--- ray/src/hd/rhdisp2.c	1997/11/19 18:01:03	3.1
+++ ray/src/hd/rhdisp2.c	1997/11/21 18:17:37	3.5
@@ -5,17 +5,17 @@ static char SCCSid[] = "$SunId$ SGI";
 #endif
 
 /*
- * Holodeck beam tracking
+ * Holodeck beam tracking for display process
  */
 
 #include "rholo.h"
 #include "rhdisp.h"
 #include "rhdriver.h"
 
-extern int	*getviewcells();
+extern GCOORD	*getviewcells();
 
 typedef struct {
-	int	hd;		/* holodeck section number */
+	int	hd;		/* holodeck section number (-1 if inactive) */
 	int	i[3];		/* voxel index (may be outside section) */
 } VOXL;			/* a voxel */
 
@@ -36,13 +36,12 @@ static int	ncbeams = 0;	/* number of sorted beams in c
 static int	xcbeams = 0;	/* extra (unregistered) beams past ncbeams */
 static int	maxcbeam = 0;	/* size of cbeam array */
 
-
 struct cellact {
 	short	vi;		/* voxel index */
 	short	add;		/* zero means delete */
+	short	rev;		/* reverse ray direction? */
 };		/* action for cell */
 
-
 struct beamact {
 	struct cellact	ca;	/* cell action */
 	GCOORD	gc;		/* grid coordinate */
@@ -157,7 +156,8 @@ int	adopt;
 }
 
 
-cbeamadd(bl, n, v, hr, vr)	/* add beams to server list */
+cbeamop(op, bl, n, v, hr, vr)	/* update beams on server list */
+int	op;
 register struct beamcomp	*bl;
 int	n;
 VIEW	*v;
@@ -171,34 +171,13 @@ int	hr, vr;
 	pa = (PACKHEAD *)malloc(n*sizeof(PACKHEAD));
 	if (pa == NULL)
 		error(SYSTEM, "out of memory in cbeamadd");
-	for (i = 0; i < n; i++)
-		pa[i].nr = npixels(v, hr, vr,
-				hdlist[pa[i].hd=bl[i].hd],
-				pa[i].bi=bl[i].bi) / 8;
-
-	serv_request(DR_ADDSET, n*sizeof(PACKHEAD), (char *)pa);
-	free((char *)pa);
-}
-
-
-cbeamdel(bl, n)		/* delete unwanted beam requests */
-register struct beamcomp	*bl;
-int	n;
-{
-	register PACKHEAD	*pa;
-	register int	i;
-
-	if (n <= 0)
-		return;
-	pa = (PACKHEAD *)malloc(n*sizeof(PACKHEAD));
-	if (pa == NULL)
-		error(SYSTEM, "out of memory in cbeamdel");
 	for (i = 0; i < n; i++) {
 		pa[i].hd = bl[i].hd;
 		pa[i].bi = bl[i].bi;
-		pa[i].nr = 0;		/* removes any request */
+		pa[i].nr = v==NULL ? 0 :
+				npixels(v, hr, vr, hdlist[bl[i].hd], bl[i].bi);
 	}
-	serv_request(DR_DELSET, n*sizeof(PACKHEAD), (char *)pa);
+	serv_request(op, n*sizeof(PACKHEAD), (char *)pa);
 	free((char *)pa);
 }
 
@@ -247,6 +226,7 @@ get_voxels(vl, vp)	/* find voxels corresponding to vie
 VOXL	vl[8];
 FVECT	vp;
 {
+	static int	lastn = 0, lastd = -1;
 	int	n = 0;
 	FVECT	gp;
 	double	d;
@@ -277,7 +257,13 @@ FVECT	vp;
 			n++;
 		}
 	}
-	return(n);
+					/* warn of dangerous moves */
+	if (n < lastn && bestd >= lastd)
+		error(WARNING, "moving outside holodeck section");
+	else if (n > lastn && bestd <= lastd)
+		error(WARNING, "moving inside holodeck section");
+	lastd = bestd;
+	return(lastn = n);
 }
 
 
@@ -289,10 +275,15 @@ register struct beamact	*bp;
 	GCOORD	gc[2];
 	int	bi, i;
 					/* compute beam index */
-	copystruct(gc, gcp);
-	copystruct(gc+1, &bp->gc);
+	if (bp->ca.rev) {
+		copystruct(gc, &bp->gc);
+		copystruct(gc+1, gcp);
+	} else {
+		copystruct(gc, gcp);
+		copystruct(gc+1, &bp->gc);
+	}
 	if ((bi = hdbindex(hdlist[voxel[bp->ca.vi].hd], gc)) <= 0)
-		return(0);		/* should report an error? */
+		error(CONSISTENCY, "bad grid coordinate in dobeam");
 	if (bp->ca.add) {		/* add it in */
 		i = getcbeam(voxel[bp->ca.vi].hd, bi);
 		cbeam[i].wants |= 1<<bp->ca.vi;	/* say we want it */
@@ -350,17 +341,15 @@ doview(cap, vp)			/* visit cells for a given view */
 struct cellact	*cap;
 VIEW	*vp;
 {
+	int	orient;
 	FVECT	org, dir[4];
 					/* compute view pyramid */
-	if (vp->type == VT_PAR) goto viewerr;
-	if (viewray(org, dir[0], vp, 0., 0.) < -FTINY) goto viewerr;
-	if (viewray(org, dir[1], vp, 0., 1.) < -FTINY) goto viewerr;
-	if (viewray(org, dir[2], vp, 1., 1.) < -FTINY) goto viewerr;
-	if (viewray(org, dir[3], vp, 1., 0.) < -FTINY) goto viewerr;
+	orient = viewpyramid(org, dir, hdlist[voxel[cap->vi].hd], vp);
+	if (!orient)
+		error(INTERNAL, "unusable view in doview");
+	cap->rev = orient < 0;
 					/* visit cells within pyramid */
 	return(visit_cells(org, dir, hdlist[voxel[cap->vi].hd], docell, cap));
-viewerr:
-	error(INTERNAL, "unusable view in doview");
 }
 
 
@@ -369,50 +358,54 @@ int	voxi;
 VIEW	*vold, *vnew;
 {
 	int	netchange = 0;
-	int	*ocl, *ncl;
-	struct cellact	ca;
+	struct cellact	oca, nca;
 	int	ocnt, ncnt;
 	int	c;
 	register GCOORD	*ogcp, *ngcp;
 				/* get old and new cell lists */
-	ocl = getviewcells(hdlist[voxel[voxi].hd], vold);
-	ncl = getviewcells(hdlist[voxel[voxi].hd], vnew);
-	if (ocl != NULL) {
-		ocnt = *ocl; ogcp = (GCOORD *)(ocl+1);
-	} else {
-		ocnt = 0; ogcp = NULL;
-	}
-	if (ncl != NULL) {
-		ncnt = *ncl; ngcp = (GCOORD *)(ncl+1);
-	} else {
-		ncnt = 0; ngcp = NULL;
-	}
-	ca.vi = voxi;		/* add and delete cells */
+	ogcp = getviewcells(&ocnt, hdlist[voxel[voxi].hd], vold);
+	ngcp = getviewcells(&ncnt, hdlist[voxel[voxi].hd], vnew);
+				/* set up actions */
+	oca.vi = nca.vi = voxi;
+	oca.rev = nca.rev = 0;
+	oca.add = 0; nca.add = 1;
+	if ((oca.rev = ocnt < 0))
+		ocnt = -ocnt;
+	if ((nca.rev = ncnt < 0))
+		ncnt = -ncnt;
+				/* add and delete cells in order */
 	while (ocnt > 0 & ncnt > 0)
-		if ((c = cellcmp(ogcp, ngcp)) > 0) {
-			ca.add = 1;		/* new cell */
-			netchange += docell(ngcp++, &ca);
+		if ((c = cellcmp(ogcp, ngcp)) > 0) {	/* new cell */
+			netchange += docell(ngcp++, &nca);
 			ncnt--;
-		} else if (c < 0) {
-			ca.add = 0;		/* obsolete cell */
-			netchange -= docell(ogcp++, &ca);
+		} else if (c < 0) {			/* obsolete cell */
+			netchange -= docell(ogcp++, &oca);
 			ocnt--;
-		} else {
-			ogcp++; ocnt--;		/* unchanged cell */
+		} else {				/* same cell? */
+			if (oca.rev != nca.rev)		/* not */
+				netchange += docell(ngcp, &nca) -
+						docell(ogcp, &oca);
+			ogcp++; ocnt--;
 			ngcp++; ncnt--;
 		}
 				/* take care of list tails */
-	for (ca.add = 1; ncnt > 0; ncnt--)
-		docell(ngcp++, &ca);
-	for (ca.add = 0; ocnt > 0; ocnt--)
-		docell(ogcp++, &ca);
+	for ( ; ncnt > 0; ncnt--)
+		netchange += docell(ngcp++, &nca);
+	for ( ; ocnt > 0; ocnt--)
+		netchange -= docell(ogcp++, &oca);
 				/* clean up */
-	if (ocl != NULL) free((char *)ocl);
-	if (ncl != NULL) free((char *)ncl);
+	if (ogcp != NULL) free((char *)ogcp);
+	if (ngcp != NULL) free((char *)ngcp);
 	return(netchange);
 }
 
 
+beam_sync()		/* synchronize beams on server */
+{
+	cbeamop(DR_NEWSET, cbeam, ncbeams, &odev.v, odev.hres, odev.vres);
+}
+
+
 beam_view(vo, vn)	/* change beam view */
 VIEW	*vo, *vn;
 {
@@ -422,7 +415,7 @@ VIEW	*vo, *vn;
 
 	if (!vn->type) {		/* clear our beam list */
 		set_voxels(vlnew, 0);
-		cbeamdel(cbeam, ncbeams);
+		cbeamop(DR_DELSET, cbeam, ncbeams, NULL, 0, 0);
 		ncbeams = 0;
 		return;
 	}
@@ -439,10 +432,10 @@ VIEW	*vo, *vn;
 		else			/* else add all new cells */
 			doview(&ca, vn);
 					/* inform server of new beams */
-	cbeamadd(cbeam+ncbeams, xcbeams, vn, odev.hres, odev.vres);
+	cbeamop(DR_ADDSET, cbeam+ncbeams, xcbeams, vn, odev.hres, odev.vres);
 					/* sort list to put orphans at end */
 	cbeamsort(0);
 					/* tell server to delete orphans */
-	cbeamdel(cbeam+ncbeams, xcbeams);
+	cbeamop(DR_DELSET, cbeam+ncbeams, xcbeams, NULL, 0, 0);
 	xcbeams = 0;			/* truncate our list */
 }