--- ray/src/rt/ambient.c	2014/05/06 17:15:11	2.85
+++ ray/src/rt/ambient.c	2021/02/19 22:05:46	2.110
@@ -1,6 +1,4 @@
-#ifndef lint
-static const char	RCSid[] = "$Id: ambient.c,v 2.85 2014/05/06 17:15:11 greg Exp $";
-#endif
+static const char	RCSid[] = "$Id: ambient.c,v 2.110 2021/02/19 22:05:46 greg Exp $";
 /*
  *  ambient.c - routines dealing with ambient (inter-reflected) component.
  *
@@ -14,9 +12,11 @@ static const char	RCSid[] = "$Id: ambient.c,v 2.85 201
 #include  "platform.h"
 #include  "ray.h"
 #include  "otypes.h"
+#include  "otspecial.h"
 #include  "resolu.h"
 #include  "ambient.h"
 #include  "random.h"
+#include  "pmapamb.h"
 
 #ifndef  OCTSCALE
 #define	 OCTSCALE	1.0	/* ceil((valid rad.)/(cube size)) */
@@ -77,8 +77,9 @@ static long  lastpos = -1;		/* last flush position */
 #define	 AMBFLUSH	(BUFSIZ/AMBVALSIZ)
 
 #define	 newambval()	(AMBVAL *)malloc(sizeof(AMBVAL))
-#define  freeav(av)	free((void *)av);
 
+#define  tfunc(lwr, x, upr)	(((x)-(lwr))/((upr)-(lwr)))
+
 static void initambfile(int creat);
 static void avsave(AMBVAL *av);
 static AMBVAL *avstore(AMBVAL  *aval);
@@ -95,6 +96,13 @@ static int aposcmp(const void *avp1, const void *avp2)
 static int avlmemi(AMBVAL *avaddr);
 static void sortambvals(int always);
 
+static int	plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang);
+static double	sumambient(COLOR acol, RAY *r, FVECT rn, int al,
+				AMBTREE *at, FVECT c0, double s);
+static int	makeambient(COLOR acol, RAY *r, FVECT rn, int al);
+static int	extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv, 
+				FVECT uvw[3]);
+
 #ifdef  F_SETLKW
 static void aflock(int  typ);
 #endif
@@ -109,12 +117,12 @@ setambres(				/* set ambient resolution */
 						/* set min & max radii */
 	if (ar <= 0) {
 		minarad = 0;
-		maxarad = thescene.cusize*0.5;
+		maxarad = thescene.cusize*0.2;
 	} else {
 		minarad = thescene.cusize / ar;
 		maxarad = 64.0 * minarad;		/* heuristic */
-		if (maxarad > thescene.cusize*0.5)
-			maxarad = thescene.cusize*0.5;
+		if (maxarad > thescene.cusize*0.2)
+			maxarad = thescene.cusize*0.2;
 	}
 	if (minarad <= FTINY)
 		minarad = 10.0*FTINY;
@@ -133,7 +141,7 @@ setambacc(				/* set ambient accuracy */
 	newa *= (newa > 0);
 	if (fabs(newa - olda) >= .05*(newa + olda)) {
 		ambacc = newa;
-		if (nambvals > 0)
+		if (ambacc > FTINY && nambvals > 0)
 			sortambvals(1);		/* rebuild tree */
 	}
 }
@@ -165,7 +173,7 @@ setambient(void)				/* initialize calculation */
 		initambfile(0);			/* file exists */
 		lastpos = ftell(ambfp);
 		while (readambval(&amb, ambfp))
-			avinsert(avstore(&amb));
+			avstore(&amb);
 		nambshare = nambvals;		/* share loaded values */
 		if (readonly) {
 			sprintf(errmsg,
@@ -185,9 +193,7 @@ setambient(void)				/* initialize calculation */
 					(flen - lastpos)/AMBVALSIZ);
 			error(WARNING, errmsg);
 			fseek(ambfp, lastpos, SEEK_SET);
-#ifndef _WIN32 /* XXX we need a replacement for that one */
 			ftruncate(fileno(ambfp), (off_t)lastpos);
-#endif
 		}
 	} else if ((ambfp = fopen(ambfile, "w+")) != NULL) {
 		initambfile(1);			/* else create new file */
@@ -197,9 +203,6 @@ setambient(void)				/* initialize calculation */
 		sprintf(errmsg, "cannot open ambient file \"%s\"", ambfile);
 		error(SYSTEM, errmsg);
 	}
-#ifdef getc_unlocked
-	flockfile(ambfp);			/* application-level lock */
-#endif
 #ifdef  F_SETLKW
 	aflock(F_UNLCK);			/* release file */
 #endif
@@ -220,7 +223,7 @@ ambdone(void)			/* close ambient file and free memory 
 		lastpos = -1;
 	}
 					/* free ambient tree */
-	unloadatree(&atrunk, &avfree);
+	unloadatree(&atrunk, avfree);
 					/* reset state variables */
 	avsum = 0.;
 	navsum = 0;
@@ -261,18 +264,7 @@ ambnotify(			/* record new modifier */
 		}
 }
 
-/************ THE FOLLOWING ROUTINES DIFFER BETWEEN NEW & OLD ***************/
 
-#ifdef NEWAMB
-
-#define tfunc(lwr, x, upr)	(((x)-(lwr))/((upr)-(lwr)))
-
-static double	sumambient(COLOR acol, RAY *r, FVECT rn, int al,
-				AMBTREE *at, FVECT c0, double s);
-static int	makeambient(COLOR acol, RAY *r, FVECT rn, int al);
-static void	extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv, 
-				FVECT uvw[3]);
-
 void
 multambient(		/* compute ambient component & multiply by coef. */
 	COLOR  aval,
@@ -281,10 +273,22 @@ multambient(		/* compute ambient component & multiply 
 )
 {
 	static int  rdepth = 0;			/* ambient recursion */
-	COLOR	acol;
-	int	ok;
+	COLOR	acol, caustic;
+	int	i, ok;
 	double	d, l;
 
+	/* PMAP: Factor in ambient from photon map, if enabled and ray is
+	 * ambient. Return as all ambient components accounted for, else
+	 * continue. */
+	if (ambPmap(aval, r, rdepth))
+		return;
+
+	/* PMAP: Factor in specular-diffuse ambient (caustics) from photon
+	 * map, if enabled and ray is primary, else caustic is zero.  Continue
+	 * with RADIANCE ambient calculation */
+	copycolor(caustic, aval);
+	ambPmapCaustic(caustic, r, rdepth);
+	
 	if (ambdiv <= 0)			/* no ambient calculation */
 		goto dumbamb;
 						/* check number of bounces */
@@ -296,13 +300,31 @@ multambient(		/* compute ambient component & multiply 
 		goto dumbamb;
 
 	if (ambacc <= FTINY) {			/* no ambient storage */
+		FVECT	uvd[2];
+		float	dgrad[2], *dgp = NULL;
+
+		if (nrm != r->ron && DOT(nrm,r->ron) < 0.9999)
+			dgp = dgrad;		/* compute rotational grad. */
 		copycolor(acol, aval);
 		rdepth++;
-		ok = doambient(acol, r, r->rweight, NULL, NULL, NULL, NULL);
+		ok = doambient(acol, r, r->rweight,
+				uvd, NULL, NULL, dgp, NULL);
 		rdepth--;
 		if (!ok)
 			goto dumbamb;
+		if ((ok > 0) & (dgp != NULL)) {	/* apply texture */
+			FVECT	v1;
+			VCROSS(v1, r->ron, nrm);
+			d = 1.0;
+			for (i = 3; i--; )
+				d += v1[i] * (dgp[0]*uvd[0][i] + dgp[1]*uvd[1][i]);
+			if (d >= 0.05)
+				scalecolor(acol, d);
+		}
 		copycolor(aval, acol);
+
+		/* PMAP: add in caustic */
+		addcolor(aval, caustic);
 		return;
 	}
 
@@ -312,25 +334,39 @@ multambient(		/* compute ambient component & multiply 
 	setcolor(acol, 0.0, 0.0, 0.0);
 	d = sumambient(acol, r, nrm, rdepth,
 			&atrunk, thescene.cuorg, thescene.cusize);
+			
 	if (d > FTINY) {
 		d = 1.0/d;
 		scalecolor(acol, d);
 		multcolor(aval, acol);
+
+		/* PMAP: add in caustic */
+		addcolor(aval, caustic);
 		return;
 	}
+	
 	rdepth++;				/* need to cache new value */
 	ok = makeambient(acol, r, nrm, rdepth-1);
 	rdepth--;
+	
 	if (ok) {
 		multcolor(aval, acol);		/* computed new value */
+
+		/* PMAP: add in caustic */
+		addcolor(aval, caustic);
 		return;
 	}
+	
 dumbamb:					/* return global value */
 	if ((ambvwt <= 0) | (navsum == 0)) {
 		multcolor(aval, ambval);
+		
+		/* PMAP: add in caustic */
+		addcolor(aval, caustic);
 		return;
 	}
-	l = bright(ambval);			/* average in computations */
+	
+	l = bright(ambval);			/* average in computations */	
 	if (l > FTINY) {
 		d = (log(l)*(double)ambvwt + avsum) /
 				(double)(ambvwt + navsum);
@@ -344,7 +380,53 @@ dumbamb:					/* return global value */
 }
 
 
-double
+/* Plug a potential leak where ambient cache value is occluded */
+static int
+plugaleak(RAY *r, AMBVAL *ap, FVECT anorm, double ang)
+{
+	const double	cost70sq = 0.1169778;	/* cos(70deg)^2 */
+	RAY		rtst;
+	FVECT		vdif;
+	double		normdot, ndotd, nadotd;
+	double		a, b, c, t[2];
+
+	ang += 2.*PI*(ang < 0);			/* check direction flags */
+	if ( !(ap->corral>>(int)(ang*(16./PI)) & 1) )
+		return(0);
+	/*
+	 * Generate test ray, targeting 20 degrees above sample point plane
+	 * along surface normal from cache position.  This should be high
+	 * enough to miss local geometry we don't really care about.
+	 */
+	VSUB(vdif, ap->pos, r->rop);
+	normdot = DOT(anorm, r->ron);
+	ndotd = DOT(vdif, r->ron);
+	nadotd = DOT(vdif, anorm);
+	a = normdot*normdot - cost70sq;
+	b = 2.0*(normdot*ndotd - nadotd*cost70sq);
+	c = ndotd*ndotd - DOT(vdif,vdif)*cost70sq;
+	if (quadratic(t, a, b, c) != 2)
+		return(1);			/* should rarely happen */
+	if (t[1] <= FTINY)
+		return(0);			/* should fail behind test */
+	rayorigin(&rtst, SHADOW, r, NULL);
+	VSUM(rtst.rdir, vdif, anorm, t[1]);	/* further dist. > plane */
+	rtst.rmax = normalize(rtst.rdir);	/* short ray test */
+	while (localhit(&rtst, &thescene)) {	/* check for occluder */
+		OBJREC	*m = findmaterial(rtst.ro);
+		if (m != NULL && !istransp(m->otype) && !isBSDFproxy(m) &&
+				(rtst.clipset == NULL ||
+					!inset(rtst.clipset, rtst.ro->omod)))
+			return(1);		/* plug light leak */
+		VCOPY(rtst.rorg, rtst.rop);	/* skip invisible surface */
+		rtst.rmax -= rtst.rot;
+		rayclear(&rtst);
+	}
+	return(0);				/* seems we're OK */
+}
+
+
+static double
 sumambient(		/* get interpolated ambient value */
 	COLOR  acol,
 	RAY  *r,
@@ -387,7 +469,7 @@ sumambient(		/* get interpolated ambient value */
 		maxangle = (maxangle - PI/2.)*pow(r->rweight,0.13) + PI/2.;
 					/* sum this node */
 	for (av = at->alist; av != NULL; av = av->next) {
-		double	d, delta_r2, delta_t2;
+		double	u, v, d, delta_r2, delta_t2;
 		COLOR	ct;
 		FVECT	uvw[3];
 					/* record access */
@@ -396,10 +478,9 @@ sumambient(		/* get interpolated ambient value */
 		/*
 		 *  Ambient level test
 		 */
-		if (av->lvl > al)	/* list sorted, so this works */
+		if (av->lvl > al ||	/* list sorted, so this works */
+				(av->lvl == al) & (av->weight < 0.9*r->rweight))
 			break;
-		if (av->weight < 0.9*r->rweight)
-			continue;
 		/*
 		 *  Direction test using unperturbed normal
 		 */
@@ -426,16 +507,22 @@ sumambient(		/* get interpolated ambient value */
 		 */
 		decodedir(uvw[0], av->udir);
 		VCROSS(uvw[1], uvw[2], uvw[0]);
-		d = DOT(ck0, uvw[0]) / av->rad[0];
+		d = (u = DOT(ck0, uvw[0])) / av->rad[0];
 		delta_t2 += d*d;
-		d = DOT(ck0, uvw[1]) / av->rad[1];
+		d = (v = DOT(ck0, uvw[1])) / av->rad[1];
 		delta_t2 += d*d;
 		if (delta_t2 >= ambacc*ambacc)
 			continue;
 		/*
+		 *  Test for potential light leak
+		 */
+		if (av->corral && plugaleak(r, av, uvw[2], atan2a(v,u)))
+			continue;
+		/*
 		 *  Extrapolate value and compute final weight (hat function)
 		 */
-		extambient(ct, av, r->rop, rn, uvw);
+		if (!extambient(ct, av, r->rop, rn, uvw))
+			continue;
 		d = tfunc(maxangle, sqrt(delta_r2), 0.0) *
 			tfunc(ambacc, sqrt(delta_t2), 0.0);
 		scalecolor(ct, d);
@@ -446,7 +533,7 @@ sumambient(		/* get interpolated ambient value */
 }
 
 
-int
+static int
 makeambient(		/* make a new ambient value for storage */
 	COLOR  acol,
 	RAY  *r,
@@ -465,7 +552,8 @@ makeambient(		/* make a new ambient value for storage 
 		amb.weight = 1.25*r->rweight;
 	setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
 						/* compute ambient */
-	i = doambient(acol, r, amb.weight, uvw, amb.rad, amb.gpos, amb.gdir);
+	i = doambient(acol, r, amb.weight,
+			uvw, amb.rad, amb.gpos, amb.gdir, &amb.corral);
 	scalecolor(acol, 1./AVGREFL);		/* undo assumed reflectance */
 	if (i <= 0 || amb.rad[0] <= FTINY)	/* no Hessian or zero radius */
 		return(i);
@@ -485,7 +573,7 @@ makeambient(		/* make a new ambient value for storage 
 }
 
 
-void
+static int
 extambient(		/* extrapolate value at pv, nv */
 	COLOR  cr,
 	AMBVAL	 *ap,
@@ -494,6 +582,8 @@ extambient(		/* extrapolate value at pv, nv */
 	FVECT  uvw[3]
 )
 {
+	const double	min_d = 0.05;
+	const double	max_d = 20.;
 	static FVECT	my_uvw[3];
 	FVECT		v1;
 	int		i;
@@ -513,12 +603,13 @@ extambient(		/* extrapolate value at pv, nv */
 	for (i = 3; i--; )
 		d += v1[i] * (ap->gdir[0]*uvw[0][i] + ap->gdir[1]*uvw[1][i]);
 	
-	if (d <= 0.0) {
-		setcolor(cr, 0.0, 0.0, 0.0);
-		return;
-	}
+	if (d < min_d)			/* clamp min/max scaling */
+		d = min_d;
+	else if (d > max_d)
+		d = max_d;
 	copycolor(cr, ap->val);
 	scalecolor(cr, d);
+	return(d > min_d);
 }
 
 
@@ -555,7 +646,9 @@ avinsert(				/* insert ambient value in our tree */
 	}
 	avh.next = at->alist;		/* order by increasing level */
 	for (ap = &avh; ap->next != NULL; ap = ap->next)
-		if (ap->next->lvl >= av->lvl)
+		if ( ap->next->lvl > av->lvl ||
+				(ap->next->lvl == av->lvl) &
+				(ap->next->weight <= av->weight) )
 			break;
 	av->next = ap->next;
 	ap->next = (AMBVAL*)av;
@@ -563,308 +656,7 @@ avinsert(				/* insert ambient value in our tree */
 }
 
 
-#else /* ! NEWAMB */
-
-static double	sumambient(COLOR acol, RAY *r, FVECT rn, int al,
-				AMBTREE *at, FVECT c0, double s);
-static double	makeambient(COLOR acol, RAY *r, FVECT rn, int al);
-static void	extambient(COLOR cr, AMBVAL *ap, FVECT pv, FVECT nv);
-
-
-void
-multambient(		/* compute ambient component & multiply by coef. */
-	COLOR  aval,
-	RAY  *r,
-	FVECT  nrm
-)
-{
-	static int  rdepth = 0;			/* ambient recursion */
-	COLOR	acol;
-	double	d, l;
-
-	if (ambdiv <= 0)			/* no ambient calculation */
-		goto dumbamb;
-						/* check number of bounces */
-	if (rdepth >= ambounce)
-		goto dumbamb;
-						/* check ambient list */
-	if (ambincl != -1 && r->ro != NULL &&
-			ambincl != inset(ambset, r->ro->omod))
-		goto dumbamb;
-
-	if (ambacc <= FTINY) {			/* no ambient storage */
-		copycolor(acol, aval);
-		rdepth++;
-		d = doambient(acol, r, r->rweight, NULL, NULL);
-		rdepth--;
-		if (d <= FTINY)
-			goto dumbamb;
-		copycolor(aval, acol);
-		return;
-	}
-
-	if (tracktime)				/* sort to minimize thrashing */
-		sortambvals(0);
-						/* interpolate ambient value */
-	setcolor(acol, 0.0, 0.0, 0.0);
-	d = sumambient(acol, r, nrm, rdepth,
-			&atrunk, thescene.cuorg, thescene.cusize);
-	if (d > FTINY) {
-		d = 1.0/d;
-		scalecolor(acol, d);
-		multcolor(aval, acol);
-		return;
-	}
-	rdepth++;				/* need to cache new value */
-	d = makeambient(acol, r, nrm, rdepth-1);
-	rdepth--;
-	if (d > FTINY) {
-		multcolor(aval, acol);		/* got new value */
-		return;
-	}
-dumbamb:					/* return global value */
-	if ((ambvwt <= 0) | (navsum == 0)) {
-		multcolor(aval, ambval);
-		return;
-	}
-	l = bright(ambval);			/* average in computations */
-	if (l > FTINY) {
-		d = (log(l)*(double)ambvwt + avsum) /
-				(double)(ambvwt + navsum);
-		d = exp(d) / l;
-		scalecolor(aval, d);
-		multcolor(aval, ambval);	/* apply color of ambval */
-	} else {
-		d = exp( avsum / (double)navsum );
-		scalecolor(aval, d);		/* neutral color */
-	}
-}
-
-
-static double
-sumambient(	/* get interpolated ambient value */
-	COLOR  acol,
-	RAY  *r,
-	FVECT  rn,
-	int  al,
-	AMBTREE	 *at,
-	FVECT  c0,
-	double	s
-)
-{
-	double	d, e1, e2, wt, wsum;
-	COLOR  ct;
-	FVECT  ck0;
-	int  i;
-	int  j;
-	AMBVAL	 *av;
-
-	wsum = 0.0;
-					/* do this node */
-	for (av = at->alist; av != NULL; av = av->next) {
-		double	rn_dot = -2.0;
-		if (tracktime)
-			av->latick = ambclock;
-		/*
-		 *  Ambient level test.
-		 */
-		if (av->lvl > al)	/* list sorted, so this works */
-			break;
-		if (av->weight < 0.9*r->rweight)
-			continue;
-		/*
-		 *  Ambient radius test.
-		 */
-		VSUB(ck0, av->pos, r->rop);
-		e1 = DOT(ck0, ck0) / (av->rad * av->rad);
-		if (e1 > ambacc*ambacc*1.21)
-			continue;
-		/*
-		 *  Direction test using closest normal.
-		 */
-		d = DOT(av->dir, r->ron);
-		if (rn != r->ron) {
-			rn_dot = DOT(av->dir, rn);
-			if (rn_dot > 1.0-FTINY)
-				rn_dot = 1.0-FTINY;
-			if (rn_dot >= d-FTINY) {
-				d = rn_dot;
-				rn_dot = -2.0;
-			}
-		}
-		e2 = (1.0 - d) * r->rweight;
-		if (e2 < 0.0)
-			e2 = 0.0;
-		else if (e1 + e2 > ambacc*ambacc*1.21)
-			continue;
-		/*
-		 *  Ray behind test.
-		 */
-		d = 0.0;
-		for (j = 0; j < 3; j++)
-			d += (r->rop[j] - av->pos[j]) *
-					(av->dir[j] + r->ron[j]);
-		if (d*0.5 < -minarad*ambacc-.001)
-			continue;
-		/*
-		 *  Jittering final test reduces image artifacts.
-		 */
-		e1 = sqrt(e1);
-		e2 = sqrt(e2);
-		wt = e1 + e2;
-		if (wt > ambacc*(.9+.2*urand(9015+samplendx)))
-			continue;
-		/*
-		 *  Recompute directional error using perturbed normal
-		 */
-		if (rn_dot > 0.0) {
-			e2 = sqrt((1.0 - rn_dot)*r->rweight);
-			wt = e1 + e2;
-		}
-		if (wt <= 1e-3)
-			wt = 1e3;
-		else
-			wt = 1.0 / wt;
-		wsum += wt;
-		extambient(ct, av, r->rop, rn);
-		scalecolor(ct, wt);
-		addcolor(acol, ct);
-	}
-	if (at->kid == NULL)
-		return(wsum);
-					/* do children */
-	s *= 0.5;
-	for (i = 0; i < 8; i++) {
-		for (j = 0; j < 3; j++) {
-			ck0[j] = c0[j];
-			if (1<<j & i)
-				ck0[j] += s;
-			if (r->rop[j] < ck0[j] - OCTSCALE*s)
-				break;
-			if (r->rop[j] > ck0[j] + (1.0+OCTSCALE)*s)
-				break;
-		}
-		if (j == 3)
-			wsum += sumambient(acol, r, rn, al,
-						at->kid+i, ck0, s);
-	}
-	return(wsum);
-}
-
-
-static double
-makeambient(		/* make a new ambient value for storage */
-	COLOR  acol,
-	RAY  *r,
-	FVECT  rn,
-	int  al
-)
-{
-	AMBVAL	amb;
-	FVECT	gp, gd;
-	int	i;
-
-	amb.weight = 1.0;			/* compute weight */
-	for (i = al; i-- > 0; )
-		amb.weight *= AVGREFL;
-	if (r->rweight < 0.1*amb.weight)	/* heuristic override */
-		amb.weight = 1.25*r->rweight;
-	setcolor(acol, AVGREFL, AVGREFL, AVGREFL);
-						/* compute ambient */
-	amb.rad = doambient(acol, r, amb.weight, gp, gd);
-	if (amb.rad <= FTINY) {
-		setcolor(acol, 0.0, 0.0, 0.0);
-		return(0.0);
-	}
-	scalecolor(acol, 1./AVGREFL);		/* undo assumed reflectance */
-						/* store value */
-	VCOPY(amb.pos, r->rop);
-	VCOPY(amb.dir, r->ron);
-	amb.lvl = al;
-	copycolor(amb.val, acol);
-	VCOPY(amb.gpos, gp);
-	VCOPY(amb.gdir, gd);
-						/* insert into tree */
-	avsave(&amb);				/* and save to file */
-	if (rn != r->ron)
-		extambient(acol, &amb, r->rop, rn);	/* texture */
-	return(amb.rad);
-}
-
-
 static void
-extambient(		/* extrapolate value at pv, nv */
-	COLOR  cr,
-	AMBVAL	 *ap,
-	FVECT  pv,
-	FVECT  nv
-)
-{
-	FVECT  v1;
-	int  i;
-	double	d;
-
-	d = 1.0;			/* zeroeth order */
-					/* gradient due to translation */
-	for (i = 0; i < 3; i++)
-		d += ap->gpos[i]*(pv[i]-ap->pos[i]);
-					/* gradient due to rotation */
-	VCROSS(v1, ap->dir, nv);
-	d += DOT(ap->gdir, v1);
-	if (d <= 0.0) {
-		setcolor(cr, 0.0, 0.0, 0.0);
-		return;
-	}
-	copycolor(cr, ap->val);
-	scalecolor(cr, d);
-}
-
-
-static void
-avinsert(				/* insert ambient value in our tree */
-	AMBVAL *av
-)
-{
-	AMBTREE  *at;
-	AMBVAL  *ap;
-	AMBVAL  avh;
-	FVECT  ck0;
-	double	s;
-	int  branch;
-	int  i;
-
-	if (av->rad <= FTINY)
-		error(CONSISTENCY, "zero ambient radius in avinsert");
-	at = &atrunk;
-	VCOPY(ck0, thescene.cuorg);
-	s = thescene.cusize;
-	while (s*(OCTSCALE/2) > av->rad*ambacc) {
-		if (at->kid == NULL)
-			if ((at->kid = newambtree()) == NULL)
-				error(SYSTEM, "out of memory in avinsert");
-		s *= 0.5;
-		branch = 0;
-		for (i = 0; i < 3; i++)
-			if (av->pos[i] > ck0[i] + s) {
-				ck0[i] += s;
-				branch |= 1 << i;
-			}
-		at = at->kid + branch;
-	}
-	avh.next = at->alist;		/* order by increasing level */
-	for (ap = &avh; ap->next != NULL; ap = ap->next)
-		if (ap->next->lvl >= av->lvl)
-			break;
-	av->next = ap->next;
-	ap->next = (AMBVAL*)av;
-	at->alist = avh.next;
-}
-
-#endif	/* ! NEWAMB */
-
-/************* FOLLOWING ROUTINES SAME FOR NEW & OLD METHODS ***************/
-
-static void
 initambfile(		/* initialize ambient file */
 	int  cre8
 )
@@ -905,7 +697,7 @@ avsave(				/* insert and save an ambient value */
 	AMBVAL	*av
 )
 {
-	avinsert(avstore(av));
+	avstore(av);
 	if (ambfp == NULL)
 		return;
 	if (writambval(av, ambfp) < 0)
@@ -920,7 +712,7 @@ writerr:
 
 
 static AMBVAL *
-avstore(				/* allocate memory and store aval */
+avstore(				/* allocate memory and save aval */
 	AMBVAL  *aval
 )
 {
@@ -938,6 +730,7 @@ avstore(				/* allocate memory and store aval */
 		avsum += log(d);
 		navsum++;
 	}
+	avinsert(av);			/* insert in our cache tree */
 	return(av);
 }
 
@@ -964,7 +757,7 @@ newambtree(void)				/* allocate 8 ambient tree structs
 	}
 	atp = atfreelist;
 	atfreelist = atp->kid;
-	memset((char *)atp, '\0', 8*sizeof(AMBTREE));
+	memset(atp, 0, 8*sizeof(AMBTREE));
 	return(atp);
 }
 
@@ -990,6 +783,7 @@ unloadatree(			/* unload an ambient value tree */
 					/* transfer values at this node */
 	for (av = at->alist; av != NULL; av = at->alist) {
 		at->alist = av->next;
+		av->next = NULL;
 		(*f)(av);
 	}
 	if (at->kid == NULL)
@@ -1067,8 +861,8 @@ avlmemi(				/* find list position from address */
 {
 	AMBVAL  **avlpp;
 
-	avlpp = (AMBVAL **)bsearch((char *)&avaddr, (char *)avlist2,
-			nambvals, sizeof(AMBVAL *), &aposcmp);
+	avlpp = (AMBVAL **)bsearch(&avaddr, avlist2,
+			nambvals, sizeof(AMBVAL *), aposcmp);
 	if (avlpp == NULL)
 		error(CONSISTENCY, "address not found in avlmemi");
 	return(avlpp - avlist2);
@@ -1111,12 +905,12 @@ sortambvals(			/* resort ambient values */
 	}
 	if (avlist1 == NULL) {		/* no time tracking -- rebuild tree? */
 		if (avlist2 != NULL)
-			free((void *)avlist2);
+			free(avlist2);
 		if (always) {		/* rebuild without sorting */
 			oldatrunk = atrunk;
 			atrunk.alist = NULL;
 			atrunk.kid = NULL;
-			unloadatree(&oldatrunk, &avinsert);
+			unloadatree(&oldatrunk, avinsert);
 		}
 	} else {			/* sort memory by last access time */
 		/*
@@ -1133,13 +927,13 @@ sortambvals(			/* resort ambient values */
 		eputs(errmsg);
 #endif
 		i_avlist = 0;
-		unloadatree(&atrunk, &av2list);	/* empty current tree */
+		unloadatree(&atrunk, av2list);	/* empty current tree */
 #ifdef DEBUG
 		if (i_avlist < nambvals)
 			error(CONSISTENCY, "missing ambient values in sortambvals");
 #endif
-		qsort((char *)avlist1, nambvals, sizeof(struct avl), &alatcmp);
-		qsort((char *)avlist2, nambvals, sizeof(AMBVAL *), &aposcmp);
+		qsort(avlist1, nambvals, sizeof(struct avl), alatcmp);
+		qsort(avlist2, nambvals, sizeof(AMBVAL *), aposcmp);
 		for (i = 0; i < nambvals; i++) {
 			if (avlist1[i].p == NULL)
 				continue;
@@ -1155,8 +949,8 @@ sortambvals(			/* resort ambient values */
 			avinsert(avlist2[j]);
 			avlist1[j].p = NULL;
 		}
-		free((void *)avlist1);
-		free((void *)avlist2);
+		free(avlist1);
+		free(avlist2);
 						/* compute new sort interval */
 		sortintvl = ambclock - lastsort;
 		if (sortintvl >= MAX_SORT_INTVL/2)
@@ -1184,9 +978,14 @@ aflock(			/* lock/unlock ambient file */
 
 	if (typ == fls.l_type)		/* already called? */
 		return;
+
 	fls.l_type = typ;
-	if (fcntl(fileno(ambfp), F_SETLKW, &fls) < 0)
-		error(SYSTEM, "cannot (un)lock ambient file");
+	do
+		if (fcntl(fileno(ambfp), F_SETLKW, &fls) != -1)
+			return;
+	while (errno == EINTR);
+	
+	error(SYSTEM, "cannot (un)lock ambient file");
 }
 
 
@@ -1205,10 +1004,10 @@ ambsync(void)			/* synchronize ambient file */
 	if ((flen = lseek(fileno(ambfp), (off_t)0, SEEK_END)) < 0)
 		goto seekerr;
 	if ((n = flen - lastpos) > 0) {		/* file has grown */
-		if (ambinp == NULL) {		/* use duplicate filedes */
-			ambinp = fdopen(dup(fileno(ambfp)), "r");
+		if (ambinp == NULL) {		/* get new file pointer */
+			ambinp = fopen(ambfile, "rb");
 			if (ambinp == NULL)
-				error(SYSTEM, "fdopen failed in ambsync");
+				error(SYSTEM, "fopen failed in ambsync");
 		}
 		if (fseek(ambinp, lastpos, SEEK_SET) < 0)
 			goto seekerr;
@@ -1220,27 +1019,21 @@ ambsync(void)			/* synchronize ambient file */
 				error(WARNING, errmsg);
 				break;
 			}
-			avinsert(avstore(&avs));
+			avstore(&avs);
 			n -= AMBVALSIZ;
 		}
-		lastpos = flen - n;
-		/*** seek always as safety measure
-		if (n) ***/			/* alignment */
-			if (lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
-				goto seekerr;
+		lastpos = flen - n;		/* check alignment */
+		if (n && lseek(fileno(ambfp), (off_t)lastpos, SEEK_SET) < 0)
+			goto seekerr;
 	}
 	n = fflush(ambfp);			/* calls write() at last */
-	if (n != EOF)
-		lastpos += (long)nunflshed*AMBVALSIZ;
-	else if ((lastpos = lseek(fileno(ambfp), (off_t)0, SEEK_CUR)) < 0)
-		goto seekerr;
-		
+	lastpos += (long)nunflshed*AMBVALSIZ;
 	aflock(F_UNLCK);			/* release file */
 	nunflshed = 0;
 	return(n);
 seekerr:
 	error(SYSTEM, "seek failed in ambsync");
-	return -1; /* pro forma return */
+	return(EOF);	/* pro forma return */
 }
 
 #else	/* ! F_SETLKW */