[ViewVC] Diff of: radiance/ray/src/rt/ambcomp.c

Comparing ray/src/rt/ambcomp.c (file contents):
Revision 2.73 by greg, Fri Oct 14 00:54:21 2016 UTC vs.
Revision 2.91 by greg, Fri Nov 17 20:02:07 2023 UTC

#	Line 21 \| Line 21 \| static const char RCSid[] = "$Id$";
21		#include "ambient.h"
22		#include "random.h"
23
24	<	#ifndef OLDAMB
24	>	#ifndef MINADIV
25	>	#define MINADIV 7 /* minimum # divisions in each dimension */
26	>	#endif
27
26	–	extern void SDsquare2disk(double ds[2], double seedx, double seedy);
27	–
28		typedef struct {
29	–	COLOR v; /* hemisphere sample value */
30	–	float d; /* reciprocal distance (1/rt) */
29		FVECT p; /* intersection point */
30	+	float d; /* reciprocal distance */
31	+	SCOLOR v; /* hemisphere sample value */
32		} AMBSAMP; /* sample value */
33
34		typedef struct {
35		RAY rp; / originating ray sample */
36		int ns; /* number of samples per axis */
37		int sampOK; /* acquired full sample set? */
38	<	COLOR acoef; /* division contribution coefficient */
39	<	double acol[3]; /* accumulated color */
38	>	SCOLOR acoef; /* division contribution coefficient */
39	>	SCOLOR acol; /* accumulated color */
40		FVECT ux, uy; /* tangent axis unit vectors */
41		AMBSAMP sa[1]; /* sample array (extends struct) */
42		} AMBHEMI; /* ambient sample hemisphere */
#	Line 58 \| Line 58 \| *ambcollision( / proposed direciton collides? /*
58		FVECT dv
59		)
60		{
61	<	const double cos_thresh = 0.9999995; /* about 3.44 arcminutes */
62	<	int ii, jj;
63	<
61	>	double cos_thresh;
62	>	int ii, jj;
63	>	/* min. spacing = 1/4th division */
64	>	cos_thresh = (PI/4.)/(double)hp->ns;
65	>	cos_thresh = 1. - .5cos_threshcos_thresh;
66	>	/* check existing neighbors */
67		for (ii = i-1; ii <= i+1; ii++) {
68		if (ii < 0) continue;
69		if (ii >= hp->ns) break;
#	Line 72 \| Line 75 \| *ambcollision( / proposed direciton collides? /*
75		if (jj >= hp->ns) break;
76		if ((ii==i) & (jj==j)) continue;
77		ap = &ambsam(hp,ii,jj);
78	<	if (ap->d <= .5/FHUGE) continue;
78	>	if (ap->d <= .5/FHUGE)
79	>	continue; /* no one home */
80		VSUB(avec, ap->p, hp->rp->rop);
81		dprod = DOT(avec, dv);
82		if (dprod >= cos_thresh*VLEN(avec))
83		return(1); /* collision */
84		}
85		}
86	<	return(0);
86	>	return(0); /* nothing to worry about */
87		}
88
89
#	Line 94 \| Line 98 \| *ambsample( / initial ambient division sample /*
98		AMBSAMP *ap = &ambsam(hp,i,j);
99		RAY ar;
100		int hlist[3], ii;
101	<	double spt[2], zd;
101	>	RREAL spt[2];
102	>	double zd;
103		/* generate hemispherical sample */
104		/* ambient coefficient for weight */
105		if (ambacc > FTINY)
106	<	setcolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL);
106	>	setscolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL);
107		else
108	<	copycolor(ar.rcoef, hp->acoef);
108	>	copyscolor(ar.rcoef, hp->acoef);
109		if (rayorigin(&ar, AMBIENT, hp->rp, ar.rcoef) < 0)
110		return(0);
111		if (ambacc > FTINY) {
112	<	multcolor(ar.rcoef, hp->acoef);
113	<	scalecolor(ar.rcoef, 1./AVGREFL);
112	>	smultscolor(ar.rcoef, hp->acoef);
113	>	scalescolor(ar.rcoef, 1./AVGREFL);
114		}
115		hlist[0] = hp->rp->rno;
116		hlist[1] = j;
117		hlist[2] = i;
118		multisamp(spt, 2, urand(ilhash(hlist,3)+n));
119		resample:
120	<	SDsquare2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns);
120	>	square2disk(spt, (j+spt[1])/hp->ns, (i+spt[0])/hp->ns);
121		zd = sqrt(1. - spt[0]spt[0] - spt[1]spt[1]);
122		for (ii = 3; ii--; )
123		ar.rdir[ii] = spt[0]*hp->ux[ii] +
#	Line 122 \| Line 127 \| resample:
127		/* avoid coincident samples */
128		if (!n && ambcollision(hp, i, j, ar.rdir)) {
129		spt[0] = frandom(); spt[1] = frandom();
130	<	goto resample;
130	>	goto resample; /* reject this sample */
131		}
132		dimlist[ndims++] = AI(hp,i,j) + 90171;
133		rayvalue(&ar); /* evaluate ray */
134		ndims--;
135	<	if (ar.rt <= FTINY)
135	>	zd = raydistance(&ar);
136	>	if (zd <= FTINY)
137		return(0); /* should never happen */
138	<	multcolor(ar.rcol, ar.rcoef); /* apply coefficient */
139	<	if (ar.rtap->d < 1.0) / new/closer distance? */
140	<	ap->d = 1.0/ar.rt;
138	>	smultscolor(ar.rcol, ar.rcoef); /* apply coefficient */
139	>	if (zdap->d < 1.0) / new/closer distance? */
140	>	ap->d = 1.0/zd;
141		if (!n) { /* record first vertex & value */
142	<	if (ar.rt > 10.0*thescene.cusize)
143	<	ar.rt = 10.0*thescene.cusize;
144	<	VSUM(ap->p, ar.rorg, ar.rdir, ar.rt);
145	<	copycolor(ap->v, ar.rcol);
142	>	if (zd > 10.0*thescene.cusize + 1000.)
143	>	zd = 10.0*thescene.cusize + 1000.;
144	>	VSUM(ap->p, ar.rorg, ar.rdir, zd);
145	>	copyscolor(ap->v, ar.rcol);
146		} else { /* else update recorded value */
147	<	hp->acol[RED] -= colval(ap->v,RED);
142	<	hp->acol[GRN] -= colval(ap->v,GRN);
143	<	hp->acol[BLU] -= colval(ap->v,BLU);
147	>	sopscolor(hp->acol, -=, ap->v);
148		zd = 1.0/(double)(n+1);
149	<	scalecolor(ar.rcol, zd);
149	>	scalescolor(ar.rcol, zd);
150		zd *= (double)n;
151	<	scalecolor(ap->v, zd);
152	<	addcolor(ap->v, ar.rcol);
151	>	scalescolor(ap->v, zd);
152	>	saddscolor(ap->v, ar.rcol);
153		}
154	<	addcolor(hp->acol, ap->v); /* add to our sum */
154	>	saddscolor(hp->acol, ap->v); /* add to our sum */
155		return(1);
156		}
157
158
159	<	/* Estimate errors based on ambient division differences */
159	>	/* Estimate variance based on ambient division differences */
160		static float *
161		getambdiffs(AMBHEMI *hp)
162		{
163	+	const double normf = 1./bright(hp->acoef);
164		float earr = (float )calloc(hp->ns*hp->ns, sizeof(float));
165		float *ep;
166		AMBSAMP *ap;
167	<	double b, d2;
167	>	double b, b1, d2;
168		int i, j;
169
170		if (earr == NULL) /* out of memory? */
171		return(NULL);
172	<	/* compute squared neighbor diffs */
172	>	/* sum squared neighbor diffs */
173		for (ap = hp->sa, ep = earr, i = 0; i < hp->ns; i++)
174		for (j = 0; j < hp->ns; j++, ap++, ep++) {
175	<	b = bright(ap[0].v);
175	>	b = pbright(ap[0].v);
176		if (i) { /* from above */
177	<	d2 = b - bright(ap[-hp->ns].v);
178	<	d2 *= d2;
177	>	b1 = pbright(ap[-hp->ns].v);
178	>	d2 = b - b1;
179	>	d2 = d2normf/(b + b1 + FTINY);
180		ep[0] += d2;
181		ep[-hp->ns] += d2;
182		}
183		if (!j) continue;
184		/* from behind */
185	<	d2 = b - bright(ap[-1].v);
186	<	d2 *= d2;
185	>	b1 = pbright(ap[-1].v);
186	>	d2 = b - b1;
187	>	d2 = d2normf/(b + b1 + FTINY);
188		ep[0] += d2;
189		ep[-1] += d2;
190		if (!i) continue;
191		/* diagonal */
192	<	d2 = b - bright(ap[-hp->ns-1].v);
193	<	d2 *= d2;
192	>	b1 = pbright(ap[-hp->ns-1].v);
193	>	d2 = b - b1;
194	>	d2 = d2normf/(b + b1 + FTINY);
195		ep[0] += d2;
196		ep[-hp->ns-1] += d2;
197		}
#	Line 210 \| Line 218 \| *ambsupersamp(AMBHEMI hp, int cnt)**
218		{
219		float *earr = getambdiffs(hp);
220		double e2rem = 0;
213	–	AMBSAMP *ap;
221		float *ep;
222		int i, j, n, nss;
223
#	Line 220 \| Line 227 \| *ambsupersamp(AMBHEMI hp, int cnt)**
227		for (ep = earr + hp->ns*hp->ns; ep > earr; )
228		e2rem += *--ep;
229		ep = earr; /* perform super-sampling */
230	<	for (ap = hp->sa, i = 0; i < hp->ns; i++)
231	<	for (j = 0; j < hp->ns; j++, ap++) {
230	>	for (i = 0; i < hp->ns; i++)
231	>	for (j = 0; j < hp->ns; j++) {
232		if (e2rem <= FTINY)
233		goto done; /* nothing left to do */
234		nss = ep/e2remcnt + frandom();
235		for (n = 1; n <= nss && ambsample(hp,i,j,n); n++)
236	<	--cnt;
236	>	if (!--cnt) goto done;
237		e2rem -= ep++; / update remainder */
238		}
239		done:
#	Line 236 \| Line 243 \| done:
243
244		static AMBHEMI *
245		samp_hemi( /* sample indirect hemisphere */
246	<	COLOR rcol,
246	>	SCOLOR rcol,
247		RAY *r,
248		double wt
249		)
#	Line 244 \| Line 251 \| *samp_hemi( / sample indirect hemisphere /*
251		AMBHEMI *hp;
252		double d;
253		int n, i, j;
254	+	/* insignificance check */
255	+	d = sintens(rcol);
256	+	if (d <= FTINY)
257	+	return(NULL);
258		/* set number of divisions */
259		if (ambacc <= FTINY &&
260	<	wt > (d = 0.8intens(rcol)r->rweight/(ambdiv*minweight)))
260	>	wt > (d = 0.8r->rweight/(ambdiv*minweight)))
261		wt = d; /* avoid ray termination */
262		n = sqrt(ambdiv * wt) + 0.5;
263	<	i = 1 + 5(ambacc > FTINY); / minimum number of samples */
264	<	if (n < i)
263	>	i = 1 + (MINADIV-1)*(ambacc > FTINY);
264	>	if (n < i) /* use minimum number of samples? */
265		n = i;
266		/* allocate sampling array */
267		hp = (AMBHEMI )malloc(sizeof(AMBHEMI) + sizeof(AMBSAMP)(n*n - 1));
#	Line 258 \| Line 269 \| *samp_hemi( / sample indirect hemisphere /*
269		error(SYSTEM, "out of memory in samp_hemi");
270		hp->rp = r;
271		hp->ns = n;
272	<	hp->acol[RED] = hp->acol[GRN] = hp->acol[BLU] = 0.0;
272	>	scolorblack(hp->acol);
273		memset(hp->sa, 0, sizeof(AMBSAMP)nn);
274		hp->sampOK = 0;
275		/* assign coefficient */
276	<	copycolor(hp->acoef, rcol);
276	>	copyscolor(hp->acoef, rcol);
277		d = 1.0/(n*n);
278	<	scalecolor(hp->acoef, d);
278	>	scalescolor(hp->acoef, d);
279		/* make tangent plane axes */
280		if (!getperpendicular(hp->ux, r->ron, 1))
281		error(CONSISTENCY, "bad ray direction in samp_hemi");
#	Line 273 \| Line 284 \| *samp_hemi( / sample indirect hemisphere /*
284		for (i = hp->ns; i--; )
285		for (j = hp->ns; j--; )
286		hp->sampOK += ambsample(hp, i, j, 0);
287	<	copycolor(rcol, hp->acol);
287	>	copyscolor(rcol, hp->acol);
288		if (!hp->sampOK) { /* utter failure? */
289		free(hp);
290		return(NULL);
#	Line 282 \| Line 293 \| *samp_hemi( / sample indirect hemisphere /*
293		hp->sampOK = -1; / soft failure */
294		return(hp);
295		}
296	+	if (hp->sampOK <= MINADIV*MINADIV)
297	+	return(hp); /* don't bother super-sampling */
298		n = ambssamp*wt + 0.5;
299		if (n > 8) { /* perform super-sampling? */
300		ambsupersamp(hp, n);
301	<	copycolor(rcol, hp->acol);
301	>	copyscolor(rcol, hp->acol);
302		}
303		return(hp); /* all is well */
304		}
#	Line 297 \| Line 310 \| *back_ambval(AMBHEMI hp, const int n1, const int n2, c**
310		{
311		if (hp->sa[n1].d <= hp->sa[n2].d) {
312		if (hp->sa[n1].d <= hp->sa[n3].d)
313	<	return(colval(hp->sa[n1].v,CIEY));
314	<	return(colval(hp->sa[n3].v,CIEY));
313	>	return(hp->sa[n1].v[0]);
314	>	return(hp->sa[n3].v[0]);
315		}
316		if (hp->sa[n2].d <= hp->sa[n3].d)
317	<	return(colval(hp->sa[n2].v,CIEY));
318	<	return(colval(hp->sa[n3].v,CIEY));
317	>	return(hp->sa[n2].v[0]);
318	>	return(hp->sa[n3].v[0]);
319		}
320
321
#	Line 616 \| Line 629 \| *ambdirgrad(AMBHEMI hp, FVECT uv[2], float dg[2])**
629		/* use vector for azimuth + 90deg */
630		VSUB(vd, ap->p, hp->rp->rop);
631		/* brightness over cosine factor */
632	<	gfact = colval(ap->v,CIEY) / DOT(hp->rp->ron, vd);
632	>	gfact = ap->v[0] / DOT(hp->rp->ron, vd);
633		/* sine = proj_radius/vd_length */
634		dgsum[0] -= DOT(uv[1], vd) * gfact;
635		dgsum[1] += DOT(uv[0], vd) * gfact;
#	Line 666 \| Line 679 \| *ambcorral(AMBHEMI hp, FVECT uv[2], const double r0, c**
679		for (a1 = ang-ang_res; a1 <= ang+ang_res; a1 += ang_step)
680		flgs \|= 1L<<(int)(16/PI(a1 + 2.PI*(a1 < 0)));
681		}
669	–	/* add low-angle incident (< 20deg) */
670	–	if (fabs(hp->rp->rod) <= 0.342) {
671	–	u = -DOT(hp->rp->rdir, uv[0]);
672	–	v = -DOT(hp->rp->rdir, uv[1]);
673	–	if ((r0r0uu + r1r1vv) > hp->rp->rot*hp->rp->rot) {
674	–	ang = atan2a(v, u);
675	–	ang += 2.PI(ang < 0);
676	–	ang *= 16/PI;
677	–	if ((ang < .5) \| (ang >= 31.5))
678	–	flgs \|= 0x80000001;
679	–	else
680	–	flgs \|= 3L<<(int)(ang-.5);
681	–	}
682	–	}
682		return(flgs);
683		}
684
685
686		int
687		doambient( /* compute ambient component */
688	<	COLOR rcol, /* input/output color */
688	>	SCOLOR rcol, /* input/output color */
689		RAY *r,
690		double wt,
691		FVECT uv[2], /* returned (optional) */
#	Line 716 \| Line 715 \| *doambient( / compute ambient component /*
715		return(0);
716
717		if ((ra == NULL) & (pg == NULL) & (dg == NULL) \|\|
718	<	(hp->sampOK < 0) \| (hp->ns < 6)) {
718	>	(hp->sampOK < 0) \| (hp->ns < MINADIV)) {
719		free(hp); /* Hessian not requested/possible */
720		return(-1); /* value-only return value */
721		}
722	<	if ((d = bright(rcol)) > FTINY) { /* normalize Y values */
723	<	d = 0.99(hp->nshp->ns)/d;
722	>	if ((d = scolor_mean(rcol)) > FTINY) {
723	>	d = 0.99(hp->nshp->ns)/d; /* normalize avg. values */
724		K = 0.01;
725		} else { /* or fall back on geometric Hessian */
726		K = 1.0;
#	Line 729 \| Line 728 \| *doambient( / compute ambient component /*
728		dg = NULL;
729		crlp = NULL;
730		}
731	<	ap = hp->sa; /* relative Y channel from here on... */
731	>	ap = hp->sa; /* single channel from here on... */
732		for (i = hp->ns*hp->ns; i--; ap++)
733	<	colval(ap->v,CIEY) = bright(ap->v)*d + K;
733	>	ap->v[0] = scolor_mean(ap->v)*d + K;
734
735		if (uv == NULL) /* make sure we have axis pointers */
736		uv = my_uv;
#	Line 764 \| Line 763 \| *doambient( / compute ambient component /*
763		ra[0] = maxarad;
764		}
765		/* flag encroached directions */
766	<	if (crlp != NULL)
766	>	if (crlp != NULL) /* XXX doesn't update with changes to ambacc */
767		crlp = ambcorral(hp, uv, ra[0]ambacc, ra[1]*ambacc);
768		if (pg != NULL) { /* cap gradient if necessary */
769		d = pg[0]pg[0]ra[0]ra[0] + pg[1]pg[1]ra[1]ra[1];
#	Line 778 \| Line 777 \| *doambient( / compute ambient component /*
777		free(hp); /* clean up and return */
778		return(1);
779		}
781	–
782	–
783	–	#else /* ! NEWAMB */
784	–
785	–
786	–	void
787	–	inithemi( /* initialize sampling hemisphere */
788	–	AMBHEMI *hp,
789	–	COLOR ac,
790	–	RAY *r,
791	–	double wt
792	–	)
793	–	{
794	–	double d;
795	–	int i;
796	–	/* set number of divisions */
797	–	if (ambacc <= FTINY &&
798	–	wt > (d = 0.8intens(ac)r->rweight/(ambdiv*minweight)))
799	–	wt = d; /* avoid ray termination */
800	–	hp->nt = sqrt(ambdiv * wt / PI) + 0.5;
801	–	i = ambacc > FTINY ? 3 : 1; /* minimum number of samples */
802	–	if (hp->nt < i)
803	–	hp->nt = i;
804	–	hp->np = PI * hp->nt + 0.5;
805	–	/* set number of super-samples */
806	–	hp->ns = ambssamp * wt + 0.5;
807	–	/* assign coefficient */
808	–	copycolor(hp->acoef, ac);
809	–	d = 1.0/(hp->nt*hp->np);
810	–	scalecolor(hp->acoef, d);
811	–	/* make axes */
812	–	VCOPY(hp->uz, r->ron);
813	–	hp->uy[0] = hp->uy[1] = hp->uy[2] = 0.0;
814	–	for (i = 0; i < 3; i++)
815	–	if (hp->uz[i] < 0.6 && hp->uz[i] > -0.6)
816	–	break;
817	–	if (i >= 3)
818	–	error(CONSISTENCY, "bad ray direction in inithemi");
819	–	hp->uy[i] = 1.0;
820	–	fcross(hp->ux, hp->uy, hp->uz);
821	–	normalize(hp->ux);
822	–	fcross(hp->uy, hp->uz, hp->ux);
823	–	}
824	–
825	–
826	–	int
827	–	divsample( /* sample a division */
828	–	AMBSAMP *dp,
829	–	AMBHEMI *h,
830	–	RAY *r
831	–	)
832	–	{
833	–	RAY ar;
834	–	int hlist[3];
835	–	double spt[2];
836	–	double xd, yd, zd;
837	–	double b2;
838	–	double phi;
839	–	int i;
840	–	/* ambient coefficient for weight */
841	–	if (ambacc > FTINY)
842	–	setcolor(ar.rcoef, AVGREFL, AVGREFL, AVGREFL);
843	–	else
844	–	copycolor(ar.rcoef, h->acoef);
845	–	if (rayorigin(&ar, AMBIENT, r, ar.rcoef) < 0)
846	–	return(-1);
847	–	if (ambacc > FTINY) {
848	–	multcolor(ar.rcoef, h->acoef);
849	–	scalecolor(ar.rcoef, 1./AVGREFL);
850	–	}
851	–	hlist[0] = r->rno;
852	–	hlist[1] = dp->t;
853	–	hlist[2] = dp->p;
854	–	multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n));
855	–	zd = sqrt((dp->t + spt[0])/h->nt);
856	–	phi = 2.0PI (dp->p + spt[1])/h->np;
857	–	xd = tcos(phi) * zd;
858	–	yd = tsin(phi) * zd;
859	–	zd = sqrt(1.0 - zd*zd);
860	–	for (i = 0; i < 3; i++)
861	–	ar.rdir[i] = xd*h->ux[i] +
862	–	yd*h->uy[i] +
863	–	zd*h->uz[i];
864	–	checknorm(ar.rdir);
865	–	dimlist[ndims++] = dp->t*h->np + dp->p + 90171;
866	–	rayvalue(&ar);
867	–	ndims--;
868	–	multcolor(ar.rcol, ar.rcoef); /* apply coefficient */
869	–	addcolor(dp->v, ar.rcol);
870	–	/* use rt to improve gradient calc */
871	–	if (ar.rt > FTINY && ar.rt < FHUGE)
872	–	dp->r += 1.0/ar.rt;
873	–	/* (re)initialize error */
874	–	if (dp->n++) {
875	–	b2 = bright(dp->v)/dp->n - bright(ar.rcol);
876	–	b2 = b2b2 + dp->k((dp->n-1)*(dp->n-1));
877	–	dp->k = b2/(dp->n*dp->n);
878	–	} else
879	–	dp->k = 0.0;
880	–	return(0);
881	–	}
882	–
883	–
884	–	static int
885	–	ambcmp( /* decreasing order */
886	–	const void *p1,
887	–	const void *p2
888	–	)
889	–	{
890	–	const AMBSAMP d1 = (const AMBSAMP )p1;
891	–	const AMBSAMP d2 = (const AMBSAMP )p2;
892	–
893	–	if (d1->k < d2->k)
894	–	return(1);
895	–	if (d1->k > d2->k)
896	–	return(-1);
897	–	return(0);
898	–	}
899	–
900	–
901	–	static int
902	–	ambnorm( /* standard order */
903	–	const void *p1,
904	–	const void *p2
905	–	)
906	–	{
907	–	const AMBSAMP d1 = (const AMBSAMP )p1;
908	–	const AMBSAMP d2 = (const AMBSAMP )p2;
909	–	int c;
910	–
911	–	if ( (c = d1->t - d2->t) )
912	–	return(c);
913	–	return(d1->p - d2->p);
914	–	}
915	–
916	–
917	–	double
918	–	doambient( /* compute ambient component */
919	–	COLOR rcol,
920	–	RAY *r,
921	–	double wt,
922	–	FVECT pg,
923	–	FVECT dg
924	–	)
925	–	{
926	–	double b, d=0;
927	–	AMBHEMI hemi;
928	–	AMBSAMP *div;
929	–	AMBSAMP dnew;
930	–	double acol[3];
931	–	AMBSAMP *dp;
932	–	double arad;
933	–	int divcnt;
934	–	int i, j;
935	–	/* initialize hemisphere */
936	–	inithemi(&hemi, rcol, r, wt);
937	–	divcnt = hemi.nt * hemi.np;
938	–	/* initialize */
939	–	if (pg != NULL)
940	–	pg[0] = pg[1] = pg[2] = 0.0;
941	–	if (dg != NULL)
942	–	dg[0] = dg[1] = dg[2] = 0.0;
943	–	setcolor(rcol, 0.0, 0.0, 0.0);
944	–	if (divcnt == 0)
945	–	return(0.0);
946	–	/* allocate super-samples */
947	–	if (hemi.ns > 0 \|\| pg != NULL \|\| dg != NULL) {
948	–	div = (AMBSAMP )malloc(divcntsizeof(AMBSAMP));
949	–	if (div == NULL)
950	–	error(SYSTEM, "out of memory in doambient");
951	–	} else
952	–	div = NULL;
953	–	/* sample the divisions */
954	–	arad = 0.0;
955	–	acol[0] = acol[1] = acol[2] = 0.0;
956	–	if ((dp = div) == NULL)
957	–	dp = &dnew;
958	–	divcnt = 0;
959	–	for (i = 0; i < hemi.nt; i++)
960	–	for (j = 0; j < hemi.np; j++) {
961	–	dp->t = i; dp->p = j;
962	–	setcolor(dp->v, 0.0, 0.0, 0.0);
963	–	dp->r = 0.0;
964	–	dp->n = 0;
965	–	if (divsample(dp, &hemi, r) < 0) {
966	–	if (div != NULL)
967	–	dp++;
968	–	continue;
969	–	}
970	–	arad += dp->r;
971	–	divcnt++;
972	–	if (div != NULL)
973	–	dp++;
974	–	else
975	–	addcolor(acol, dp->v);
976	–	}
977	–	if (!divcnt) {
978	–	if (div != NULL)
979	–	free((void *)div);
980	–	return(0.0); /* no samples taken */
981	–	}
982	–	if (divcnt < hemi.nt*hemi.np) {
983	–	pg = dg = NULL; /* incomplete sampling */
984	–	hemi.ns = 0;
985	–	} else if (arad > FTINY && divcnt/arad < minarad) {
986	–	hemi.ns = 0; /* close enough */
987	–	} else if (hemi.ns > 0) { /* else perform super-sampling? */
988	–	comperrs(div, &hemi); /* compute errors */
989	–	qsort(div, divcnt, sizeof(AMBSAMP), ambcmp); /* sort divs */
990	–	/* super-sample */
991	–	for (i = hemi.ns; i > 0; i--) {
992	–	dnew = *div;
993	–	if (divsample(&dnew, &hemi, r) < 0) {
994	–	dp++;
995	–	continue;
996	–	}
997	–	dp = div; /* reinsert */
998	–	j = divcnt < i ? divcnt : i;
999	–	while (--j > 0 && dnew.k < dp[1].k) {
1000	–	dp = (dp+1);
1001	–	dp++;
1002	–	}
1003	–	*dp = dnew;
1004	–	}
1005	–	if (pg != NULL \|\| dg != NULL) /* restore order */
1006	–	qsort(div, divcnt, sizeof(AMBSAMP), ambnorm);
1007	–	}
1008	–	/* compute returned values */
1009	–	if (div != NULL) {
1010	–	arad = 0.0; /* note: divcnt may be < ntnp /
1011	–	for (i = hemi.nt*hemi.np, dp = div; i-- > 0; dp++) {
1012	–	arad += dp->r;
1013	–	if (dp->n > 1) {
1014	–	b = 1.0/dp->n;
1015	–	scalecolor(dp->v, b);
1016	–	dp->r *= b;
1017	–	dp->n = 1;
1018	–	}
1019	–	addcolor(acol, dp->v);
1020	–	}
1021	–	b = bright(acol);
1022	–	if (b > FTINY) {
1023	–	b = 1.0/b; /* compute & normalize gradient(s) */
1024	–	if (pg != NULL) {
1025	–	posgradient(pg, div, &hemi);
1026	–	for (i = 0; i < 3; i++)
1027	–	pg[i] *= b;
1028	–	}
1029	–	if (dg != NULL) {
1030	–	dirgradient(dg, div, &hemi);
1031	–	for (i = 0; i < 3; i++)
1032	–	dg[i] *= b;
1033	–	}
1034	–	}
1035	–	free((void *)div);
1036	–	}
1037	–	copycolor(rcol, acol);
1038	–	if (arad <= FTINY)
1039	–	arad = maxarad;
1040	–	else
1041	–	arad = (divcnt+hemi.ns)/arad;
1042	–	if (pg != NULL) { /* reduce radius if gradient large */
1043	–	d = DOT(pg,pg);
1044	–	if (daradarad > 1.0)
1045	–	arad = 1.0/sqrt(d);
1046	–	}
1047	–	if (arad < minarad) {
1048	–	arad = minarad;
1049	–	if (pg != NULL && daradarad > 1.0) { /* cap gradient */
1050	–	d = 1.0/arad/sqrt(d);
1051	–	for (i = 0; i < 3; i++)
1052	–	pg[i] *= d;
1053	–	}
1054	–	}
1055	–	if ((arad /= sqrt(wt)) > maxarad)
1056	–	arad = maxarad;
1057	–	return(arad);
1058	–	}
1059	–
1060	–
1061	–	void
1062	–	comperrs( /* compute initial error estimates */
1063	–	AMBSAMP da, / assumes standard ordering */
1064	–	AMBHEMI *hp
1065	–	)
1066	–	{
1067	–	double b, b2;
1068	–	int i, j;
1069	–	AMBSAMP *dp;
1070	–	/* sum differences from neighbors */
1071	–	dp = da;
1072	–	for (i = 0; i < hp->nt; i++)
1073	–	for (j = 0; j < hp->np; j++) {
1074	–	#ifdef DEBUG
1075	–	if (dp->t != i \|\| dp->p != j)
1076	–	error(CONSISTENCY,
1077	–	"division order in comperrs");
1078	–	#endif
1079	–	b = bright(dp[0].v);
1080	–	if (i > 0) { /* from above */
1081	–	b2 = bright(dp[-hp->np].v) - b;
1082	–	b2 = b2 0.25;
1083	–	dp[0].k += b2;
1084	–	dp[-hp->np].k += b2;
1085	–	}
1086	–	if (j > 0) { /* from behind */
1087	–	b2 = bright(dp[-1].v) - b;
1088	–	b2 = b2 0.25;
1089	–	dp[0].k += b2;
1090	–	dp[-1].k += b2;
1091	–	} else { /* around */
1092	–	b2 = bright(dp[hp->np-1].v) - b;
1093	–	b2 = b2 0.25;
1094	–	dp[0].k += b2;
1095	–	dp[hp->np-1].k += b2;
1096	–	}
1097	–	dp++;
1098	–	}
1099	–	/* divide by number of neighbors */
1100	–	dp = da;
1101	–	for (j = 0; j < hp->np; j++) /* top row */
1102	–	(dp++)->k *= 1.0/3.0;
1103	–	if (hp->nt < 2)
1104	–	return;
1105	–	for (i = 1; i < hp->nt-1; i++) /* central region */
1106	–	for (j = 0; j < hp->np; j++)
1107	–	(dp++)->k *= 0.25;
1108	–	for (j = 0; j < hp->np; j++) /* bottom row */
1109	–	(dp++)->k *= 1.0/3.0;
1110	–	}
1111	–
1112	–
1113	–	void
1114	–	posgradient( /* compute position gradient */
1115	–	FVECT gv,
1116	–	AMBSAMP da, / assumes standard ordering */
1117	–	AMBHEMI *hp
1118	–	)
1119	–	{
1120	–	int i, j;
1121	–	double nextsine, lastsine, b, d;
1122	–	double mag0, mag1;
1123	–	double phi, cosp, sinp, xd, yd;
1124	–	AMBSAMP *dp;
1125	–
1126	–	xd = yd = 0.0;
1127	–	for (j = 0; j < hp->np; j++) {
1128	–	dp = da + j;
1129	–	mag0 = mag1 = 0.0;
1130	–	lastsine = 0.0;
1131	–	for (i = 0; i < hp->nt; i++) {
1132	–	#ifdef DEBUG
1133	–	if (dp->t != i \|\| dp->p != j)
1134	–	error(CONSISTENCY,
1135	–	"division order in posgradient");
1136	–	#endif
1137	–	b = bright(dp->v);
1138	–	if (i > 0) {
1139	–	d = dp[-hp->np].r;
1140	–	if (dp[0].r > d) d = dp[0].r;
1141	–	/* sin(t)cos(t)^2 /
1142	–	d = lastsine (1.0 - (double)i/hp->nt);
1143	–	mag0 += d*(b - bright(dp[-hp->np].v));
1144	–	}
1145	–	nextsine = sqrt((double)(i+1)/hp->nt);
1146	–	if (j > 0) {
1147	–	d = dp[-1].r;
1148	–	if (dp[0].r > d) d = dp[0].r;
1149	–	mag1 += d * (nextsine - lastsine) *
1150	–	(b - bright(dp[-1].v));
1151	–	} else {
1152	–	d = dp[hp->np-1].r;
1153	–	if (dp[0].r > d) d = dp[0].r;
1154	–	mag1 += d * (nextsine - lastsine) *
1155	–	(b - bright(dp[hp->np-1].v));
1156	–	}
1157	–	dp += hp->np;
1158	–	lastsine = nextsine;
1159	–	}
1160	–	mag0 = 2.0PI / hp->np;
1161	–	phi = 2.0PI (double)j/hp->np;
1162	–	cosp = tcos(phi); sinp = tsin(phi);
1163	–	xd += mag0cosp - mag1sinp;
1164	–	yd += mag0sinp + mag1cosp;
1165	–	}
1166	–	for (i = 0; i < 3; i++)
1167	–	gv[i] = (xdhp->ux[i] + ydhp->uy[i])(hp->nthp->np)/PI;
1168	–	}
1169	–
1170	–
1171	–	void
1172	–	dirgradient( /* compute direction gradient */
1173	–	FVECT gv,
1174	–	AMBSAMP da, / assumes standard ordering */
1175	–	AMBHEMI *hp
1176	–	)
1177	–	{
1178	–	int i, j;
1179	–	double mag;
1180	–	double phi, xd, yd;
1181	–	AMBSAMP *dp;
1182	–
1183	–	xd = yd = 0.0;
1184	–	for (j = 0; j < hp->np; j++) {
1185	–	dp = da + j;
1186	–	mag = 0.0;
1187	–	for (i = 0; i < hp->nt; i++) {
1188	–	#ifdef DEBUG
1189	–	if (dp->t != i \|\| dp->p != j)
1190	–	error(CONSISTENCY,
1191	–	"division order in dirgradient");
1192	–	#endif
1193	–	/* tan(t) */
1194	–	mag += bright(dp->v)/sqrt(hp->nt/(i+.5) - 1.0);
1195	–	dp += hp->np;
1196	–	}
1197	–	phi = 2.0PI (j+.5)/hp->np + PI/2.0;
1198	–	xd += mag * tcos(phi);
1199	–	yd += mag * tsin(phi);
1200	–	}
1201	–	for (i = 0; i < 3; i++)
1202	–	gv[i] = xdhp->ux[i] + ydhp->uy[i];
1203	–	}
1204	–
1205	–	#endif /* ! NEWAMB */

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Comparing ray/src/rt/ambcomp.c (file contents): Revision 2.73 by greg, Fri Oct 14 00:54:21 2016 UTC vs. Revision 2.91 by greg, Fri Nov 17 20:02:07 2023 UTC

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Comparing ray/src/rt/ambcomp.c (file contents):
Revision 2.73 by greg, Fri Oct 14 00:54:21 2016 UTC vs.
Revision 2.91 by greg, Fri Nov 17 20:02:07 2023 UTC