--- ray/src/px/x11image.c	1991/05/02 17:24:54	1.17
+++ ray/src/px/x11image.c	1991/08/26 10:15:01	1.25
@@ -1,4 +1,4 @@
-/* Copyright (c) 1990 Regents of the University of California */
+/* Copyright (c) 1991 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -37,7 +37,7 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #define  BORWIDTH	5		/* border width */
 
-#define  ICONSIZ	80		/* maximum icon dimension */
+#define  ICONSIZ	(8*10)		/* maximum icon dimension (even 8) */
 
 #define  ourscreen	DefaultScreen(thedisplay)
 #define  ourblack	BlackPixel(thedisplay,ourscreen)
@@ -92,7 +92,7 @@ struct {
 
 char  *geometry = NULL;			/* geometry specification */
 
-char  icondata[(ICONSIZ+7)/8*ICONSIZ];	/* icon bitmap data */
+char  icondata[ICONSIZ*ICONSIZ/8];	/* icon bitmap data */
 int  iconwidth = 0, iconheight = 0;
 
 char  *progname;
@@ -246,9 +246,9 @@ init()			/* get data and open window */
 	XSetFont(thedisplay, ourgc, fontid);
 	revgc = XCreateGC(thedisplay, wind, 0, 0);
 	XSetFunction(thedisplay, revgc, GXinvert);
-	XStoreName(thedisplay, wind, fname == NULL ? progname : fname);
 	XDefineCursor(thedisplay, wind, XCreateFontCursor(thedisplay, 
 			XC_diamond_cross));
+	XStoreName(thedisplay, wind, fname == NULL ? progname : fname);
 	if (geometry != NULL) {
 		bzero((char *)&oursizhints, sizeof(oursizhints));
 		i = XParseGeometry(geometry, &oursizhints.x, &oursizhints.y,
@@ -580,6 +580,8 @@ int  x0, y0, x1, y1;
 avgbox(clr)				/* average color over current box */
 COLOR  clr;
 {
+	static COLOR  lc;
+	static int  ll, lr, lt, lb;
 	int  left, right, top, bottom;
 	int  y;
 	double  d;
@@ -603,6 +605,10 @@ COLOR  clr;
 		bottom = ymax;
 	if (top >= bottom)
 		return(-1);
+	if (left == ll && right == lr && top == lt && bottom == lb) {
+		copycolor(clr, lc);
+		return;
+	}
 	for (y = top; y < bottom; y++) {
 		if (getscan(y) == -1)
 			return(-1);
@@ -613,6 +619,8 @@ COLOR  clr;
 	}
 	d = 1.0/((right-left)*(bottom-top));
 	scalecolor(clr, d);
+	ll = left; lr = right; lt = top; lb = bottom;
+	copycolor(lc, clr);
 	return(0);
 }
 
@@ -621,7 +629,7 @@ getmono()			/* get monochrome data */
 {
 	register unsigned char	*dp;
 	register int	x, err;
-	int	y;
+	int	y, errp;
 	short	*cerr;
 
 	if ((cerr = (short *)calloc(xmax,sizeof(short))) == NULL)
@@ -636,12 +644,14 @@ getmono()			/* get monochrome data */
 		for (x = 0; x < xmax; x++) {
 			if (!(x&7))
 				*++dp = 0;
+			errp = err;
 			err += normbright(scanline[x]) + cerr[x];
 			if (err > 127)
 				err -= 255;
 			else
 				*dp |= 1<<(7-(x&07));
-			cerr[x] = err >>= 1;
+			err /= 3;
+			cerr[x] = err + errp;
 		}
 	}
 	free((char *)cerr);
@@ -652,42 +662,48 @@ add2icon(y, scan)		/* add a scanline to our icon data 
 int  y;
 COLR  *scan;
 {
-	static char  *dp = NULL;
 	static short  cerr[ICONSIZ];
+	static int  ynext;
+	static char  *dp;
 	register int  err;
-	register int	x, xi;
+	register int	x, ti;
+	int  errp;
 
 	if (iconheight == 0) {		/* initialize */
-		if (xmax < ICONSIZ && ymax < ICONSIZ) {
+		if (xmax <= ICONSIZ && ymax <= ICONSIZ) {
 			iconwidth = xmax;
 			iconheight = ymax;
 		} else if (xmax > ymax) {
 			iconwidth = ICONSIZ;
 			iconheight = ICONSIZ*ymax/xmax;
+			if (iconheight < 1)
+				iconheight = 1;
 		} else {
 			iconwidth = ICONSIZ*xmax/ymax;
+			if (iconwidth < 1)
+				iconwidth = 1;
 			iconheight = ICONSIZ;
 		}
+		ynext = 0;
 		dp = icondata - 1;
 	}
-	if (dp == NULL)			/* done already */
+	if (y < ynext*ymax/iconheight)	/* skip this one */
 		return;
-	if (y % (ymax/iconheight))	/* skip this one */
-		return;
 	err = 0;
 	for (x = 0; x < iconwidth; x++) {
 		if (!(x&7))
 			*++dp = 0;
-		xi = x*xmax/iconwidth;
-		err += normbright(scan[xi]) + cerr[x];
+		errp = err;
+		ti = x*xmax/iconwidth;
+		err += normbright(scan[ti]) + cerr[x];
 		if (err > 127)
 			err -= 255;
 		else
 			*dp |= 1<<(x&07);
-		cerr[x] = err >>= 1;
+		err /= 3;
+		cerr[x] = err + errp;
 	}
-	if (y >= ymax-ymax/iconheight)	/* all done */
-		dp = NULL;
+	ynext++;
 }