--- ray/src/hd/rhd_odraw.c	1998/12/21 13:17:00	3.3
+++ ray/src/hd/rhd_odraw.c	1998/12/22 17:05:54	3.5
@@ -131,6 +131,7 @@ int	n;
 		DCHECK(count<=0 | nextsamp>=n,
 				CONSISTENCY, "counter botch in odInit");
 		if (!i) count = j;
+		odView[i].sfirst = nextsamp;
 		while (j--) {		/* initialize blocks & free lists */
 			odView[i].bmap[j].pthresh = FHUGE;
 			odView[i].bmap[j].first = k = nextsamp;
@@ -142,6 +143,7 @@ int	n;
 			odS.nextfree(k-1) = ENDFREE;
 			odView[i].bmap[j].nused = 0;
 		}
+		odView[i].snext = nextsamp;
 	}
 	CLR4ALL(odS.redraw, odS.nsamp);		/* clear redraw flags */
 	for (i = odS.nsamp; i--; ) {		/* clear values */
@@ -424,9 +426,7 @@ GLfloat	*dm;
 odUpdate(vn)				/* update this view */
 int	vn;
 {
-	int	i, j;
-	register struct ODblock	*bp;
-	register int	k;
+	register int	i, j;
 
 	DCHECK(vn<0 | vn>=odNViews, CONSISTENCY,
 			"bad view number in odUpdate");
@@ -439,35 +439,44 @@ int	vn;
 				return;
 			if (tmComputeMapping(0.,0.,0.) != TM_E_OK)
 				return;
-			for (k = odS.nsamp; k--; )	/* redraw all */
-				if (odS.ip[k][0] >= 0)
-					SET4(odS.redraw, k);
+			for (i = odS.nsamp; i--; )	/* redraw all */
+				if (odS.ip[i][0] >= 0)
+					SET4(odS.redraw, i);
 		}
 		if (tmMapPixels(odS.rgb,odS.brt,odS.chr,odS.nsamp) != TM_E_OK)
 			return;
 		needmapping = 0;		/* reset flag */
 	}
-					/* draw each block in view */
-	for (j = odView[vn].vlow; j--; )
-		for (i = 0; i < odView[vn].hlow; i++) {
-					/* get block */
-			bp = odView[vn].bmap + j*odView[vn].hlow + i;
-					/* do quick, conservative flag check */
-			for (k = (bp->first+bp->nsamp+31)>>5;
-					k-- > bp->first>>5; )
-				if (odS.redraw[k])
-					break;		/* non-zero flag */
-			if (k < bp->first>>5)
-				continue;		/* no flags set */
-			for (k = bp->nsamp; k--; )	/* sample by sample */
-				if (CHK4(odS.redraw, bp->first+k)) {
-					odDrawBlockSamp(vn, i, j, bp->first+k);
-					CLR4(odS.redraw, bp->first+k);
-				}
+					/* this code segment was too slow */
+#if 0
+	for (i = odView[vn].sfirst; i < odView[vn].snext; i++)
+		if (CHK4(odS.redraw, i)) {
+			odDrawSamp(vn, i);
+			CLR4(odS.redraw, i);
 		}
+#endif
+					/* redraw samples at each end */
+	for (i = odView[vn].sfirst; i < odView[vn].sfirst+31; i++)
+		if (CHK4(odS.redraw, i)) {
+			odDrawSamp(vn, i);
+			CLR4(odS.redraw, i);
+		}
+	for (i = odView[vn].snext-31; i < odView[vn].snext; i++)
+		if (CHK4(odS.redraw, i)) {
+			odDrawSamp(vn, i);
+			CLR4(odS.redraw, i);
+		}
+					/* faster flag checks in middle */
+	for (j = odView[vn].snext>>5; j-- > (odView[vn].sfirst+0x1f)>>5; )
+		for (i = 0; odS.redraw[j]; i++)		/* skips faster */
+			if (odS.redraw[j] & 1L<<i) {
+				odDrawSamp(vn, (j<<5)+i);
+				odS.redraw[j] &= ~(1L<<i);
+			}
 }
 
 
+					/* this turned out to be unnecessary */
 #if 0
 static
 clip_end(p, o, vp)			/* clip line segment to view */
@@ -603,8 +612,8 @@ register int	h, v;
 }
 
 
-odDrawBlockSamp(vn, h, v, id)		/* draw sample in view block */
-int	vn, h, v;
+odDrawSamp(vn, id)			/* draw view sample */
+int	vn;
 register int	id;
 {
 	GLshort	arm[MAXFAN][3];
@@ -615,12 +624,10 @@ register int	id;
 	register int	i;
 
 	vp = odView + vn;
-	blockindex = v*vp->hlow + h;
-	DCHECK(odS.ip[id][0]*vp->hlow/vp->hhi != h |
-			odS.ip[id][1]*vp->vlow/vp->vhi != v,
-			CONSISTENCY, "bad sample position in odDrawBlockSamp");
+	blockindex = getblock(vp, odS.ip[id][0], odS.ip[id][1]);
+	DCHECK(blockindex<0, CONSISTENCY, "bad sample handed to odDrawSamp");
 	DCHECK(vp->bmap[blockindex].nused <= 0,
-			CONSISTENCY, "bad in-use count in odDrawBlockSamp");
+			CONSISTENCY, "bad in-use count in odDrawSamp");
 					/* create triangle fan */
 	size = 1./sqrt((double)vp->bmap[blockindex].nused);
 	narms = make_arms(arm, odS.ip[id], vp, size);