return(getsphere());
        case 'c':
                if (strncmp(s,"cylinder",len) && strncmp(s,"cylindrical",len))
                        return(0);
                return(getcylinder());
        case 'r':
                if (strncmp(s, "ring", len) && strncmp(s, "disk", len))
                        return(0);
                return(getring());
        }
        return(0);
}


outpcheck(s)                    /* check lumen output value */
register char   *s;
{
        if ((*s < '0' || *s > '9') && *s != '.')
                return(0);
        lumens = atof(s);
        return(1);
}


compute()                       /* compute lamp radiance */
{
        double  whiteval;

        whiteval = lumens/area/(WHTEFFICACY*PI);

        printf("Lamp color (RGB) = %f %f %f\n",
                        lampcolor[0]*whiteval,
                        lampcolor[1]*whiteval,
                        lampcolor[2]*whiteval);
}


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);
        return(1);
}


getpolygon()                    /* get projected area for a polygon */
{
        static double   area = 1.0;

        getd("Polygon area", &area,
                "Enter the total radiating area of the polygon.");
        area = unit2meter*unit2meter * area;
        return(1);
}


getsphere()                     /* get projected area for a sphere */
{
        static double   radius = 1.0;

        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 double   length = 1.0, radius = 0.1;

        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 double   radius = 1.0;

        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);
}
Revision:	1.8
Committed:	Thu Oct 24 12:17:38 1991 UTC (32 years, 11 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.7:	+3 -1 lines
Log Message:	fixed conversion between lumens and watts
#	User	Rev	Content
1	greg	1.1	/* Copyright (c) 1991 Regents of the University of California */
2
3			#ifndef lint
4			static char SCCSid[] = "$SunId$ LBL";
5			#endif
6
7			/*
8	greg	1.2	* Program to convert lamp color from table and compute radiance.
9	greg	1.1	*/
10
11			#include <stdio.h>
12
13	greg	1.8	#include "color.h"
14
15	greg	1.2	#define PI 3.14159265358979323846
16
17			extern char gets(), strcpy();
18			extern double atof();
19	greg	1.1	extern float *matchlamp();
20
21	greg	1.2	/* lamp parameters */
22			#define LTYPE 0
23			#define LUNIT 1
24			#define LGEOM 2
25			#define LOUTP 3
26			#define NPARAMS 4
27	greg	1.1
28	greg	1.2	int typecheck(), unitcheck(), geomcheck(), outpcheck();
29
30			float lampcolor; / the lamp color (RGB) */
31			double unit2meter; /* conversion from units to meters */
32	greg	1.7	double area; /* radiating area for this geometry */
33	greg	1.2	double lumens; /* total lamp lumens */
34
35			struct {
36			char *name;
37			char value[64];
38			int (*check)();
39			char *help;
40			} param[NPARAMS] = {
41			{ "lamp type", "white", typecheck,
42			"The lamp type is a string which corresponds to one of the types registered\n\
43			in the lamp table file. A value of \"white\" means an uncolored source,\n\
44			which may be preferable because it results in a color balanced image." },
45			{ "length unit", "meter", unitcheck,
46			"Unit must be one of: \"meter\", \"centimeter\", \"foot\", or \"inch\".\n\
47			These may be abbreviated as a single letter." },
48			{ "lamp geometry", "polygon", geomcheck,
49			"The lamp geometry must be one of: \"polygon\", \"sphere\", \"cylinder\"\n\
50			or \"ring\". These may be abbreviated as a single letter." },
51			{ "total lamp lumens", "0", outpcheck,
52			"This is the overall light output of the lamp and its fixture. If you do\n\
53			not know this value explicitly, you can compute the approximate lumens\n\
54	greg	1.3	by multiplying the input wattage by 14 for incandescent fixtures or 70\n\
55	greg	1.2	for fluorescent fixtures." },
56			};
57
58
59	greg	1.1	main(argc, argv)
60			int argc;
61			char *argv[];
62			{
63			char *lamptab = "lamp.tab";
64	greg	1.2	char buf[64];
65			int i;
66	greg	1.1
67			if (argc > 1) lamptab = argv[1];
68			if (loadlamps(lamptab) == 0) {
69	greg	1.2	fprintf(stderr, "%s: no such lamp table\n", lamptab);
70	greg	1.1	exit(1);
71			}
72	greg	1.2	printf("Program to compute lamp radiance. Enter '?' for help.\n");
73	greg	1.1	for ( ; ; ) {
74	greg	1.2	i = 0;
75			while (i < NPARAMS) {
76			printf("Enter %s [%s]: ", param[i].name,
77			param[i].value);
78			if (gets(buf) == NULL)
79			exit(0);
80			if (buf[0] == '?') {
81			puts(param[i].help);
82			continue;
83			}
84			if (buf[0])
85			strcpy(param[i].value, buf);
86			if (!(*param[i].check)(param[i].value)) {
87			fprintf(stderr, "%s: bad value for %s\n",
88			param[i].value, param[i].name);
89			continue;
90			}
91			i++;
92			}
93			compute();
94	greg	1.1	}
95	greg	1.2	}
96
97
98			typecheck(s) /* check lamp type */
99			char *s;
100			{
101			lampcolor = matchlamp(s);
102			return(lampcolor != NULL);
103			}
104
105
106			unitcheck(s) /* compute conversion to meters */
107			char *s;
108			{
109			int len = strlen(s);
110
111			switch (*s) {
112			case 'm':
113			if (strncmp(s, "meters", len))
114			return(0);
115			unit2meter = 1.0;
116			return(1);
117			case 'c':
118			if (strncmp(s, "centimeters", len) && strncmp(s, "cms", len))
119			return(0);
120			unit2meter = 0.01;
121			return(1);
122			case 'f':
123			if (strncmp(s, "foot", len) && strncmp(s, "feet", len))
124			return(0);
125			unit2meter = 0.3048;
126			return(1);
127			case 'i':
128			if (strncmp(s, "inches", len))
129			return(0);
130			unit2meter = 0.0254;
131			return(1);
132			}
133			return(0);
134			}
135
136
137			geomcheck(s) /* check/set lamp geometry */
138			char *s;
139			{
140			int len = strlen(s);
141
142			switch (*s) {
143			case 'p':
144			if (strncmp(s, "polygonal", len))
145			return(0);
146			return(getpolygon());
147			case 's':
148			if (strncmp(s, "sphere", len) && strncmp(s, "spherical", len))
149			return(0);
150			return(getsphere());
151			case 'c':
152			if (strncmp(s,"cylinder",len) && strncmp(s,"cylindrical",len))
153			return(0);
154			return(getcylinder());
155			case 'r':
156			if (strncmp(s, "ring", len) && strncmp(s, "disk", len))
157			return(0);
158			return(getring());
159			}
160			return(0);
161			}
162
163
164			outpcheck(s) /* check lumen output value */
165			register char *s;
166			{
167			if ((s < '0' \|\| s > '9') && *s != '.')
168			return(0);
169			lumens = atof(s);
170			return(1);
171			}
172
173
174			compute() /* compute lamp radiance */
175			{
176			double whiteval;
177
178	greg	1.8	whiteval = lumens/area/(WHTEFFICACY*PI);
179	greg	1.2
180			printf("Lamp color (RGB) = %f %f %f\n",
181			lampcolor[0]*whiteval,
182			lampcolor[1]*whiteval,
183			lampcolor[2]*whiteval);
184			}
185
186
187	greg	1.6	getd(name, dp, help) /* get a positive double from stdin */
188			char *name;
189	greg	1.2	double *dp;
190	greg	1.6	char *help;
191	greg	1.2	{
192			char buf[32];
193	greg	1.6	again:
194			printf("%s [%g]: ", name, *dp);
195	greg	1.2	if (gets(buf) == NULL)
196			return(0);
197	greg	1.6	if (buf[0] == '?') {
198			puts(help);
199			goto again;
200			}
201	greg	1.2	if ((buf[0] < '0' \|\| buf[0] > '9') && buf[0] != '.')
202			return(0);
203			*dp = atof(buf);
204			return(1);
205			}
206
207
208			getpolygon() /* get projected area for a polygon */
209			{
210	greg	1.5	static double area = 1.0;
211
212	greg	1.6	getd("Polygon area", &area,
213			"Enter the total radiating area of the polygon.");
214	greg	1.7	area = unit2meterunit2meter area;
215	greg	1.2	return(1);
216			}
217
218
219			getsphere() /* get projected area for a sphere */
220			{
221	greg	1.5	static double radius = 1.0;
222	greg	1.2
223	greg	1.6	getd("Sphere radius", &radius,
224			"Enter the distance from the sphere's center to its surface.");
225	greg	1.7	area = 4.PIunit2meterunit2meter radius*radius;
226	greg	1.2	return(1);
227			}
228
229
230			getcylinder() /* get projected area for a cylinder */
231			{
232	greg	1.5	static double length = 1.0, radius = 0.1;
233	greg	1.2
234	greg	1.6	getd("Cylinder length", &length,
235			"Enter the length of the cylinder.");
236			getd("Cylinder radius", &radius,
237			"Enter the distance from the cylinder's axis to its surface.");
238	greg	1.7	area = 2.PIunit2meterunit2meter radius*length;
239	greg	1.2	return(1);
240			}
241
242
243			getring() /* get projected area for a ring */
244			{
245	greg	1.5	static double radius = 1.0;
246	greg	1.2
247	greg	1.6	getd("Disk radius", &radius,
248			"Enter the distance from the ring's center to its outer edge.\n\
249			The inner radius must be zero.");
250	greg	1.7	area = PIunit2meterunit2meter * radius*radius;
251	greg	1.2	return(1);
252	greg	1.1	}