--- ray/src/hd/rhd_glx.c	1998/01/01 14:48:46	3.11
+++ ray/src/hd/rhd_glx.c	1998/01/06 05:26:19	3.14
@@ -195,6 +195,14 @@ dev_close()			/* close our display and free resources 
 }
 
 
+dev_clear()			/* clear our quadtree */
+{
+	qtCompost(100);
+	glClear(GL_DEPTH_BUFFER_BIT);
+	rayqleft = 0;			/* hold off update */
+}
+
+
 int
 dev_view(nv)			/* assign new driver view */
 register VIEW	*nv;
@@ -278,6 +286,9 @@ double	rad;
 {
 	register int	ci, j;
 	double	apexh, basez;
+					/* is window mapped? */
+	if (!mapped)
+		return;
 					/* compute apex height (0. to 1.) */
 	if (ip[2] > 1e6)
 		apexh = 1. - 1./DEPTHFACT;
@@ -591,6 +602,7 @@ register XKeyPressedEvent  *ekey;
 		glFlush();
 		qtCompost(100);			/* get rid of old values */
 		inpresflags |= DFL(DC_REDRAW);	/* resend values from server */
+		rayqleft = 0;			/* hold off update */
 		return;
 	case 'K':			/* kill rtrace process(es) */
 		inpresflags |= DFL(DC_KILL);