--- ray/src/common/bsdf_t.c	2018/04/17 18:11:16	3.46
+++ ray/src/common/bsdf_t.c	2021/12/15 01:38:50	3.53
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdf_t.c,v 3.46 2018/04/17 18:11:16 greg Exp $";
+static const char RCSid[] = "$Id: bsdf_t.c,v 3.53 2021/12/15 01:38:50 greg Exp $";
 #endif
 /*
  *  bsdf_t.c
@@ -518,12 +518,12 @@ SDyuv2rgb(double yval, double uprime, double vprime, f
 /* Query BSDF value and sample hypercube for the given vectors */
 static int
 SDqueryTre(const SDTre *sdt, float *coef,
-		const FVECT outVec, const FVECT inVec, double *hc)
+		const FVECT inVec, const FVECT outVec, double *hc)
 {
 	const RREAL	*vtmp;
 	float		yval;
 	FVECT		rOutVec;
-	double		gridPos[4];
+	RREAL		gridPos[4];
 
 	if (sdt->stc[tt_Y] == NULL)	/* paranoia, I hope */
 		return 0;
@@ -561,10 +561,10 @@ SDqueryTre(const SDTre *sdt, float *coef,
 		spinvector(rOutVec, outVec, zvec, -atan2(-inVec[1],-inVec[0]));
 		gridPos[0] = (.5-FTINY) -
 				.5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
-		SDdisk2square(gridPos+1, rOutVec[0], rOutVec[1]);
+		disk2square(gridPos+1, rOutVec[0], rOutVec[1]);
 	} else if (sdt->stc[tt_Y]->ndim == 4) {
-		SDdisk2square(gridPos, -inVec[0], -inVec[1]);
-		SDdisk2square(gridPos+2, outVec[0], outVec[1]);
+		disk2square(gridPos, -inVec[0], -inVec[1]);
+		disk2square(gridPos+2, outVec[0], outVec[1]);
 	} else
 		return 0;		/* should be internal error */
 					/* get BSDF value */
@@ -744,11 +744,12 @@ make_cdist(const SDTre *sdt, const double *invec, int 
 const SDCDst *
 SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
 {
+	unsigned long	cacheLeft = SDmaxCache;
 	const SDTre	*sdt;
-	double		inCoord[2];
+	RREAL		inCoord[2];
 	int		i;
 	int		mode;
-	SDTreCDst	*cd, *cdlast;
+	SDTreCDst	*cd, *cdlast, *cdlimit;
 					/* check arguments */
 	if ((inVec == NULL) | (sdc == NULL) ||
 			(sdt = (SDTre *)sdc->dist) == NULL)
@@ -780,18 +781,28 @@ SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
 				.5*sqrt(inVec[0]*inVec[0] + inVec[1]*inVec[1]);
 	} else if (sdt->stc[tt_Y]->ndim == 4) {
 		if (mode != sdt->sidef)	/* use reciprocity? */
-			SDdisk2square(inCoord, inVec[0], inVec[1]);
+			disk2square(inCoord, inVec[0], inVec[1]);
 		else
-			SDdisk2square(inCoord, -inVec[0], -inVec[1]);
+			disk2square(inCoord, -inVec[0], -inVec[1]);
 	} else
 		return NULL;		/* should be internal error */
 					/* quantize to avoid f.p. errors */
 	for (i = sdt->stc[tt_Y]->ndim - 2; i--; )
 		inCoord[i] = floor(inCoord[i]/quantum)*quantum + .5*quantum;
-	cdlast = NULL;			/* check for direction in cache list */
+	cdlast = cdlimit = NULL;	/* check for direction in cache list */
 	/* PLACE MUTEX LOCK HERE FOR THREAD-SAFE */
 	for (cd = (SDTreCDst *)sdc->cdList; cd != NULL;
 					cdlast = cd, cd = cd->next) {
+		if (cacheLeft) {	/* check cache size limit */
+			long	csiz = sizeof(SDTreCDst) +
+					sizeof(cd->carr[0])*cd->calen;
+			if (cacheLeft > csiz)
+				cacheLeft -= csiz;
+			else {
+				cdlimit = cdlast;
+				cacheLeft = 0;
+			}
+		}
 		if (cd->sidef != mode)
 			continue;
 		for (i = sdt->stc[tt_Y]->ndim - 2; i--; )
@@ -801,8 +812,14 @@ SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
 		if (i < 0)
 			break;		/* means we have a match */
 	}
-	if (cd == NULL)			/* need to create new entry? */
+	if (cd == NULL) {		/* need to create new entry? */
+		if (cdlimit != NULL)	/* exceeded cache size limit? */
+			while ((cd = cdlimit->next) != NULL) {
+				cdlimit->next = cd->next;
+				free(cd);
+			}
 		cdlast = cd = make_cdist(sdt, inCoord, mode != sdt->sidef);
+	}
 	if (cdlast != NULL) {		/* move entry to head of cache list */
 		cdlast->next = cd->next;
 		cd->next = (SDTreCDst *)sdc->cdList;
@@ -871,7 +888,8 @@ SDsampTreCDist(FVECT ioVec, double randX, const SDCDst
 	const SDTreCDst	*cd = (const SDTreCDst *)cdp;
 	const unsigned	target = randX*cumlmax;
 	bitmask_t	hndx, hcoord[2];
-	double		gpos[3], rotangle;
+	FVECT		gpos;
+	double		rotangle;
 	int		i, iupper, ilower;
 					/* check arguments */
 	if ((ioVec == NULL) | (cd == NULL))
@@ -901,7 +919,7 @@ SDsampTreCDist(FVECT ioVec, double randX, const SDCDst
 	for (i = 2; i--; )
 		gpos[i] = ((double)hcoord[i] + rand()*(1./(RAND_MAX+.5))) /
 				(double)((bitmask_t)1 << nBitsC);
-	SDsquare2disk(gpos, gpos[0], gpos[1]);
+	square2disk(gpos, gpos[0], gpos[1]);
 					/* compute Z-coordinate */
 	gpos[2] = 1. - gpos[0]*gpos[0] - gpos[1]*gpos[1];
 	gpos[2] = sqrt(gpos[2]*(gpos[2]>0));
@@ -1361,8 +1379,8 @@ extract_diffuse(SDValue *dv, SDSpectralDF *df)
 		dv->cieY = subtract_min_Y(sdt->stc[tt_Y]);
 	}
 	df->maxHemi -= dv->cieY;	/* adjust maximum hemispherical */
-					/* make sure everything is set */
-	c_ccvt(&dv->spec, C_CSXY+C_CSSPEC);
+				
+	c_ccvt(&dv->spec, C_CSXY);	/* make sure (x,y) is set */
 }
 
 /* Load a variable-resolution BSDF tree from an open XML file */
@@ -1413,10 +1431,13 @@ SDloadTre(SDData *sd, ezxml_t wtl)
 					/* separate diffuse components */
 	extract_diffuse(&sd->rLambFront, sd->rf);
 	extract_diffuse(&sd->rLambBack, sd->rb);
-	if (sd->tf != NULL)
-		extract_diffuse(&sd->tLamb, sd->tf);
-	if (sd->tb != NULL)
-		extract_diffuse(&sd->tLamb, sd->tb);
+	extract_diffuse(&sd->tLambFront, sd->tf);
+	if (sd->tb != NULL) {
+		extract_diffuse(&sd->tLambBack, sd->tb);
+		if (sd->tf == NULL)
+			sd->tLambFront = sd->tLambBack;
+	} else if (sd->tf != NULL)
+		sd->tLambBack = sd->tLambFront;
 					/* return success */
 	return SDEnone;
 }