--- ray/src/rt/mx_data.c	1998/08/10 18:35:14	2.4
+++ ray/src/rt/mx_data.c	1999/01/20 14:10:06	2.5
@@ -17,19 +17,29 @@ static char SCCSid[] = "$SunId$ SGI";
 #include  "func.h"
 
 /*
- *	A stored mixture is specified:
+ *  A stored mixture is specified:
  *
  *	modifier mixdata name
  *	6+ foremod backmod func dfname vfname v0 v1 .. xf
  *	0
  *	n A1 A2 ..
  *
+ *  A picture mixture is specified as:
+ *
+ *	modifier mixpict name
+ *	7+ foremod backmod func pfname vfname vx vy xf
+ *	0
+ *	n A1 A2 ..
+ *
+ *
  *  Vfname is the name of the file where the variable definitions
  *  can be found.  The list of real arguments can be accessed by
  *  definitions in the file.  Dfname is the data file.
+ *  (Pfname is a picture file.)
  *  The dimensions of the data files and the number
  *  of variables must match.  The func is a single argument
- *  function which returns the corrected data value given the
+ *  function in the case of mixdata (three argument in the case
+ *  of mixpict), which returns the corrected data value given the
  *  interpolated value from the file.  The xf is a transformation
  *  to get from the original coordinates to the current coordinates.
  */
@@ -71,6 +81,55 @@ RAY  *r;
 	coef = datavalue(dp, pt);
 	errno = 0;
 	coef = funvalue(m->oargs.sarg[2], 1, &coef);
+	if (errno)
+		goto computerr;
+	if (raymixture(r, mod[0], mod[1], coef)) {
+		if (m->omod != OVOID)
+			objerror(m, USER, "inappropriate modifier");
+		return(1);
+	}
+	return(0);
+computerr:
+	objerror(m, WARNING, "compute error");
+	return(0);
+}
+
+
+mx_pdata(m, r)			/* interpolate mixture picture */
+register OBJREC  *m;
+RAY  *r;
+{
+	OBJECT	obj;
+	double	col[3], coef;
+	double  pt[MAXDIM];
+	DATARRAY  *dp;
+	OBJECT  mod[2];
+	register MFUNC  *mf;
+	register int  i;
+
+	if (m->oargs.nsargs < 7)
+		objerror(m, USER, "bad # arguments");
+	obj = objndx(m);
+	for (i = 0; i < 2; i++)
+		if (!strcmp(m->oargs.sarg[i], VOIDID))
+			mod[i] = OVOID;
+		else if ((mod[i] = lastmod(obj, m->oargs.sarg[i])) == OVOID) {
+			sprintf(errmsg, "undefined modifier \"%s\"",
+					m->oargs.sarg[i]);
+			objerror(m, USER, errmsg);
+		}
+	dp = getpict(m->oargs.sarg[3]);
+	mf = getfunc(m, 4, 0x3<<5, 0);
+	setfunc(m, r);
+	errno = 0;
+	pt[1] = evalue(mf->ep[0]);	/* y major ordering */
+	pt[0] = evalue(mf->ep[1]);
+	if (errno)
+		goto computerr;
+	for (i = 0; i < 3; i++)		/* get pixel from picture */
+		col[i] = datavalue(dp+i, pt);
+	errno = 0;			/* evaluate function on pixel */
+	coef = funvalue(m->oargs.sarg[2], 3, col);
 	if (errno)
 		goto computerr;
 	if (raymixture(r, mod[0], mod[1], coef)) {