Index: work/polybloat/bloat.sh
===================================================================
--- work/polybloat/bloat.sh	(revision 19439)
+++ work/polybloat/bloat.sh	(revision 19440)
@@ -1,7 +1,8 @@
 #!/bin/sh
 
 
-awk -v "bloat=$1" '
+awk -v "bloat=$1" -v "target_edge=$2" '
+
 function draw(POLY   ,n)
 {
 	printf("lines")
@@ -11,9 +12,86 @@
 	print ""
 }
 
+function pwrap(POLY, n)
+{
+	if (n < 0) n+=POLY["len"]
+	else if (n >= POLY["len"]) n -= POLY["len"]
+	return n
+}
+
+function edge_shift(POLY, bloat, n0    ,x0,y0,xp,yp,x1,y1,xn,yn, dx,dy,l,nx,ny  ,ax,ay,al)
+{
+	x0 = POLY[n0, "x"]
+	y0 = POLY[n0, "y"]
+	x1 = POLY[pwrap(POLY, n0+1), "x"]
+	y1 = POLY[pwrap(POLY, n0+1), "y"]
+	xn = POLY[pwrap(POLY, n0+2), "x"]
+	yn = POLY[pwrap(POLY, n0+2), "y"]
+	xp = POLY[pwrap(POLY, n0-1), "x"]
+	yp = POLY[pwrap(POLY, n0-1), "y"]
+
+	# targe edge normal
+	dx = x1 - x0
+	dy = y1 - y0
+	l = sqrt(dx*dx + dy*dy)
+	dx /= l
+	dy /= l
+	nx = -dy
+	ny = dx
+
+ # previous edge offset
+	ax = x0 - xp
+	ay = y0 - yp
+
+	al = sqrt(ax*ax + ay*ay)
+	ax /= al
+	ay /= al
+
+	a1l = ax*nx + ay*ny;
+
+	a1x = bloat/a1l*ax
+	a1y = bloat/a1l*ay
+
+	x0 += a1x
+	y0 += a1y
+
+ # next edge offset
+	ax = xn - x1
+	ay = yn - y1
+
+
+	al = sqrt(ax*ax + ay*ay)
+	ax /= al
+	ay /= al
+
+	a1l = ax*nx + ay*ny;
+
+	a1x = bloat/a1l*ax
+	a1y = bloat/a1l*ay
+
+	x1 += a1x
+	y1 += a1y
+
+	POLY[n0, "x"] = x0
+	POLY[n0, "y"] = y0
+	POLY[pwrap(POLY, n0+1), "x"] = x1
+	POLY[pwrap(POLY, n0+1), "y"] = y1
+}
+
+function poly_bloat(POLY, bloat,   n)
+{
+	if (target_edge == "")
+		for(n = 0; n < POLY["len"]; n++)
+			edge_shift(POLY, bloat, n)
+	else
+			edge_shift(POLY, bloat, target_edge)
+}
+
+### loader 
+
 /^[ \t]*#/ { next }
 
-{
+(NF == 2) {
 	len = int(POLY["len"])
 	POLY["len"] = len+1
 	POLY[len, "x"] = $1
@@ -20,11 +98,13 @@
 	POLY[len, "y"] = $2
 }
 
+### main 
 END {
 	print "viewport 0 0 - 10 10"
 	print "frame"
 	print "color #aaaaaa"
 	draw(POLY)
+	poly_bloat(POLY, bloat)
 	print "color #000000"
 	draw(POLY)
 	print "flush"