--- ray/src/common/bsdf_t.c	2015/04/06 16:00:15	3.39
+++ ray/src/common/bsdf_t.c	2018/04/17 18:11:16	3.46
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdf_t.c,v 3.39 2015/04/06 16:00:15 greg Exp $";
+static const char RCSid[] = "$Id: bsdf_t.c,v 3.46 2018/04/17 18:11:16 greg Exp $";
 #endif
 /*
  *  bsdf_t.c
@@ -569,12 +569,12 @@ SDqueryTre(const SDTre *sdt, float *coef,
 		return 0;		/* should be internal error */
 					/* get BSDF value */
 	yval = SDlookupTre(sdt->stc[tt_Y], gridPos, hc);
+	if (coef == NULL)		/* just getting hypercube? */
+		return 1;
 	if (sdt->stc[tt_u] == NULL || sdt->stc[tt_v] == NULL) {
-		if (coef != NULL) *coef = yval;
+		*coef = yval;
 		return 1;		/* no color */
 	}
-	if (coef == NULL)		/* just getting hypercube? */
-		return 1;
 					/* else decode color */
 	SDyuv2rgb(yval, SDlookupTre(sdt->stc[tt_u], gridPos, NULL),
 			SDlookupTre(sdt->stc[tt_v], gridPos, NULL), coef);
@@ -789,6 +789,7 @@ SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
 	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 */
+	/* PLACE MUTEX LOCK HERE FOR THREAD-SAFE */
 	for (cd = (SDTreCDst *)sdc->cdList; cd != NULL;
 					cdlast = cd, cd = cd->next) {
 		if (cd->sidef != mode)
@@ -807,6 +808,7 @@ SDgetTreCDist(const FVECT inVec, SDComponent *sdc)
 		cd->next = (SDTreCDst *)sdc->cdList;
 		sdc->cdList = (SDCDst *)cd;
 	}
+	/* END MUTEX LOCK */
 	return (SDCDst *)cd;		/* ready to go */
 }
 
@@ -924,7 +926,7 @@ next_token(char **spp)
 }
 
 /* Advance pointer past matching token (or any token if c==0) */
-#define eat_token(spp,c)	(next_token(spp)==(c) ^ !(c) ? *(*(spp))++ : 0)
+#define eat_token(spp,c)	((next_token(spp)==(c)) ^ !(c) ? *(*(spp))++ : 0)
 
 /* Count words from this point in string to '}' */
 static int
@@ -1174,11 +1176,12 @@ SDsubtractTreVal(SDNode *st, float val)
 static double
 subtract_min_Y(SDNode *st)
 {
-	float	vmin;
+	const float	vmaxmin = 1.5/M_PI;
+	float		vmin;
 					/* be sure to skip unused portion */
 	if (st->ndim == 3) {
 		int	n;
-		vmin = 1./M_PI;
+		vmin = vmaxmin;
 		if (st->log2GR < 0) {
 			for (n = 0; n < 8; n += 2) {
 				float	v = SDgetTreMin(st->u.t[n]);
@@ -1194,7 +1197,7 @@ subtract_min_Y(SDNode *st)
 	} else				/* anisotropic covers entire tree */
 		vmin = SDgetTreMin(st);
 
-	if (vmin <= .01/M_PI)
+	if ((vmin >= vmaxmin) | (vmin <= .01/M_PI))
 		return .0;		/* not worth bothering about */
 
 	SDsubtractTreVal(st, vmin);
@@ -1314,24 +1317,20 @@ subtract_min_RGB(C_COLOR *cs, SDNode *stc[])
 	my_min.new_stu = my_min.new_stv = NULL;
 					/* get minimum RGB value */
 	SDtraverseTre(stc[tt_Y], NULL, 0, get_min_RGB, &my_min);
-	ymin = tt_RGB_coef[0]*my_min.rgb[0] +
-			tt_RGB_coef[1]*my_min.rgb[1] +
-					tt_RGB_coef[2]*my_min.rgb[2];
-	if (ymin <= .01/M_PI) {
-		*cs = c_dfcolor;
-		return .0;		/* not worth bothering about */
-	}
-					/* adjust u' & v' values */
+					/* convert to C_COLOR */
+	ymin = 	c_fromSharpRGB(my_min.rgb, cs);
+	if ((ymin >= .5*FHUGE) | (ymin <= .01/M_PI))
+		return .0;		/* close to zero or no tree */
+					/* adjust u' & v' trees */
 	SDtraverseTre(stc[tt_u], NULL, 0, adjust_utree, &my_min);
 	SDtraverseTre(stc[tt_v], NULL, 0, adjust_vtree, &my_min);
 	SDfreeTre(stc[tt_u]); SDfreeTre(stc[tt_v]);
 	stc[tt_u] = SDsimplifyTre(my_min.new_stu);
 	stc[tt_v] = SDsimplifyTre(my_min.new_stv);
-					/* finally, subtract Y value */
+					/* subtract Y & return hemispherical */
 	SDsubtractTreVal(stc[tt_Y], ymin);
-					/* return color and Y */
-	c_fromSharpRGB(my_min.rgb, cs);
-	return M_PI*ymin;
+
+	return M_PI * ymin;
 }
 
 /* Extract and separate diffuse portion of BSDF */
@@ -1358,7 +1357,7 @@ extract_diffuse(SDValue *dv, SDSpectralDF *df)
 		memcpy(df->comp[0].cspec, tt_RGB_prim, sizeof(tt_RGB_prim));
 		dv->cieY = subtract_min_RGB(&dv->spec, sdt->stc);
 	} else {
-		df->comp[0].cspec[0] = c_dfcolor;
+		df->comp[0].cspec[0] = dv->spec = c_dfcolor;
 		dv->cieY = subtract_min_Y(sdt->stc[tt_Y]);
 	}
 	df->maxHemi -= dv->cieY;	/* adjust maximum hemispherical */
@@ -1423,7 +1422,7 @@ SDloadTre(SDData *sd, ezxml_t wtl)
 }
 
 /* Variable resolution BSDF methods */
-SDFunc SDhandleTre = {
+const SDFunc SDhandleTre = {
 	&SDgetTreBSDF,
 	&SDqueryTreProjSA,
 	&SDgetTreCDist,