| 1 |
#ifndef lint |
| 2 |
static const char RCSid[] = "$Id$"; |
| 3 |
#endif |
| 4 |
/* |
| 5 |
* Compute Glare Index given by program name or -t option: |
| 6 |
* |
| 7 |
* dgi - Daylight Glare Index |
| 8 |
* brs_gi - Building Research Station Glare Index (Petherbridge |
| 9 |
* & Hopkinson) |
| 10 |
* ugr - Unified Glare Rating System (Fischer) |
| 11 |
* guth_dgr - Guth discomfort glare rating |
| 12 |
* guth_vcp - Guth visual comfort probability |
| 13 |
* cie_cgi - CIE Glare Index (1983, due to Einhorn) |
| 14 |
* vert_dir - Direct vertical illuminance |
| 15 |
* vert_ind - Indirect vertical illuminance (from input) |
| 16 |
* vert_ill - Total vertical illuminance |
| 17 |
* |
| 18 |
* 12 April 1991 Greg Ward EPFL |
| 19 |
* 19 April 1993 R. Compagnon EPFL (added dgi, brs_gi, ugr) |
| 20 |
*/ |
| 21 |
|
| 22 |
#include "standard.h" |
| 23 |
#include "view.h" |
| 24 |
|
| 25 |
|
| 26 |
double posindex(); |
| 27 |
|
| 28 |
double direct(), guth_dgr(), guth_vcp(), cie_cgi(), |
| 29 |
indirect(), total(), dgi(), brs_gi(), ugr(); |
| 30 |
|
| 31 |
struct named_func { |
| 32 |
char *name; |
| 33 |
double (*func)(); |
| 34 |
char *descrip; |
| 35 |
} all_funcs[] = { |
| 36 |
{"dgi", dgi, "Daylight Glare Index"}, |
| 37 |
{"brs_gi", brs_gi, "BRS Glare Index"}, |
| 38 |
{"ugr", ugr, "Unified Glare Rating"}, |
| 39 |
{"guth_vcp", guth_vcp, "Guth Visual Comfort Probability"}, |
| 40 |
{"cie_cgi", cie_cgi, "CIE Glare Index (Einhorn)"}, |
| 41 |
{"guth_dgr", guth_dgr, "Guth Disability Glare Rating"}, |
| 42 |
{"vert_dir", direct, "Direct Vertical Illuminance"}, |
| 43 |
{"vert_ill", total, "Total Vertical Illuminance"}, |
| 44 |
{"vert_ind", indirect, "Indirect Vertical Illuminance"}, |
| 45 |
{NULL} |
| 46 |
}; |
| 47 |
|
| 48 |
struct glare_src { |
| 49 |
FVECT dir; /* source direction */ |
| 50 |
double dom; /* solid angle */ |
| 51 |
double lum; /* average luminance */ |
| 52 |
struct glare_src *next; |
| 53 |
} *all_srcs = NULL; |
| 54 |
|
| 55 |
struct glare_dir { |
| 56 |
double ang; /* angle (in radians) */ |
| 57 |
double indirect; /* indirect illuminance */ |
| 58 |
struct glare_dir *next; |
| 59 |
} *all_dirs = NULL; |
| 60 |
|
| 61 |
#define newp(type) (type *)malloc(sizeof(type)) |
| 62 |
|
| 63 |
char *progname; |
| 64 |
int print_header = 1; |
| 65 |
|
| 66 |
VIEW midview = STDVIEW; |
| 67 |
|
| 68 |
int wrongformat = 0; |
| 69 |
|
| 70 |
|
| 71 |
main(argc, argv) |
| 72 |
int argc; |
| 73 |
char *argv[]; |
| 74 |
{ |
| 75 |
extern char *rindex(); |
| 76 |
struct named_func *funp; |
| 77 |
char *progtail; |
| 78 |
int i; |
| 79 |
/* get program name */ |
| 80 |
progname = argv[0]; |
| 81 |
progtail = rindex(progname, '/'); /* final component */ |
| 82 |
if (progtail == NULL) |
| 83 |
progtail = progname; |
| 84 |
else |
| 85 |
progtail++; |
| 86 |
/* get options */ |
| 87 |
for (i = 1; i < argc && argv[i][0] == '-'; i++) |
| 88 |
switch (argv[i][1]) { |
| 89 |
case 't': |
| 90 |
progtail = argv[++i]; |
| 91 |
break; |
| 92 |
case 'h': |
| 93 |
print_header = 0; |
| 94 |
break; |
| 95 |
default: |
| 96 |
goto userr; |
| 97 |
} |
| 98 |
if (i < argc-1) |
| 99 |
goto userr; |
| 100 |
if (i == argc-1) /* open file */ |
| 101 |
if (freopen(argv[i], "r", stdin) == NULL) { |
| 102 |
perror(argv[i]); |
| 103 |
exit(1); |
| 104 |
} |
| 105 |
/* find and run calculation */ |
| 106 |
for (funp = all_funcs; funp->name != NULL; funp++) |
| 107 |
if (!strcmp(funp->name, progtail)) { |
| 108 |
init(); |
| 109 |
read_input(); |
| 110 |
if (print_header) { |
| 111 |
printargs(i, argv, stdout); |
| 112 |
putchar('\n'); |
| 113 |
} |
| 114 |
print_values(funp->func); |
| 115 |
exit(0); /* we're done */ |
| 116 |
} |
| 117 |
/* invalid function */ |
| 118 |
userr: |
| 119 |
fprintf(stderr, "Usage: %s -t type [-h] [input]\n", progname); |
| 120 |
fprintf(stderr, "\twhere 'type' is one of the following:\n"); |
| 121 |
for (funp = all_funcs; funp->name != NULL; funp++) |
| 122 |
fprintf(stderr, "\t%12s\t%s\n", funp->name, funp->descrip); |
| 123 |
exit(1); |
| 124 |
} |
| 125 |
|
| 126 |
|
| 127 |
int |
| 128 |
headline(s) /* get line from header */ |
| 129 |
char *s; |
| 130 |
{ |
| 131 |
char fmt[32]; |
| 132 |
|
| 133 |
if (print_header) /* copy to output */ |
| 134 |
fputs(s, stdout); |
| 135 |
if (isview(s)) |
| 136 |
sscanview(&midview, s); |
| 137 |
else if (isformat(s)) { |
| 138 |
formatval(fmt, s); |
| 139 |
wrongformat = strcmp(fmt, "ascii"); |
| 140 |
} |
| 141 |
return(0); |
| 142 |
} |
| 143 |
|
| 144 |
|
| 145 |
init() /* initialize calculation */ |
| 146 |
{ |
| 147 |
/* read header */ |
| 148 |
getheader(stdin, headline, NULL); |
| 149 |
if (wrongformat) { |
| 150 |
fprintf(stderr, "%s: bad input format\n", progname); |
| 151 |
exit(1); |
| 152 |
} |
| 153 |
/* set view */ |
| 154 |
if (setview(&midview) != NULL) { |
| 155 |
fprintf(stderr, "%s: bad view information in input\n", |
| 156 |
progname); |
| 157 |
exit(1); |
| 158 |
} |
| 159 |
} |
| 160 |
|
| 161 |
|
| 162 |
read_input() /* read glare sources from stdin */ |
| 163 |
{ |
| 164 |
#define S_SEARCH 0 |
| 165 |
#define S_SOURCE 1 |
| 166 |
#define S_DIREC 2 |
| 167 |
int state = S_SEARCH; |
| 168 |
char buf[128]; |
| 169 |
register struct glare_src *gs; |
| 170 |
register struct glare_dir *gd; |
| 171 |
|
| 172 |
while (fgets(buf, sizeof(buf), stdin) != NULL) |
| 173 |
switch (state) { |
| 174 |
case S_SEARCH: |
| 175 |
if (!strcmp(buf, "BEGIN glare source\n")) |
| 176 |
state = S_SOURCE; |
| 177 |
else if (!strcmp(buf, "BEGIN indirect illuminance\n")) |
| 178 |
state = S_DIREC; |
| 179 |
break; |
| 180 |
case S_SOURCE: |
| 181 |
if (!strncmp(buf, "END", 3)) { |
| 182 |
state = S_SEARCH; |
| 183 |
break; |
| 184 |
} |
| 185 |
if ((gs = newp(struct glare_src)) == NULL) |
| 186 |
goto memerr; |
| 187 |
if (sscanf(buf, "%lf %lf %lf %lf %lf", |
| 188 |
&gs->dir[0], &gs->dir[1], &gs->dir[2], |
| 189 |
&gs->dom, &gs->lum) != 5) |
| 190 |
goto readerr; |
| 191 |
normalize(gs->dir); |
| 192 |
gs->next = all_srcs; |
| 193 |
all_srcs = gs; |
| 194 |
break; |
| 195 |
case S_DIREC: |
| 196 |
if (!strncmp(buf, "END", 3)) { |
| 197 |
state = S_SEARCH; |
| 198 |
break; |
| 199 |
} |
| 200 |
if ((gd = newp(struct glare_dir)) == NULL) |
| 201 |
goto memerr; |
| 202 |
if (sscanf(buf, "%lf %lf", |
| 203 |
&gd->ang, &gd->indirect) != 2) |
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goto readerr; |
| 205 |
gd->ang *= PI/180.0; /* convert to radians */ |
| 206 |
gd->next = all_dirs; |
| 207 |
all_dirs = gd; |
| 208 |
break; |
| 209 |
} |
| 210 |
return; |
| 211 |
memerr: |
| 212 |
perror(progname); |
| 213 |
exit(1); |
| 214 |
readerr: |
| 215 |
fprintf(stderr, "%s: read error on input\n", progname); |
| 216 |
exit(1); |
| 217 |
#undef S_SEARCH |
| 218 |
#undef S_SOURCE |
| 219 |
#undef S_DIREC |
| 220 |
} |
| 221 |
|
| 222 |
|
| 223 |
print_values(funp) /* print out calculations */ |
| 224 |
double (*funp)(); |
| 225 |
{ |
| 226 |
register struct glare_dir *gd; |
| 227 |
|
| 228 |
for (gd = all_dirs; gd != NULL; gd = gd->next) |
| 229 |
printf("%f\t%f\n", gd->ang*(180.0/PI), (*funp)(gd)); |
| 230 |
} |
| 231 |
|
| 232 |
|
| 233 |
double |
| 234 |
direct(gd) /* compute direct vertical illuminance */ |
| 235 |
struct glare_dir *gd; |
| 236 |
{ |
| 237 |
FVECT mydir; |
| 238 |
double d, dval; |
| 239 |
register struct glare_src *gs; |
| 240 |
|
| 241 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 242 |
dval = 0.0; |
| 243 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 244 |
d = DOT(mydir,gs->dir); |
| 245 |
if (d > FTINY) |
| 246 |
dval += d * gs->dom * gs->lum; |
| 247 |
} |
| 248 |
return(dval); |
| 249 |
} |
| 250 |
|
| 251 |
|
| 252 |
double |
| 253 |
indirect(gd) /* return indirect vertical illuminance */ |
| 254 |
struct glare_dir *gd; |
| 255 |
{ |
| 256 |
return(gd->indirect); |
| 257 |
} |
| 258 |
|
| 259 |
|
| 260 |
double |
| 261 |
total(gd) /* return total vertical illuminance */ |
| 262 |
struct glare_dir *gd; |
| 263 |
{ |
| 264 |
return(direct(gd)+gd->indirect); |
| 265 |
} |
| 266 |
|
| 267 |
|
| 268 |
/* |
| 269 |
* posindex - compute glare position index from: |
| 270 |
* |
| 271 |
* Source Direction |
| 272 |
* View Direction |
| 273 |
* View Up Direction |
| 274 |
* |
| 275 |
* All vectors are assumed to be normalized. |
| 276 |
* This function is an implementation of the method proposed by |
| 277 |
* Robert Levin in his 1975 JIES article. |
| 278 |
* This calculation presumes the view direction and up vectors perpendicular. |
| 279 |
* We return a value less than zero for improper positions. |
| 280 |
*/ |
| 281 |
|
| 282 |
double |
| 283 |
posindex(sd, vd, vu) /* compute position index */ |
| 284 |
FVECT sd, vd, vu; |
| 285 |
{ |
| 286 |
double sigma, tau; |
| 287 |
double d; |
| 288 |
|
| 289 |
d = DOT(sd,vd); |
| 290 |
if (d <= 0.0) |
| 291 |
return(-1.0); |
| 292 |
if (d >= 1.0) |
| 293 |
return(1.0); |
| 294 |
sigma = acos(d) * (180./PI); |
| 295 |
d = fabs(DOT(sd,vu)/sqrt(1.0-d*d)); |
| 296 |
if (d >= 1.0) |
| 297 |
tau = 0.0; |
| 298 |
else |
| 299 |
tau = acos(d) * (180./PI); |
| 300 |
return( exp( sigma*( (35.2 - tau*.31889 - 1.22*exp(-.22222*tau))*1e-3 |
| 301 |
+ sigma*(21. + tau*(.26667 + tau*-.002963))*1e-5 ) |
| 302 |
) ); |
| 303 |
} |
| 304 |
|
| 305 |
|
| 306 |
double |
| 307 |
dgi(gd) /* compute Daylight Glare Index */ |
| 308 |
struct glare_dir *gd; |
| 309 |
{ |
| 310 |
register struct glare_src *gs; |
| 311 |
FVECT mydir,testdir[7],vhor; |
| 312 |
double r,omega,p[7],sum; |
| 313 |
int i,n; |
| 314 |
|
| 315 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 316 |
sum = 0.0; n = 0; |
| 317 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 318 |
|
| 319 |
/* compute 1/p^2 weighted solid angle of the source */ |
| 320 |
r = sqrt(1 - pow(1.-gs->dom/2./PI,2.)); |
| 321 |
fcross(vhor,gs->dir,midview.vup); |
| 322 |
normalize(vhor); |
| 323 |
VCOPY(testdir[0],gs->dir); |
| 324 |
fvsum(testdir[1],gs->dir,vhor,r); |
| 325 |
fvsum(testdir[2],gs->dir,vhor,0.5*r); |
| 326 |
fvsum(testdir[5],testdir[2],midview.vup,-0.866*r); |
| 327 |
fvsum(testdir[2],testdir[2],midview.vup,0.866*r); |
| 328 |
fvsum(testdir[3],gs->dir,vhor,-r); |
| 329 |
fvsum(testdir[4],gs->dir,vhor,-0.5*r); |
| 330 |
fvsum(testdir[6],testdir[4],midview.vup,0.866*r); |
| 331 |
fvsum(testdir[4],testdir[4],midview.vup,-0.866*r); |
| 332 |
for (i = 0; i < 7; i++) { |
| 333 |
normalize(testdir[i]); |
| 334 |
p[i] = pow(posindex(testdir[i],mydir,midview.vup),-2.0); |
| 335 |
if (p[i] <= FTINY) p[i] = 0.0; |
| 336 |
} |
| 337 |
r = 1-gs->dom/2./PI; |
| 338 |
omega = gs->dom*p[0]; |
| 339 |
omega += (r*PI*(1+1/r/r)-2*PI)*(-p[0]+(p[1]+p[2])*0.5); |
| 340 |
omega += (2*PI-r*PI*(1+1/r/r))*(-p[0]-0.1667*(p[1]+p[3]) |
| 341 |
+0.3334*(p[2]+p[4]+p[5]+p[6])); |
| 342 |
|
| 343 |
sum += pow(gs->lum,1.6) * pow(omega,0.8) / |
| 344 |
(gd->indirect/PI + 0.07*sqrt(gs->dom)*gs->lum); |
| 345 |
n++; |
| 346 |
} |
| 347 |
if (n == 0) |
| 348 |
return(0.0); |
| 349 |
return( 10*log10(0.478*sum) ); |
| 350 |
} |
| 351 |
|
| 352 |
|
| 353 |
double |
| 354 |
brs_gi(gd) /* compute BRS Glare Index */ |
| 355 |
struct glare_dir *gd; |
| 356 |
{ |
| 357 |
register struct glare_src *gs; |
| 358 |
FVECT mydir; |
| 359 |
double p; |
| 360 |
double sum; |
| 361 |
|
| 362 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 363 |
sum = 0.0; |
| 364 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 365 |
p = posindex(gs->dir, mydir, midview.vup); |
| 366 |
if (p <= FTINY) |
| 367 |
continue; |
| 368 |
sum += pow(gs->lum/p,1.6) * pow(gs->dom,0.8); |
| 369 |
} |
| 370 |
if (sum <= FTINY) |
| 371 |
return(0.0); |
| 372 |
sum /= gd->indirect/PI; |
| 373 |
return(10*log10(0.478*sum)); |
| 374 |
} |
| 375 |
|
| 376 |
|
| 377 |
double |
| 378 |
guth_dgr(gd) /* compute Guth discomfort glare rating */ |
| 379 |
struct glare_dir *gd; |
| 380 |
{ |
| 381 |
#define q(w) (20.4*w+1.52*pow(w,.2)-.075) |
| 382 |
register struct glare_src *gs; |
| 383 |
FVECT mydir; |
| 384 |
double p; |
| 385 |
double sum; |
| 386 |
double wtot, brsum; |
| 387 |
int n; |
| 388 |
|
| 389 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 390 |
sum = wtot = brsum = 0.0; n = 0; |
| 391 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 392 |
p = posindex(gs->dir, mydir, midview.vup); |
| 393 |
if (p <= FTINY) |
| 394 |
continue; |
| 395 |
sum += gs->lum * q(gs->dom) / p; |
| 396 |
brsum += gs->lum * gs->dom; |
| 397 |
wtot += gs->dom; |
| 398 |
n++; |
| 399 |
} |
| 400 |
if (n == 0) |
| 401 |
return(0.0); |
| 402 |
return( pow(.5*sum/pow((brsum+(5.-wtot)*gd->indirect/PI)/5.,.44), |
| 403 |
pow((double)n, -.0914) ) ); |
| 404 |
#undef q |
| 405 |
} |
| 406 |
|
| 407 |
|
| 408 |
#ifndef M_SQRT2 |
| 409 |
#define M_SQRT2 1.41421356237309504880 |
| 410 |
#endif |
| 411 |
|
| 412 |
#define norm_integral(z) (1.-.5*erfc((z)/M_SQRT2)) |
| 413 |
|
| 414 |
|
| 415 |
double |
| 416 |
guth_vcp(gd) /* compute Guth visual comfort probability */ |
| 417 |
struct glare_dir *gd; |
| 418 |
{ |
| 419 |
extern double erfc(); |
| 420 |
double dgr; |
| 421 |
|
| 422 |
dgr = guth_dgr(gd); |
| 423 |
if (dgr <= FTINY) |
| 424 |
return(100.0); |
| 425 |
return(100.*norm_integral(6.374-1.3227*log(dgr))); |
| 426 |
} |
| 427 |
|
| 428 |
|
| 429 |
double |
| 430 |
cie_cgi(gd) /* compute CIE Glare Index */ |
| 431 |
struct glare_dir *gd; |
| 432 |
{ |
| 433 |
register struct glare_src *gs; |
| 434 |
FVECT mydir; |
| 435 |
double dillum; |
| 436 |
double p; |
| 437 |
double sum; |
| 438 |
|
| 439 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 440 |
sum = 0.0; |
| 441 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 442 |
p = posindex(gs->dir, mydir, midview.vup); |
| 443 |
if (p <= FTINY) |
| 444 |
continue; |
| 445 |
sum += gs->lum*gs->lum * gs->dom / (p*p); |
| 446 |
} |
| 447 |
if (sum <= FTINY) |
| 448 |
return(0.0); |
| 449 |
dillum = direct(gd); |
| 450 |
return(8.*log10(2.*sum*(1.+dillum/500.)/(dillum+gd->indirect))); |
| 451 |
} |
| 452 |
|
| 453 |
|
| 454 |
double |
| 455 |
ugr(gd) /* compute Unified Glare Rating */ |
| 456 |
struct glare_dir *gd; |
| 457 |
{ |
| 458 |
register struct glare_src *gs; |
| 459 |
FVECT mydir; |
| 460 |
double p; |
| 461 |
double sum; |
| 462 |
|
| 463 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 464 |
sum = 0.0; |
| 465 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 466 |
p = posindex(gs->dir, mydir, midview.vup); |
| 467 |
if (p <= FTINY) |
| 468 |
continue; |
| 469 |
sum += gs->lum*gs->lum * gs->dom / (p*p); |
| 470 |
} |
| 471 |
if (sum <= FTINY) |
| 472 |
return(0.0); |
| 473 |
return(8.*log10(0.25*sum*PI/gd->indirect)); |
| 474 |
} |
