--- ray/src/common/bsdf_m.c	2015/08/23 00:56:00	3.34
+++ ray/src/common/bsdf_m.c	2021/03/27 20:08:30	3.42
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bsdf_m.c,v 3.34 2015/08/23 00:56:00 greg Exp $";
+static const char RCSid[] = "$Id: bsdf_m.c,v 3.42 2021/03/27 20:08:30 greg Exp $";
 #endif
 /*
  *  bsdf_m.c
@@ -191,6 +191,7 @@ fo_getndx(const FVECT v, void *p)
 double
 io_getohm(int ndx, void *p)
 {
+	static void	*last_p = NULL;
 	static int	last_li = -1;
 	static double	last_ohm;
 	ANGLE_BASIS	*ab = (ANGLE_BASIS *)p;
@@ -201,8 +202,9 @@ io_getohm(int ndx, void *p)
 		return -1.;
 	for (li = 0; ndx >= ab->lat[li].nphis; li++)
 		ndx -= ab->lat[li].nphis;
-	if (li == last_li)			/* cached latitude? */
+	if ((p == last_p) & (li == last_li))		/* cached latitude? */
 		return last_ohm;
+	last_p = p;
 	last_li = li;
 	theta = M_PI/180. * ab->lat[li].tmin;
 	theta1 = M_PI/180. * ab->lat[li+1].tmin;
@@ -294,11 +296,11 @@ mBSDF_color(float coef[], const SDMat *dp, int i, int 
 {
 	C_COLOR	cxy;
 
-	coef[0] = mBSDF_value(dp, i, o);
+	coef[0] = mBSDF_value(dp, o, i);
 	if (dp->chroma == NULL)
 		return 1;	/* grayscale */
 
-	c_decodeChroma(&cxy, dp->chroma[o*dp->ninc + i]);
+	c_decodeChroma(&cxy, mBSDF_chroma(dp,o,i));
 	c_toSharpRGB(&cxy, coef[0], coef);
 	coef[0] *= mtx_RGB_coef[0];
 	coef[1] *= mtx_RGB_coef[1];
@@ -381,7 +383,7 @@ get_extrema(SDSpectralDF *df)
 	for (i = dp->ninc; i--; ) {
 		double	hemi = .0;
 		for (o = dp->nout; o--; )
-			hemi += ohma[o] * mBSDF_value(dp, i, o);
+			hemi += ohma[o] * mBSDF_value(dp, o, i);
 		if (hemi > df->maxHemi)
 			df->maxHemi = hemi;
 	}
@@ -517,7 +519,7 @@ load_bsdf_data(SDData *sd, ezxml_t wdb, int ct, int ro
 		if (rowinc) {
 			int	r = i/dp->nout;
 			int	c = i - r*dp->nout;
-			mBSDF_value(dp,r,c) = val;
+			mBSDF_value(dp,c,r) = val;
 		} else
 			dp->bsdf[i] = val;
 		sdata = sdnext;
@@ -622,8 +624,8 @@ subtract_min(C_COLOR *cs, SDMat *sm)
 				coef[c] = (coef[c] - min_coef[c]) /
 						mtx_RGB_coef[c];
 			if (c_fromSharpRGB(coef, &cxy) > 1e-5)
-				sm->chroma[o*sm->ninc + i] = c_encodeChroma(&cxy);
-			mBSDF_value(sm,i,o) -= ymin;
+				mBSDF_chroma(sm,o,i) = c_encodeChroma(&cxy);
+			mBSDF_value(sm,o,i) -= ymin;
 		}
 					/* return colored minimum */
 	for (i = 3; i--; )
@@ -647,8 +649,8 @@ extract_diffuse(SDValue *dv, SDSpectralDF *df)
 					/* subtract minimum value */
 	dv->cieY = subtract_min(&dv->spec, (SDMat *)df->comp[0].dist);
 	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 */
 	return df;
 }
 
@@ -707,10 +709,13 @@ SDloadMtx(SDData *sd, ezxml_t wtl)
 					/* separate diffuse components */
 	sd->rf = extract_diffuse(&sd->rLambFront, sd->rf);
 	sd->rb = extract_diffuse(&sd->rLambBack, sd->rb);
-	if (sd->tf != NULL)
-		sd->tf = extract_diffuse(&sd->tLamb, sd->tf);
-	if (sd->tb != NULL)
-		sd->tb = extract_diffuse(&sd->tLamb, sd->tb);
+	sd->tf = extract_diffuse(&sd->tLambFront, sd->tf);
+	if (sd->tb != NULL) {
+		sd->tb = 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;
 }
@@ -803,10 +808,10 @@ make_cdist(SDMatCDst *cd, const FVECT inVec, SDMat *dp
 	cmtab[0] = .0;
 	for (o = 0; o < cd->calen; o++) {
 		if (rev)
-			cmtab[o+1] = mBSDF_value(dp, o, cd->indx) *
+			cmtab[o+1] = mBSDF_value(dp, cd->indx, o) *
 					(*dp->ib_ohm)(o, dp->ib_priv);
 		else
-			cmtab[o+1] = mBSDF_value(dp, cd->indx, o) *
+			cmtab[o+1] = mBSDF_value(dp, o, cd->indx) *
 					(*dp->ob_ohm)(o, dp->ob_priv);
 		cmtab[o+1] += cmtab[o];
 	}
@@ -906,7 +911,7 @@ SDsampMtxCDist(FVECT ioVec, double randX, const SDCDst
 }
 
 /* Fixed resolution BSDF methods */
-SDFunc			SDhandleMtx = {
+const SDFunc		SDhandleMtx = {
 				&SDgetMtxBSDF,
 				&SDqueryMtxProjSA,
 				&SDgetMtxCDist,