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root/radiance/ray/src/cv/lampcolor.c
Revision: 2.2
Committed: Thu Dec 19 15:06:15 1991 UTC (32 years, 3 months ago) by greg
Content type: text/plain
Branch: MAIN
Changes since 2.1: +2 -0 lines
Log Message:
removed atof declaration for NeXT

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 #ifndef atof
19 extern double atof();
20 #endif
21 extern float *matchlamp();
22
23 /* lamp parameters */
24 #define LTYPE 0
25 #define LUNIT 1
26 #define LGEOM 2
27 #define LOUTP 3
28 #define NPARAMS 4
29
30 int typecheck(), unitcheck(), geomcheck(), outpcheck();
31
32 float *lampcolor; /* the lamp color (RGB) */
33 double unit2meter; /* conversion from units to meters */
34 double area; /* radiating area for this geometry */
35 double lumens; /* total lamp lumens */
36
37 struct {
38 char *name;
39 char value[64];
40 int (*check)();
41 char *help;
42 } param[NPARAMS] = {
43 { "lamp type", "white", typecheck,
44 "The lamp type is a string which corresponds to one of the types registered\n\
45 in the lamp table file. A value of \"white\" means an uncolored source,\n\
46 which may be preferable because it results in a color balanced image." },
47 { "length unit", "meter", unitcheck,
48 "Unit must be one of: \"meter\", \"centimeter\", \"foot\", or \"inch\".\n\
49 These may be abbreviated as a single letter." },
50 { "lamp geometry", "polygon", geomcheck,
51 "The lamp geometry must be one of: \"polygon\", \"sphere\", \"cylinder\"\n\
52 or \"ring\". These may be abbreviated as a single letter." },
53 { "total lamp lumens", "0", outpcheck,
54 "This is the overall light output of the lamp and its fixture. If you do\n\
55 not know this value explicitly, you can compute the approximate lumens\n\
56 by multiplying the input wattage by 14 for incandescent fixtures or 70\n\
57 for fluorescent fixtures." },
58 };
59
60
61 main(argc, argv)
62 int argc;
63 char *argv[];
64 {
65 char *lamptab = "lamp.tab";
66 char buf[64];
67 int i;
68
69 if (argc > 1) lamptab = argv[1];
70 if (loadlamps(lamptab) == 0) {
71 fprintf(stderr, "%s: no such lamp table\n", lamptab);
72 exit(1);
73 }
74 printf("Program to compute lamp radiance. Enter '?' for help.\n");
75 for ( ; ; ) {
76 i = 0;
77 while (i < NPARAMS) {
78 printf("Enter %s [%s]: ", param[i].name,
79 param[i].value);
80 if (gets(buf) == NULL)
81 exit(0);
82 if (buf[0] == '?') {
83 puts(param[i].help);
84 continue;
85 }
86 if (buf[0])
87 strcpy(param[i].value, buf);
88 if (!(*param[i].check)(param[i].value)) {
89 fprintf(stderr, "%s: bad value for %s\n",
90 param[i].value, param[i].name);
91 continue;
92 }
93 i++;
94 }
95 compute();
96 }
97 }
98
99
100 typecheck(s) /* check lamp type */
101 char *s;
102 {
103 lampcolor = matchlamp(s);
104 return(lampcolor != NULL);
105 }
106
107
108 unitcheck(s) /* compute conversion to meters */
109 char *s;
110 {
111 int len = strlen(s);
112
113 switch (*s) {
114 case 'm':
115 if (strncmp(s, "meters", len))
116 return(0);
117 unit2meter = 1.0;
118 return(1);
119 case 'c':
120 if (strncmp(s, "centimeters", len) && strncmp(s, "cms", len))
121 return(0);
122 unit2meter = 0.01;
123 return(1);
124 case 'f':
125 if (strncmp(s, "foot", len) && strncmp(s, "feet", len))
126 return(0);
127 unit2meter = 0.3048;
128 return(1);
129 case 'i':
130 if (strncmp(s, "inches", len))
131 return(0);
132 unit2meter = 0.0254;
133 return(1);
134 }
135 return(0);
136 }
137
138
139 geomcheck(s) /* check/set lamp geometry */
140 char *s;
141 {
142 int len = strlen(s);
143
144 switch (*s) {
145 case 'p':
146 if (strncmp(s, "polygonal", len))
147 return(0);
148 return(getpolygon());
149 case 's':
150 if (strncmp(s, "sphere", len) && strncmp(s, "spherical", len))
151 return(0);
152 return(getsphere());
153 case 'c':
154 if (strncmp(s,"cylinder",len) && strncmp(s,"cylindrical",len))
155 return(0);
156 return(getcylinder());
157 case 'r':
158 if (strncmp(s, "ring", len) && strncmp(s, "disk", len))
159 return(0);
160 return(getring());
161 }
162 return(0);
163 }
164
165
166 outpcheck(s) /* check lumen output value */
167 register char *s;
168 {
169 if ((*s < '0' || *s > '9') && *s != '.')
170 return(0);
171 lumens = atof(s);
172 return(1);
173 }
174
175
176 compute() /* compute lamp radiance */
177 {
178 double whiteval;
179
180 whiteval = lumens/area/(WHTEFFICACY*PI);
181
182 printf("Lamp color (RGB) = %f %f %f\n",
183 lampcolor[0]*whiteval,
184 lampcolor[1]*whiteval,
185 lampcolor[2]*whiteval);
186 }
187
188
189 getd(name, dp, help) /* get a positive double from stdin */
190 char *name;
191 double *dp;
192 char *help;
193 {
194 char buf[32];
195 again:
196 printf("%s [%g]: ", name, *dp);
197 if (gets(buf) == NULL)
198 return(0);
199 if (buf[0] == '?') {
200 puts(help);
201 goto again;
202 }
203 if ((buf[0] < '0' || buf[0] > '9') && buf[0] != '.')
204 return(0);
205 *dp = atof(buf);
206 return(1);
207 }
208
209
210 getpolygon() /* get projected area for a polygon */
211 {
212 static double parea = 1.0;
213
214 getd("Polygon area", &parea,
215 "Enter the total radiating area of the polygon.");
216 area = unit2meter*unit2meter * parea;
217 return(1);
218 }
219
220
221 getsphere() /* get projected area for a sphere */
222 {
223 static double radius = 1.0;
224
225 getd("Sphere radius", &radius,
226 "Enter the distance from the sphere's center to its surface.");
227 area = 4.*PI*unit2meter*unit2meter * radius*radius;
228 return(1);
229 }
230
231
232 getcylinder() /* get projected area for a cylinder */
233 {
234 static double length = 1.0, radius = 0.1;
235
236 getd("Cylinder length", &length,
237 "Enter the length of the cylinder.");
238 getd("Cylinder radius", &radius,
239 "Enter the distance from the cylinder's axis to its surface.");
240 area = 2.*PI*unit2meter*unit2meter * radius*length;
241 return(1);
242 }
243
244
245 getring() /* get projected area for a ring */
246 {
247 static double radius = 1.0;
248
249 getd("Disk radius", &radius,
250 "Enter the distance from the ring's center to its outer edge.\n\
251 The inner radius must be zero.");
252 area = PI*unit2meter*unit2meter * radius*radius;
253 return(1);
254 }