| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id: lampcolor.c,v 2.9 2003/11/15 17:54:06 schorsch Exp $"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Program to convert lamp color from table and compute radiance. |
| 6 |
*/ |
| 7 |
|
| 8 |
#include <stdio.h> |
| 9 |
#include <string.h> |
| 10 |
#include <math.h> |
| 11 |
|
| 12 |
#include "rtmath.h" |
| 13 |
#include "rtio.h" |
| 14 |
#include "color.h" |
| 15 |
|
| 16 |
/* lamp parameters */ |
| 17 |
#define LTYPE 0 |
| 18 |
#define LUNIT 1 |
| 19 |
#define LGEOM 2 |
| 20 |
#define LOUTP 3 |
| 21 |
#define NPARAMS 4 |
| 22 |
|
| 23 |
static int typecheck(char *s); |
| 24 |
static int unitcheck(char *s); |
| 25 |
static int geomcheck(char *s); |
| 26 |
static int outpcheck(char *s); |
| 27 |
static void compute(void); |
| 28 |
static int getpolygon(void), getsphere(void), getcylinder(void), getring(void); |
| 29 |
static int getd(char *name, double *dp, char *help); |
| 30 |
|
| 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 |
int |
| 62 |
main( |
| 63 |
int argc, |
| 64 |
char *argv[] |
| 65 |
) |
| 66 |
{ |
| 67 |
char *lamptab = "lamp.tab"; |
| 68 |
char buf[64]; |
| 69 |
int i; |
| 70 |
|
| 71 |
if (argc > 1) lamptab = argv[1]; |
| 72 |
if (loadlamps(lamptab) == 0) { |
| 73 |
fprintf(stderr, "%s: no such lamp table\n", lamptab); |
| 74 |
exit(1); |
| 75 |
} |
| 76 |
printf("Program to compute lamp radiance. Enter '?' for help.\n"); |
| 77 |
for ( ; ; ) { |
| 78 |
i = 0; |
| 79 |
while (i < NPARAMS) { |
| 80 |
printf("Enter %s [%s]: ", param[i].name, |
| 81 |
param[i].value); |
| 82 |
if (fgetline(buf, sizeof(buf), stdin) == NULL) |
| 83 |
exit(0); |
| 84 |
if (buf[0] == '?') { |
| 85 |
puts(param[i].help); |
| 86 |
continue; |
| 87 |
} |
| 88 |
if (buf[0]) |
| 89 |
strcpy(param[i].value, buf); |
| 90 |
if (!(*param[i].check)(param[i].value)) { |
| 91 |
fprintf(stderr, "%s: bad value for %s\n", |
| 92 |
param[i].value, param[i].name); |
| 93 |
continue; |
| 94 |
} |
| 95 |
i++; |
| 96 |
} |
| 97 |
compute(); |
| 98 |
} |
| 99 |
} |
| 100 |
|
| 101 |
|
| 102 |
static int |
| 103 |
typecheck( /* check lamp type */ |
| 104 |
char *s |
| 105 |
) |
| 106 |
{ |
| 107 |
lampcolor = matchlamp(s); |
| 108 |
return(lampcolor != NULL); |
| 109 |
} |
| 110 |
|
| 111 |
|
| 112 |
static int |
| 113 |
unitcheck( /* compute conversion to meters */ |
| 114 |
char *s |
| 115 |
) |
| 116 |
{ |
| 117 |
int len = strlen(s); |
| 118 |
|
| 119 |
switch (*s) { |
| 120 |
case 'm': |
| 121 |
if (strncmp(s, "meters", len)) |
| 122 |
return(0); |
| 123 |
unit2meter = 1.0; |
| 124 |
return(1); |
| 125 |
case 'c': |
| 126 |
if (strncmp(s, "centimeters", len) && strncmp(s, "cms", len)) |
| 127 |
return(0); |
| 128 |
unit2meter = 0.01; |
| 129 |
return(1); |
| 130 |
case 'f': |
| 131 |
if (strncmp(s, "foot", len) && strncmp(s, "feet", len)) |
| 132 |
return(0); |
| 133 |
unit2meter = 0.3048; |
| 134 |
return(1); |
| 135 |
case 'i': |
| 136 |
if (strncmp(s, "inches", len)) |
| 137 |
return(0); |
| 138 |
unit2meter = 0.0254; |
| 139 |
return(1); |
| 140 |
} |
| 141 |
return(0); |
| 142 |
} |
| 143 |
|
| 144 |
|
| 145 |
static int |
| 146 |
geomcheck( /* check/set lamp geometry */ |
| 147 |
char *s |
| 148 |
) |
| 149 |
{ |
| 150 |
int len = strlen(s); |
| 151 |
|
| 152 |
switch (*s) { |
| 153 |
case 'p': |
| 154 |
if (strncmp(s, "polygonal", len)) |
| 155 |
return(0); |
| 156 |
return(getpolygon()); |
| 157 |
case 's': |
| 158 |
if (strncmp(s, "sphere", len) && strncmp(s, "spherical", len)) |
| 159 |
return(0); |
| 160 |
return(getsphere()); |
| 161 |
case 'c': |
| 162 |
if (strncmp(s,"cylinder",len) && strncmp(s,"cylindrical",len)) |
| 163 |
return(0); |
| 164 |
return(getcylinder()); |
| 165 |
case 'r': |
| 166 |
if (strncmp(s, "ring", len) && strncmp(s, "disk", len)) |
| 167 |
return(0); |
| 168 |
return(getring()); |
| 169 |
} |
| 170 |
return(0); |
| 171 |
} |
| 172 |
|
| 173 |
|
| 174 |
static int |
| 175 |
outpcheck( /* check lumen output value */ |
| 176 |
register char *s |
| 177 |
) |
| 178 |
{ |
| 179 |
if ((*s < '0' || *s > '9') && *s != '.') |
| 180 |
return(0); |
| 181 |
lumens = atof(s); |
| 182 |
return(1); |
| 183 |
} |
| 184 |
|
| 185 |
|
| 186 |
static void |
| 187 |
compute(void) /* compute lamp radiance */ |
| 188 |
{ |
| 189 |
double whiteval; |
| 190 |
|
| 191 |
whiteval = lumens/area/(WHTEFFICACY*PI); |
| 192 |
|
| 193 |
printf("Lamp color (RGB) = %f %f %f\n", |
| 194 |
lampcolor[0]*whiteval, |
| 195 |
lampcolor[1]*whiteval, |
| 196 |
lampcolor[2]*whiteval); |
| 197 |
} |
| 198 |
|
| 199 |
|
| 200 |
static int |
| 201 |
getd( /* get a positive double from stdin */ |
| 202 |
char *name, |
| 203 |
double *dp, |
| 204 |
char *help |
| 205 |
) |
| 206 |
{ |
| 207 |
char buf[32]; |
| 208 |
again: |
| 209 |
printf("%s [%g]: ", name, *dp); |
| 210 |
if (fgets(buf, sizeof(buf), stdin) == NULL) |
| 211 |
return(0); |
| 212 |
if (buf[0] == '?') { |
| 213 |
puts(help); |
| 214 |
goto again; |
| 215 |
} |
| 216 |
if ((buf[0] < '0' || buf[0] > '9') && buf[0] != '.') |
| 217 |
return(0); |
| 218 |
*dp = atof(buf); |
| 219 |
return(1); |
| 220 |
} |
| 221 |
|
| 222 |
|
| 223 |
static int |
| 224 |
getpolygon(void) /* get projected area for a polygon */ |
| 225 |
{ |
| 226 |
static double parea = 1.0; |
| 227 |
|
| 228 |
getd("Polygon area", &parea, |
| 229 |
"Enter the total radiating area of the polygon."); |
| 230 |
area = unit2meter*unit2meter * parea; |
| 231 |
return(1); |
| 232 |
} |
| 233 |
|
| 234 |
|
| 235 |
static int |
| 236 |
getsphere(void) /* get projected area for a sphere */ |
| 237 |
{ |
| 238 |
static double radius = 1.0; |
| 239 |
|
| 240 |
getd("Sphere radius", &radius, |
| 241 |
"Enter the distance from the sphere's center to its surface."); |
| 242 |
area = 4.*PI*unit2meter*unit2meter * radius*radius; |
| 243 |
return(1); |
| 244 |
} |
| 245 |
|
| 246 |
|
| 247 |
static int |
| 248 |
getcylinder(void) /* get projected area for a cylinder */ |
| 249 |
{ |
| 250 |
static double length = 1.0, radius = 0.1; |
| 251 |
|
| 252 |
getd("Cylinder length", &length, |
| 253 |
"Enter the length of the cylinder."); |
| 254 |
getd("Cylinder radius", &radius, |
| 255 |
"Enter the distance from the cylinder's axis to its surface."); |
| 256 |
area = 2.*PI*unit2meter*unit2meter * radius*length; |
| 257 |
return(1); |
| 258 |
} |
| 259 |
|
| 260 |
|
| 261 |
static int |
| 262 |
getring(void) /* get projected area for a ring */ |
| 263 |
{ |
| 264 |
static double radius = 1.0; |
| 265 |
|
| 266 |
getd("Disk radius", &radius, |
| 267 |
"Enter the distance from the ring's center to its outer edge.\n\ |
| 268 |
The inner radius must be zero."); |
| 269 |
area = PI*unit2meter*unit2meter * radius*radius; |
| 270 |
return(1); |
| 271 |
} |
