--- ray/src/hd/rholo4.c	1997/10/31 10:23:29	3.1
+++ ray/src/hd/rholo4.c	1997/11/03 18:33:14	3.2
@@ -10,23 +10,172 @@ static char SCCSid[] = "$SunId$ SGI";
 
 #include "rholo.h"
 #include "rhdisp.h"
+#include <sys/uio.h>
 
+#ifndef HDSUF
+#define HDSUF	".hdisp"
+#endif
 
-open_display(dname)		/* open a display process */
+static int	inp_flags;
+static int	dpd[3];
+static int	pipesiz;
+
+
+disp_open(dname)		/* open the named display driver */
 char	*dname;
 {
-	error(INTERNAL, "display process unimplemented");
+	char	dpath[128], *com[2];
+	int	i;
+
+#ifdef DEVPATH
+	sprintf(dpath, "%s/%s%s", DEVPATH, dname, HDSUF);
+#else
+	sprintf(dpath, "dev/%s%s", dname, HDSUF);
+#endif
+	com[0] = dpath; com[1] = NULL;
+	pipesiz = open_process(dpd, com);
+	if (pipesiz <= 0)
+		error(USER, "cannot start display process");
+	inp_flags = 0;
+				/* write out hologram grids */
+	for (i = 0; hdlist[i] != NULL; i++)
+		disp_result(DS_ADDHOLO, sizeof(HDGRID), (char *)hdlist[i]);
 }
 
 
+disp_packet(p)			/* display a packet */
+register PACKET	*p;
+{
+	if (pipesiz <= 0)
+		return;
+	disp_result(DS_BUNDLE, sizeof(PACKHEAD) + p->nr*sizeof(RAYVAL),
+			(char *)p);
+}
+
+
 disp_check(block)		/* check display process */
 int	block;
 {
-	return(1);
+	MSGHEAD	msg;
+	int	n;
+	char	*buf = NULL;
+
+	if (pipesiz <= 0)
+		return(-1);
+restart:				/* check read blocking */
+	if (block != (inp_flags == 0)) {
+		inp_flags = block ? 0 : FNONBLK;
+		if (fcntl(dpd[0], F_SETFL, inp_flags) < 0)
+			goto fcntlerr;
+	}
+					/* read message header */
+	n = read(dpd[0], (char *)&msg, sizeof(MSGHEAD));
+	if (n != sizeof(MSGHEAD)) {
+		if (n >= 0)
+			error(USER, "display process died");
+		if (errno != EAGAIN & errno != EINTR)
+			goto readerr;
+		return(2);		/* else acceptable failure */
+	}
+	if (msg.nbytes) {		/* get the message body */
+		buf = (char *)malloc(msg.nbytes);
+		if (buf == NULL)
+			error(SYSTEM, "out of memory in disp_check");
+		if (fcntl(dpd[0], F_SETFL, inp_flags=0) < 0)
+			goto fcntlerr;
+		if (readbuf(dpd[0], buf, msg.nbytes) != msg.nbytes)
+			goto readerr;
+	}
+	switch (msg.type) {		/* take appropriate action */
+	case DR_BUNDLE:
+		if (msg.nbytes != sizeof(PACKHEAD))
+			error(INTERNAL, "bad DR_BUNDLE from display process");
+		bundle_set(BS_ADD, (PACKHEAD *)buf, 1);
+		break;
+	case DR_NEWSET:
+		if (msg.nbytes % sizeof(PACKHEAD))
+			error(INTERNAL, "bad DR_NEWSET from display process");
+		disp_result(DS_STARTIMM, 0, NULL);
+		bundle_set(BS_NEW, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
+		disp_result(DS_ENDIMM, 0, NULL);
+		break;
+	case DR_ADDSET:
+		if (msg.nbytes % sizeof(PACKHEAD))
+			error(INTERNAL, "bad DR_ADDSET from display process");
+		disp_result(DS_STARTIMM, 0, NULL);
+		bundle_set(BS_ADD, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
+		disp_result(DS_ENDIMM, 0, NULL);
+		break;
+	case DR_DELSET:
+		if (msg.nbytes % sizeof(PACKHEAD))
+			error(INTERNAL, "bad DR_DELSET from display process");
+		bundle_set(BS_DEL, (PACKHEAD *)buf, msg.nbytes/sizeof(PACKHEAD));
+		break;
+	case DR_ATTEN:
+		if (msg.nbytes)
+			error(INTERNAL, "bad DR_ATTEN from display process");
+					/* send acknowledgement */
+		disp_result(DS_ACKNOW, 0, NULL);
+		block = 1;		/* block on following request */
+		goto restart;
+	case DR_SHUTDOWN:
+		if (msg.nbytes)
+			error(INTERNAL, "bad DR_SHUTDOWN from display process");
+		return(0);		/* zero return signals shutdown */
+	default:
+		error(INTERNAL, "unrecognized request from display process");
+	}
+	if (msg.nbytes)
+		free(buf);
+	return(1);			/* normal return value */
+fcntlerr:
+	error(SYSTEM, "cannot change display blocking mode");
+readerr:
+	error(SYSTEM, "error reading from display process");
 }
 
 
-disp_packet(p)			/* display a packet */
-register PACKET	*p;
+int
+disp_close()			/* close our display process */
 {
+	int	rval;
+
+	if (pipesiz <= 0)
+		return(-1);
+	disp_result(DS_SHUTDOWN, 0, NULL);
+	pipesiz = 0;
+	return(close_process(dpd));
+}
+
+
+disp_result(type, nbytes, p)	/* send result message to display process */
+int	type, nbytes;
+char	*p;
+{
+	struct iovec	iov[2];
+	MSGHEAD	msg;
+	int	n;
+
+	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");
 }