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; |
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|
70 |
|
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main(argc, argv) |
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int argc; |
73 |
char *argv[]; |
74 |
{ |
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extern char *rindex(); |
76 |
struct named_func *funp; |
77 |
char *progtail; |
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int i; |
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/* get program name */ |
80 |
progname = argv[0]; |
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progtail = rindex(progname, '/'); /* final component */ |
82 |
if (progtail == NULL) |
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progtail = progname; |
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else |
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progtail++; |
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/* get options */ |
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for (i = 1; i < argc && argv[i][0] == '-'; i++) |
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switch (argv[i][1]) { |
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case 't': |
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progtail = argv[++i]; |
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break; |
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case 'h': |
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print_header = 0; |
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break; |
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default: |
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goto userr; |
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} |
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if (i < argc-1) |
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goto userr; |
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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(); |
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read_input(); |
110 |
if (print_header) { |
111 |
printargs(i, argv, stdout); |
112 |
putchar('\n'); |
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} |
114 |
print_values(funp->func); |
115 |
exit(0); /* we're done */ |
116 |
} |
117 |
/* invalid function */ |
118 |
userr: |
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fprintf(stderr, "Usage: %s -t type [-h] [input]\n", progname); |
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fprintf(stderr, "\twhere 'type' is one of the following:\n"); |
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for (funp = all_funcs; funp->name != NULL; funp++) |
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fprintf(stderr, "\t%12s\t%s\n", funp->name, funp->descrip); |
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exit(1); |
124 |
} |
125 |
|
126 |
|
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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)) { |
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formatval(fmt, s); |
139 |
wrongformat = strcmp(fmt, "ascii"); |
140 |
} |
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return(0); |
142 |
} |
143 |
|
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|
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init() /* initialize calculation */ |
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{ |
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/* read header */ |
148 |
getheader(stdin, headline, NULL); |
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if (wrongformat) { |
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fprintf(stderr, "%s: bad input format\n", progname); |
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exit(1); |
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} |
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/* set view */ |
154 |
if (setview(&midview) != NULL) { |
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fprintf(stderr, "%s: bad view information in input\n", |
156 |
progname); |
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exit(1); |
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} |
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} |
160 |
|
161 |
|
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read_input() /* read glare sources from stdin */ |
163 |
{ |
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#define S_SEARCH 0 |
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#define S_SOURCE 1 |
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#define S_DIREC 2 |
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int state = S_SEARCH; |
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char buf[128]; |
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register struct glare_src *gs; |
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register struct glare_dir *gd; |
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|
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while (fgets(buf, sizeof(buf), stdin) != NULL) |
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switch (state) { |
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case S_SEARCH: |
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if (!strcmp(buf, "BEGIN glare source\n")) |
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state = S_SOURCE; |
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else if (!strcmp(buf, "BEGIN indirect illuminance\n")) |
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state = S_DIREC; |
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break; |
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case S_SOURCE: |
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if (!strncmp(buf, "END", 3)) { |
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state = S_SEARCH; |
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break; |
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} |
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if ((gs = newp(struct glare_src)) == NULL) |
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goto memerr; |
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if (sscanf(buf, "%lf %lf %lf %lf %lf", |
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&gs->dir[0], &gs->dir[1], &gs->dir[2], |
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&gs->dom, &gs->lum) != 5) |
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goto readerr; |
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normalize(gs->dir); |
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gs->next = all_srcs; |
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all_srcs = gs; |
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break; |
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case S_DIREC: |
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if (!strncmp(buf, "END", 3)) { |
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state = S_SEARCH; |
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break; |
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} |
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if ((gd = newp(struct glare_dir)) == NULL) |
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goto memerr; |
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if (sscanf(buf, "%lf %lf", |
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&gd->ang, &gd->indirect) != 2) |
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goto readerr; |
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gd->ang *= PI/180.0; /* convert to radians */ |
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gd->next = all_dirs; |
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all_dirs = gd; |
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break; |
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} |
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return; |
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memerr: |
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perror(progname); |
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exit(1); |
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readerr: |
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fprintf(stderr, "%s: read error on input\n", progname); |
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exit(1); |
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#undef S_SEARCH |
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#undef S_SOURCE |
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#undef S_DIREC |
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} |
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|
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|
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print_values(funp) /* print out calculations */ |
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double (*funp)(); |
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{ |
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register struct glare_dir *gd; |
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|
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for (gd = all_dirs; gd != NULL; gd = gd->next) |
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printf("%f\t%f\n", gd->ang*(180.0/PI), (*funp)(gd)); |
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} |
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|
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|
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double |
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direct(gd) /* compute direct vertical illuminance */ |
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struct glare_dir *gd; |
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{ |
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FVECT mydir; |
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double d, dval; |
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register struct glare_src *gs; |
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|
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spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
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dval = 0.0; |
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for (gs = all_srcs; gs != NULL; gs = gs->next) { |
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d = DOT(mydir,gs->dir); |
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if (d > FTINY) |
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dval += d * gs->dom * gs->lum; |
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} |
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return(dval); |
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} |
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|
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|
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double |
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indirect(gd) /* return indirect vertical illuminance */ |
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struct glare_dir *gd; |
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{ |
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return(gd->indirect); |
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} |
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|
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|
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double |
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total(gd) /* return total vertical illuminance */ |
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struct glare_dir *gd; |
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{ |
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return(direct(gd)+gd->indirect); |
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} |
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|
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|
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/* |
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* posindex - compute glare position index from: |
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* |
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* Source Direction |
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* View Direction |
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* View Up Direction |
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* |
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* All vectors are assumed to be normalized. |
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* This function is an implementation of the method proposed by |
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* Robert Levin in his 1975 JIES article. |
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* This calculation presumes the view direction and up vectors perpendicular. |
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* We return a value less than zero for improper positions. |
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*/ |
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|
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double |
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posindex(sd, vd, vu) /* compute position index */ |
284 |
FVECT sd, vd, vu; |
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{ |
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double sigma, tau; |
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double d; |
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|
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d = DOT(sd,vd); |
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if (d <= 0.0) |
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return(-1.0); |
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if (d >= 1.0) |
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return(1.0); |
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sigma = acos(d) * (180./PI); |
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d = fabs(DOT(sd,vu)/sqrt(1.0-d*d)); |
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if (d >= 1.0) |
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tau = 0.0; |
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else |
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tau = acos(d) * (180./PI); |
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return( exp( sigma*( (35.2 - tau*.31889 - 1.22*exp(-.22222*tau))*1e-3 |
301 |
+ sigma*(21. + tau*(.26667 + tau*-.002963))*1e-5 ) |
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) ); |
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} |
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|
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 |
|
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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 |
|
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/* 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); |
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VCOPY(testdir[0],gs->dir); |
324 |
fvsum(testdir[1],gs->dir,vhor,r); |
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fvsum(testdir[2],gs->dir,vhor,0.5*r); |
326 |
fvsum(testdir[5],testdir[2],midview.vup,-0.866*r); |
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fvsum(testdir[2],testdir[2],midview.vup,0.866*r); |
328 |
fvsum(testdir[3],gs->dir,vhor,-r); |
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fvsum(testdir[4],gs->dir,vhor,-0.5*r); |
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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]); |
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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 |
} |