| 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 |
* Compute Glare Index given by program name or -t option: |
| 9 |
* |
| 10 |
* dgi - Daylight Glare Index |
| 11 |
* brs_gi - Building Research Station Glare Index (Petherbridge |
| 12 |
* & Hopkinson) |
| 13 |
* ugr - Unified Glare Rating System (Fischer) |
| 14 |
* guth_dgr - Guth discomfort glare rating |
| 15 |
* guth_vcp - Guth visual comfort probability |
| 16 |
* cie_cgi - CIE Glare Index (1983, due to Einhorn) |
| 17 |
* vert_dir - Direct vertical illuminance |
| 18 |
* vert_ind - Indirect vertical illuminance (from input) |
| 19 |
* vert_ill - Total vertical illuminance |
| 20 |
* |
| 21 |
* 12 April 1991 Greg Ward EPFL |
| 22 |
* 19 April 1993 R. Compagnon EPFL (added dgi, brs_gi, ugr) |
| 23 |
*/ |
| 24 |
|
| 25 |
#include "standard.h" |
| 26 |
#include "view.h" |
| 27 |
|
| 28 |
|
| 29 |
double posindex(); |
| 30 |
|
| 31 |
double direct(), guth_dgr(), guth_vcp(), cie_cgi(), |
| 32 |
indirect(), total(), dgi(), brs_gi(), ugr(); |
| 33 |
|
| 34 |
struct named_func { |
| 35 |
char *name; |
| 36 |
double (*func)(); |
| 37 |
char *descrip; |
| 38 |
} all_funcs[] = { |
| 39 |
{"dgi", dgi, "Daylight Glare Index"}, |
| 40 |
{"brs_gi", brs_gi, "BRS Glare Index"}, |
| 41 |
{"ugr", ugr, "Unified Glare Rating"}, |
| 42 |
{"guth_vcp", guth_vcp, "Guth Visual Comfort Probability"}, |
| 43 |
{"cie_cgi", cie_cgi, "CIE Glare Index (Einhorn)"}, |
| 44 |
{"guth_dgr", guth_dgr, "Guth Disability Glare Rating"}, |
| 45 |
{"vert_dir", direct, "Direct Vertical Illuminance"}, |
| 46 |
{"vert_ill", total, "Total Vertical Illuminance"}, |
| 47 |
{"vert_ind", indirect, "Indirect Vertical Illuminance"}, |
| 48 |
{NULL} |
| 49 |
}; |
| 50 |
|
| 51 |
struct glare_src { |
| 52 |
FVECT dir; /* source direction */ |
| 53 |
double dom; /* solid angle */ |
| 54 |
double lum; /* average luminance */ |
| 55 |
struct glare_src *next; |
| 56 |
} *all_srcs = NULL; |
| 57 |
|
| 58 |
struct glare_dir { |
| 59 |
double ang; /* angle (in radians) */ |
| 60 |
double indirect; /* indirect illuminance */ |
| 61 |
struct glare_dir *next; |
| 62 |
} *all_dirs = NULL; |
| 63 |
|
| 64 |
#define newp(type) (type *)malloc(sizeof(type)) |
| 65 |
|
| 66 |
char *progname; |
| 67 |
int print_header = 1; |
| 68 |
|
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VIEW midview = STDVIEW; |
| 70 |
|
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int wrongformat = 0; |
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|
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|
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main(argc, argv) |
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int argc; |
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char *argv[]; |
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{ |
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extern char *rindex(); |
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struct named_func *funp; |
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char *progtail; |
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int i; |
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/* get program name */ |
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progname = argv[0]; |
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progtail = rindex(progname, '/'); /* final component */ |
| 85 |
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; |
| 95 |
case 'h': |
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print_header = 0; |
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break; |
| 98 |
default: |
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goto userr; |
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} |
| 101 |
if (i < argc-1) |
| 102 |
goto userr; |
| 103 |
if (i == argc-1) /* open file */ |
| 104 |
if (freopen(argv[i], "r", stdin) == NULL) { |
| 105 |
perror(argv[i]); |
| 106 |
exit(1); |
| 107 |
} |
| 108 |
/* find and run calculation */ |
| 109 |
for (funp = all_funcs; funp->name != NULL; funp++) |
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if (!strcmp(funp->name, progtail)) { |
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init(); |
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read_input(); |
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if (print_header) { |
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printargs(i, argv, stdout); |
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putchar('\n'); |
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} |
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print_values(funp->func); |
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exit(0); /* we're done */ |
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} |
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/* invalid function */ |
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userr: |
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fprintf(stderr, "Usage: %s -t type [-h] [input]\n", progname); |
| 123 |
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); |
| 126 |
exit(1); |
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} |
| 128 |
|
| 129 |
|
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int |
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headline(s) /* get line from header */ |
| 132 |
char *s; |
| 133 |
{ |
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char fmt[32]; |
| 135 |
|
| 136 |
if (print_header) /* copy to output */ |
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fputs(s, stdout); |
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if (isview(s)) |
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sscanview(&midview, s); |
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else if (isformat(s)) { |
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formatval(fmt, s); |
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wrongformat = strcmp(fmt, "ascii"); |
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} |
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return(0); |
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} |
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|
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|
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init() /* initialize calculation */ |
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{ |
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/* read header */ |
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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 */ |
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if (setview(&midview) != NULL) { |
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fprintf(stderr, "%s: bad view information in input\n", |
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progname); |
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exit(1); |
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} |
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} |
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|
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|
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read_input() /* read glare sources from stdin */ |
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{ |
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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 */ |
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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 |
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+ sigma*(21. + tau*(.26667 + tau*-.002963))*1e-5 ) |
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) ); |
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} |
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|
| 308 |
|
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double |
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dgi(gd) /* compute Daylight Glare Index */ |
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struct glare_dir *gd; |
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{ |
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register struct glare_src *gs; |
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FVECT mydir,testdir[7],vhor; |
| 315 |
double r,omega,p[7],sum; |
| 316 |
int i,n; |
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|
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spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
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sum = 0.0; n = 0; |
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for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 321 |
|
| 322 |
/* compute 1/p^2 weighted solid angle of the source */ |
| 323 |
r = sqrt(1 - pow(1.-gs->dom/2./PI,2.)); |
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fcross(vhor,gs->dir,midview.vup); |
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normalize(vhor); |
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VCOPY(testdir[0],gs->dir); |
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fvsum(testdir[1],gs->dir,vhor,r); |
| 328 |
fvsum(testdir[2],gs->dir,vhor,0.5*r); |
| 329 |
fvsum(testdir[5],testdir[2],midview.vup,-0.866*r); |
| 330 |
fvsum(testdir[2],testdir[2],midview.vup,0.866*r); |
| 331 |
fvsum(testdir[3],gs->dir,vhor,-r); |
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fvsum(testdir[4],gs->dir,vhor,-0.5*r); |
| 333 |
fvsum(testdir[6],testdir[4],midview.vup,0.866*r); |
| 334 |
fvsum(testdir[4],testdir[4],midview.vup,-0.866*r); |
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for (i = 0; i < 7; i++) { |
| 336 |
normalize(testdir[i]); |
| 337 |
p[i] = pow(posindex(testdir[i],mydir,midview.vup),-2.0); |
| 338 |
if (p[i] <= FTINY) p[i] = 0.0; |
| 339 |
} |
| 340 |
r = 1-gs->dom/2./PI; |
| 341 |
omega = gs->dom*p[0]; |
| 342 |
omega += (r*PI*(1+1/r/r)-2*PI)*(-p[0]+(p[1]+p[2])*0.5); |
| 343 |
omega += (2*PI-r*PI*(1+1/r/r))*(-p[0]-0.1667*(p[1]+p[3]) |
| 344 |
+0.3334*(p[2]+p[4]+p[5]+p[6])); |
| 345 |
|
| 346 |
sum += pow(gs->lum,1.6) * pow(omega,0.8) / |
| 347 |
(gd->indirect/PI + 0.07*sqrt(gs->dom)*gs->lum); |
| 348 |
n++; |
| 349 |
} |
| 350 |
if (n == 0) |
| 351 |
return(0.0); |
| 352 |
return( 10*log10(0.478*sum) ); |
| 353 |
} |
| 354 |
|
| 355 |
|
| 356 |
double |
| 357 |
brs_gi(gd) /* compute BRS Glare Index */ |
| 358 |
struct glare_dir *gd; |
| 359 |
{ |
| 360 |
register struct glare_src *gs; |
| 361 |
FVECT mydir; |
| 362 |
double p; |
| 363 |
double sum; |
| 364 |
|
| 365 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 366 |
sum = 0.0; |
| 367 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 368 |
p = posindex(gs->dir, mydir, midview.vup); |
| 369 |
if (p <= FTINY) |
| 370 |
continue; |
| 371 |
sum += pow(gs->lum/p,1.6) * pow(gs->dom,0.8); |
| 372 |
} |
| 373 |
if (sum <= FTINY) |
| 374 |
return(0.0); |
| 375 |
sum /= gd->indirect/PI; |
| 376 |
return(10*log10(0.478*sum)); |
| 377 |
} |
| 378 |
|
| 379 |
|
| 380 |
double |
| 381 |
guth_dgr(gd) /* compute Guth discomfort glare rating */ |
| 382 |
struct glare_dir *gd; |
| 383 |
{ |
| 384 |
#define q(w) (20.4*w+1.52*pow(w,.2)-.075) |
| 385 |
register struct glare_src *gs; |
| 386 |
FVECT mydir; |
| 387 |
double p; |
| 388 |
double sum; |
| 389 |
double wtot, brsum; |
| 390 |
int n; |
| 391 |
|
| 392 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 393 |
sum = wtot = brsum = 0.0; n = 0; |
| 394 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 395 |
p = posindex(gs->dir, mydir, midview.vup); |
| 396 |
if (p <= FTINY) |
| 397 |
continue; |
| 398 |
sum += gs->lum * q(gs->dom) / p; |
| 399 |
brsum += gs->lum * gs->dom; |
| 400 |
wtot += gs->dom; |
| 401 |
n++; |
| 402 |
} |
| 403 |
if (n == 0) |
| 404 |
return(0.0); |
| 405 |
return( pow(.5*sum/pow((brsum+(5.-wtot)*gd->indirect/PI)/5.,.44), |
| 406 |
pow((double)n, -.0914) ) ); |
| 407 |
#undef q |
| 408 |
} |
| 409 |
|
| 410 |
|
| 411 |
#ifndef M_SQRT2 |
| 412 |
#define M_SQRT2 1.41421356237309504880 |
| 413 |
#endif |
| 414 |
|
| 415 |
#define norm_integral(z) (1.-.5*erfc((z)/M_SQRT2)) |
| 416 |
|
| 417 |
|
| 418 |
double |
| 419 |
guth_vcp(gd) /* compute Guth visual comfort probability */ |
| 420 |
struct glare_dir *gd; |
| 421 |
{ |
| 422 |
extern double erfc(); |
| 423 |
double dgr; |
| 424 |
|
| 425 |
dgr = guth_dgr(gd); |
| 426 |
if (dgr <= FTINY) |
| 427 |
return(100.0); |
| 428 |
return(100.*norm_integral(6.374-1.3227*log(dgr))); |
| 429 |
} |
| 430 |
|
| 431 |
|
| 432 |
double |
| 433 |
cie_cgi(gd) /* compute CIE Glare Index */ |
| 434 |
struct glare_dir *gd; |
| 435 |
{ |
| 436 |
register struct glare_src *gs; |
| 437 |
FVECT mydir; |
| 438 |
double dillum; |
| 439 |
double p; |
| 440 |
double sum; |
| 441 |
|
| 442 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 443 |
sum = 0.0; |
| 444 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 445 |
p = posindex(gs->dir, mydir, midview.vup); |
| 446 |
if (p <= FTINY) |
| 447 |
continue; |
| 448 |
sum += gs->lum*gs->lum * gs->dom / (p*p); |
| 449 |
} |
| 450 |
if (sum <= FTINY) |
| 451 |
return(0.0); |
| 452 |
dillum = direct(gd); |
| 453 |
return(8.*log10(2.*sum*(1.+dillum/500.)/(dillum+gd->indirect))); |
| 454 |
} |
| 455 |
|
| 456 |
|
| 457 |
double |
| 458 |
ugr(gd) /* compute Unified Glare Rating */ |
| 459 |
struct glare_dir *gd; |
| 460 |
{ |
| 461 |
register struct glare_src *gs; |
| 462 |
FVECT mydir; |
| 463 |
double p; |
| 464 |
double sum; |
| 465 |
|
| 466 |
spinvector(mydir, midview.vdir, midview.vup, gd->ang); |
| 467 |
sum = 0.0; |
| 468 |
for (gs = all_srcs; gs != NULL; gs = gs->next) { |
| 469 |
p = posindex(gs->dir, mydir, midview.vup); |
| 470 |
if (p <= FTINY) |
| 471 |
continue; |
| 472 |
sum += gs->lum*gs->lum * gs->dom / (p*p); |
| 473 |
} |
| 474 |
if (sum <= FTINY) |
| 475 |
return(0.0); |
| 476 |
return(8.*log10(0.25*sum*PI/gd->indirect)); |
| 477 |
} |
