--- ray/src/util/rmatrix.h	2019/09/03 23:43:07	2.11
+++ ray/src/util/rmatrix.h	2021/01/19 23:32:00	2.13
@@ -1,4 +1,4 @@
-/* RCSid $Id: rmatrix.h,v 2.11 2019/09/03 23:43:07 greg Exp $ */
+/* RCSid $Id: rmatrix.h,v 2.13 2021/01/19 23:32:00 greg Exp $ */
 /*
  * Header file for general matrix routines.
  */
@@ -12,6 +12,10 @@
 extern "C" {
 #endif
 
+/* Preferred BSDF component:
+	transmission, reflection front (normal side), reflection back */
+typedef enum {RMPtrans=0, RMPreflF, RMPreflB} RMPref;
+
 /* General plane-ordered component matrix */
 typedef struct {
 	int	nrows, ncols;
@@ -19,7 +23,7 @@ typedef struct {
 	uby8	dtype;
 	uby8	swapin;
 	char	*info;
-	double	mtx[1];			/* extends struct */
+	double	mtx[3];			/* extends struct */
 } RMATRIX;
 
 #define rmx_lval(rm,r,c,i)	(rm)->mtx[(i)+(rm)->ncomp*((c)+(size_t)(rm)->ncols*(r))]
@@ -34,7 +38,7 @@ extern void	rmx_free(RMATRIX *rm);
 extern int	rmx_newtype(int dtyp1, int dtyp2);
 
 /* Load matrix from supported file type (NULL for stdin, '!' with command) */
-extern RMATRIX	*rmx_load(const char *inspec);
+extern RMATRIX	*rmx_load(const char *inspec, RMPref rmp);
 
 /* Append header information associated with matrix data */
 extern int	rmx_addinfo(RMATRIX *rm, const char *info);