--- ray/src/rt/rv2.c	2008/08/21 07:05:59	2.55
+++ ray/src/rt/rv2.c	2009/01/14 20:27:00	2.59
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: rv2.c,v 2.55 2008/08/21 07:05:59 greg Exp $";
+static const char	RCSid[] = "$Id: rv2.c,v 2.59 2009/01/14 20:27:00 greg Exp $";
 #endif
 /*
  *  rv2.c - command routines used in tracing a view.
@@ -427,6 +427,7 @@ getexposure(				/* get new exposure */
 			e *= atof(cp);
 	}
 	if (p != NULL) {		/* relative setting */
+		compavg(p);
 		if (bright(p->v) < 1e-15) {
 			error(COMMAND, "cannot normalize to zero");
 			return;
@@ -444,6 +445,7 @@ getexposure(				/* get new exposure */
 }
 
 typedef union {int i; double d; COLOR C;}	*MyUptr;
+#define  FEQ(x,y)     (fabs((x)-(y)) <= FTINY)
 
 int
 getparam(		/* get variable from user */
@@ -468,6 +470,8 @@ getparam(		/* get variable from user */
 			if (sscanf(buf, "%d", &i0) != 1)
 				return(0);
 		}
+		if (ptr->i == i0)
+			return(0);
 		ptr->i = i0;
 		break;
 	case 'r':			/* real */
@@ -479,6 +483,8 @@ getparam(		/* get variable from user */
 			if (sscanf(buf, "%lf", &d0) != 1)
 				return(0);
 		}
+		if (FEQ(ptr->d, d0))
+			return(0);
 		ptr->d = d0;
 		break;
 	case 'b':			/* boolean */
@@ -487,11 +493,15 @@ getparam(		/* get variable from user */
 			sprintf(buf, "? (%c): ", ptr->i ? 'y' : 'n');
 			(*dev->comout)(buf);
 			(*dev->comin)(buf, NULL);
-			if (buf[0] == '\0' ||
-					strchr("yY+1tTnN-0fF", buf[0]) == NULL)
+			if (buf[0] == '\0')
 				return(0);
 		}
-		ptr->i = strchr("yY+1tT", buf[0]) != NULL;
+		if (strchr("yY+1tTnN-0fF", buf[0]) == NULL)
+			return(0);
+		i0 = strchr("yY+1tT", buf[0]) != NULL;
+		if (ptr->i == i0)
+			return(0);
+		ptr->i = i0;
 		break;
 	case 'C':			/* color */
 		if (sscanf(str, "%lf %lf %lf", &d0, &d1, &d2) != 3) {
@@ -505,6 +515,10 @@ getparam(		/* get variable from user */
 			if (sscanf(buf, "%lf %lf %lf", &d0, &d1, &d2) != 3)
 				return(0);
 		}
+		if (FEQ(colval(ptr->C,RED), d0) &&
+				FEQ(colval(ptr->C,GRN), d1) &&
+				FEQ(colval(ptr->C,BLU), d2))
+			return(0);
 		setcolor(ptr->C, d0, d1, d2);
 		break;
 	default:
@@ -520,6 +534,7 @@ setparam(				/* get/set program parameter */
 	char  *s
 )
 {
+	int  prev_newp = newparam;
 	char  buf[128];
 	
 	if (s[0] == '\0') {
@@ -585,6 +600,7 @@ setparam(				/* get/set program parameter */
 		case 'n': case 'N': case 'f': case 'F': case '0': case '-':
 			getparam(s+1, "black and white", 'b',
 					(void *)&greyscale);
+			newparam = prev_newp;
 			break;
 		default:
 			goto badparam;
@@ -667,6 +683,7 @@ setparam(				/* get/set program parameter */
 		default:
 			goto badparam;
 		}
+		newparam = prev_newp;
 		break;
 	case 's':			/* specular */
 		switch (s[1]) {
@@ -726,9 +743,7 @@ traceray(				/* trace a single ray */
 		return;
 	}
 
-	rayorigin(&thisray, PRIMARY, NULL, NULL);
-	
-	rayvalue(&thisray);
+	ray_trace(&thisray);
 
 	if (thisray.ro == NULL)
 		(*dev->comout)("ray hit nothing");