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root/radiance/ray/src/cv/lampcolor.c
Revision: 2.4
Committed: Fri Jun 4 14:32:44 1993 UTC (30 years, 10 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.3: +2 -3 lines
Log Message:
Removed unnecessary declaration of atof()

File Contents

# 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 2.4 #include <math.h>
14    
15 greg 1.8 #include "color.h"
16    
17 greg 1.2 #define PI 3.14159265358979323846
18    
19     extern char *gets(), *strcpy();
20 greg 1.1 extern float *matchlamp();
21    
22 greg 1.2 /* lamp parameters */
23     #define LTYPE 0
24     #define LUNIT 1
25     #define LGEOM 2
26     #define LOUTP 3
27     #define NPARAMS 4
28 greg 1.1
29 greg 1.2 int typecheck(), unitcheck(), geomcheck(), outpcheck();
30    
31     float *lampcolor; /* the lamp color (RGB) */
32     double unit2meter; /* conversion from units to meters */
33 greg 1.7 double area; /* radiating area for this geometry */
34 greg 1.2 double lumens; /* total lamp lumens */
35    
36     struct {
37     char *name;
38     char value[64];
39     int (*check)();
40     char *help;
41     } param[NPARAMS] = {
42 greg 2.3 { "lamp type", "D65WHITE", typecheck,
43 greg 1.2 "The lamp type is a string which corresponds to one of the types registered\n\
44 greg 2.3 in the lamp table file. A value of \"D65WHITE\" means an uncolored source,\n\
45 greg 1.2 which may be preferable because it results in a color balanced image." },
46     { "length unit", "meter", unitcheck,
47     "Unit must be one of: \"meter\", \"centimeter\", \"foot\", or \"inch\".\n\
48     These may be abbreviated as a single letter." },
49     { "lamp geometry", "polygon", geomcheck,
50     "The lamp geometry must be one of: \"polygon\", \"sphere\", \"cylinder\"\n\
51     or \"ring\". These may be abbreviated as a single letter." },
52     { "total lamp lumens", "0", outpcheck,
53     "This is the overall light output of the lamp and its fixture. If you do\n\
54     not know this value explicitly, you can compute the approximate lumens\n\
55 greg 1.3 by multiplying the input wattage by 14 for incandescent fixtures or 70\n\
56 greg 1.2 for fluorescent fixtures." },
57     };
58    
59    
60 greg 1.1 main(argc, argv)
61     int argc;
62     char *argv[];
63     {
64     char *lamptab = "lamp.tab";
65 greg 1.2 char buf[64];
66     int i;
67 greg 1.1
68     if (argc > 1) lamptab = argv[1];
69     if (loadlamps(lamptab) == 0) {
70 greg 1.2 fprintf(stderr, "%s: no such lamp table\n", lamptab);
71 greg 1.1 exit(1);
72     }
73 greg 1.2 printf("Program to compute lamp radiance. Enter '?' for help.\n");
74 greg 1.1 for ( ; ; ) {
75 greg 1.2 i = 0;
76     while (i < NPARAMS) {
77     printf("Enter %s [%s]: ", param[i].name,
78     param[i].value);
79     if (gets(buf) == NULL)
80     exit(0);
81     if (buf[0] == '?') {
82     puts(param[i].help);
83     continue;
84     }
85     if (buf[0])
86     strcpy(param[i].value, buf);
87     if (!(*param[i].check)(param[i].value)) {
88     fprintf(stderr, "%s: bad value for %s\n",
89     param[i].value, param[i].name);
90     continue;
91     }
92     i++;
93     }
94     compute();
95 greg 1.1 }
96 greg 1.2 }
97    
98    
99     typecheck(s) /* check lamp type */
100     char *s;
101     {
102     lampcolor = matchlamp(s);
103     return(lampcolor != NULL);
104     }
105    
106    
107     unitcheck(s) /* compute conversion to meters */
108     char *s;
109     {
110     int len = strlen(s);
111    
112     switch (*s) {
113     case 'm':
114     if (strncmp(s, "meters", len))
115     return(0);
116     unit2meter = 1.0;
117     return(1);
118     case 'c':
119     if (strncmp(s, "centimeters", len) && strncmp(s, "cms", len))
120     return(0);
121     unit2meter = 0.01;
122     return(1);
123     case 'f':
124     if (strncmp(s, "foot", len) && strncmp(s, "feet", len))
125     return(0);
126     unit2meter = 0.3048;
127     return(1);
128     case 'i':
129     if (strncmp(s, "inches", len))
130     return(0);
131     unit2meter = 0.0254;
132     return(1);
133     }
134     return(0);
135     }
136    
137    
138     geomcheck(s) /* check/set lamp geometry */
139     char *s;
140     {
141     int len = strlen(s);
142    
143     switch (*s) {
144     case 'p':
145     if (strncmp(s, "polygonal", len))
146     return(0);
147     return(getpolygon());
148     case 's':
149     if (strncmp(s, "sphere", len) && strncmp(s, "spherical", len))
150     return(0);
151     return(getsphere());
152     case 'c':
153     if (strncmp(s,"cylinder",len) && strncmp(s,"cylindrical",len))
154     return(0);
155     return(getcylinder());
156     case 'r':
157     if (strncmp(s, "ring", len) && strncmp(s, "disk", len))
158     return(0);
159     return(getring());
160     }
161     return(0);
162     }
163    
164    
165     outpcheck(s) /* check lumen output value */
166     register char *s;
167     {
168     if ((*s < '0' || *s > '9') && *s != '.')
169     return(0);
170     lumens = atof(s);
171     return(1);
172     }
173    
174    
175     compute() /* compute lamp radiance */
176     {
177     double whiteval;
178    
179 greg 1.8 whiteval = lumens/area/(WHTEFFICACY*PI);
180 greg 1.2
181     printf("Lamp color (RGB) = %f %f %f\n",
182     lampcolor[0]*whiteval,
183     lampcolor[1]*whiteval,
184     lampcolor[2]*whiteval);
185     }
186    
187    
188 greg 1.6 getd(name, dp, help) /* get a positive double from stdin */
189     char *name;
190 greg 1.2 double *dp;
191 greg 1.6 char *help;
192 greg 1.2 {
193     char buf[32];
194 greg 1.6 again:
195     printf("%s [%g]: ", name, *dp);
196 greg 1.2 if (gets(buf) == NULL)
197     return(0);
198 greg 1.6 if (buf[0] == '?') {
199     puts(help);
200     goto again;
201     }
202 greg 1.2 if ((buf[0] < '0' || buf[0] > '9') && buf[0] != '.')
203     return(0);
204     *dp = atof(buf);
205     return(1);
206     }
207    
208    
209     getpolygon() /* get projected area for a polygon */
210     {
211 greg 1.9 static double parea = 1.0;
212 greg 1.5
213 greg 1.9 getd("Polygon area", &parea,
214 greg 1.6 "Enter the total radiating area of the polygon.");
215 greg 1.9 area = unit2meter*unit2meter * parea;
216 greg 1.2 return(1);
217     }
218    
219    
220     getsphere() /* get projected area for a sphere */
221     {
222 greg 1.5 static double radius = 1.0;
223 greg 1.2
224 greg 1.6 getd("Sphere radius", &radius,
225     "Enter the distance from the sphere's center to its surface.");
226 greg 1.7 area = 4.*PI*unit2meter*unit2meter * radius*radius;
227 greg 1.2 return(1);
228     }
229    
230    
231     getcylinder() /* get projected area for a cylinder */
232     {
233 greg 1.5 static double length = 1.0, radius = 0.1;
234 greg 1.2
235 greg 1.6 getd("Cylinder length", &length,
236     "Enter the length of the cylinder.");
237     getd("Cylinder radius", &radius,
238     "Enter the distance from the cylinder's axis to its surface.");
239 greg 1.7 area = 2.*PI*unit2meter*unit2meter * radius*length;
240 greg 1.2 return(1);
241     }
242    
243    
244     getring() /* get projected area for a ring */
245     {
246 greg 1.5 static double radius = 1.0;
247 greg 1.2
248 greg 1.6 getd("Disk radius", &radius,
249     "Enter the distance from the ring's center to its outer edge.\n\
250     The inner radius must be zero.");
251 greg 1.7 area = PI*unit2meter*unit2meter * radius*radius;
252 greg 1.2 return(1);
253 greg 1.1 }