--- ray/src/rt/devcomm.c	1990/01/30 11:37:36	1.11
+++ ray/src/rt/devcomm.c	1990/03/06 17:44:37	1.15
@@ -12,8 +12,6 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include "standard.h"
 
-#include <signal.h>
-
 #include "color.h"
 
 #include "driver.h"
@@ -22,24 +20,24 @@ static char SCCSid[] = "$SunId$ LBL";
 #define DEVPATH		getenv("PATH")	/* device search path */
 #endif
 
+#ifndef DELAY
+#define DELAY		20		/* seconds to wait for response */
+#endif
+
 #ifndef BSD
 #define vfork		fork
 #endif
 
-#ifndef WFLUSH
-#define WFLUSH		30		/* flush after this many rays */
-#endif
-
 extern char	*getpath(), *getenv();
 
 int	onsigio();
 
 int	comm_close(), comm_clear(), comm_paintr(), comm_errout(),
-		comm_getcur(), comm_comout(), comm_comin();
+		comm_getcur(), comm_comout(), comm_comin(), comm_flush();
 
-struct driver	comm_driver, comm_default = {
+struct driver	comm_driver = {
 	comm_close, comm_clear, comm_paintr, comm_getcur,
-	comm_comout, comm_comin
+	comm_comout, comm_comin, comm_flush
 };
 
 FILE	*devin, *devout;
@@ -80,18 +78,13 @@ char	*dname, *id;
 		goto syserr;
 	if ((devin = fdopen(p2[0], "r")) == NULL)
 		goto syserr;
-	copystruct(&comm_driver, &comm_default);
-						/* verify & get resolution */
+						/* verify initialization */
 	putw(COM_SENDM, devout);
 	fflush(devout);
 	if (getw(devin) != COM_RECVM)
 		return(NULL);
-	fread((char *)&comm_driver.pixaspect,
-			sizeof(comm_driver.pixaspect), 1, devin);
-	comm_driver.xsiz = getw(devin);
-	comm_driver.ysiz = getw(devin);
-						/* input handling */
-	signal(SIGIO, onsigio);
+						/* get driver parameters */
+	comm_flush();
 						/* set error vectors */
 	cmdvec = comm_comout;
 	if (wrnvec != NULL)
@@ -111,7 +104,6 @@ comm_close()			/* done with driver */
 	cmdvec = NULL;				/* reset error vectors */
 	if (wrnvec != NULL)
 		wrnvec = stderr_v;
-	signal(SIGIO, SIG_DFL);
 	fclose(devout);
 	fclose(devin);
 	while ((pid = wait(0)) != -1 && pid != devchild)
@@ -135,22 +127,30 @@ comm_paintr(col, xmin, ymin, xmax, ymax)	/* paint a re
 COLOR	col;
 int	xmin, ymin, xmax, ymax;
 {
-	extern long	nrays;		/* number of rays traced */
-	static long	lastflush = 0;	/* ray count at last flush */
-
 	putc(COM_PAINTR, devout);
 	fwrite((char *)col, sizeof(COLOR), 1, devout);
 	putw(xmin, devout);
 	putw(ymin, devout);
 	putw(xmax, devout);
 	putw(ymax, devout);
-	if (nrays - lastflush >= WFLUSH) {
-		fflush(devout);
-		lastflush = nrays;
-	}
 }
 
 
+static
+comm_flush()				/* flush output to driver */
+{
+	putc(COM_FLUSH, devout);
+	fflush(devout);
+	if (getc(devin) != COM_FLUSH)
+		reply_error("flush");
+	fread((char *)&comm_driver.pixaspect,
+			sizeof(comm_driver.pixaspect), 1, devin);
+	comm_driver.xsiz = getw(devin);
+	comm_driver.ysiz = getw(devin);
+	comm_driver.inpready = getw(devin);
+}
+
+
 static int
 comm_getcur(xp, yp)			/* get and return cursor position */
 int	*xp, *yp;
@@ -174,7 +174,6 @@ char	*str;
 {
 	putc(COM_COMOUT, devout);
 	myputs(str, devout);
-	fflush(devout);
 }
 
 
@@ -194,8 +193,7 @@ char	*prompt;
 	if (getc(devin) != COM_COMIN)
 		reply_error("comin");
 	mygets(buf, devin);
-	if (comm_driver.inpready > 0)
-		comm_driver.inpready--;
+	comm_driver.inpready = getw(devin);
 }
 
 
@@ -240,11 +238,4 @@ char	*routine;
 	stderr_v(routine);
 	stderr_v(": driver reply error\n");
 	quit(1);
-}
-
-
-static
-onsigio()				/* input ready */
-{
-	comm_driver.inpready++;
 }