--- ray/src/hd/rholo4.c	1997/11/03 18:33:14	3.2
+++ ray/src/hd/rholo4.c	1997/11/20 11:40:11	3.6
@@ -18,13 +18,13 @@ static char SCCSid[] = "$SunId$ SGI";
 
 static int	inp_flags;
 static int	dpd[3];
-static int	pipesiz;
+static FILE	*dpout;
 
 
 disp_open(dname)		/* open the named display driver */
 char	*dname;
 {
-	char	dpath[128], *com[2];
+	char	dpath[128], *com[3];
 	int	i;
 
 #ifdef DEVPATH
@@ -32,24 +32,24 @@ char	*dname;
 #else
 	sprintf(dpath, "dev/%s%s", dname, HDSUF);
 #endif
-	com[0] = dpath; com[1] = NULL;
-	pipesiz = open_process(dpd, com);
-	if (pipesiz <= 0)
+	com[0] = dpath; com[1] = froot; com[2] = NULL;
+	i = open_process(dpd, com);
+	if (i <= 0)
 		error(USER, "cannot start display process");
+	if ((dpout = fdopen(dup(dpd[1]), "w")) == NULL)
+		error(SYSTEM, "cannot associate FILE with display pipe");
 	inp_flags = 0;
 				/* write out hologram grids */
 	for (i = 0; hdlist[i] != NULL; i++)
 		disp_result(DS_ADDHOLO, sizeof(HDGRID), (char *)hdlist[i]);
+	disp_flush();
 }
 
 
 disp_packet(p)			/* display a packet */
-register PACKET	*p;
+register PACKHEAD	*p;
 {
-	if (pipesiz <= 0)
-		return;
-	disp_result(DS_BUNDLE, sizeof(PACKHEAD) + p->nr*sizeof(RAYVAL),
-			(char *)p);
+	disp_result(DS_BUNDLE, packsiz(p->nr), (char *)p);
 }
 
 
@@ -60,9 +60,11 @@ int	block;
 	int	n;
 	char	*buf = NULL;
 
-	if (pipesiz <= 0)
+	if (dpout == NULL)
 		return(-1);
-restart:				/* check read blocking */
+					/* flush display output */
+	disp_flush();
+					/* check read blocking */
 	if (block != (inp_flags == 0)) {
 		inp_flags = block ? 0 : FNONBLK;
 		if (fcntl(dpd[0], F_SETFL, inp_flags) < 0)
@@ -75,7 +77,7 @@ restart:				/* check read blocking */
 			error(USER, "display process died");
 		if (errno != EAGAIN & errno != EINTR)
 			goto readerr;
-		return(2);		/* else acceptable failure */
+		return(2);		/* acceptable failure */
 	}
 	if (msg.nbytes) {		/* get the message body */
 		buf = (char *)malloc(msg.nbytes);
@@ -98,6 +100,7 @@ restart:				/* check read blocking */
 		disp_result(DS_STARTIMM, 0, NULL);
 		bundle_set(BS_NEW, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
 		disp_result(DS_ENDIMM, 0, NULL);
+		disp_flush();
 		break;
 	case DR_ADDSET:
 		if (msg.nbytes % sizeof(PACKHEAD))
@@ -105,6 +108,7 @@ restart:				/* check read blocking */
 		disp_result(DS_STARTIMM, 0, NULL);
 		bundle_set(BS_ADD, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
 		disp_result(DS_ENDIMM, 0, NULL);
+		disp_flush();
 		break;
 	case DR_DELSET:
 		if (msg.nbytes % sizeof(PACKHEAD))
@@ -116,8 +120,7 @@ restart:				/* check read blocking */
 			error(INTERNAL, "bad DR_ATTEN from display process");
 					/* send acknowledgement */
 		disp_result(DS_ACKNOW, 0, NULL);
-		block = 1;		/* block on following request */
-		goto restart;
+		return(disp_check(1));	/* block on following request */
 	case DR_SHUTDOWN:
 		if (msg.nbytes)
 			error(INTERNAL, "bad DR_SHUTDOWN from display process");
@@ -125,7 +128,7 @@ restart:				/* check read blocking */
 	default:
 		error(INTERNAL, "unrecognized request from display process");
 	}
-	if (msg.nbytes)
+	if (msg.nbytes)			/* clean up */
 		free(buf);
 	return(1);			/* normal return value */
 fcntlerr:
@@ -140,42 +143,33 @@ disp_close()			/* close our display process */
 {
 	int	rval;
 
-	if (pipesiz <= 0)
+	if (dpout == NULL)
 		return(-1);
 	disp_result(DS_SHUTDOWN, 0, NULL);
-	pipesiz = 0;
+	fclose(dpout);
+	dpout = NULL;
 	return(close_process(dpd));
 }
 
 
-disp_result(type, nbytes, p)	/* send result message to display process */
+disp_result(type, nbytes, p)	/* queue result message to display process */
 int	type, nbytes;
 char	*p;
 {
-	struct iovec	iov[2];
 	MSGHEAD	msg;
-	int	n;
 
+	if (dpout == NULL)
+		return;
 	msg.type = type;
 	msg.nbytes = nbytes;
-	if (nbytes == 0 || sizeof(MSGHEAD)+nbytes > pipesiz) {
-		n = write(dpd[1], (char *)&msg, sizeof(MSGHEAD));
-		if (n != sizeof(MSGHEAD))
-			goto writerr;
-		if (nbytes > 0) {
-			n = writebuf(dpd[1], p, nbytes);
-			if (n != nbytes)
-				goto writerr;
-		}
-		return;
-	}
-	iov[0].iov_base = (char *)&msg;
-	iov[0].iov_len = sizeof(MSGHEAD);
-	iov[1].iov_base = p;
-	iov[1].iov_len = nbytes;
-	n = writev(dpd[1], iov, 2);
-	if (n == nbytes+sizeof(MSGHEAD))
-		return;
-writerr:
-	error(SYSTEM, "write error in disp_result");
+	fwrite((char *)&msg, sizeof(MSGHEAD), 1, dpout);
+	if (nbytes > 0)
+		fwrite(p, 1, nbytes, dpout);
+}
+
+
+disp_flush()			/* flush output to display */
+{
+	if (fflush(dpout) < 0)
+		error(SYSTEM, "error writing to the display process");
 }