--- ray/src/hd/rholo.c	1999/03/09 08:51:39	3.50
+++ ray/src/hd/rholo.c	2003/05/29 16:26:22	3.54
@@ -1,9 +1,6 @@
-/* Copyright (c) 1999 Silicon Graphics, Inc. */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ SGI";
+static const char	RCSid[] = "$Id: rholo.c,v 3.54 2003/05/29 16:26:22 greg Exp $";
 #endif
-
 /*
  * Radiance holodeck generation controller
  */
@@ -42,13 +39,13 @@ char	*outdev = NULL;		/* output device name */
 
 int	readinp = 0;		/* read commands from stdin */
 
-int	force = 0;		/* allow overwrite of holodeck */
+int	force = 0;		/* allow overwrite of holodeck (-1 == read-only) */
 
 time_t	starttime;		/* time we got started */
 time_t	endtime;		/* time we should end by */
 time_t	reporttime;		/* time for next report */
 
-long	maxdisk;		/* maximum file space (bytes) */
+off_t	maxdisk;		/* maximum file space (bytes) */
 
 int	rtargc = 1;		/* rtrace command */
 char	*rtargv[128] = {"rtrace", NULL};
@@ -82,8 +79,11 @@ char	*argv[];
 			nowarn++;
 			break;
 		case 'f':			/* force overwrite */
-			force++;
+			force = 1;
 			break;
+		case 'r':			/* read-only mode */
+			force = -1;
+			break;
 		case 'i':			/* read input from stdin */
 			readinp++;
 			break;
@@ -126,6 +126,9 @@ char	*argv[];
 		HDGRID	hdg[HDMAX];
 							/* set defaults */
 		setdefaults(hdg);
+							/* check read-only */
+		if (force < 0)
+			error(USER, "cannot create read-only holodeck");
 							/* holodeck exists? */
 		if (!force && access(hdkfile, R_OK|W_OK) == 0)
 			error(USER,
@@ -143,7 +146,7 @@ char	*argv[];
 	quit(0);
 userr:
 	fprintf(stderr,
-"Usage: %s [-n nprocs][-o disp][-w][-f] output.hdk [control.hif|+|- [VAR=val ..]]\n",
+"Usage: %s [-n nprocs][-o disp][-w][-r|-f] output.hdk [control.hif|+|- [VAR=val ..]]\n",
 			progname);
 	quit(1);
 }
@@ -211,7 +214,7 @@ initrholo()			/* get our holodeck running */
 		init_global();
 						/* record disk space limit */
 	if (!vdef(DISKSPACE))
-		maxdisk = 0;
+		maxdisk = (1L<<(sizeof(off_t)*8-2)) - 1024;
 	else
 		maxdisk = 1024.*1024.*vflt(DISKSPACE);
 						/* set up memory cache */
@@ -272,7 +275,7 @@ initrholo()			/* get our holodeck running */
 	sigdie(SIGXFSZ, "File size exceeded");
 #endif
 					/* protect holodeck file */
-	orig_mode = resfmode(hdlist[0]->fd, ncprocs>0 ? 0 : 0444);
+	orig_mode = resfmode(hdlist[0]->fd, ncprocs>0&force>=0 ? 0 : 0444);
 	return;
 memerr:
 	error(SYSTEM, "out of memory in initrholo");
@@ -284,7 +287,7 @@ rholo()				/* holodeck main loop */
 	static long	nextfragwarn = 100*(1L<<20);
 	static int	idle = 0;
 	PACKET	*pl = NULL, *plend;
-	long	fsiz;
+	off_t	fsiz;
 	int	pksiz;
 	register PACKET	*p;
 	time_t	t;
@@ -427,7 +430,7 @@ HDGRID	*gp;
 	putw(HOLOMAGIC, fp);		/* put magic number */
 	fd = dup(fileno(fp));
 	fclose(fp);			/* flush and close stdio stream */
-	lastloc = lseek(fd, 0L, 2);
+	lastloc = lseek(fd, (off_t)0L, 2);
 	for (n = vdef(SECTION); n--; gp++) {	/* initialize each section */
 		nextloc = 0L;
 		write(fd, (char *)&nextloc, sizeof(nextloc));
@@ -435,11 +438,11 @@ HDGRID	*gp;
 		if (!n)
 			break;
 		nextloc = hdfilen(fd);		/* write section pointer */
-		if (lseek(fd, (long)lastloc, 0) < 0)
+		if (lseek(fd, (off_t)lastloc, 0) < 0)
 			error(SYSTEM,
 				"cannot seek on holodeck file in creatholo");
 		write(fd, (char *)&nextloc, sizeof(nextloc));
-		lseek(fd, (long)(lastloc=nextloc), 0);
+		lseek(fd, (off_t)(lastloc=nextloc), 0);
 	}
 }
 
@@ -472,16 +475,27 @@ char	*s;
 
 loadholo()			/* start loading a holodeck from fname */
 {
-	extern long	ftell();
 	FILE	*fp;
 	int	fd;
 	int	n;
 	int4	nextloc;
-					/* open holodeck file */
-	if ((fp = fopen(hdkfile, ncprocs>0 ? "r+" : "r")) == NULL) {
-		sprintf(errmsg, "cannot %s \"%s\"",
-				ncprocs>0 ? "append" : "read", hdkfile);
-		error(SYSTEM, errmsg);
+	
+	if (ncprocs > 0 & force >= 0)
+		fp = fopen(hdkfile, "r+");
+	else
+		fp = NULL;
+	if (fp == NULL) {
+		if ((fp = fopen(hdkfile, "r")) == NULL) {
+			sprintf(errmsg, "cannot open \"%s\"", hdkfile);
+			error(SYSTEM, errmsg);
+		}
+		if (ncprocs > 0) {
+			sprintf(errmsg,
+			"\"%s\" opened read-only; new rays will be discarded",
+					hdkfile);
+			error(WARNING, errmsg);
+			force = -1;
+		}
 	}
 					/* load variables from header */
 	getheader(fp, headline, NULL);
@@ -495,7 +509,7 @@ loadholo()			/* start loading a holodeck from fname */
 	fd = dup(fileno(fp));
 	fclose(fp);				/* done with stdio */
 	for (n = 0; nextloc > 0L; n++) {	/* initialize each section */
-		lseek(fd, (long)nextloc, 0);
+		lseek(fd, (off_t)nextloc, 0);
 		read(fd, (char *)&nextloc, sizeof(nextloc));
 		hdinit(fd, NULL);
 	}
@@ -516,8 +530,8 @@ PACKET	*pl;
 	while (pl != NULL) {
 		p = pl; pl = p->next; p->next = NULL;
 		if (p->nr > 0) {		/* add to holodeck */
-			bcopy((char *)p->ra,
-				(char *)hdnewrays(hdlist[p->hd],p->bi,p->nr),
+			bcopy((void *)p->ra,
+				(void *)hdnewrays(hdlist[p->hd],p->bi,p->nr),
 				p->nr*sizeof(RAYVAL));
 			if (outdev != NULL)	/* display it */
 				disp_packet((PACKHEAD *)p);
@@ -563,6 +577,7 @@ int	vc;
 }
 
 
+void
 eputs(s)			/* put error message to stderr */
 register char  *s;
 {
@@ -582,6 +597,7 @@ register char  *s;
 }
 
 
+void
 quit(ec)			/* exit program gracefully */
 int	ec;
 {
@@ -590,8 +606,8 @@ int	ec;
 	if (hdlist[0] != NULL) {	/* close holodeck */
 		if (nprocs > 0)
 			status = done_rtrace();		/* calls hdsync() */
-		if (ncprocs > 0 && vdef(REPORT)) {
-			long	fsiz, fuse;
+		if (ncprocs > 0 & force >= 0 && vdef(REPORT)) {
+			off_t	fsiz, fuse;
 			fsiz = hdfilen(hdlist[0]->fd);
 			fuse = hdfiluse(hdlist[0]->fd, 1);
 			fprintf(stderr,