1 |
greg |
1.1 |
#ifndef lint |
2 |
schorsch |
2.8 |
static const char RCSid[] = "$Id: glarendx.c,v 2.7 2003/02/22 02:07:30 greg Exp $"; |
3 |
greg |
1.1 |
#endif |
4 |
|
|
/* |
5 |
greg |
1.9 |
* Compute Glare Index given by program name or -t option: |
6 |
greg |
1.1 |
* |
7 |
greg |
2.4 |
* dgi - Daylight Glare Index |
8 |
|
|
* brs_gi - Building Research Station Glare Index (Petherbridge |
9 |
|
|
* & Hopkinson) |
10 |
|
|
* ugr - Unified Glare Rating System (Fischer) |
11 |
greg |
1.2 |
* guth_dgr - Guth discomfort glare rating |
12 |
|
|
* guth_vcp - Guth visual comfort probability |
13 |
greg |
1.9 |
* 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 |
greg |
1.1 |
* |
18 |
|
|
* 12 April 1991 Greg Ward EPFL |
19 |
greg |
2.4 |
* 19 April 1993 R. Compagnon EPFL (added dgi, brs_gi, ugr) |
20 |
greg |
1.1 |
*/ |
21 |
greg |
2.4 |
|
22 |
schorsch |
2.8 |
#include <string.h> |
23 |
|
|
|
24 |
greg |
1.1 |
#include "standard.h" |
25 |
|
|
#include "view.h" |
26 |
greg |
2.4 |
|
27 |
|
|
|
28 |
greg |
1.1 |
double posindex(); |
29 |
greg |
2.4 |
|
30 |
greg |
1.9 |
double direct(), guth_dgr(), guth_vcp(), cie_cgi(), |
31 |
greg |
2.4 |
indirect(), total(), dgi(), brs_gi(), ugr(); |
32 |
|
|
|
33 |
greg |
1.1 |
struct named_func { |
34 |
|
|
char *name; |
35 |
|
|
double (*func)(); |
36 |
greg |
1.9 |
char *descrip; |
37 |
greg |
1.1 |
} all_funcs[] = { |
38 |
greg |
2.4 |
{"dgi", dgi, "Daylight Glare Index"}, |
39 |
|
|
{"brs_gi", brs_gi, "BRS Glare Index"}, |
40 |
|
|
{"ugr", ugr, "Unified Glare Rating"}, |
41 |
greg |
1.9 |
{"guth_vcp", guth_vcp, "Guth Visual Comfort Probability"}, |
42 |
|
|
{"cie_cgi", cie_cgi, "CIE Glare Index (Einhorn)"}, |
43 |
|
|
{"guth_dgr", guth_dgr, "Guth Disability Glare Rating"}, |
44 |
|
|
{"vert_dir", direct, "Direct Vertical Illuminance"}, |
45 |
|
|
{"vert_ill", total, "Total Vertical Illuminance"}, |
46 |
|
|
{"vert_ind", indirect, "Indirect Vertical Illuminance"}, |
47 |
greg |
1.1 |
{NULL} |
48 |
|
|
}; |
49 |
greg |
2.4 |
|
50 |
greg |
1.1 |
struct glare_src { |
51 |
|
|
FVECT dir; /* source direction */ |
52 |
|
|
double dom; /* solid angle */ |
53 |
|
|
double lum; /* average luminance */ |
54 |
|
|
struct glare_src *next; |
55 |
|
|
} *all_srcs = NULL; |
56 |
greg |
2.4 |
|
57 |
greg |
1.1 |
struct glare_dir { |
58 |
|
|
double ang; /* angle (in radians) */ |
59 |
|
|
double indirect; /* indirect illuminance */ |
60 |
|
|
struct glare_dir *next; |
61 |
|
|
} *all_dirs = NULL; |
62 |
greg |
2.4 |
|
63 |
greg |
1.1 |
#define newp(type) (type *)malloc(sizeof(type)) |
64 |
greg |
2.4 |
|
65 |
greg |
1.1 |
char *progname; |
66 |
|
|
int print_header = 1; |
67 |
greg |
2.4 |
|
68 |
greg |
1.1 |
VIEW midview = STDVIEW; |
69 |
greg |
2.4 |
|
70 |
greg |
1.4 |
int wrongformat = 0; |
71 |
greg |
2.4 |
|
72 |
|
|
|
73 |
greg |
1.1 |
main(argc, argv) |
74 |
|
|
int argc; |
75 |
|
|
char *argv[]; |
76 |
|
|
{ |
77 |
|
|
struct named_func *funp; |
78 |
|
|
char *progtail; |
79 |
|
|
int i; |
80 |
|
|
/* get program name */ |
81 |
|
|
progname = argv[0]; |
82 |
schorsch |
2.8 |
progtail = strrchr(progname, '/'); /* final component */ |
83 |
greg |
1.1 |
if (progtail == NULL) |
84 |
|
|
progtail = progname; |
85 |
|
|
else |
86 |
|
|
progtail++; |
87 |
|
|
/* get options */ |
88 |
|
|
for (i = 1; i < argc && argv[i][0] == '-'; i++) |
89 |
|
|
switch (argv[i][1]) { |
90 |
|
|
case 't': |
91 |
|
|
progtail = argv[++i]; |
92 |
|
|
break; |
93 |
|
|
case 'h': |
94 |
|
|
print_header = 0; |
95 |
|
|
break; |
96 |
|
|
default: |
97 |
|
|
goto userr; |
98 |
|
|
} |
99 |
|
|
if (i < argc-1) |
100 |
|
|
goto userr; |
101 |
|
|
if (i == argc-1) /* open file */ |
102 |
|
|
if (freopen(argv[i], "r", stdin) == NULL) { |
103 |
|
|
perror(argv[i]); |
104 |
|
|
exit(1); |
105 |
|
|
} |
106 |
greg |
1.9 |
/* find and run calculation */ |
107 |
greg |
1.1 |
for (funp = all_funcs; funp->name != NULL; funp++) |
108 |
|
|
if (!strcmp(funp->name, progtail)) { |
109 |
greg |
1.9 |
init(); |
110 |
|
|
read_input(); |
111 |
|
|
if (print_header) { |
112 |
|
|
printargs(i, argv, stdout); |
113 |
|
|
putchar('\n'); |
114 |
|
|
} |
115 |
greg |
1.1 |
print_values(funp->func); |
116 |
|
|
exit(0); /* we're done */ |
117 |
|
|
} |
118 |
|
|
/* invalid function */ |
119 |
|
|
userr: |
120 |
greg |
1.9 |
fprintf(stderr, "Usage: %s -t type [-h] [input]\n", progname); |
121 |
|
|
fprintf(stderr, "\twhere 'type' is one of the following:\n"); |
122 |
|
|
for (funp = all_funcs; funp->name != NULL; funp++) |
123 |
|
|
fprintf(stderr, "\t%12s\t%s\n", funp->name, funp->descrip); |
124 |
greg |
1.1 |
exit(1); |
125 |
|
|
} |
126 |
greg |
2.4 |
|
127 |
|
|
|
128 |
gwlarson |
2.6 |
int |
129 |
greg |
1.1 |
headline(s) /* get line from header */ |
130 |
|
|
char *s; |
131 |
|
|
{ |
132 |
greg |
1.4 |
char fmt[32]; |
133 |
greg |
2.4 |
|
134 |
greg |
1.1 |
if (print_header) /* copy to output */ |
135 |
|
|
fputs(s, stdout); |
136 |
greg |
2.2 |
if (isview(s)) |
137 |
|
|
sscanview(&midview, s); |
138 |
greg |
1.4 |
else if (isformat(s)) { |
139 |
|
|
formatval(fmt, s); |
140 |
greg |
1.6 |
wrongformat = strcmp(fmt, "ascii"); |
141 |
greg |
1.4 |
} |
142 |
gwlarson |
2.6 |
return(0); |
143 |
greg |
1.1 |
} |
144 |
greg |
2.4 |
|
145 |
|
|
|
146 |
greg |
1.9 |
init() /* initialize calculation */ |
147 |
|
|
{ |
148 |
|
|
/* read header */ |
149 |
|
|
getheader(stdin, headline, NULL); |
150 |
|
|
if (wrongformat) { |
151 |
|
|
fprintf(stderr, "%s: bad input format\n", progname); |
152 |
|
|
exit(1); |
153 |
|
|
} |
154 |
|
|
/* set view */ |
155 |
|
|
if (setview(&midview) != NULL) { |
156 |
|
|
fprintf(stderr, "%s: bad view information in input\n", |
157 |
|
|
progname); |
158 |
|
|
exit(1); |
159 |
|
|
} |
160 |
|
|
} |
161 |
greg |
2.4 |
|
162 |
|
|
|
163 |
greg |
1.1 |
read_input() /* read glare sources from stdin */ |
164 |
|
|
{ |
165 |
|
|
#define S_SEARCH 0 |
166 |
|
|
#define S_SOURCE 1 |
167 |
|
|
#define S_DIREC 2 |
168 |
|
|
int state = S_SEARCH; |
169 |
|
|
char buf[128]; |
170 |
|
|
register struct glare_src *gs; |
171 |
|
|
register struct glare_dir *gd; |
172 |
greg |
2.4 |
|
173 |
greg |
1.1 |
while (fgets(buf, sizeof(buf), stdin) != NULL) |
174 |
|
|
switch (state) { |
175 |
|
|
case S_SEARCH: |
176 |
|
|
if (!strcmp(buf, "BEGIN glare source\n")) |
177 |
|
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state = S_SOURCE; |
178 |
|
|
else if (!strcmp(buf, "BEGIN indirect illuminance\n")) |
179 |
|
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state = S_DIREC; |
180 |
|
|
break; |
181 |
|
|
case S_SOURCE: |
182 |
|
|
if (!strncmp(buf, "END", 3)) { |
183 |
|
|
state = S_SEARCH; |
184 |
|
|
break; |
185 |
|
|
} |
186 |
|
|
if ((gs = newp(struct glare_src)) == NULL) |
187 |
|
|
goto memerr; |
188 |
|
|
if (sscanf(buf, "%lf %lf %lf %lf %lf", |
189 |
|
|
&gs->dir[0], &gs->dir[1], &gs->dir[2], |
190 |
|
|
&gs->dom, &gs->lum) != 5) |
191 |
|
|
goto readerr; |
192 |
greg |
1.2 |
normalize(gs->dir); |
193 |
greg |
1.1 |
gs->next = all_srcs; |
194 |
|
|
all_srcs = gs; |
195 |
|
|
break; |
196 |
|
|
case S_DIREC: |
197 |
|
|
if (!strncmp(buf, "END", 3)) { |
198 |
|
|
state = S_SEARCH; |
199 |
|
|
break; |
200 |
|
|
} |
201 |
|
|
if ((gd = newp(struct glare_dir)) == NULL) |
202 |
|
|
goto memerr; |
203 |
|
|
if (sscanf(buf, "%lf %lf", |
204 |
|
|
&gd->ang, &gd->indirect) != 2) |
205 |
|
|
goto readerr; |
206 |
|
|
gd->ang *= PI/180.0; /* convert to radians */ |
207 |
|
|
gd->next = all_dirs; |
208 |
|
|
all_dirs = gd; |
209 |
|
|
break; |
210 |
|
|
} |
211 |
|
|
return; |
212 |
|
|
memerr: |
213 |
|
|
perror(progname); |
214 |
|
|
exit(1); |
215 |
|
|
readerr: |
216 |
|
|
fprintf(stderr, "%s: read error on input\n", progname); |
217 |
|
|
exit(1); |
218 |
|
|
#undef S_SEARCH |
219 |
|
|
#undef S_SOURCE |
220 |
|
|
#undef S_DIREC |
221 |
|
|
} |
222 |
greg |
2.4 |
|
223 |
|
|
|
224 |
greg |
1.1 |
print_values(funp) /* print out calculations */ |
225 |
|
|
double (*funp)(); |
226 |
|
|
{ |
227 |
|
|
register struct glare_dir *gd; |
228 |
greg |
2.4 |
|
229 |
greg |
1.1 |
for (gd = all_dirs; gd != NULL; gd = gd->next) |
230 |
|
|
printf("%f\t%f\n", gd->ang*(180.0/PI), (*funp)(gd)); |
231 |
|
|
} |
232 |
greg |
2.4 |
|
233 |
|
|
|
234 |
greg |
1.1 |
double |
235 |
greg |
1.9 |
direct(gd) /* compute direct vertical illuminance */ |
236 |
greg |
1.1 |
struct glare_dir *gd; |
237 |
|
|
{ |
238 |
|
|
FVECT mydir; |
239 |
|
|
double d, dval; |
240 |
|
|
register struct glare_src *gs; |
241 |
greg |
2.4 |
|
242 |
greg |
1.1 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
243 |
|
|
dval = 0.0; |
244 |
|
|
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
245 |
|
|
d = DOT(mydir,gs->dir); |
246 |
|
|
if (d > FTINY) |
247 |
|
|
dval += d * gs->dom * gs->lum; |
248 |
|
|
} |
249 |
|
|
return(dval); |
250 |
greg |
1.9 |
} |
251 |
greg |
2.4 |
|
252 |
|
|
|
253 |
greg |
1.9 |
double |
254 |
|
|
indirect(gd) /* return indirect vertical illuminance */ |
255 |
|
|
struct glare_dir *gd; |
256 |
|
|
{ |
257 |
|
|
return(gd->indirect); |
258 |
|
|
} |
259 |
greg |
2.4 |
|
260 |
|
|
|
261 |
greg |
1.9 |
double |
262 |
|
|
total(gd) /* return total vertical illuminance */ |
263 |
|
|
struct glare_dir *gd; |
264 |
|
|
{ |
265 |
|
|
return(direct(gd)+gd->indirect); |
266 |
greg |
1.1 |
} |
267 |
greg |
2.4 |
|
268 |
|
|
|
269 |
greg |
1.1 |
/* |
270 |
|
|
* posindex - compute glare position index from: |
271 |
|
|
* |
272 |
|
|
* Source Direction |
273 |
|
|
* View Direction |
274 |
|
|
* View Up Direction |
275 |
|
|
* |
276 |
|
|
* All vectors are assumed to be normalized. |
277 |
|
|
* This function is an implementation of the method proposed by |
278 |
|
|
* Robert Levin in his 1975 JIES article. |
279 |
greg |
1.5 |
* This calculation presumes the view direction and up vectors perpendicular. |
280 |
greg |
1.1 |
* We return a value less than zero for improper positions. |
281 |
|
|
*/ |
282 |
greg |
2.4 |
|
283 |
greg |
1.1 |
double |
284 |
|
|
posindex(sd, vd, vu) /* compute position index */ |
285 |
|
|
FVECT sd, vd, vu; |
286 |
|
|
{ |
287 |
|
|
double sigma, tau; |
288 |
|
|
double d; |
289 |
greg |
2.4 |
|
290 |
greg |
1.1 |
d = DOT(sd,vd); |
291 |
|
|
if (d <= 0.0) |
292 |
|
|
return(-1.0); |
293 |
greg |
1.5 |
if (d >= 1.0) |
294 |
|
|
return(1.0); |
295 |
greg |
1.1 |
sigma = acos(d) * (180./PI); |
296 |
greg |
2.4 |
d = fabs(DOT(sd,vu)/sqrt(1.0-d*d)); |
297 |
greg |
1.5 |
if (d >= 1.0) |
298 |
|
|
tau = 0.0; |
299 |
|
|
else |
300 |
|
|
tau = acos(d) * (180./PI); |
301 |
greg |
1.1 |
return( exp( sigma*( (35.2 - tau*.31889 - 1.22*exp(-.22222*tau))*1e-3 |
302 |
|
|
+ sigma*(21. + tau*(.26667 + tau*-.002963))*1e-5 ) |
303 |
|
|
) ); |
304 |
|
|
} |
305 |
greg |
2.4 |
|
306 |
|
|
|
307 |
|
|
double |
308 |
|
|
dgi(gd) /* compute Daylight Glare Index */ |
309 |
|
|
struct glare_dir *gd; |
310 |
|
|
{ |
311 |
|
|
register struct glare_src *gs; |
312 |
|
|
FVECT mydir,testdir[7],vhor; |
313 |
|
|
double r,omega,p[7],sum; |
314 |
|
|
int i,n; |
315 |
|
|
|
316 |
|
|
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
317 |
|
|
sum = 0.0; n = 0; |
318 |
|
|
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
319 |
greg |
1.1 |
|
320 |
greg |
2.4 |
/* compute 1/p^2 weighted solid angle of the source */ |
321 |
|
|
r = sqrt(1 - pow(1.-gs->dom/2./PI,2.)); |
322 |
|
|
fcross(vhor,gs->dir,midview.vup); |
323 |
|
|
normalize(vhor); |
324 |
|
|
VCOPY(testdir[0],gs->dir); |
325 |
|
|
fvsum(testdir[1],gs->dir,vhor,r); |
326 |
|
|
fvsum(testdir[2],gs->dir,vhor,0.5*r); |
327 |
|
|
fvsum(testdir[5],testdir[2],midview.vup,-0.866*r); |
328 |
|
|
fvsum(testdir[2],testdir[2],midview.vup,0.866*r); |
329 |
|
|
fvsum(testdir[3],gs->dir,vhor,-r); |
330 |
|
|
fvsum(testdir[4],gs->dir,vhor,-0.5*r); |
331 |
|
|
fvsum(testdir[6],testdir[4],midview.vup,0.866*r); |
332 |
|
|
fvsum(testdir[4],testdir[4],midview.vup,-0.866*r); |
333 |
|
|
for (i = 0; i < 7; i++) { |
334 |
|
|
normalize(testdir[i]); |
335 |
|
|
p[i] = pow(posindex(testdir[i],mydir,midview.vup),-2.0); |
336 |
|
|
if (p[i] <= FTINY) p[i] = 0.0; |
337 |
|
|
} |
338 |
|
|
r = 1-gs->dom/2./PI; |
339 |
|
|
omega = gs->dom*p[0]; |
340 |
|
|
omega += (r*PI*(1+1/r/r)-2*PI)*(-p[0]+(p[1]+p[2])*0.5); |
341 |
|
|
omega += (2*PI-r*PI*(1+1/r/r))*(-p[0]-0.1667*(p[1]+p[3]) |
342 |
|
|
+0.3334*(p[2]+p[4]+p[5]+p[6])); |
343 |
greg |
1.1 |
|
344 |
greg |
2.4 |
sum += pow(gs->lum,1.6) * pow(omega,0.8) / |
345 |
|
|
(gd->indirect/PI + 0.07*sqrt(gs->dom)*gs->lum); |
346 |
|
|
n++; |
347 |
|
|
} |
348 |
|
|
if (n == 0) |
349 |
|
|
return(0.0); |
350 |
|
|
return( 10*log10(0.478*sum) ); |
351 |
|
|
} |
352 |
|
|
|
353 |
|
|
|
354 |
greg |
1.1 |
double |
355 |
greg |
2.4 |
brs_gi(gd) /* compute BRS Glare Index */ |
356 |
|
|
struct glare_dir *gd; |
357 |
|
|
{ |
358 |
|
|
register struct glare_src *gs; |
359 |
|
|
FVECT mydir; |
360 |
|
|
double p; |
361 |
|
|
double sum; |
362 |
|
|
|
363 |
|
|
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
364 |
|
|
sum = 0.0; |
365 |
|
|
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
366 |
|
|
p = posindex(gs->dir, mydir, midview.vup); |
367 |
|
|
if (p <= FTINY) |
368 |
|
|
continue; |
369 |
|
|
sum += pow(gs->lum/p,1.6) * pow(gs->dom,0.8); |
370 |
|
|
} |
371 |
|
|
if (sum <= FTINY) |
372 |
|
|
return(0.0); |
373 |
|
|
sum /= gd->indirect/PI; |
374 |
|
|
return(10*log10(0.478*sum)); |
375 |
|
|
} |
376 |
|
|
|
377 |
|
|
|
378 |
|
|
double |
379 |
greg |
1.2 |
guth_dgr(gd) /* compute Guth discomfort glare rating */ |
380 |
greg |
1.1 |
struct glare_dir *gd; |
381 |
|
|
{ |
382 |
|
|
#define q(w) (20.4*w+1.52*pow(w,.2)-.075) |
383 |
|
|
register struct glare_src *gs; |
384 |
greg |
1.7 |
FVECT mydir; |
385 |
greg |
1.1 |
double p; |
386 |
|
|
double sum; |
387 |
greg |
1.3 |
double wtot, brsum; |
388 |
greg |
1.1 |
int n; |
389 |
greg |
2.4 |
|
390 |
greg |
1.7 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
391 |
greg |
1.3 |
sum = wtot = brsum = 0.0; n = 0; |
392 |
greg |
1.1 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
393 |
greg |
1.7 |
p = posindex(gs->dir, mydir, midview.vup); |
394 |
greg |
1.1 |
if (p <= FTINY) |
395 |
|
|
continue; |
396 |
|
|
sum += gs->lum * q(gs->dom) / p; |
397 |
greg |
1.3 |
brsum += gs->lum * gs->dom; |
398 |
|
|
wtot += gs->dom; |
399 |
greg |
1.1 |
n++; |
400 |
|
|
} |
401 |
|
|
if (n == 0) |
402 |
|
|
return(0.0); |
403 |
greg |
1.8 |
return( pow(.5*sum/pow((brsum+(5.-wtot)*gd->indirect/PI)/5.,.44), |
404 |
greg |
1.1 |
pow((double)n, -.0914) ) ); |
405 |
|
|
#undef q |
406 |
|
|
} |
407 |
greg |
2.4 |
|
408 |
|
|
|
409 |
greg |
1.1 |
#ifndef M_SQRT2 |
410 |
|
|
#define M_SQRT2 1.41421356237309504880 |
411 |
|
|
#endif |
412 |
greg |
2.4 |
|
413 |
greg |
1.1 |
#define norm_integral(z) (1.-.5*erfc((z)/M_SQRT2)) |
414 |
greg |
2.4 |
|
415 |
|
|
|
416 |
greg |
1.1 |
double |
417 |
greg |
1.2 |
guth_vcp(gd) /* compute Guth visual comfort probability */ |
418 |
greg |
1.1 |
struct glare_dir *gd; |
419 |
|
|
{ |
420 |
greg |
2.5 |
extern double erfc(); |
421 |
greg |
1.7 |
double dgr; |
422 |
greg |
2.4 |
|
423 |
greg |
1.7 |
dgr = guth_dgr(gd); |
424 |
|
|
if (dgr <= FTINY) |
425 |
|
|
return(100.0); |
426 |
|
|
return(100.*norm_integral(6.374-1.3227*log(dgr))); |
427 |
greg |
1.8 |
} |
428 |
greg |
2.4 |
|
429 |
|
|
|
430 |
greg |
1.8 |
double |
431 |
|
|
cie_cgi(gd) /* compute CIE Glare Index */ |
432 |
|
|
struct glare_dir *gd; |
433 |
|
|
{ |
434 |
|
|
register struct glare_src *gs; |
435 |
|
|
FVECT mydir; |
436 |
|
|
double dillum; |
437 |
|
|
double p; |
438 |
|
|
double sum; |
439 |
greg |
2.4 |
|
440 |
greg |
1.8 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
441 |
|
|
sum = 0.0; |
442 |
|
|
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
443 |
|
|
p = posindex(gs->dir, mydir, midview.vup); |
444 |
|
|
if (p <= FTINY) |
445 |
|
|
continue; |
446 |
|
|
sum += gs->lum*gs->lum * gs->dom / (p*p); |
447 |
|
|
} |
448 |
|
|
if (sum <= FTINY) |
449 |
|
|
return(0.0); |
450 |
|
|
dillum = direct(gd); |
451 |
|
|
return(8.*log10(2.*sum*(1.+dillum/500.)/(dillum+gd->indirect))); |
452 |
greg |
2.4 |
} |
453 |
|
|
|
454 |
|
|
|
455 |
|
|
double |
456 |
|
|
ugr(gd) /* compute Unified Glare Rating */ |
457 |
|
|
struct glare_dir *gd; |
458 |
|
|
{ |
459 |
|
|
register struct glare_src *gs; |
460 |
|
|
FVECT mydir; |
461 |
|
|
double p; |
462 |
|
|
double sum; |
463 |
|
|
|
464 |
|
|
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
465 |
|
|
sum = 0.0; |
466 |
|
|
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
467 |
|
|
p = posindex(gs->dir, mydir, midview.vup); |
468 |
|
|
if (p <= FTINY) |
469 |
|
|
continue; |
470 |
|
|
sum += gs->lum*gs->lum * gs->dom / (p*p); |
471 |
|
|
} |
472 |
|
|
if (sum <= FTINY) |
473 |
|
|
return(0.0); |
474 |
|
|
return(8.*log10(0.25*sum*PI/gd->indirect)); |
475 |
greg |
1.1 |
} |