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);
                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));
        }
        close_allsrcs();
        free((char *)spanbr);
}


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++;
                        }
                }
                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++;
                        }
                }
                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++;
                }
        }
}


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) {
                pict_stats();
                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 {
                                        mergesource(cs, this);
                                        last->next = this->next;
                                        free((char *)this);
                                        this = last;
                                }
                                break;
                        }
                }
                last = this;
        }
        if (cs == NULL) {
                cs = (struct source *)malloc(sizeof(struct source));
                if (cs == NULL)
                        memerr("source records");
                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;
        ap->first = NULL;
}


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);
}
Revision:	1.6
Committed:	Tue Mar 19 17:21:31 1991 UTC (33 years, 1 month ago) by greg
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+0 -2 lines
Log Message:	added -t option to set threshold
#	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	1.1	getviewspan(v, spanbr);
53			left = hsize + 1;
54	greg	1.2	for (h = -hsize; h <= hsize; h++) {
55	greg	1.1	if (spanbr[h+hsize] < 0.0) { /* off view */
56			if (left < h) {
57	greg	1.2	addsrcspan(newspan(left,h,v,spanbr));
58	greg	1.1	left = hsize + 1;
59			}
60			continue;
61			}
62			if (spanbr[h+hsize] > threshold) { /* in source */
63	greg	1.2	if (left > h)
64	greg	1.1	left = h;
65			} else { /* out of source */
66			if (left < h) {
67	greg	1.2	addsrcspan(newspan(left,h,v,spanbr));
68	greg	1.1	left = hsize + 1;
69			}
70			addindirect(h, spanbr[h+hsize]);
71			}
72	greg	1.2	}
73	greg	1.1	if (left < h)
74	greg	1.2	addsrcspan(newspan(left,h,v,spanbr));
75	greg	1.1	}
76			close_allsrcs();
77			free((char *)spanbr);
78			}
79
80
81			addindirect(h, br) /* add brightness to indirect illuminances */
82			int h;
83			double br;
84			{
85			double tanb, d;
86			register int i;
87
88			if (h <= -hlim) { /* left region */
89	greg	1.3	d = (double)(h+hlim)/sampdens;
90	greg	1.1	if (d <= -1.0+FTINY)
91			return;
92			tanb = d/sqrt(1.0-d*d);
93			for (i = 0; i < nglardirs; i++) {
94			d = indirect[i].lcos - tanb*indirect[i].lsin;
95			if (d > 0.0) {
96			indirect[i].sum += d * br;
97			indirect[i].n++;
98			}
99			}
100			return;
101			}
102			if (h >= hlim) { /* right region */
103	greg	1.3	d = (double)(h-hlim)/sampdens;
104	greg	1.1	if (d >= 1.0-FTINY)
105			return;
106			tanb = d/sqrt(1.0-d*d);
107			for (i = 0; i < nglardirs; i++) {
108			d = indirect[i].rcos - tanb*indirect[i].rsin;
109			if (d > 0.0) {
110			indirect[i].sum += d * br;
111			indirect[i].n++;
112			}
113			}
114			return;
115			}
116			/* central region */
117			for (i = 0; i < nglardirs; i++) {
118			d = cos(h_theta(h) - indirect[i].theta);
119			if (d > 0.0) {
120			indirect[i].sum += d * br;
121			indirect[i].n++;
122			}
123			}
124			}
125
126
127			comp_thresh() /* compute glare threshold */
128			{
129			int h, v;
130			int nsamps;
131			double brsum, br;
132
133			if (verbose)
134			fprintf(stderr, "%s: computing glare threshold...\n",
135			progname);
136			brsum = 0.0;
137			nsamps = 0;
138			for (v = vsize; v >= -vsize; v -= TSAMPSTEP)
139			for (h = -hsize; h <= hsize; h += TSAMPSTEP) {
140			if ((br = getviewpix(h, v)) < 0.0)
141			continue;
142			brsum += br;
143			nsamps++;
144			}
145			if (nsamps == 0) {
146			fprintf(stderr, "%s: no viewable scene!\n", progname);
147			exit(1);
148			}
149			threshold = GLAREBR * brsum / nsamps;
150			if (threshold <= FTINY) {
151			fprintf(stderr, "%s: threshold zero!\n", progname);
152			exit(1);
153			}
154	greg	1.2	if (verbose) {
155			pict_stats();
156	greg	1.1	fprintf(stderr,
157			"%s: threshold set to %f cd/m2 from %d samples\n",
158			progname, threshold, nsamps);
159	greg	1.2	}
160	greg	1.1	}
161
162
163			addsrcspan(nss) /* add new source span to our list */
164			struct srcspan *nss;
165			{
166			struct source last, cs, *this;
167			register struct srcspan *ss;
168
169			cs = NULL;
170			for (this = curlist; this != NULL; this = this->next) {
171			for (ss = this->first; ss != NULL; ss = ss->next) {
172			if (!vcont(nss->v, ss->v))
173			break;
174			if (hcont(ss, nss)) {
175			if (cs == NULL)
176			cs = this;
177			else {
178			mergesource(cs, this);
179			last->next = this->next;
180			free((char *)this);
181	greg	1.5	this = last;
182	greg	1.1	}
183			break;
184			}
185			}
186			last = this;
187			}
188			if (cs == NULL) {
189			cs = (struct source *)malloc(sizeof(struct source));
190			if (cs == NULL)
191			memerr("source records");
192			cs->first = NULL;
193			cs->next = curlist;
194			curlist = cs;
195			}
196			nss->next = cs->first;
197			cs->first = nss;
198			}
199
200
201			mergesource(sp, ap) /* merge source ap into source sp */
202			struct source sp, ap;
203			{
204			struct srcspan head;
205			register struct srcspan alp, prev, *tp;
206
207			head.next = sp->first;
208			prev = &head;
209			alp = ap->first;
210			while (alp != NULL && prev->next != NULL) {
211			if (prev->next->v > alp->v) {
212			tp = alp->next;
213			alp->next = prev->next;
214			prev->next = alp;
215			alp = tp;
216			}
217			prev = prev->next;
218			}
219			if (prev->next == NULL)
220			prev->next = alp;
221			sp->first = head.next;
222			ap->first = NULL;
223			}
224
225
226			close_sources(v) /* close sources above v */
227			int v;
228			{
229			struct source head;
230			register struct source last, this;
231
232			head.next = curlist;
233			last = &head;
234			for (this = curlist; this != NULL; this = this->next)
235			if (!vcont(v, this->first->v)) {
236			last->next = this->next;
237			donesource(this);
238			this = last;
239			} else
240			last = this;
241			curlist = head.next;
242			}
243
244
245			close_allsrcs() /* done with everything */
246			{
247	greg	1.5	register struct source this, next;
248	greg	1.1
249	greg	1.5	this = curlist;
250			while (this != NULL) {
251			next = this->next;
252	greg	1.1	donesource(this);
253	greg	1.5	this = next;
254	greg	1.4	}
255	greg	1.1	curlist = NULL;
256			}
257
258
259			donesource(sp) /* finished with this source */
260			register struct source *sp;
261			{
262			FVECT dthis, dright;
263			register struct srcspan *ss;
264			int h, n;
265			double d;
266
267			sp->dom = 0.0;
268	greg	1.5	sp->dir[0] = sp->dir[1] = sp->dir[2] = 0.0;
269	greg	1.1	sp->brt = 0.0;
270	greg	1.3	n = 0;
271	greg	1.1	for (ss = sp->first; ss != NULL; ss = ss->next) {
272			sp->brt += ss->brsum;
273			n += ss->r - ss->l;
274	greg	1.5	if (compdir(dright, ss->r, ss->v) < 0)
275			compdir(dright, ss->r-2, ss->v);
276			for (h = ss->r-1; h >= ss->l; h--)
277			if (compdir(dthis, h, ss->v) == 0) {
278			d = dist2(dthis, dright);
279			fvsum(sp->dir, sp->dir, dthis, d);
280			sp->dom += d;
281			VCOPY(dright, dthis);
282			}
283	greg	1.1	free((char *)ss);
284			}
285			sp->first = NULL;
286			sp->brt /= (double)n;
287	greg	1.5	normalize(sp->dir);
288	greg	1.1	sp->next = donelist;
289			donelist = sp;
290			if (verbose)
291			fprintf(stderr,
292	greg	1.5	"%s: found source at (%.3f,%.3f,%.3f), dw %.5f, br %.1f (%d samps)\n",
293	greg	1.2	progname, sp->dir[0], sp->dir[1], sp->dir[2],
294	greg	1.5	sp->dom, sp->brt, n);
295	greg	1.1	}