src/util/glaresrc.c

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

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

/*
 * Gather samples and compute glare sources.
 */

#include "glare.h"

#define vcont(vd,vu)    ((vu)-(vd)<=SEPS)
#define hcont(s1,s2)    ((s1)->r-(s2)->l>=-SEPS&&(s2)->r-(s1)->l>=-SEPS)

struct source   *curlist = NULL;        /* current source list */
struct source   *donelist = NULL;       /* finished sources */


struct srcspan *
newspan(l, r, v, sb)            /* allocate a new source span */
int     l, r, v;
float   *sb;
{
        register struct srcspan *ss;
        register int    i;

        ss = (struct srcspan *)malloc(sizeof(struct srcspan));
        if (ss == NULL)
                memerr("source spans");
        ss->l = l;
        ss->r = r;
        ss->v = v;
        ss->brsum = 0.0;
        for (i = l; i < r; i++)
                ss->brsum += sb[i+hsize];
        return(ss);
}


analyze()                       /* analyze our scene */
{
        int     h, v;
        int     left;
        float   *spanbr;

        spanbr = (float *)malloc((2*hsize+1)*sizeof(float));
        if (spanbr == NULL)
                memerr("view span brightness buffer");
        for (v = vsize; v >= -vsize; v--) {
                close_sources(v);
#ifndef DEBUG
                if (verbose)
                        fprintf(stderr, "%s: analyzing... %3ld%%\r",
                                progname, 100L*(vsize-v)/(2*vsize));
#endif
                getviewspan(v, spanbr);
                left = hsize + 1;
                for (h = -hsize; h <= hsize; h++) {
                        if (spanbr[h+hsize] < 0.0) {    /* off view */
                                if (left < h) {
                                        addsrcspan(newspan(left,h,v,spanbr));
                                        left = hsize + 1;
                                }
                                continue;
                        }
                        if (spanbr[h+hsize] > threshold) {      /* in source */
                                if (left > h)
                                        left = h;
                        } else {                        /* out of source */
                                if (left < h) {
                                        addsrcspan(newspan(left,h,v,spanbr));
                                        left = hsize + 1;
                                }
                                addindirect(h, spanbr[h+hsize]);
                        }
                }
                if (left < h)
                        addsrcspan(newspan(left,h,v,spanbr));
        }
        free((char *)spanbr);
        close_allsrcs();
}


addindirect(h, br)              /* add brightness to indirect illuminances */
int     h;
double  br;
{
        double  tanb, d;
        register int    i;

        if (h <= -hlim) {                       /* left region */
                d = (double)(-h-hlim)/sampdens;
                if (d >= 1.0-FTINY)
                        return;
                tanb = d/sqrt(1.0-d*d);
                for (i = 0; i < nglardirs; i++) {
                        d = indirect[i].lcos - tanb*indirect[i].lsin;
                        if (d > 0.0) {
                                indirect[i].sum += d * br;
                                indirect[i].n += d;
                        }
                }
                return;
        }
        if (h >= hlim) {                        /* right region */
                d = (double)(-h+hlim)/sampdens;
                if (d <= -1.0+FTINY)
                        return;
                tanb = d/sqrt(1.0-d*d);
                for (i = 0; i < nglardirs; i++) {
                        d = indirect[i].rcos - tanb*indirect[i].rsin;
                        if (d > 0.0) {
                                indirect[i].sum += d * br;
                                indirect[i].n += d;
                        }
                }
                return;
        }
                                        /* central region */
        for (i = 0; i < nglardirs; i++) {
                d = cos(h_theta(h) - indirect[i].theta);
                if (d > 0.0) {
                        indirect[i].sum += d * br;
                        indirect[i].n += d;
                }
        }
}


comp_thresh()                   /* compute glare threshold */
{
        int     h, v;
        int     nsamps;
        double  brsum, br;

        if (verbose)
                fprintf(stderr, "%s: computing glare threshold...\n",
                                progname);
        brsum = 0.0;
        nsamps = 0;
        for (v = vsize; v >= -vsize; v -= TSAMPSTEP)
                for (h = -hsize; h <= hsize; h += TSAMPSTEP) {
                        if ((br = getviewpix(h, v)) < 0.0)
                                continue;
                        brsum += br;
                        nsamps++;
                }
        if (nsamps == 0) {
                fprintf(stderr, "%s: no viewable scene!\n", progname);
                exit(1);
        }
        threshold = GLAREBR * brsum / nsamps;
        if (threshold <= FTINY) {
                fprintf(stderr, "%s: threshold zero!\n", progname);
                exit(1);
        }
        if (verbose) {
#ifdef DEBUG
                pict_stats();
#endif
                fprintf(stderr,
                        "%s: threshold set to %f cd/m2 from %d samples\n",
                                progname, threshold, nsamps);
        }
}


addsrcspan(nss)                 /* add new source span to our list */
struct srcspan  *nss;
{
        struct source   *last, *cs, *this;
        register struct srcspan *ss;

        cs = NULL;
        for (this = curlist; this != NULL; this = this->next) {
                for (ss = this->first; ss != NULL; ss = ss->next) {
                        if (!vcont(nss->v, ss->v))
                                break;
                        if (hcont(ss, nss)) {
                                if (cs == NULL)
                                        cs = this;
                                else {
                                        last->next = this->next;
                                        mergesource(cs, this);
                                        this = last;
                                }
                                break;
                        }
                }
                last = this;
        }
        if (cs == NULL) {
                cs = (struct source *)malloc(sizeof(struct source));
                if (cs == NULL)
                        memerr("source records");
                cs->dom = 0.0;
                cs->first = NULL;
                cs->next = curlist;
                curlist = cs;
        }
        nss->next = cs->first;
        cs->first = nss;
}


mergesource(sp, ap)             /* merge source ap into source sp */
struct source   *sp, *ap;
{
        struct srcspan  head;
        register struct srcspan *alp, *prev, *tp;

        head.next = sp->first;
        prev = &head;
        alp = ap->first;
        while (alp != NULL && prev->next != NULL) {
                if (prev->next->v > alp->v) {
                        tp = alp->next;
                        alp->next = prev->next;
                        prev->next = alp;
                        alp = tp;
                }
                prev = prev->next;
        }
        if (prev->next == NULL)
                prev->next = alp;
        sp->first = head.next;
        if (ap->dom > 0.0 && sp->dom > 0.0) {           /* sources are done */
                sp->dir[0] *= sp->dom;
                sp->dir[1] *= sp->dom;
                sp->dir[2] *= sp->dom;
                fvsum(sp->dir, sp->dir, ap->dir, ap->dom);
                normalize(sp->dir);
                sp->brt = (sp->brt*sp->dom + ap->brt*ap->dom)
                                / (sp->dom + ap->dom);
        }
        free((char *)ap);
}


close_sources(v)                /* close sources above v */
int     v;
{
        struct source   head;
        register struct source  *last, *this;

        head.next = curlist;
        last = &head;
        for (this = curlist; this != NULL; this = this->next)
                if (!vcont(v, this->first->v)) {
                        last->next = this->next;
                        donesource(this);
                        this = last;
                } else
                        last = this;
        curlist = head.next;
}


close_allsrcs()                 /* done with everything */
{
        register struct source  *this, *next;

        this = curlist;
        while (this != NULL) {
                next = this->next;
                donesource(this);
                this = next;
        }
        curlist = NULL;
}


donesource(sp)                  /* finished with this source */
register struct source  *sp;
{
        FVECT   dthis, dright;
        register struct srcspan *ss;
        int     h, n;
        double  d;

        sp->dom = 0.0;
        sp->dir[0] = sp->dir[1] = sp->dir[2] = 0.0;
        sp->brt = 0.0;
        n = 0;
        for (ss = sp->first; ss != NULL; ss = ss->next) {
                sp->brt += ss->brsum;
                n += ss->r - ss->l;
                if (compdir(dright, ss->r, ss->v) < 0)
                        compdir(dright, ss->r-2, ss->v);
                for (h = ss->r-1; h >= ss->l; h--)
                        if (compdir(dthis, h, ss->v) == 0) {
                                d = dist2(dthis, dright);
                                fvsum(sp->dir, sp->dir, dthis, d);
                                sp->dom += d;
                                VCOPY(dright, dthis);
                        }
                free((char *)ss);
        }
        sp->first = NULL;
        sp->brt /= (double)n;
        normalize(sp->dir);
        sp->next = donelist;
        donelist = sp;
        if (verbose)
                fprintf(stderr,
        "%s: found source at (%.3f,%.3f,%.3f), dw %.5f, br %.1f (%d samps)\n",
                        progname, sp->dir[0], sp->dir[1], sp->dir[2], 
                        sp->dom, sp->brt, n);
}


struct source *
findbuddy(s, l)                 /* find close enough source to s in l*/
register struct source  *s, *l;
{
        struct source   *bestbuddy = NULL;
        double  d, r, mindist = MAXBUDDY;

        r = sqrt(s->dom/PI);
        for ( ; l != NULL; l = l->next) {
                d = sqrt(dist2(l->dir, s->dir)) - sqrt(l->dom/PI) - r;
                if (d < mindist) {
                        bestbuddy = l;
                        mindist = d;
                }
        }
        return(bestbuddy);
}


absorb_specks()                 /* eliminate too-small sources */
{
        struct source   head, *buddy;
        register struct source  *last, *this;

        if (verbose)
                fprintf(stderr, "%s: absorbing small sources...\n", progname);
        head.next = donelist;
        last = &head;
        for (this = head.next; this != NULL; this = this->next)
                if (TOOSMALL(this)) {
                        last->next = this->next;
                        buddy = findbuddy(this, head.next);
                        if (buddy != NULL)
                                mergesource(buddy, this);
                        else
                                absorb(this);
                        this = last;
                } else
                        last = this;
        donelist = head.next;
}


absorb(s)                       /* absorb a source into indirect */
register struct source  *s;
{
        FVECT   dir;
        double  d;
        register int    i;

        for (i = 0; i < nglardirs; i++) {
                spinvector(dir, ourview.vdir, ourview.vup, indirect[i].theta);
                d = DOT(dir,s->dir)*s->dom*(sampdens*sampdens);
                if (d <= 0.0)
                        continue;
                indirect[i].sum += d * s->brt;
                indirect[i].n += d;
        }
        for ( ; s->first != NULL; s->first = s->first->next)
                free((char *)s->first);
        free((char *)s);
}
Revision:	1.11
Committed:	Wed Apr 10 15:59:10 1991 UTC (33 years ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.10:	+2 -3 lines
Log Message:	fixed small bug in absorb_specks() and added -c option
#	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			* Gather samples and compute glare sources.
9			*/
10
11			#include "glare.h"
12
13			#define vcont(vd,vu) ((vu)-(vd)<=SEPS)
14			#define hcont(s1,s2) ((s1)->r-(s2)->l>=-SEPS&&(s2)->r-(s1)->l>=-SEPS)
15
16			struct source curlist = NULL; / current source list */
17			struct source donelist = NULL; / finished sources */
18
19
20			struct srcspan *
21			newspan(l, r, v, sb) /* allocate a new source span */
22			int l, r, v;
23			float *sb;
24			{
25			register struct srcspan *ss;
26			register int i;
27
28			ss = (struct srcspan *)malloc(sizeof(struct srcspan));
29			if (ss == NULL)
30			memerr("source spans");
31			ss->l = l;
32			ss->r = r;
33			ss->v = v;
34			ss->brsum = 0.0;
35			for (i = l; i < r; i++)
36			ss->brsum += sb[i+hsize];
37			return(ss);
38			}
39
40
41			analyze() /* analyze our scene */
42			{
43			int h, v;
44			int left;
45			float *spanbr;
46
47			spanbr = (float )malloc((2hsize+1)*sizeof(float));
48			if (spanbr == NULL)
49			memerr("view span brightness buffer");
50			for (v = vsize; v >= -vsize; v--) {
51	greg	1.5	close_sources(v);
52	greg	1.8	#ifndef DEBUG
53			if (verbose)
54			fprintf(stderr, "%s: analyzing... %3ld%%\r",
55			progname, 100L(vsize-v)/(2vsize));
56			#endif
57	greg	1.1	getviewspan(v, spanbr);
58			left = hsize + 1;
59	greg	1.2	for (h = -hsize; h <= hsize; h++) {
60	greg	1.1	if (spanbr[h+hsize] < 0.0) { /* off view */
61			if (left < h) {
62	greg	1.2	addsrcspan(newspan(left,h,v,spanbr));
63	greg	1.1	left = hsize + 1;
64			}
65			continue;
66			}
67			if (spanbr[h+hsize] > threshold) { /* in source */
68	greg	1.2	if (left > h)
69	greg	1.1	left = h;
70			} else { /* out of source */
71			if (left < h) {
72	greg	1.2	addsrcspan(newspan(left,h,v,spanbr));
73	greg	1.1	left = hsize + 1;
74			}
75			addindirect(h, spanbr[h+hsize]);
76			}
77	greg	1.2	}
78	greg	1.1	if (left < h)
79	greg	1.2	addsrcspan(newspan(left,h,v,spanbr));
80	greg	1.1	}
81	greg	1.7	free((char *)spanbr);
82	greg	1.1	close_allsrcs();
83			}
84
85
86			addindirect(h, br) /* add brightness to indirect illuminances */
87			int h;
88			double br;
89			{
90			double tanb, d;
91			register int i;
92
93			if (h <= -hlim) { /* left region */
94	greg	1.9	d = (double)(-h-hlim)/sampdens;
95			if (d >= 1.0-FTINY)
96	greg	1.1	return;
97			tanb = d/sqrt(1.0-d*d);
98			for (i = 0; i < nglardirs; i++) {
99			d = indirect[i].lcos - tanb*indirect[i].lsin;
100			if (d > 0.0) {
101			indirect[i].sum += d * br;
102	greg	1.10	indirect[i].n += d;
103	greg	1.1	}
104			}
105			return;
106			}
107			if (h >= hlim) { /* right region */
108	greg	1.9	d = (double)(-h+hlim)/sampdens;
109			if (d <= -1.0+FTINY)
110	greg	1.1	return;
111			tanb = d/sqrt(1.0-d*d);
112			for (i = 0; i < nglardirs; i++) {
113			d = indirect[i].rcos - tanb*indirect[i].rsin;
114			if (d > 0.0) {
115			indirect[i].sum += d * br;
116	greg	1.10	indirect[i].n += d;
117	greg	1.1	}
118			}
119			return;
120			}
121			/* central region */
122			for (i = 0; i < nglardirs; i++) {
123			d = cos(h_theta(h) - indirect[i].theta);
124			if (d > 0.0) {
125			indirect[i].sum += d * br;
126	greg	1.10	indirect[i].n += d;
127	greg	1.1	}
128			}
129			}
130
131
132			comp_thresh() /* compute glare threshold */
133			{
134			int h, v;
135			int nsamps;
136			double brsum, br;
137
138			if (verbose)
139			fprintf(stderr, "%s: computing glare threshold...\n",
140			progname);
141			brsum = 0.0;
142			nsamps = 0;
143			for (v = vsize; v >= -vsize; v -= TSAMPSTEP)
144			for (h = -hsize; h <= hsize; h += TSAMPSTEP) {
145			if ((br = getviewpix(h, v)) < 0.0)
146			continue;
147			brsum += br;
148			nsamps++;
149			}
150			if (nsamps == 0) {
151			fprintf(stderr, "%s: no viewable scene!\n", progname);
152			exit(1);
153			}
154			threshold = GLAREBR * brsum / nsamps;
155			if (threshold <= FTINY) {
156			fprintf(stderr, "%s: threshold zero!\n", progname);
157			exit(1);
158			}
159	greg	1.2	if (verbose) {
160	greg	1.8	#ifdef DEBUG
161	greg	1.2	pict_stats();
162	greg	1.8	#endif
163	greg	1.1	fprintf(stderr,
164			"%s: threshold set to %f cd/m2 from %d samples\n",
165			progname, threshold, nsamps);
166	greg	1.2	}
167	greg	1.1	}
168
169
170			addsrcspan(nss) /* add new source span to our list */
171			struct srcspan *nss;
172			{
173			struct source last, cs, *this;
174			register struct srcspan *ss;
175
176			cs = NULL;
177			for (this = curlist; this != NULL; this = this->next) {
178			for (ss = this->first; ss != NULL; ss = ss->next) {
179			if (!vcont(nss->v, ss->v))
180			break;
181			if (hcont(ss, nss)) {
182			if (cs == NULL)
183			cs = this;
184			else {
185	greg	1.7	last->next = this->next;
186	greg	1.1	mergesource(cs, this);
187	greg	1.5	this = last;
188	greg	1.1	}
189			break;
190			}
191			}
192			last = this;
193			}
194			if (cs == NULL) {
195			cs = (struct source *)malloc(sizeof(struct source));
196			if (cs == NULL)
197			memerr("source records");
198	greg	1.7	cs->dom = 0.0;
199	greg	1.1	cs->first = NULL;
200			cs->next = curlist;
201			curlist = cs;
202			}
203			nss->next = cs->first;
204			cs->first = nss;
205			}
206
207
208			mergesource(sp, ap) /* merge source ap into source sp */
209			struct source sp, ap;
210			{
211			struct srcspan head;
212			register struct srcspan alp, prev, *tp;
213
214			head.next = sp->first;
215			prev = &head;
216			alp = ap->first;
217			while (alp != NULL && prev->next != NULL) {
218			if (prev->next->v > alp->v) {
219			tp = alp->next;
220			alp->next = prev->next;
221			prev->next = alp;
222			alp = tp;
223			}
224			prev = prev->next;
225			}
226			if (prev->next == NULL)
227			prev->next = alp;
228			sp->first = head.next;
229	greg	1.7	if (ap->dom > 0.0 && sp->dom > 0.0) { /* sources are done */
230			sp->dir[0] *= sp->dom;
231			sp->dir[1] *= sp->dom;
232			sp->dir[2] *= sp->dom;
233			fvsum(sp->dir, sp->dir, ap->dir, ap->dom);
234			normalize(sp->dir);
235			sp->brt = (sp->brtsp->dom + ap->brtap->dom)
236			/ (sp->dom + ap->dom);
237			}
238			free((char *)ap);
239	greg	1.1	}
240
241
242			close_sources(v) /* close sources above v */
243			int v;
244			{
245			struct source head;
246			register struct source last, this;
247
248			head.next = curlist;
249			last = &head;
250			for (this = curlist; this != NULL; this = this->next)
251			if (!vcont(v, this->first->v)) {
252			last->next = this->next;
253			donesource(this);
254			this = last;
255			} else
256			last = this;
257			curlist = head.next;
258			}
259
260
261			close_allsrcs() /* done with everything */
262			{
263	greg	1.5	register struct source this, next;
264	greg	1.1
265	greg	1.5	this = curlist;
266			while (this != NULL) {
267			next = this->next;
268	greg	1.1	donesource(this);
269	greg	1.5	this = next;
270	greg	1.4	}
271	greg	1.1	curlist = NULL;
272			}
273
274
275			donesource(sp) /* finished with this source */
276			register struct source *sp;
277			{
278			FVECT dthis, dright;
279			register struct srcspan *ss;
280			int h, n;
281			double d;
282
283			sp->dom = 0.0;
284	greg	1.5	sp->dir[0] = sp->dir[1] = sp->dir[2] = 0.0;
285	greg	1.1	sp->brt = 0.0;
286	greg	1.3	n = 0;
287	greg	1.1	for (ss = sp->first; ss != NULL; ss = ss->next) {
288			sp->brt += ss->brsum;
289			n += ss->r - ss->l;
290	greg	1.5	if (compdir(dright, ss->r, ss->v) < 0)
291			compdir(dright, ss->r-2, ss->v);
292			for (h = ss->r-1; h >= ss->l; h--)
293			if (compdir(dthis, h, ss->v) == 0) {
294			d = dist2(dthis, dright);
295			fvsum(sp->dir, sp->dir, dthis, d);
296			sp->dom += d;
297			VCOPY(dright, dthis);
298			}
299	greg	1.1	free((char *)ss);
300			}
301			sp->first = NULL;
302			sp->brt /= (double)n;
303	greg	1.5	normalize(sp->dir);
304	greg	1.1	sp->next = donelist;
305			donelist = sp;
306			if (verbose)
307			fprintf(stderr,
308	greg	1.5	"%s: found source at (%.3f,%.3f,%.3f), dw %.5f, br %.1f (%d samps)\n",
309	greg	1.2	progname, sp->dir[0], sp->dir[1], sp->dir[2],
310	greg	1.5	sp->dom, sp->brt, n);
311	greg	1.7	}
312
313
314			struct source *
315			findbuddy(s, l) /* find close enough source to s in l*/
316			register struct source s, l;
317			{
318			struct source *bestbuddy = NULL;
319			double d, r, mindist = MAXBUDDY;
320
321			r = sqrt(s->dom/PI);
322			for ( ; l != NULL; l = l->next) {
323			d = sqrt(dist2(l->dir, s->dir)) - sqrt(l->dom/PI) - r;
324			if (d < mindist) {
325			bestbuddy = l;
326			mindist = d;
327			}
328			}
329			return(bestbuddy);
330			}
331
332
333			absorb_specks() /* eliminate too-small sources */
334			{
335			struct source head, *buddy;
336			register struct source last, this;
337
338			if (verbose)
339			fprintf(stderr, "%s: absorbing small sources...\n", progname);
340			head.next = donelist;
341			last = &head;
342	greg	1.11	for (this = head.next; this != NULL; this = this->next)
343	greg	1.7	if (TOOSMALL(this)) {
344			last->next = this->next;
345	greg	1.11	buddy = findbuddy(this, head.next);
346	greg	1.7	if (buddy != NULL)
347			mergesource(buddy, this);
348			else
349			absorb(this);
350			this = last;
351			} else
352			last = this;
353			donelist = head.next;
354			}
355
356
357			absorb(s) /* absorb a source into indirect */
358			register struct source *s;
359			{
360			FVECT dir;
361	greg	1.10	double d;
362			register int i;
363	greg	1.7
364			for (i = 0; i < nglardirs; i++) {
365			spinvector(dir, ourview.vdir, ourview.vup, indirect[i].theta);
366	greg	1.10	d = DOT(dir,s->dir)s->dom(sampdens*sampdens);
367			if (d <= 0.0)
368	greg	1.7	continue;
369	greg	1.10	indirect[i].sum += d * s->brt;
370			indirect[i].n += d;
371	greg	1.7	}
372			for ( ; s->first != NULL; s->first = s->first->next)
373			free((char *)s->first);
374			free((char *)s);
375	greg	1.1	}