--- ray/src/util/glareval.c	1991/04/03 15:43:12	1.9
+++ ray/src/util/glareval.c	1991/04/18 15:18:25	1.13
@@ -20,7 +20,7 @@ static char SCCSid[] = "$SunId$ LBL";
 #define vfork		fork
 #endif
 
-#define MAXSBUF		1023980	/* maximum total size of scanline buffer */
+#define MAXSBUF		524268	/* maximum total size of scanline buffer */
 #define HSIZE		317	/* size of scanline hash table */
 #define NRETIRE		16	/* number of scanlines to retire at once */
 
@@ -50,6 +50,8 @@ static SCAN	*hashtab[HSIZE];	/* scanline hash table */
 static long	ncall = 0L;	/* number of calls to getpictscan */
 static long	nread = 0L;	/* number of scanlines read */
 
+static int	wrongformat = 0;
+
 SCAN	*scanretire();
 
 extern long	ftell();
@@ -75,6 +77,12 @@ int	y;
 			if (sl->y == y) {		/* reclaim */
 				sl->next = hashtab[hi];
 				hashtab[hi] = sl;
+#ifdef DEBUG
+				if (verbose)
+					fprintf(stderr,
+						"%s: scanline %d reclaimed\n",
+							progname, y);
+#endif
 			}
 			return(sl);
 		}
@@ -171,14 +179,15 @@ FVECT	vd;
 
 
 double
-getviewpix(vh, vv)		/* compute single view pixel */
+getviewpix(vh, vv, se)		/* compute single view pixel */
 int	vh, vv;
+SPANERR	*se;
 {
 	FVECT	dir;
 	float	rt_buf[6];
 	double	res;
 
-	if (compdir(dir, vh, vv) < 0)
+	if (compdir(dir, vh, vv, se) < 0)
 		return(-1.0);
 	npixinvw++;
 	if ((res = pict_val(dir)) >= 0.0)
@@ -205,6 +214,7 @@ float	*vb;
 	float	rt_buf[6*MAXPIX];	/* rtrace send/receive buffer */
 	register int	n;		/* number of pixels in buffer */
 	short	buf_vh[MAXPIX];		/* pixel positions */
+	SPANERR	sperr;
 	FVECT	dir;
 	register int	vh;
 
@@ -213,9 +223,10 @@ float	*vb;
 		fprintf(stderr, "%s: computing view span at %d...\n",
 				progname, vv);
 #endif
+	setspanerr(&sperr, vv);
 	n = 0;
 	for (vh = -hsize; vh <= hsize; vh++) {
-		if (compdir(dir, vh, vv) < 0) {	/* off viewable region */
+		if (compdir(dir, vh, vv, &sperr) < 0) {	/* not in view */
 			vb[vh+hsize] = -1.0;
 			continue;
 		}
@@ -281,24 +292,29 @@ int	np;
 getexpos(s)			/* get exposure from header line */
 char	*s;
 {
+	char	fmt[32];
+
 	if (isexpos(s))
 		exposure *= exposval(s);
+	else if (isformat(s)) {
+		formatval(fmt, s);
+		wrongformat = strcmp(fmt, COLRFMT);
+	}
 }
 
 
 open_pict(fn)			/* open picture file */
 char	*fn;
 {
-	register int	i;
-
 	if ((pictfp = fopen(fn, "r")) == NULL) {
 		fprintf("%s: cannot open\n", fn);
 		exit(1);
 	}
 	exposure = 1.0;
-	getheader(pictfp, getexpos);
-	if (fgetresolu(&pxsiz, &pysiz, pictfp) != (YMAJOR|YDECR)) {
-		fprintf("%s: bad picture resolution\n", fn);
+	getheader(pictfp, getexpos, NULL);
+	if (wrongformat ||
+			fgetresolu(&pxsiz, &pysiz, pictfp) != (YMAJOR|YDECR)) {
+		fprintf("%s: bad picture format\n", fn);
 		exit(1);
 	}
 	initscans();
@@ -307,8 +323,6 @@ char	*fn;
 
 close_pict()			/* done with picture */
 {
-	register int	i;
-
 	if (pictfp == NULL)
 		return;
 	fclose(pictfp);
@@ -410,44 +424,38 @@ SCAN *
 scanretire()			/* retire old scanlines to free list */
 {
 	SCAN	*sold[NRETIRE];
-	SCAN	head;
 	int	n;
 	int	h;
 	register SCAN	*sl;
 	register int	i;
 					/* grab the NRETIRE oldest scanlines */
 	sold[n = 0] = NULL;
-	for (h = 0; h < HSIZE; h++) {
-		head.next = hashtab[h];
-		sl = &head;
-		while (sl->next != NULL) {
-			for (i = n; i && sold[i-1]->lused > sl->next->lused; i--)
-				if (i == NRETIRE) {	/* reallocate */
-					register int	oh;
-					oh = shash(sold[NRETIRE-1]->y);
-					sold[NRETIRE-1]->next = hashtab[oh];
-					if (h == oh) {
-						head.next = sold[NRETIRE-1];
-						if (sl == &head)
-							sl = head.next;
-					} else
-						hashtab[oh] = sold[NRETIRE-1];
-				} else			/* else bubble up */
+	for (h = 0; h < HSIZE; h++)
+		for (sl = hashtab[h]; sl != NULL; sl = sl->next) {
+			for (i = n; i && sold[i-1]->lused > sl->lused; i--)
+				if (i < NRETIRE)
 					sold[i] = sold[i-1];
 			if (i < NRETIRE) {
-				sold[i] = sl->next;
-				sl->next = sl->next->next;
+				sold[i] = sl;
 				if (n < NRETIRE)	/* grow list */
 					n++;
-			} else
-				sl = sl->next;
+			}
 		}
-		hashtab[h] = head.next;
-	}
 					/* put scanlines into free list */
-	for (i = 1; i < n; i++) {
-		sold[i]->next = freelist;
-		freelist = sold[i];
+	for (i = 0; i < n; i++) {
+		h = shash(sold[i]->y);
+		sl = hashtab[h];
+		if (sl == sold[i])
+			hashtab[h] = sl->next;
+		else {
+			while (sl->next != sold[i])	/* IS in list */
+				sl = sl->next;
+			sl->next = sold[i]->next;
+		}
+		if (i > 0) {		/* save oldest as return value */
+			sold[i]->next = freelist;
+			freelist = sold[i];
+		}
 	}
 	return(sold[0]);
 }