--- ray/src/hd/rhdisp2.c	1998/01/01 13:00:16	3.17
+++ ray/src/hd/rhdisp2.c	2003/07/27 22:12:02	3.36
@@ -1,9 +1,6 @@
-/* Copyright (c) 1998 Silicon Graphics, Inc. */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ SGI";
+static const char	RCSid[] = "$Id: rhdisp2.c,v 3.36 2003/07/27 22:12:02 schorsch Exp $";
 #endif
-
 /*
  * Holodeck beam tracking for display process
  */
@@ -12,48 +9,20 @@ static char SCCSid[] = "$SunId$ SGI";
 #include "rhdisp.h"
 #include "rhdriver.h"
 
-#ifndef MAXDIST
-#define MAXDIST		42	/* maximum distance outside section */
+#ifndef MEYERNG
+#define MEYERNG		0.2	/* target mean eye range (rel. to grid) */
 #endif
 
-extern GCOORD	*getviewcells();
-
-static VIEW	dvw;		/* current view corresponding to beam list */
-
-typedef struct {
-	int	hd;		/* holodeck section number (-1 if inactive) */
-	int	i[3];		/* voxel index (may be outside section) */
-} VOXL;			/* a voxel */
-
-static VOXL voxel[8] = {	/* current voxel list */
-	{-1}, {-1}, {-1}, {-1},
-	{-1}, {-1}, {-1}, {-1}
-};
-
 #define CBEAMBLK	1024	/* cbeam allocation block size */
 
-static struct beamcomp {
-	short	wants;		/* flags telling which voxels want us */
-	short	hd;		/* holodeck section number */
-	int	bi;		/* beam index */
-} *cbeam = NULL;	/* current beam list */
-
+static PACKHEAD	*cbeam = NULL;	/* current beam list */
 static int	ncbeams = 0;	/* number of sorted beams in cbeam */
 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 */
+VIEWPOINT	cureye;		/* current eye position */
 
-struct beamact {
-	struct cellact	ca;	/* cell action */
-	GCOORD	gc;		/* grid coordinate */
-};		/* beam origin and action */
 
-
 int
 newcbeam()		/* allocate new entry at end of cbeam array */
 {
@@ -62,11 +31,11 @@ newcbeam()		/* allocate new entry at end of cbeam arra
 	if ((i = ncbeams + xcbeams++) >= maxcbeam) {	/* grow array */
 		maxcbeam += CBEAMBLK;
 		if (cbeam == NULL)
-			cbeam = (struct beamcomp *)malloc(
-					maxcbeam*sizeof(struct beamcomp) );
+			cbeam = (PACKHEAD *)malloc(
+					maxcbeam*sizeof(PACKHEAD) );
 		else
-			cbeam = (struct beamcomp *)realloc( (char *)cbeam,
-					maxcbeam*sizeof(struct beamcomp) );
+			cbeam = (PACKHEAD *)realloc((void *)cbeam,
+					maxcbeam*sizeof(PACKHEAD) );
 		if (cbeam == NULL)
 			error(SYSTEM, "out of memory in newcbeam");
 	}
@@ -76,7 +45,7 @@ newcbeam()		/* allocate new entry at end of cbeam arra
 
 int
 cbeamcmp(cb1, cb2)	/* compare two cbeam entries for sort: keep orphans */
-register struct beamcomp	*cb1, *cb2;
+register PACKHEAD	*cb1, *cb2;
 {
 	register int	c;
 
@@ -88,13 +57,13 @@ register struct beamcomp	*cb1, *cb2;
 
 int
 cbeamcmp2(cb1, cb2)	/* compare two cbeam entries for sort: no orphans */
-register struct beamcomp	*cb1, *cb2;
+register PACKHEAD	*cb1, *cb2;
 {
 	register int	c;
 
-	if (!cb1->wants)		/* put orphans at the end, unsorted */
-		return(cb2->wants);
-	if (!cb2->wants)
+	if (!cb1->nr)			/* put orphans at the end, unsorted */
+		return(cb2->nr);
+	if (!cb2->nr)
 		return(-1);
 	if ((c = cb1->bi - cb2->bi))	/* sort on beam index first */
 		return(c);
@@ -106,14 +75,14 @@ int
 findcbeam(hd, bi)	/* find the specified beam in our sorted list */
 int	hd, bi;
 {
-	struct beamcomp	cb;
-	register struct beamcomp	*p;
+	PACKHEAD	cb;
+	register PACKHEAD	*p;
 
 	if (ncbeams <= 0)
 		return(-1);
-	cb.wants = 0; cb.hd = hd; cb.bi = bi;
-	p = (struct beamcomp *)bsearch((char *)&cb, (char *)cbeam, ncbeams,
-			sizeof(struct beamcomp), cbeamcmp);
+	cb.hd = hd; cb.bi = bi; cb.nr = cb.nc = 0;
+	p = (PACKHEAD *)bsearch((char *)&cb, (char *)cbeam, ncbeams,
+			sizeof(PACKHEAD), cbeamcmp);
 	if (p == NULL)
 		return(-1);
 	return(p - cbeam);
@@ -134,12 +103,12 @@ int	bi;
 		if (cbeam[n].bi == bi && cbeam[n].hd == hd)
 			return(n);
 				/* check legality */
-	if (hd < 0 | hd >= HDMAX || hdlist[hd] == NULL)
+	if ((hd < 0) | (hd >= HDMAX) || hdlist[hd] == NULL)
 		error(INTERNAL, "illegal holodeck number in getcbeam");
-	if (bi < 1 | bi > nbeams(hdlist[hd]))
+	if ((bi < 1) | (bi > nbeams(hdlist[hd])))
 		error(INTERNAL, "illegal beam index in getcbeam");
 	n = newcbeam();		/* allocate and assign */
-	cbeam[n].wants = 0; cbeam[n].hd = hd; cbeam[n].bi = bi;
+	cbeam[n].hd = hd; cbeam[n].bi = bi; cbeam[n].nr = cbeam[n].nc = 0;
 	return(n);
 }
 
@@ -152,328 +121,150 @@ int	adopt;
 	if (!(ncbeams += xcbeams))
 		return;
 	xcbeams = 0;
-	qsort((char *)cbeam, ncbeams, sizeof(struct beamcomp),
+	qsort((char *)cbeam, ncbeams, sizeof(PACKHEAD),
 			adopt ? cbeamcmp : cbeamcmp2);
 	if (adopt)
 		return;
 	for (i = ncbeams; i--; )	/* identify orphans */
-		if (cbeam[i].wants)
+		if (cbeam[i].nr)
 			break;
 	xcbeams = ncbeams - ++i;	/* put orphans after ncbeams */
 	ncbeams = i;
 }
 
 
-cbeamop(op, bl, n, v, hr, vr)	/* update beams on server list */
-int	op;
-register struct beamcomp	*bl;
-int	n;
-VIEW	*v;
-int	hr, vr;
+beam_init(fresh)		/* clear beam list for new view(s) */
+int	fresh;
 {
-	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 cbeamadd");
-	for (i = 0; i < n; i++) {
-		pa[i].hd = bl[i].hd;
-		pa[i].bi = bl[i].bi;
-		pa[i].nr = v==NULL ? 0 :
-				npixels(v, hr, vr, hdlist[bl[i].hd], bl[i].bi);
-		pa[i].nc = 0;
-	}
-	serv_request(op, n*sizeof(PACKHEAD), (char *)pa);
-	free((char *)pa);
+	if (fresh)			/* discard old beams? */
+		ncbeams = xcbeams = 0;
+	else				/* else clear sample requests */
+		for (i = ncbeams+xcbeams; i--; )
+			cbeam[i].nr = 0;
+	cureye.rng = 0.;
 }
 
 
-int
-set_voxels(vl, n)	/* set new voxel array */
-VOXL	vl[8];
-int	n;
+int16 *
+beam_view(vn, hr, vr)		/* add beam view (if advisable) */
+VIEW	*vn;
+int	hr, vr;
 {
-	short	wmap[256];
-	int	vmap[8];
-	int	comn = 0;
-	int	no;
-	register int	i, j;
-					/* find common voxels */
-	for (j = 0; j < 8 && voxel[j].hd >= 0; j++) {
-		vmap[j] = -1;
-		for (i = n; i--; )
-			if (!bcmp((char *)(vl+i), (char *)(voxel+j),
-					sizeof(VOXL))) {
-				vmap[j] = i;
-				comn |= 1<<i;
-				break;
-			}
+	int16	*slist;
+	BEAMLIST	blist;
+	double	eravg, d;
+	register HOLO	*hp;
+	register int	i, n;
+					/* compute beams for view */
+	slist = viewbeams(vn, hr, vr, &blist);
+	if (*slist < 0) {
+		error(COMMAND, "no sections visible from this view");
+		return(NULL);
 	}
-	no = comn ? j : 0;		/* compute flag mapping */
-	for (i = 256; i--; ) {
-		wmap[i] = 0;
-		for (j = no; j--; )
-			if (vmap[j] >= 0 && i & 1<<j)
-				wmap[i] |= 1<<vmap[j];
+					/* sort current beam list */
+	cbeamsort(1);
+					/* add new beams to list */
+	for (i = blist.nb; i--; ) {
+		n = getcbeam(blist.bl[i].hd, blist.bl[i].bi);
+		if (blist.bl[i].nr > cbeam[n].nr)
+			cbeam[n].nr = blist.bl[i].nr;
 	}
-					/* fix cbeam flags */
-	for (i = ncbeams; i--; )
-		cbeam[i].wants = wmap[cbeam[i].wants];
-					/* update our voxel list */
-	bcopy((char *)vl, (char *)voxel, n*sizeof(VOXL));
-	for (j = n; j < 8; j++)
-		voxel[j].hd = -1;
-	return(comn);			/* return bit array of common voxels */
-}
-
-
-int
-get_voxels(vl, vp)	/* find voxels corresponding to view point */
-VOXL	vl[8];
-FVECT	vp;
-{
-	int	n = 0;
-	FVECT	gp;
-	double	d;
-	int	dist, bestd = 0x7fff;
-	VOXL	vox;
-	register int	i, j, k;
-					/* find closest voxels */
-	for (i = 0; n < 8 && hdlist[i]; i++) {
-		hdgrid(gp, hdlist[i], vp);
-		for (j = 0; n < 8 && j < 8; j++) {
-			dist = 0;
-			for (k = 0; k < 3; k++) {
-				d = gp[k] - .5 + (j>>k & 1);
-				if (d < 0.)
-					dist += -(vox.i[k] = (int)d - 1);
-				else if ((vox.i[k] = d) >= hdlist[i]->grid[k])
-					dist += vox.i[k] -
-							hdlist[i]->grid[k] + 1;
-			}
-			if (dist > bestd)	/* others were closer */
-				continue;
-			if (dist < bestd) {	/* start closer list */
-				n = 0;
-				bestd = dist;
-			}
-			vox.hd = i;		/* add this voxel */
-			copystruct(&vl[n], &vox);
-			n++;
-		}
+	free((void *)blist.bl);		/* free list */
+	if (MEYERNG <= FTINY)
+		return(slist);
+					/* compute average eye range */
+	eravg = 0.;
+	for (n = 0; slist[n] >= 0; n++) {
+		hp = hdlist[slist[n]];
+		eravg += 	MEYERNG/3. / VLEN(hp->wg[0]) +
+				MEYERNG/3. / VLEN(hp->wg[1]) +
+				MEYERNG/3. / VLEN(hp->wg[2]) ;
 	}
-					/* check for really stupid move */
-	if (bestd > MAXDIST) {
-		error(COMMAND, "move past outer limits");
-		return(0);
+	eravg /= (double)n;
+					/* add to current eye position */
+	if (cureye.rng <= FTINY) {
+		VCOPY(cureye.vpt, vn->vp);
+		cureye.rng = eravg;
+	} else if ((d = sqrt(dist2(vn->vp,cureye.vpt))) + eravg > cureye.rng) {
+		for (i = 3; i--; )
+			cureye.vpt[i] = 0.5*(cureye.vpt[i] + vn->vp[i]);
+		cureye.rng = 0.5*(cureye.rng + eravg + d);
 	}
-	return(n);
+	return(slist);
 }
 
 
 int
-dobeam(gcp, bp)		/* express interest or disintrest in a beam */
-GCOORD	*gcp;
-register struct beamact	*bp;
+beam_sync(all)			/* update beam list on server */
+int	all;
 {
-	GCOORD	gc[2];
-	int	bi, i;
-					/* compute beam index */
-	if (bp->ca.rev) {
-		copystruct(gc, &bp->gc);
-		copystruct(gc+1, gcp);
+					/* set new eye position */
+	serv_request(DR_VIEWPOINT, sizeof(VIEWPOINT), (char *)&cureye);
+					/* sort list (put orphans at end) */
+	cbeamsort(all < 0);
+					/* send beam request */
+	if (all) {
+		if (ncbeams > 0)
+			serv_request(DR_NEWSET,
+					ncbeams*sizeof(PACKHEAD), cbeam);
 	} else {
-		copystruct(gc, gcp);
-		copystruct(gc+1, &bp->gc);
+		if (ncbeams+xcbeams > 0)
+			serv_request(DR_ADJSET,
+				(ncbeams+xcbeams)*sizeof(PACKHEAD), cbeam);
 	}
-	if ((bi = hdbindex(hdlist[voxel[bp->ca.vi].hd], gc)) <= 0)
-		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 */
-		return(i == ncbeams+xcbeams-1);	/* return 1 if totally new */
-	}
-					/* else delete it */
-	i = findcbeam(voxel[bp->ca.vi].hd, bi);
-	if (i >= 0 && cbeam[i].wants & 1<<bp->ca.vi) {
-		cbeam[i].wants &= ~(1<<bp->ca.vi);	/* we don't want it */
-		return(1);			/* indicate change */
-	}
-	return(0);
-}
-
-
-
-int
-docell(gcp, cap)	/* find beams corresponding to cell and voxel */
-GCOORD	*gcp;
-register struct cellact	*cap;
-{
-	register HOLO	*hp = hdlist[voxel[cap->vi].hd];
-	FVECT	org, dir[4];
-	FVECT	vgp, cgp, vc;
-	FVECT	v1, v2;
-	struct beamact	bo;
-	int	axmax, j;
-	double	d, avmax;
-	register int	i;
-				/* compute cell center */
-	cgp[gcp->w>>1] = gcp->w&1 ? hp->grid[gcp->w>>1] : 0 ;
-	cgp[((gcp->w>>1)+1)%3] = gcp->i[0] + .5;
-	cgp[((gcp->w>>1)+2)%3] = gcp->i[1] + .5;
-	hdworld(org, hp, cgp);
-				/* compute direction to voxel center */
-	for (i = 3; i--; )
-		vgp[i] = voxel[cap->vi].i[i] + .5;
-	hdworld(vc, hp, vgp);
-	for (i = 3; i--; )
-		vc[i] -= org[i];
-				/* compute maximum area axis */
-	axmax = -1; avmax = 0;
-	for (i = 3; i--; ) {
-		d = vgp[i] - cgp[i];
-		if (d < 0.) d = -d;
-		if (d > avmax) {
-			avmax = d;
-			axmax = i;
-		}
-	}
-#ifdef DEBUG
-	if (axmax < 0.)
-		error(CONSISTENCY, "botched axis computation in docell");
-#endif
-				/* compute offset vectors */
-	d = 0.5/hp->grid[j=(axmax+1)%3];
-	for (i = 3; i--; )
-		v1[i] = hp->xv[j][i] * d;
-	d = 0.5/hp->grid[j=(axmax+2)%3];
-	if (DOT(hp->wn[axmax], vc) < 0.)
-		d = -d;	/* reverse vertex ordering */
-	for (i = 3; i--; )
-		v2[i] = hp->xv[j][i] * d;
-				/* compute voxel pyramid */
-	for (i = 3; i--; ) {
-		dir[0][i] = vc[i] - v1[i] - v2[i];
-		dir[1][i] = vc[i] + v1[i] - v2[i];
-		dir[2][i] = vc[i] + v1[i] + v2[i];
-		dir[3][i] = vc[i] - v1[i] + v2[i];
-	}
-				/* visit beams for opposite cells */
-	copystruct(&bo.ca, cap);
-	copystruct(&bo.gc, gcp);
-	return(visit_cells(org, dir, hp, dobeam, &bo));
-}
-
-
-int
-doview(cap, vp)			/* visit cells for a given view */
-struct cellact	*cap;
-VIEW	*vp;
-{
-	int	orient;
-	FVECT	org, dir[4];
-					/* compute view pyramid */
-	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));
-}
-
-
-mvview(voxi, vold, vnew)	/* move view for a voxel */
-int	voxi;
-VIEW	*vold, *vnew;
-{
-	int	netchange = 0;
-	struct cellact	oca, nca;
-	int	ocnt, ncnt;
-	int	c;
-	GCOORD	*ogcl, *ngcl;
-	register GCOORD	*ogcp, *ngcp;
-				/* get old and new cell lists */
-	ogcp = ogcl = getviewcells(&ocnt, hdlist[voxel[voxi].hd], vold);
-	ngcp = ngcl = getviewcells(&ncnt, hdlist[voxel[voxi].hd], vnew);
-				/* set up actions */
-	oca.vi = nca.vi = voxi;
-	oca.add = 0; nca.add = 1;
-	if ((oca.rev = ocnt < 0))
-		ocnt = -ocnt;
-	if ((nca.rev = ncnt < 0))
-		ncnt = -ncnt;
-	if (nca.rev == oca.rev)		/* add and delete cells in order */
-		while (ocnt > 0 & ncnt > 0)
-			if ((c = cellcmp(ogcp, ngcp)) > 0) {	/* new cell */
-				netchange += docell(ngcp++, &nca);
-				ncnt--;
-			} else if (c < 0) {			/* old cell */
-				netchange -= docell(ogcp++, &oca);
-				ocnt--;
-			} else {				/* same cell */
-				ogcp++; ocnt--;
-				ngcp++; ncnt--;
-			}
-				/* take care of list tails */
-	for ( ; ncnt > 0; ncnt--)
-		netchange += docell(ngcp++, &nca);
-	for ( ; ocnt > 0; ocnt--)
-		netchange -= docell(ogcp++, &oca);
-				/* clean up */
-	if (ogcl != NULL) free((char *)ogcl);
-	if (ngcl != NULL) free((char *)ngcl);
-	return(netchange);
-}
-
-
-int
-beam_sync()		/* synchronize beams on server */
-{
-	cbeamop(DR_NEWSET, cbeam, ncbeams, &odev.v, odev.hres, odev.vres);
+	xcbeams = 0;			/* truncate our list */
 	return(ncbeams);
 }
 
 
-beam_view(vn)			/* change beam view (if advisable) */
-VIEW	*vn;
+gridlines(f)			/* run through holodeck section grid lines */
+int	(*f)();
 {
-	struct cellact	ca;
-	VOXL	vlnew[8];
-	int	n, comn;
-
-	if (vn == NULL || !vn->type) {	/* clear our beam list */
-		set_voxels(vlnew, 0);
-		cbeamop(DR_DELSET, cbeam, ncbeams, NULL, 0, 0);
-		ncbeams = 0;
-		dvw.type = 0;
-		return(1);
-	}
-					/* find our new voxels */
-	n = get_voxels(vlnew, vn->vp);
-	if (dvw.type && !n) {
-		copystruct(vn, &dvw);		/* cancel move */
-		return(0);
-	}
-					/* set the new voxels */
-	comn = set_voxels(vlnew, n);
-	if (!dvw.type)
-		comn = 0;
-	ca.add = 1;			/* update our beam list */
-	for (ca.vi = n; ca.vi--; )
-		if (comn & 1<<ca.vi)	/* change which cells we see */
-			mvview(ca.vi, &dvw, vn);
-		else			/* else add all new cells */
-			doview(&ca, vn);
-					/* inform server of new beams */
-	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 */
-	cbeamop(DR_DELSET, cbeam+ncbeams, xcbeams, NULL, 0, 0);
-	xcbeams = 0;			/* truncate our list */
-	copystruct(&dvw, vn);		/* record new view */
-	return(1);
+	register int	hd, w, i;
+	int	g0, g1;
+	FVECT	wp[2], mov;
+	double	d;
+					/* do each wall on each section */
+	for (hd = 0; hdlist[hd] != NULL; hd++)
+		for (w = 0; w < 6; w++) {
+			g0 = hdwg0[w];
+			g1 = hdwg1[w];
+			d = 1.0/hdlist[hd]->grid[g0];
+			mov[0] = d * hdlist[hd]->xv[g0][0];
+			mov[1] = d * hdlist[hd]->xv[g0][1];
+			mov[2] = d * hdlist[hd]->xv[g0][2];
+			if (w & 1) {
+				VSUM(wp[0], hdlist[hd]->orig,
+						hdlist[hd]->xv[w>>1], 1.);
+				VSUM(wp[0], wp[0], mov, 1.);
+			} else
+				VCOPY(wp[0], hdlist[hd]->orig);
+			VSUM(wp[1], wp[0], hdlist[hd]->xv[g1], 1.);
+			for (i = hdlist[hd]->grid[g0]; ; ) {	/* g0 lines */
+				(*f)(wp);
+				if (!--i) break;
+				wp[0][0] += mov[0]; wp[0][1] += mov[1];
+				wp[0][2] += mov[2]; wp[1][0] += mov[0];
+				wp[1][1] += mov[1]; wp[1][2] += mov[2];
+			}
+			d = 1.0/hdlist[hd]->grid[g1];
+			mov[0] = d * hdlist[hd]->xv[g1][0];
+			mov[1] = d * hdlist[hd]->xv[g1][1];
+			mov[2] = d * hdlist[hd]->xv[g1][2];
+			if (w & 1)
+				VSUM(wp[0], hdlist[hd]->orig,
+						hdlist[hd]->xv[w>>1], 1.);
+			else
+				VSUM(wp[0], hdlist[hd]->orig, mov, 1.);
+			VSUM(wp[1], wp[0], hdlist[hd]->xv[g0], 1.);
+			for (i = hdlist[hd]->grid[g1]; ; ) {	/* g1 lines */
+				(*f)(wp);
+				if (!--i) break;
+				wp[0][0] += mov[0]; wp[0][1] += mov[1];
+				wp[0][2] += mov[2]; wp[1][0] += mov[0];
+				wp[1][1] += mov[1]; wp[1][2] += mov[2];
+			}
+		}
 }