--- ray/src/common/color.c	2004/09/14 02:53:50	2.15
+++ ray/src/common/color.c	2019/05/27 15:44:26	2.21
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: color.c,v 2.15 2004/09/14 02:53:50 greg Exp $";
+static const char	RCSid[] = "$Id: color.c,v 2.21 2019/05/27 15:44:26 greg Exp $";
 #endif
 /*
  *  color.c - routines for color calculations.
@@ -10,18 +10,17 @@ static const char	RCSid[] = "$Id: color.c,v 2.15 2004/
 #include "copyright.h"
 
 #include  <stdio.h>
-
 #include  <stdlib.h>
-
 #include  <math.h>
-
 #include  "color.h"
 
 #ifdef getc_unlocked		/* avoid horrendous overhead of flockfile */
 #undef getc
 #undef putc
+#undef ferror
 #define getc    getc_unlocked
 #define putc    putc_unlocked
+#define ferror	ferror_unlocked
 #endif
 
 #define  MINELEN	8	/* minimum scanline length for encoding */
@@ -30,30 +29,31 @@ static const char	RCSid[] = "$Id: color.c,v 2.15 2004/
 
 
 char *
-tempbuffer(len)			/* get a temporary buffer */
-unsigned int  len;
+tempbuffer(			/* get a temporary buffer */
+	unsigned int  len
+)
 {
 	static char  *tempbuf = NULL;
 	static unsigned  tempbuflen = 0;
 
-	if (len > tempbuflen) {
-		if (tempbuflen > 0)
-			tempbuf = (char *)realloc((void *)tempbuf, len);
-		else
-			tempbuf = (char *)malloc(len);
-		tempbuflen = tempbuf==NULL ? 0 : len;
+	if (!len | (len > tempbuflen)) {
+		if (tempbuflen)
+			free(tempbuf);
+		tempbuf = len ? (char *)malloc(len) : (char *)NULL;
+		tempbuflen = len*(tempbuf != NULL);
 	}
 	return(tempbuf);
 }
 
 
 int
-fwritecolrs(scanline, len, fp)		/* write out a colr scanline */
-register COLR  *scanline;
-int  len;
-register FILE  *fp;
+fwritecolrs(			/* write out a colr scanline */
+	COLR  *scanline,
+	int  len,
+	FILE  *fp
+)
 {
-	register int  i, j, beg, cnt = 1;
+	int  i, j, beg, cnt = 1;
 	int  c2;
 	
 	if ((len < MINELEN) | (len > MAXELEN))	/* OOBs, write out flat */
@@ -62,18 +62,18 @@ register FILE  *fp;
 	putc(2, fp);
 	putc(2, fp);
 	putc(len>>8, fp);
-	putc(len&255, fp);
+	putc(len&0xff, fp);
 					/* put components seperately */
 	for (i = 0; i < 4; i++) {
 	    for (j = 0; j < len; j += cnt) {	/* find next run */
 		for (beg = j; beg < len; beg += cnt) {
-		    for (cnt = 1; cnt < 127 && beg+cnt < len &&
+		    for (cnt = 1; (cnt < 127) & (beg+cnt < len) &&
 			    scanline[beg+cnt][i] == scanline[beg][i]; cnt++)
 			;
 		    if (cnt >= MINRUN)
 			break;			/* long enough */
 		}
-		if (beg-j > 1 && beg-j < MINRUN) {
+		if ((beg-j > 1) & (beg-j < MINRUN)) {
 		    c2 = j+1;
 		    while (scanline[c2++][i] == scanline[j][i])
 			if (c2 == beg) {	/* short run */
@@ -101,30 +101,31 @@ register FILE  *fp;
 
 
 static int
-oldreadcolrs(scanline, len, fp)		/* read in an old colr scanline */
-register COLR  *scanline;
-int  len;
-register FILE  *fp;
+oldreadcolrs(			/* read in an old-style colr scanline */
+	COLR  *scanline,
+	int  len,
+	FILE  *fp
+)
 {
-	int  rshift;
-	register int  i;
+	int  rshift = 0;
+	int  i;
 	
-	rshift = 0;
-	
 	while (len > 0) {
 		scanline[0][RED] = getc(fp);
 		scanline[0][GRN] = getc(fp);
 		scanline[0][BLU] = getc(fp);
-		scanline[0][EXP] = getc(fp);
-		if (feof(fp) || ferror(fp))
+		scanline[0][EXP] = i = getc(fp);
+		if (i == EOF)
 			return(-1);
-		if (scanline[0][RED] == 1 &&
-				scanline[0][GRN] == 1 &&
-				scanline[0][BLU] == 1) {
-			for (i = scanline[0][EXP] << rshift; i > 0; i--) {
+		if (scanline[0][GRN] == 1 &&
+				(scanline[0][RED] == 1) &
+				(scanline[0][BLU] == 1)) {
+			i = scanline[0][EXP] << rshift;
+			while (i--) {
 				copycolr(scanline[0], scanline[-1]);
+				if (--len <= 0)
+					return(0);
 				scanline++;
-				len--;
 			}
 			rshift += 8;
 		} else {
@@ -138,12 +139,13 @@ register FILE  *fp;
 
 
 int
-freadcolrs(scanline, len, fp)		/* read in an encoded colr scanline */
-register COLR  *scanline;
-int  len;
-register FILE  *fp;
+freadcolrs(			/* read in an encoded colr scanline */
+	COLR  *scanline,
+	int  len,
+	FILE  *fp
+)
 {
-	register int  i, j;
+	int  i, j;
 	int  code, val;
 					/* determine scanline type */
 	if ((len < MINELEN) | (len > MAXELEN))
@@ -158,7 +160,7 @@ register FILE  *fp;
 	scanline[0][BLU] = getc(fp);
 	if ((i = getc(fp)) == EOF)
 		return(-1);
-	if (scanline[0][GRN] != 2 || scanline[0][BLU] & 128) {
+	if ((scanline[0][GRN] != 2) | ((scanline[0][BLU] & 0x80) != 0)) {
 		scanline[0][RED] = 2;
 		scanline[0][EXP] = i;
 		return(oldreadcolrs(scanline+1, len-1, fp));
@@ -174,28 +176,34 @@ register FILE  *fp;
 		    code &= 127;
 		    if ((val = getc(fp)) == EOF)
 			return -1;
+		    if (j + code > len)
+		    	return -1;	/* overrun */
 		    while (code--)
 			scanline[j++][i] = val;
-		} else			/* non-run */
+		} else {		/* non-run */
+		    if (j + code > len)
+		    	return -1;	/* overrun */
 		    while (code--) {
 			if ((val = getc(fp)) == EOF)
 			    return -1;
 			scanline[j++][i] = val;
 		    }
+		}
 	    }
 	return(0);
 }
 
 
 int
-fwritescan(scanline, len, fp)		/* write out a scanline */
-register COLOR  *scanline;
-int  len;
-FILE  *fp;
+fwritescan(			/* write out a scanline */
+	COLOR  *scanline,
+	int  len,
+	FILE  *fp
+)
 {
 	COLR  *clrscan;
 	int  n;
-	register COLR  *sp;
+	COLR  *sp;
 					/* get scanline buffer */
 	if ((sp = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
 		return(-1);
@@ -214,12 +222,13 @@ FILE  *fp;
 
 
 int
-freadscan(scanline, len, fp)		/* read in a scanline */
-register COLOR  *scanline;
-int  len;
-FILE  *fp;
+freadscan(			/* read in a scanline */
+	COLOR  *scanline,
+	int  len,
+	FILE  *fp
+)
 {
-	register COLR  *clrscan;
+	COLR  *clrscan;
 
 	if ((clrscan = (COLR *)tempbuffer(len*sizeof(COLR))) == NULL)
 		return(-1);
@@ -229,10 +238,10 @@ FILE  *fp;
 	colr_color(scanline[0], clrscan[0]);
 	while (--len > 0) {
 		scanline++; clrscan++;
-		if (clrscan[0][RED] == clrscan[-1][RED] &&
-			    clrscan[0][GRN] == clrscan[-1][GRN] &&
-			    clrscan[0][BLU] == clrscan[-1][BLU] &&
-			    clrscan[0][EXP] == clrscan[-1][EXP])
+		if (clrscan[0][GRN] == clrscan[-1][GRN] &&
+			    (clrscan[0][RED] == clrscan[-1][RED]) &
+			    (clrscan[0][BLU] == clrscan[-1][BLU]) &
+			    (clrscan[0][EXP] == clrscan[-1][EXP]))
 			copycolor(scanline[0], scanline[-1]);
 		else
 			colr_color(scanline[0], clrscan[0]);
@@ -242,9 +251,12 @@ FILE  *fp;
 
 
 void
-setcolr(clr, r, g, b)		/* assign a short color value */
-register COLR  clr;
-double  r, g, b;
+setcolr(			/* assign a short color value */
+	COLR  clr,
+	double  r,
+	double  g,
+	double  b
+)
 {
 	double  d;
 	int  e;
@@ -258,7 +270,7 @@ double  r, g, b;
 		return;
 	}
 
-	d = frexp(d, &e) * 255.9999 / d;
+	d = frexp(d, &e) * 256.0 / d;
 
 	if (r > 0.0)
 		clr[RED] = r * d;
@@ -278,9 +290,10 @@ double  r, g, b;
 
 
 void
-colr_color(col, clr)		/* convert short to float color */
-register COLOR  col;
-register COLR  clr;
+colr_color(			/* convert short to float color */
+	COLOR  col,
+	COLR  clr
+)
 {
 	double  f;
 	
@@ -296,15 +309,17 @@ register COLR  clr;
 
 
 int
-bigdiff(c1, c2, md)			/* c1 delta c2 > md? */
-register COLOR  c1, c2;
-double  md;
+bigdiff(				/* c1 delta c2 > md? */
+	COLOR  c1,
+	COLOR  c2,
+	double  md
+)
 {
-	register int  i;
+	int  i;
 
 	for (i = 0; i < 3; i++)
 		if (colval(c1,i)-colval(c2,i) > md*colval(c2,i) ||
-			colval(c2,i)-colval(c1,i) > md*colval(c1,i))
+				colval(c2,i)-colval(c1,i) > md*colval(c1,i))
 			return(1);
 	return(0);
 }