--- ray/src/common/color.c	1991/08/23 12:33:49	1.14
+++ ray/src/common/color.c	1992/10/02 15:59:58	2.4
@@ -17,7 +17,11 @@ static char SCCSid[] = "$SunId$ LBL";
 #define  MINELEN	8	/* minimum scanline length for encoding */
 #define  MINRUN		4	/* minimum run length */
 
+#ifndef frexp
+extern double  frexp();
+#endif
 
+
 char *
 tempbuffer(len)			/* get a temporary buffer */
 unsigned  len;
@@ -39,18 +43,17 @@ unsigned  len;
 
 fwritecolrs(scanline, len, fp)		/* write out a colr scanline */
 register COLR  *scanline;
-int  len;
+unsigned  len;
 register FILE  *fp;
 {
 	register int  i, j, beg, cnt;
 	int  c2;
 	
-	if (len < MINELEN)		/* too small to encode */
+	if (len < MINELEN | len > 0x7fff)	/* OOBs, write out flat */
 		return(fwrite((char *)scanline,sizeof(COLR),len,fp) - len);
-	if (len > 32767)		/* too big! */
-		return(-1);
-	putc(2, fp);			/* put magic header */
+					/* put magic header */
 	putc(2, fp);
+	putc(2, fp);
 	putc(len>>8, fp);
 	putc(len&255, fp);
 					/* put components seperately */
@@ -63,7 +66,17 @@ register FILE  *fp;
 		    if (cnt >= MINRUN)
 			break;			/* long enough */
 		}
-		while (j < beg) {		/* write out non-run(s) */
+		if (beg-j > 1 && beg-j < MINRUN) {
+		    c2 = j+1;
+		    while (scanline[c2++][i] == scanline[j][i])
+			if (c2 == beg) {	/* short run */
+			    putc(128+beg-j, fp);
+			    putc(scanline[j][i], fp);
+			    j = beg;
+			    break;
+			}
+		}
+		while (j < beg) {		/* write out non-run */
 		    if ((c2 = beg-j) > 128) c2 = 128;
 		    putc(c2, fp);
 		    while (c2--)
@@ -88,7 +101,7 @@ register FILE  *fp;
 	register int  i, j;
 	int  code;
 					/* determine scanline type */
-	if (len < MINELEN)
+	if (len < MINELEN | len > 0x7fff)
 		return(oldreadcolrs(scanline, len, fp));
 	if ((i = getc(fp)) == EOF)
 		return(-1);
@@ -216,7 +229,6 @@ setcolr(clr, r, g, b)		/* assign a short color value *
 register COLR  clr;
 double  r, g, b;
 {
-	double  frexp();
 	double  d;
 	int  e;