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root/radiance/ray/src/cv/lampcolor.c
Revision: 2.1
Committed: Tue Nov 12 17:02:10 1991 UTC (32 years, 4 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 1.9: +0 -0 lines
Log Message:
updated revision number for release 2.0

File Contents

# Content
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 * Program to convert lamp color from table and compute radiance.
9 */
10
11 #include <stdio.h>
12
13 #include "color.h"
14
15 #define PI 3.14159265358979323846
16
17 extern char *gets(), *strcpy();
18 extern double atof();
19 extern float *matchlamp();
20
21 /* lamp parameters */
22 #define LTYPE 0
23 #define LUNIT 1
24 #define LGEOM 2
25 #define LOUTP 3
26 #define NPARAMS 4
27
28 int typecheck(), unitcheck(), geomcheck(), outpcheck();
29
30 float *lampcolor; /* the lamp color (RGB) */
31 double unit2meter; /* conversion from units to meters */
32 double area; /* radiating area for this geometry */
33 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 by multiplying the input wattage by 14 for incandescent fixtures or 70\n\
55 for fluorescent fixtures." },
56 };
57
58
59 main(argc, argv)
60 int argc;
61 char *argv[];
62 {
63 char *lamptab = "lamp.tab";
64 char buf[64];
65 int i;
66
67 if (argc > 1) lamptab = argv[1];
68 if (loadlamps(lamptab) == 0) {
69 fprintf(stderr, "%s: no such lamp table\n", lamptab);
70 exit(1);
71 }
72 printf("Program to compute lamp radiance. Enter '?' for help.\n");
73 for ( ; ; ) {
74 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 }
95 }
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 whiteval = lumens/area/(WHTEFFICACY*PI);
179
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 getd(name, dp, help) /* get a positive double from stdin */
188 char *name;
189 double *dp;
190 char *help;
191 {
192 char buf[32];
193 again:
194 printf("%s [%g]: ", name, *dp);
195 if (gets(buf) == NULL)
196 return(0);
197 if (buf[0] == '?') {
198 puts(help);
199 goto again;
200 }
201 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 static double parea = 1.0;
211
212 getd("Polygon area", &parea,
213 "Enter the total radiating area of the polygon.");
214 area = unit2meter*unit2meter * parea;
215 return(1);
216 }
217
218
219 getsphere() /* get projected area for a sphere */
220 {
221 static double radius = 1.0;
222
223 getd("Sphere radius", &radius,
224 "Enter the distance from the sphere's center to its surface.");
225 area = 4.*PI*unit2meter*unit2meter * radius*radius;
226 return(1);
227 }
228
229
230 getcylinder() /* get projected area for a cylinder */
231 {
232 static double length = 1.0, radius = 0.1;
233
234 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 area = 2.*PI*unit2meter*unit2meter * radius*length;
239 return(1);
240 }
241
242
243 getring() /* get projected area for a ring */
244 {
245 static double radius = 1.0;
246
247 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 area = PI*unit2meter*unit2meter * radius*radius;
251 return(1);
252 }