src/util/findglare.c

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

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

/*
 * Find glare sources in a scene or image.
 *
 *      Greg Ward       March 1991
 */

#include "glare.h"

#define FEQ(a,b)        ((a)-(b)<=FTINY&&(b)-(a)<=FTINY)
#define VEQ(v1,v2)      (FEQ((v1)[0],(v2)[0])&&FEQ((v1)[1],(v2)[1]) \
                                &&FEQ((v1)[2],(v2)[2]))

char    *rtargv[32] = {"rtrace", "-h-", "-ov", "-fff"};
int     rtargc = 4;

VIEW    ourview = STDVIEW;              /* our view */
VIEW    pictview = STDVIEW;             /* picture view */
VIEW    leftview, rightview;            /* leftmost and rightmost views */

char    *picture = NULL;                /* picture file name */
char    *octree = NULL;                 /* octree file name */

int     verbose = 0;                    /* verbose reporting */
char    *progname;                      /* global argv[0] */

double  threshold = 0.;                 /* glare threshold */

int     sampdens = SAMPDENS;            /* sample density */
ANGLE   glarang[180] = {AEND};          /* glare calculation angles */
int     nglarangs = 0;
double  maxtheta;                       /* maximum angle (in radians) */
int     hsize;                          /* horizontal size */

struct illum    *indirect;              /* array of indirect illuminances */

long    npixinvw;                       /* number of pixels in view */
long    npixmiss;                       /* number of pixels missed */


main(argc, argv)
int     argc;
char    *argv[];
{
        int     combine = 1;
        int     gotview = 0;
        int     rval, i;
        char    *err;

        progname = argv[0];
                                        /* process options */
        for (i = 1; i < argc && argv[i][0] == '-'; i++) {
                rval = getviewopt(&ourview, argc-i, argv+i);
                if (rval >= 0) {
                        i += rval;
                        gotview++;
                        continue;
                }
                switch (argv[i][1]) {
                case 't':
                        threshold = atof(argv[++i]);
                        break;
                case 'r':
                        sampdens = atoi(argv[++i])/2;
                        break;
                case 'v':
                        if (argv[i][2] == '\0') {
                                verbose++;
                                break;
                        }
                        if (argv[i][2] != 'f')
                                goto userr;
                        rval = viewfile(argv[++i], &ourview, NULL);
                        if (rval < 0) {
                                fprintf(stderr,
                                "%s: cannot open view file \"%s\"\n",
                                                progname, argv[i]);
                                exit(1);
                        } else if (rval == 0) {
                                fprintf(stderr,
                                        "%s: bad view file \"%s\"\n",
                                                progname, argv[i]);
                                exit(1);
                        } else
                                gotview++;
                        break;
                case 'g':
                        if (argv[i][2] != 'a')
                                goto userr;
                        if (setscan(glarang, argv[++i]) < 0) {
                                fprintf(stderr, "%s: bad angle spec \"%s\"\n",
                                        progname, argv[i]);
                                exit(1);
                        }
                        break;
                case 'p':
                        picture = argv[++i];
                        break;
                case 'c':
                        combine = !combine;
                        break;
                case 'd':
                        if (argv[i][2] == 'v') {
                                rtargv[rtargc++] = argv[i];
                                break;
                        }
                        /* FALL THROUGH */
                case 'l':
                case 's':
                        rtargv[rtargc++] = argv[i];
                        rtargv[rtargc++] = argv[++i];
                        break;
                case 'w':
                        rtargv[rtargc++] = argv[i];
                        break;
                case 'a':
                        rtargv[rtargc++] = argv[i];
                        if (argv[i][2] == 'v') {
                                rtargv[rtargc++] = argv[++i];
                                rtargv[rtargc++] = argv[++i];
                        }
                        rtargv[rtargc++] = argv[++i];
                        break;
                default:
                        goto userr;
                }
        }
                                                /* get octree */
        if (i < argc-1)
                goto userr;
        if (i == argc-1) {
                rtargv[rtargc++] = octree = argv[i];
                rtargv[rtargc] = NULL;
        }
                                                /* get view */
        if (picture != NULL) {
                rval = viewfile(picture, &pictview, NULL);
                if (rval < 0) {
                        fprintf(stderr, "%s: cannot open picture file \"%s\"\n",
                                        progname, picture);
                        exit(1);
                } else if (rval == 0) {
                        fprintf(stderr,
                                "%s: cannot get view from picture \"%s\"\n",
                                        progname, picture);
                        exit(1);
                }
                if (pictview.type == VT_PAR) {
                        fprintf(stderr, "%s: %s: cannot use parallel view\n",
                                        progname, picture);
                        exit(1);
                }
                if ((err = setview(&pictview)) != NULL) {
                        fprintf(stderr, "%s: %s\n", picture, err);
                        exit(1);
                }
        }
        if (!gotview) {
                if (picture == NULL) {
                        fprintf(stderr, "%s: must have view or picture\n",
                                        progname);
                        exit(1);
                }
                copystruct(&ourview, &pictview);
        } else if (picture != NULL && !VEQ(ourview.vp, pictview.vp)) {
                fprintf(stderr, "%s: picture must have same viewpoint\n",
                                progname);
                exit(1);
        }
        ourview.type = VT_HEM;
        ourview.horiz = ourview.vert = 180.0;
        ourview.hoff = ourview.voff = 0.0;
        fvsum(ourview.vdir, ourview.vdir, ourview.vup,
                        -DOT(ourview.vdir,ourview.vup));
        if ((err = setview(&ourview)) != NULL) {
                fprintf(stderr, "%s: %s\n", progname, err);
                exit(1);
        }
        if (octree == NULL && picture == NULL) {
                fprintf(stderr,
                "%s: must specify at least one of picture or octree\n",
                                progname);
                exit(1);
        }
        init();                                 /* initialize program */
        if (threshold <= FTINY)
                comp_thresh();                  /* compute glare threshold */
        analyze();                              /* analyze view */
        if (combine)
                absorb_specks();                /* eliminate tiny sources */
        cleanup();                              /* tidy up */
                                                /* print header */
        printargs(argc, argv, stdout);
        fputs(VIEWSTR, stdout);
        fprintview(&ourview, stdout);
        printf("\n");
        fputformat("ascii", stdout);
        printf("\n");
        printsources();                         /* print glare sources */
        printillum();                           /* print illuminances */
        exit(0);
userr:
        fprintf(stderr,
"Usage: %s [view options][-ga angles][-p picture][[rtrace options] octree]\n",
                        progname);
        exit(1);
}


int
angcmp(ap1, ap2)                /* compare two angles */
ANGLE   *ap1, *ap2;
{
        register int    a1, a2;

        a1 = *ap1;
        a2 = *ap2;
        if (a1 == a2) {
                fprintf(stderr, "%s: duplicate glare angle (%d)\n",
                                progname, a1);
                exit(1);
        }
        return(a1-a2);
}


init()                          /* initialize global variables */
{
        double  d;
        register int    i;

        if (verbose)
                fprintf(stderr, "%s: initializing data structures...\n",
                                progname);
                                                /* set direction vectors */
        for (i = 0; glarang[i] != AEND; i++)
                ;
        qsort(glarang, i, sizeof(ANGLE), angcmp);
        if (i > 0 && (glarang[0] <= 0 || glarang[i-1] > 180)) {
                fprintf(stderr, "%s: glare angles must be between 1 and 180\n",
                                progname);
                exit(1);
        }
        nglarangs = i;
        /* nglardirs = 2*nglarangs + 1; */
        /* vsize = sampdens - 1; */
        if (nglarangs > 0)
                maxtheta = (PI/180.)*glarang[nglarangs-1];
        else
                maxtheta = 0.0;
        hsize = hlim(0) + sampdens - 1;
        if (hsize > (int)(PI*sampdens))
                hsize = PI*sampdens;
        indirect = (struct illum *)calloc(nglardirs, sizeof(struct illum));
        if (indirect == NULL)
                memerr("indirect illuminances");
        npixinvw = npixmiss = 0L;
        copystruct(&leftview, &ourview);
        copystruct(&rightview, &ourview);
        spinvector(leftview.vdir, ourview.vdir, ourview.vup, maxtheta);
        spinvector(rightview.vdir, ourview.vdir, ourview.vup, -maxtheta);
        setview(&leftview);
        setview(&rightview);
        indirect[nglarangs].lcos =
        indirect[nglarangs].rcos = cos(maxtheta);
        indirect[nglarangs].rsin =
        -(indirect[nglarangs].lsin = sin(maxtheta));
        indirect[nglarangs].theta = 0.0;
        for (i = 0; i < nglarangs; i++) {
                d = (glarang[nglarangs-1] - glarang[i])*(PI/180.);
                indirect[nglarangs-i-1].lcos =
                indirect[nglarangs+i+1].rcos = cos(d);
                indirect[nglarangs+i+1].rsin =
                -(indirect[nglarangs-i-1].lsin = sin(d));
                d = (glarang[nglarangs-1] + glarang[i])*(PI/180.);
                indirect[nglarangs-i-1].rcos =
                indirect[nglarangs+i+1].lcos = cos(d);
                indirect[nglarangs-i-1].rsin =
                -(indirect[nglarangs+i+1].lsin = sin(d));
                indirect[nglarangs-i-1].theta = (PI/180.)*glarang[i];
                indirect[nglarangs+i+1].theta = -(PI/180.)*glarang[i];
        }
                                                /* open picture */
        if (picture != NULL) {
                if (verbose)
                        fprintf(stderr, "%s: opening picture file \"%s\"...\n",
                                        progname, picture);
                open_pict(picture);
        }
                                                /* start rtrace */
        if (octree != NULL) {
                if (verbose) {
                        fprintf(stderr,
                                "%s: starting luminance calculation...\n\t",
                                        progname);
                        printargs(rtargc, rtargv, stderr);
                }
                fork_rtrace(rtargv);
        }
}


cleanup()                               /* close files, wait for children */
{
        if (verbose)
                fprintf(stderr, "%s: cleaning up...        \n", progname);
        if (picture != NULL)
                close_pict();
        if (octree != NULL)
                done_rtrace();
        if (npixinvw < 100*npixmiss)
                fprintf(stderr, "%s: warning -- missing %d%% of samples\n",
                                progname, (int)(100L*npixmiss/npixinvw));
}


compdir(vd, x, y)                       /* compute direction for x,y */
FVECT   vd;
int     x, y;
{
        int     hl;
        FVECT   org;                    /* dummy variable */

        hl = hlim(y);
        if (x <= -hl) {                 /* left region */
                if (x <= -hl-sampdens)
                        return(-1);
                return(viewray(org, vd, &leftview,
                                (double)(x+hl)/(2*sampdens)+.5,
                                (double)y/(2*sampdens)+.5));
        }
        if (x >= hl) {                  /* right region */
                if (x >= hl+sampdens)
                        return(-1);
                return(viewray(org, vd, &rightview,
                                (double)(x-hl)/(2*sampdens)+.5,
                                (double)y/(2*sampdens)+.5));
        }
                                        /* central region */
        if (viewray(org, vd, &ourview, .5, (double)y/(2*sampdens)+.5) < 0)
                return(-1);
        spinvector(vd, vd, ourview.vup, h_theta(x,y));
        return(0);
}


double
pixsize(x, y)           /* return the solid angle of pixel at (x,y) */
int     x, y;
{
        register int    hl, xo;
        double  disc;

        hl = hlim(y);
        if (x < -hl)
                xo = x+hl;
        else if (x > hl)
                xo = x-hl;
        else
                xo = 0;
        disc = 1. - (double)(xo*xo + y*y)/(sampdens*sampdens);
        if (disc <= FTINY)
                return(0.);
        return(1./(sampdens*sampdens*sqrt(disc)));
}


memerr(s)                       /* malloc failure */
char    *s;
{
        fprintf(stderr, "%s: out of memory for %s\n", progname, s);
        exit(1);
}


printsources()                  /* print out glare sources */
{
        register struct source  *sp;

        printf("BEGIN glare source\n");
        for (sp = donelist; sp != NULL; sp = sp->next)
                printf("\t%f %f %f\t%f\t%f\n",
                                sp->dir[0], sp->dir[1], sp->dir[2],
                                sp->dom, sp->brt);
        printf("END glare source\n");
}


printillum()                    /* print out indirect illuminances */
{
        register int    i;

        printf("BEGIN indirect illuminance\n");
        for (i = 0; i < nglardirs; i++)
                if (indirect[i].n > FTINY)
                        printf("\t%.0f\t%f\n", (180.0/PI)*indirect[i].theta,
                                        PI * indirect[i].sum / indirect[i].n);
        printf("END indirect illuminance\n");
}
Revision:	2.4
Committed:	Mon Dec 7 09:13:58 1992 UTC (31 years, 4 months ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 2.3:	+8 -0 lines
Log Message:	added provisions for -dv and -w rtrace switches
#	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			* Find glare sources in a scene or image.
9			*
10			* Greg Ward March 1991
11			*/
12
13			#include "glare.h"
14
15	greg	1.25	#define FEQ(a,b) ((a)-(b)<=FTINY&&(b)-(a)<=FTINY)
16	greg	1.1	#define VEQ(v1,v2) (FEQ((v1)[0],(v2)[0])&&FEQ((v1)[1],(v2)[1]) \
17			&&FEQ((v1)[2],(v2)[2]))
18
19	greg	1.24	char *rtargv[32] = {"rtrace", "-h-", "-ov", "-fff"};
20	greg	1.1	int rtargc = 4;
21
22	greg	1.6	VIEW ourview = STDVIEW; /* our view */
23	greg	1.1	VIEW pictview = STDVIEW; /* picture view */
24			VIEW leftview, rightview; /* leftmost and rightmost views */
25
26			char picture = NULL; / picture file name */
27			char octree = NULL; / octree file name */
28
29			int verbose = 0; /* verbose reporting */
30			char progname; / global argv[0] */
31
32	greg	1.8	double threshold = 0.; /* glare threshold */
33
34	greg	1.4	int sampdens = SAMPDENS; /* sample density */
35	greg	1.1	ANGLE glarang[180] = {AEND}; /* glare calculation angles */
36			int nglarangs = 0;
37	greg	1.2	double maxtheta; /* maximum angle (in radians) */
38	greg	1.1	int hsize; /* horizontal size */
39
40			struct illum indirect; / array of indirect illuminances */
41
42	greg	1.13	long npixinvw; /* number of pixels in view */
43			long npixmiss; /* number of pixels missed */
44	greg	1.1
45	greg	1.13
46	greg	1.1	main(argc, argv)
47			int argc;
48			char *argv[];
49			{
50	greg	1.16	int combine = 1;
51	greg	1.1	int gotview = 0;
52			int rval, i;
53			char *err;
54
55			progname = argv[0];
56			/* process options */
57			for (i = 1; i < argc && argv[i][0] == '-'; i++) {
58			rval = getviewopt(&ourview, argc-i, argv+i);
59			if (rval >= 0) {
60			i += rval;
61			gotview++;
62			continue;
63			}
64			switch (argv[i][1]) {
65	greg	1.8	case 't':
66			threshold = atof(argv[++i]);
67			break;
68	greg	1.4	case 'r':
69			sampdens = atoi(argv[++i])/2;
70			break;
71	greg	1.1	case 'v':
72			if (argv[i][2] == '\0') {
73			verbose++;
74			break;
75			}
76			if (argv[i][2] != 'f')
77			goto userr;
78	greg	2.3	rval = viewfile(argv[++i], &ourview, NULL);
79	greg	1.1	if (rval < 0) {
80			fprintf(stderr,
81			"%s: cannot open view file \"%s\"\n",
82			progname, argv[i]);
83			exit(1);
84			} else if (rval == 0) {
85			fprintf(stderr,
86			"%s: bad view file \"%s\"\n",
87			progname, argv[i]);
88			exit(1);
89			} else
90			gotview++;
91			break;
92			case 'g':
93			if (argv[i][2] != 'a')
94			goto userr;
95			if (setscan(glarang, argv[++i]) < 0) {
96			fprintf(stderr, "%s: bad angle spec \"%s\"\n",
97			progname, argv[i]);
98			exit(1);
99			}
100			break;
101			case 'p':
102			picture = argv[++i];
103			break;
104	greg	1.16	case 'c':
105			combine = !combine;
106			break;
107	greg	1.1	case 'd':
108	greg	2.4	if (argv[i][2] == 'v') {
109			rtargv[rtargc++] = argv[i];
110			break;
111			}
112			/* FALL THROUGH */
113	greg	1.1	case 'l':
114	greg	2.2	case 's':
115	greg	1.1	rtargv[rtargc++] = argv[i];
116			rtargv[rtargc++] = argv[++i];
117	greg	2.4	break;
118			case 'w':
119			rtargv[rtargc++] = argv[i];
120	greg	1.1	break;
121			case 'a':
122			rtargv[rtargc++] = argv[i];
123			if (argv[i][2] == 'v') {
124			rtargv[rtargc++] = argv[++i];
125			rtargv[rtargc++] = argv[++i];
126			}
127			rtargv[rtargc++] = argv[++i];
128			break;
129			default:
130			goto userr;
131			}
132			}
133			/* get octree */
134			if (i < argc-1)
135			goto userr;
136			if (i == argc-1) {
137			rtargv[rtargc++] = octree = argv[i];
138			rtargv[rtargc] = NULL;
139			}
140			/* get view */
141			if (picture != NULL) {
142	greg	2.3	rval = viewfile(picture, &pictview, NULL);
143	greg	1.1	if (rval < 0) {
144			fprintf(stderr, "%s: cannot open picture file \"%s\"\n",
145			progname, picture);
146			exit(1);
147			} else if (rval == 0) {
148			fprintf(stderr,
149			"%s: cannot get view from picture \"%s\"\n",
150			progname, picture);
151			exit(1);
152			}
153			if (pictview.type == VT_PAR) {
154			fprintf(stderr, "%s: %s: cannot use parallel view\n",
155			progname, picture);
156			exit(1);
157			}
158			if ((err = setview(&pictview)) != NULL) {
159			fprintf(stderr, "%s: %s\n", picture, err);
160			exit(1);
161			}
162			}
163			if (!gotview) {
164			if (picture == NULL) {
165			fprintf(stderr, "%s: must have view or picture\n",
166			progname);
167			exit(1);
168			}
169			copystruct(&ourview, &pictview);
170			} else if (picture != NULL && !VEQ(ourview.vp, pictview.vp)) {
171			fprintf(stderr, "%s: picture must have same viewpoint\n",
172			progname);
173			exit(1);
174			}
175			ourview.type = VT_HEM;
176			ourview.horiz = ourview.vert = 180.0;
177			ourview.hoff = ourview.voff = 0.0;
178			fvsum(ourview.vdir, ourview.vdir, ourview.vup,
179			-DOT(ourview.vdir,ourview.vup));
180			if ((err = setview(&ourview)) != NULL) {
181			fprintf(stderr, "%s: %s\n", progname, err);
182			exit(1);
183			}
184			if (octree == NULL && picture == NULL) {
185			fprintf(stderr,
186			"%s: must specify at least one of picture or octree\n",
187			progname);
188			exit(1);
189			}
190			init(); /* initialize program */
191	greg	1.8	if (threshold <= FTINY)
192			comp_thresh(); /* compute glare threshold */
193	greg	1.1	analyze(); /* analyze view */
194	greg	1.16	if (combine)
195			absorb_specks(); /* eliminate tiny sources */
196	greg	1.1	cleanup(); /* tidy up */
197			/* print header */
198			printargs(argc, argv, stdout);
199			fputs(VIEWSTR, stdout);
200			fprintview(&ourview, stdout);
201	greg	1.18	printf("\n");
202	greg	1.21	fputformat("ascii", stdout);
203	greg	1.18	printf("\n");
204	greg	1.1	printsources(); /* print glare sources */
205			printillum(); /* print illuminances */
206			exit(0);
207			userr:
208			fprintf(stderr,
209			"Usage: %s [view options][-ga angles][-p picture][[rtrace options] octree]\n",
210			progname);
211			exit(1);
212			}
213
214
215	greg	1.23	int
216			angcmp(ap1, ap2) /* compare two angles */
217			ANGLE ap1, ap2;
218			{
219			register int a1, a2;
220
221			a1 = *ap1;
222			a2 = *ap2;
223			if (a1 == a2) {
224			fprintf(stderr, "%s: duplicate glare angle (%d)\n",
225			progname, a1);
226			exit(1);
227			}
228			return(a1-a2);
229			}
230
231
232	greg	1.1	init() /* initialize global variables */
233			{
234			double d;
235			register int i;
236
237			if (verbose)
238			fprintf(stderr, "%s: initializing data structures...\n",
239			progname);
240			/* set direction vectors */
241			for (i = 0; glarang[i] != AEND; i++)
242			;
243	greg	1.23	qsort(glarang, i, sizeof(ANGLE), angcmp);
244			if (i > 0 && (glarang[0] <= 0 \|\| glarang[i-1] > 180)) {
245			fprintf(stderr, "%s: glare angles must be between 1 and 180\n",
246	greg	1.1	progname);
247			exit(1);
248			}
249			nglarangs = i;
250			/* nglardirs = 2nglarangs + 1; /
251	greg	1.5	/* vsize = sampdens - 1; */
252	greg	1.2	if (nglarangs > 0)
253			maxtheta = (PI/180.)*glarang[nglarangs-1];
254			else
255			maxtheta = 0.0;
256	greg	1.19	hsize = hlim(0) + sampdens - 1;
257	greg	1.4	if (hsize > (int)(PI*sampdens))
258			hsize = PI*sampdens;
259	greg	1.1	indirect = (struct illum *)calloc(nglardirs, sizeof(struct illum));
260			if (indirect == NULL)
261			memerr("indirect illuminances");
262	greg	1.13	npixinvw = npixmiss = 0L;
263	greg	1.1	copystruct(&leftview, &ourview);
264			copystruct(&rightview, &ourview);
265	greg	1.3	spinvector(leftview.vdir, ourview.vdir, ourview.vup, maxtheta);
266			spinvector(rightview.vdir, ourview.vdir, ourview.vup, -maxtheta);
267	greg	1.1	setview(&leftview);
268			setview(&rightview);
269			indirect[nglarangs].lcos =
270			indirect[nglarangs].rcos = cos(maxtheta);
271	greg	1.9	indirect[nglarangs].rsin =
272			-(indirect[nglarangs].lsin = sin(maxtheta));
273	greg	1.1	indirect[nglarangs].theta = 0.0;
274			for (i = 0; i < nglarangs; i++) {
275			d = (glarang[nglarangs-1] - glarang[i])*(PI/180.);
276			indirect[nglarangs-i-1].lcos =
277			indirect[nglarangs+i+1].rcos = cos(d);
278	greg	1.9	indirect[nglarangs+i+1].rsin =
279			-(indirect[nglarangs-i-1].lsin = sin(d));
280	greg	1.1	d = (glarang[nglarangs-1] + glarang[i])*(PI/180.);
281			indirect[nglarangs-i-1].rcos =
282			indirect[nglarangs+i+1].lcos = cos(d);
283	greg	1.9	indirect[nglarangs-i-1].rsin =
284			-(indirect[nglarangs+i+1].lsin = sin(d));
285			indirect[nglarangs-i-1].theta = (PI/180.)*glarang[i];
286			indirect[nglarangs+i+1].theta = -(PI/180.)*glarang[i];
287	greg	1.1	}
288			/* open picture */
289			if (picture != NULL) {
290			if (verbose)
291			fprintf(stderr, "%s: opening picture file \"%s\"...\n",
292			progname, picture);
293			open_pict(picture);
294			}
295			/* start rtrace */
296			if (octree != NULL) {
297			if (verbose) {
298			fprintf(stderr,
299			"%s: starting luminance calculation...\n\t",
300			progname);
301			printargs(rtargc, rtargv, stderr);
302			}
303			fork_rtrace(rtargv);
304			}
305			}
306
307
308			cleanup() /* close files, wait for children */
309			{
310			if (verbose)
311	greg	1.17	fprintf(stderr, "%s: cleaning up... \n", progname);
312	greg	1.1	if (picture != NULL)
313			close_pict();
314			if (octree != NULL)
315			done_rtrace();
316	greg	1.13	if (npixinvw < 100*npixmiss)
317	greg	2.3	fprintf(stderr, "%s: warning -- missing %d%% of samples\n",
318			progname, (int)(100L*npixmiss/npixinvw));
319	greg	1.1	}
320
321
322	greg	1.19	compdir(vd, x, y) /* compute direction for x,y */
323	greg	1.1	FVECT vd;
324			int x, y;
325			{
326	greg	1.19	int hl;
327	greg	1.1	FVECT org; /* dummy variable */
328
329	greg	1.19	hl = hlim(y);
330	greg	1.22	if (x <= -hl) { /* left region */
331			if (x <= -hl-sampdens)
332			return(-1);
333	greg	1.1	return(viewray(org, vd, &leftview,
334	greg	1.19	(double)(x+hl)/(2*sampdens)+.5,
335	greg	1.13	(double)y/(2*sampdens)+.5));
336	greg	1.22	}
337			if (x >= hl) { /* right region */
338			if (x >= hl+sampdens)
339			return(-1);
340	greg	1.1	return(viewray(org, vd, &rightview,
341	greg	1.19	(double)(x-hl)/(2*sampdens)+.5,
342	greg	1.13	(double)y/(2*sampdens)+.5));
343	greg	1.22	}
344	greg	1.14	/* central region */
345	greg	1.13	if (viewray(org, vd, &ourview, .5, (double)y/(2*sampdens)+.5) < 0)
346	greg	1.1	return(-1);
347	greg	1.19	spinvector(vd, vd, ourview.vup, h_theta(x,y));
348	greg	1.1	return(0);
349	greg	1.17	}
350
351
352	greg	1.19	double
353			pixsize(x, y) /* return the solid angle of pixel at (x,y) */
354			int x, y;
355	greg	1.17	{
356	greg	1.19	register int hl, xo;
357			double disc;
358
359			hl = hlim(y);
360			if (x < -hl)
361			xo = x+hl;
362			else if (x > hl)
363			xo = x-hl;
364			else
365			xo = 0;
366	greg	1.20	disc = 1. - (double)(xoxo + yy)/(sampdens*sampdens);
367	greg	1.19	if (disc <= FTINY)
368			return(0.);
369			return(1./(sampdenssampdenssqrt(disc)));
370	greg	1.1	}
371
372
373			memerr(s) /* malloc failure */
374			char *s;
375			{
376	greg	1.5	fprintf(stderr, "%s: out of memory for %s\n", progname, s);
377	greg	1.1	exit(1);
378			}
379
380
381			printsources() /* print out glare sources */
382			{
383			register struct source *sp;
384
385			printf("BEGIN glare source\n");
386			for (sp = donelist; sp != NULL; sp = sp->next)
387			printf("\t%f %f %f\t%f\t%f\n",
388			sp->dir[0], sp->dir[1], sp->dir[2],
389			sp->dom, sp->brt);
390			printf("END glare source\n");
391			}
392
393
394			printillum() /* print out indirect illuminances */
395			{
396			register int i;
397
398			printf("BEGIN indirect illuminance\n");
399			for (i = 0; i < nglardirs; i++)
400	greg	1.12	if (indirect[i].n > FTINY)
401			printf("\t%.0f\t%f\n", (180.0/PI)*indirect[i].theta,
402			PI * indirect[i].sum / indirect[i].n);
403	greg	1.2	printf("END indirect illuminance\n");
404	greg	1.1	}