src/util/glarendx.c

/* Copyright (c) 1991 Regents of the University of California */

#ifndef lint
static char SCCSid[] = "$SunId$ LBL";
#endif

/*
 * Compute Glare Index given by program name:
 *
 *      guth_dgr -      Guth discomfort glare rating
 *      guth_vcp -      Guth visual comfort probability
 *      cie_cgi -       CIE Glare Index (1983)
 *
 *              12 April 1991   Greg Ward       EPFL
 */

#include "standard.h"
#include "view.h"

extern double   erfc();

double  posindex();
int     headline();

double  direct(), guth_dgr(), guth_vcp(), cie_cgi();

struct named_func {
        char    *name;
        double  (*func)();
} all_funcs[] = {
        {"direct", direct},
        {"guth_dgr", guth_dgr},
        {"guth_vcp", guth_vcp},
        {"cie_cgi", cie_cgi},
        {NULL}
};

struct glare_src {
        FVECT   dir;            /* source direction */
        double  dom;            /* solid angle */
        double  lum;            /* average luminance */
        struct glare_src        *next;
} *all_srcs = NULL;

struct glare_dir {
        double  ang;            /* angle (in radians) */
        double  indirect;       /* indirect illuminance */
        struct glare_dir        *next;
} *all_dirs = NULL;

#define newp(type)      (type *)malloc(sizeof(type))

char    *progname;
int     print_header = 1;

VIEW    midview = STDVIEW;

int     wrongformat = 0;


main(argc, argv)
int     argc;
char    *argv[];
{
        extern char     *rindex();
        struct named_func       *funp;
        char    *progtail;
        int     i;
                                        /* get program name */
        progname = argv[0];
        progtail = rindex(progname, '/');       /* final component */
        if (progtail == NULL)
                progtail = progname;
        else
                progtail++;
                                        /* get options */
        for (i = 1; i < argc && argv[i][0] == '-'; i++)
                switch (argv[i][1]) {
                case 't':
                        progtail = argv[++i];
                        break;
                case 'h':
                        print_header = 0;
                        break;
                default:
                        goto userr;
                }
        if (i < argc-1)
                goto userr;
        if (i == argc-1)                /* open file */
                if (freopen(argv[i], "r", stdin) == NULL) {
                        perror(argv[i]);
                        exit(1);
                }
                                        /* read header */
        getheader(stdin, headline, NULL);
        if (wrongformat) {
                fprintf(stderr, "%s: bad input format\n", progname);
                exit(1);
        }
        if (print_header) {             /* add to header */
                printargs(i, argv, stdout);
                putchar('\n');
        }
                                        /* set view */
        if (setview(&midview) != NULL) {
                fprintf(stderr, "%s: bad view information in input\n",
                                progname);
                exit(1);
        }
                                        /* get findglare data */
        read_input();
                                        /* find calculation */
        for (funp = all_funcs; funp->name != NULL; funp++)
                if (!strcmp(funp->name, progtail)) {
                        print_values(funp->func);
                        exit(0);                /* we're done */
                }
                                        /* invalid function */
        fprintf(stderr, "%s: unknown function!\n", progtail);
        exit(1);
userr:
        fprintf(stderr, "Usage: %s [-t type][-h] [input]\n", progname);
        exit(1);
}


headline(s)                     /* get line from header */
char    *s;
{
        char    fmt[32];

        if (print_header)               /* copy to output */
                fputs(s, stdout);
        if (!strncmp(s, VIEWSTR, VIEWSTRL))
                sscanview(&midview, s+VIEWSTRL);
        else if (isformat(s)) {
                formatval(fmt, s);
                wrongformat = strcmp(fmt, "ascii");
        }
}


read_input()                    /* read glare sources from stdin */
{
#define S_SEARCH        0
#define S_SOURCE        1
#define S_DIREC         2
        int     state = S_SEARCH;
        char    buf[128];
        register struct glare_src       *gs;
        register struct glare_dir       *gd;

        while (fgets(buf, sizeof(buf), stdin) != NULL)
                switch (state) {
                case S_SEARCH:
                        if (!strcmp(buf, "BEGIN glare source\n"))
                                state = S_SOURCE;
                        else if (!strcmp(buf, "BEGIN indirect illuminance\n"))
                                state = S_DIREC;
                        break;
                case S_SOURCE:
                        if (!strncmp(buf, "END", 3)) {
                                state = S_SEARCH;
                                break;
                        }
                        if ((gs = newp(struct glare_src)) == NULL)
                                goto memerr;
                        if (sscanf(buf, "%lf %lf %lf %lf %lf",
                                        &gs->dir[0], &gs->dir[1], &gs->dir[2],
                                        &gs->dom, &gs->lum) != 5)
                                goto readerr;
                        normalize(gs->dir);
                        gs->next = all_srcs;
                        all_srcs = gs;
                        break;
                case S_DIREC:
                        if (!strncmp(buf, "END", 3)) {
                                state = S_SEARCH;
                                break;
                        }
                        if ((gd = newp(struct glare_dir)) == NULL)
                                goto memerr;
                        if (sscanf(buf, "%lf %lf",
                                        &gd->ang, &gd->indirect) != 2)
                                goto readerr;
                        gd->ang *= PI/180.0;    /* convert to radians */
                        gd->next = all_dirs;
                        all_dirs = gd;
                        break;
                }
        return;
memerr:
        perror(progname);
        exit(1);
readerr:
        fprintf(stderr, "%s: read error on input\n", progname);
        exit(1);
#undef S_SEARCH
#undef S_SOURCE
#undef S_DIREC
}


print_values(funp)              /* print out calculations */
double  (*funp)();
{
        register struct glare_dir       *gd;

        for (gd = all_dirs; gd != NULL; gd = gd->next)
                printf("%f\t%f\n", gd->ang*(180.0/PI), (*funp)(gd));
}


double
direct(gd)                      /* compute direct illuminance */
struct glare_dir        *gd;
{
        FVECT   mydir;
        double  d, dval;
        register struct glare_src       *gs;

        spinvector(mydir, midview.vdir, midview.vup, gd->ang);
        dval = 0.0;
        for (gs = all_srcs; gs != NULL; gs = gs->next) {
                d = DOT(mydir,gs->dir);
                if (d > FTINY)
                        dval += d * gs->dom * gs->lum;
        }
        return(dval);
}


/*
 * posindex -   compute glare position index from:
 *
 *      Source Direction
 *      View Direction
 *      View Up Direction
 *
 * All vectors are assumed to be normalized.
 * This function is an implementation of the method proposed by
 * Robert Levin in his 1975 JIES article.
 * This calculation presumes the view direction and up vectors perpendicular.
 * We return a value less than zero for improper positions.
 */

double
posindex(sd, vd, vu)                    /* compute position index */
FVECT   sd, vd, vu;
{
        double  sigma, tau;
        double  d;

        d = DOT(sd,vd);
        if (d <= 0.0)
                return(-1.0);
        if (d >= 1.0)
                return(1.0);
        sigma = acos(d) * (180./PI);
        d = DOT(sd,vu)/sqrt(1.0-d*d);
        if (d >= 1.0)
                tau = 0.0;
        else
                tau = acos(d) * (180./PI);
        return( exp( sigma*( (35.2 - tau*.31889 - 1.22*exp(-.22222*tau))*1e-3
                        + sigma*(21. + tau*(.26667 + tau*-.002963))*1e-5 )
                ) );
}


double
guth_dgr(gd)            /* compute Guth discomfort glare rating */
struct glare_dir        *gd;
{
#define q(w)    (20.4*w+1.52*pow(w,.2)-.075)
        register struct glare_src       *gs;
        FVECT   mydir;
        double  p;
        double  sum;
        double  wtot, brsum;
        int     n;

        spinvector(mydir, midview.vdir, midview.vup, gd->ang);
        sum = wtot = brsum = 0.0; n = 0;
        for (gs = all_srcs; gs != NULL; gs = gs->next) {
                p = posindex(gs->dir, mydir, midview.vup);
                if (p <= FTINY)
                        continue;
                sum += gs->lum * q(gs->dom) / p;
                brsum += gs->lum * gs->dom;
                wtot += gs->dom;
                n++;
        }
        if (n == 0)
                return(0.0);

        return( pow(.5*sum/pow((brsum+(5.-wtot)*gd->indirect/PI)/5.,.44),
                        pow((double)n, -.0914) ) );
#undef q
}


extern double   erf(), erfc();

#ifndef M_SQRT2
#define M_SQRT2 1.41421356237309504880
#endif

#define norm_integral(z)        (1.-.5*erfc((z)/M_SQRT2))


double
guth_vcp(gd)            /* compute Guth visual comfort probability */
struct glare_dir        *gd;
{
        double  dgr;

        dgr = guth_dgr(gd);
        if (dgr <= FTINY)
                return(100.0);
        return(100.*norm_integral(6.374-1.3227*log(dgr)));
}


double
cie_cgi(gd)             /* compute CIE Glare Index */
struct glare_dir        *gd;
{
        register struct glare_src       *gs;
        FVECT   mydir;
        double  dillum;
        double  p;
        double  sum;

        spinvector(mydir, midview.vdir, midview.vup, gd->ang);
        sum = 0.0;
        for (gs = all_srcs; gs != NULL; gs = gs->next) {
                p = posindex(gs->dir, mydir, midview.vup);
                if (p <= FTINY)
                        continue;
                sum += gs->lum*gs->lum * gs->dom / (p*p);
        }
        if (sum <= FTINY)
                return(0.0);
        dillum = direct(gd);
        return(8.*log10(2.*sum*(1.+dillum/500.)/(dillum+gd->indirect)));
}
Revision:	1.8
Committed:	Thu May 2 13:17:41 1991 UTC (34 years, 6 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.7:	+30 -4 lines
Log Message:	added CGI (Einhorn) formula
#	User	Rev	Content
1	greg	1.1	/* 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:
9			*
10	greg	1.2	* guth_dgr - Guth discomfort glare rating
11			* guth_vcp - Guth visual comfort probability
12	greg	1.8	* cie_cgi - CIE Glare Index (1983)
13	greg	1.1	*
14			* 12 April 1991 Greg Ward EPFL
15			*/
16
17			#include "standard.h"
18			#include "view.h"
19
20			extern double erfc();
21
22			double posindex();
23			int headline();
24
25	greg	1.8	double direct(), guth_dgr(), guth_vcp(), cie_cgi();
26	greg	1.1
27			struct named_func {
28			char *name;
29			double (*func)();
30			} all_funcs[] = {
31			{"direct", direct},
32	greg	1.2	{"guth_dgr", guth_dgr},
33			{"guth_vcp", guth_vcp},
34	greg	1.8	{"cie_cgi", cie_cgi},
35	greg	1.1	{NULL}
36			};
37
38			struct glare_src {
39			FVECT dir; /* source direction */
40			double dom; /* solid angle */
41			double lum; /* average luminance */
42			struct glare_src *next;
43			} *all_srcs = NULL;
44
45			struct glare_dir {
46			double ang; /* angle (in radians) */
47			double indirect; /* indirect illuminance */
48			struct glare_dir *next;
49			} *all_dirs = NULL;
50
51			#define newp(type) (type *)malloc(sizeof(type))
52
53			char *progname;
54			int print_header = 1;
55
56			VIEW midview = STDVIEW;
57
58	greg	1.4	int wrongformat = 0;
59	greg	1.1
60	greg	1.4
61	greg	1.1	main(argc, argv)
62			int argc;
63			char *argv[];
64			{
65			extern char *rindex();
66			struct named_func *funp;
67			char *progtail;
68			int i;
69			/* get program name */
70			progname = argv[0];
71			progtail = rindex(progname, '/'); /* final component */
72			if (progtail == NULL)
73			progtail = progname;
74			else
75			progtail++;
76			/* get options */
77			for (i = 1; i < argc && argv[i][0] == '-'; i++)
78			switch (argv[i][1]) {
79			case 't':
80			progtail = argv[++i];
81			break;
82			case 'h':
83			print_header = 0;
84			break;
85			default:
86			goto userr;
87			}
88			if (i < argc-1)
89			goto userr;
90			if (i == argc-1) /* open file */
91			if (freopen(argv[i], "r", stdin) == NULL) {
92			perror(argv[i]);
93			exit(1);
94			}
95			/* read header */
96	greg	1.4	getheader(stdin, headline, NULL);
97			if (wrongformat) {
98			fprintf(stderr, "%s: bad input format\n", progname);
99			exit(1);
100			}
101	greg	1.1	if (print_header) { /* add to header */
102			printargs(i, argv, stdout);
103			putchar('\n');
104			}
105			/* set view */
106			if (setview(&midview) != NULL) {
107	greg	1.4	fprintf(stderr, "%s: bad view information in input\n",
108			progname);
109	greg	1.1	exit(1);
110			}
111			/* get findglare data */
112			read_input();
113			/* find calculation */
114			for (funp = all_funcs; funp->name != NULL; funp++)
115			if (!strcmp(funp->name, progtail)) {
116			print_values(funp->func);
117			exit(0); /* we're done */
118			}
119			/* invalid function */
120			fprintf(stderr, "%s: unknown function!\n", progtail);
121			exit(1);
122			userr:
123			fprintf(stderr, "Usage: %s [-t type][-h] [input]\n", progname);
124			exit(1);
125			}
126
127
128			headline(s) /* get line from header */
129			char *s;
130			{
131	greg	1.4	char fmt[32];
132
133	greg	1.1	if (print_header) /* copy to output */
134			fputs(s, stdout);
135			if (!strncmp(s, VIEWSTR, VIEWSTRL))
136			sscanview(&midview, s+VIEWSTRL);
137	greg	1.4	else if (isformat(s)) {
138			formatval(fmt, s);
139	greg	1.6	wrongformat = strcmp(fmt, "ascii");
140	greg	1.4	}
141	greg	1.1	}
142
143
144			read_input() /* read glare sources from stdin */
145			{
146			#define S_SEARCH 0
147			#define S_SOURCE 1
148			#define S_DIREC 2
149			int state = S_SEARCH;
150			char buf[128];
151			register struct glare_src *gs;
152			register struct glare_dir *gd;
153
154			while (fgets(buf, sizeof(buf), stdin) != NULL)
155			switch (state) {
156			case S_SEARCH:
157			if (!strcmp(buf, "BEGIN glare source\n"))
158			state = S_SOURCE;
159			else if (!strcmp(buf, "BEGIN indirect illuminance\n"))
160			state = S_DIREC;
161			break;
162			case S_SOURCE:
163			if (!strncmp(buf, "END", 3)) {
164			state = S_SEARCH;
165			break;
166			}
167			if ((gs = newp(struct glare_src)) == NULL)
168			goto memerr;
169			if (sscanf(buf, "%lf %lf %lf %lf %lf",
170			&gs->dir[0], &gs->dir[1], &gs->dir[2],
171			&gs->dom, &gs->lum) != 5)
172			goto readerr;
173	greg	1.2	normalize(gs->dir);
174	greg	1.1	gs->next = all_srcs;
175			all_srcs = gs;
176			break;
177			case S_DIREC:
178			if (!strncmp(buf, "END", 3)) {
179			state = S_SEARCH;
180			break;
181			}
182			if ((gd = newp(struct glare_dir)) == NULL)
183			goto memerr;
184			if (sscanf(buf, "%lf %lf",
185			&gd->ang, &gd->indirect) != 2)
186			goto readerr;
187			gd->ang = PI/180.0; / convert to radians */
188			gd->next = all_dirs;
189			all_dirs = gd;
190			break;
191			}
192			return;
193			memerr:
194			perror(progname);
195			exit(1);
196			readerr:
197			fprintf(stderr, "%s: read error on input\n", progname);
198			exit(1);
199			#undef S_SEARCH
200			#undef S_SOURCE
201			#undef S_DIREC
202			}
203
204
205			print_values(funp) /* print out calculations */
206			double (*funp)();
207			{
208			register struct glare_dir *gd;
209
210			for (gd = all_dirs; gd != NULL; gd = gd->next)
211			printf("%f\t%f\n", gd->ang(180.0/PI), (funp)(gd));
212			}
213
214
215			double
216			direct(gd) /* compute direct illuminance */
217			struct glare_dir *gd;
218			{
219			FVECT mydir;
220			double d, dval;
221			register struct glare_src *gs;
222
223			spinvector(mydir, midview.vdir, midview.vup, gd->ang);
224			dval = 0.0;
225			for (gs = all_srcs; gs != NULL; gs = gs->next) {
226			d = DOT(mydir,gs->dir);
227			if (d > FTINY)
228			dval += d * gs->dom * gs->lum;
229			}
230			return(dval);
231			}
232
233
234			/*
235			* posindex - compute glare position index from:
236			*
237			* Source Direction
238			* View Direction
239			* View Up Direction
240			*
241			* All vectors are assumed to be normalized.
242			* This function is an implementation of the method proposed by
243			* Robert Levin in his 1975 JIES article.
244	greg	1.5	* This calculation presumes the view direction and up vectors perpendicular.
245	greg	1.1	* We return a value less than zero for improper positions.
246			*/
247
248			double
249			posindex(sd, vd, vu) /* compute position index */
250			FVECT sd, vd, vu;
251			{
252			double sigma, tau;
253			double d;
254
255			d = DOT(sd,vd);
256			if (d <= 0.0)
257			return(-1.0);
258	greg	1.5	if (d >= 1.0)
259			return(1.0);
260	greg	1.1	sigma = acos(d) * (180./PI);
261	greg	1.5	d = DOT(sd,vu)/sqrt(1.0-d*d);
262			if (d >= 1.0)
263			tau = 0.0;
264			else
265			tau = acos(d) * (180./PI);
266	greg	1.1	return( exp( sigma( (35.2 - tau.31889 - 1.22exp(-.22222tau))*1e-3
267			+ sigma(21. + tau(.26667 + tau-.002963))1e-5 )
268			) );
269			}
270
271
272			double
273	greg	1.2	guth_dgr(gd) /* compute Guth discomfort glare rating */
274	greg	1.1	struct glare_dir *gd;
275			{
276			#define q(w) (20.4w+1.52pow(w,.2)-.075)
277			register struct glare_src *gs;
278	greg	1.7	FVECT mydir;
279	greg	1.1	double p;
280			double sum;
281	greg	1.3	double wtot, brsum;
282	greg	1.1	int n;
283
284	greg	1.7	spinvector(mydir, midview.vdir, midview.vup, gd->ang);
285	greg	1.3	sum = wtot = brsum = 0.0; n = 0;
286	greg	1.1	for (gs = all_srcs; gs != NULL; gs = gs->next) {
287	greg	1.7	p = posindex(gs->dir, mydir, midview.vup);
288	greg	1.1	if (p <= FTINY)
289			continue;
290			sum += gs->lum * q(gs->dom) / p;
291	greg	1.3	brsum += gs->lum * gs->dom;
292			wtot += gs->dom;
293	greg	1.1	n++;
294			}
295			if (n == 0)
296			return(0.0);
297	greg	1.8
298			return( pow(.5sum/pow((brsum+(5.-wtot)gd->indirect/PI)/5.,.44),
299	greg	1.1	pow((double)n, -.0914) ) );
300			#undef q
301			}
302
303
304			extern double erf(), erfc();
305
306			#ifndef M_SQRT2
307			#define M_SQRT2 1.41421356237309504880
308			#endif
309
310			#define norm_integral(z) (1.-.5*erfc((z)/M_SQRT2))
311
312
313			double
314	greg	1.2	guth_vcp(gd) /* compute Guth visual comfort probability */
315	greg	1.1	struct glare_dir *gd;
316			{
317	greg	1.7	double dgr;
318
319			dgr = guth_dgr(gd);
320			if (dgr <= FTINY)
321			return(100.0);
322			return(100.norm_integral(6.374-1.3227log(dgr)));
323	greg	1.8	}
324
325
326			double
327			cie_cgi(gd) /* compute CIE Glare Index */
328			struct glare_dir *gd;
329			{
330			register struct glare_src *gs;
331			FVECT mydir;
332			double dillum;
333			double p;
334			double sum;
335
336			spinvector(mydir, midview.vdir, midview.vup, gd->ang);
337			sum = 0.0;
338			for (gs = all_srcs; gs != NULL; gs = gs->next) {
339			p = posindex(gs->dir, mydir, midview.vup);
340			if (p <= FTINY)
341			continue;
342			sum += gs->lumgs->lum gs->dom / (p*p);
343			}
344			if (sum <= FTINY)
345			return(0.0);
346			dillum = direct(gd);
347			return(8.log10(2.sum*(1.+dillum/500.)/(dillum+gd->indirect)));
348	greg	1.1	}