Index: work/polybloat/bloat.sh
===================================================================
--- work/polybloat/bloat.sh	(revision 19444)
+++ work/polybloat/bloat.sh	(revision 19445)
@@ -94,6 +94,24 @@
 			edge_shift(POLY, NX, NY, bloat, n)
 	else
 			edge_shift(POLY, NX, NY, bloat, target_edge)
+
+
+	for(n = 0; n < POLY["len"]; n++) {
+		x0 = POLY[n, "x"]
+		y0 = POLY[n, "y"]
+		x1 = POLY[pwrap(POLY, n+1), "x"]
+		y1 = POLY[pwrap(POLY, n+1), "y"]
+
+		# targe edge normal
+		dx = x1 - x0
+		dy = y1 - y0
+		l = sqrt(dx*dx + dy*dy)
+		dx /= l
+		dy /= l
+		if ((NX[n] != -dy) || (NY[n] != dx))
+			print "Normal FLIP!" > "/dev/stderr"
+	}
+
 }
 
 ### loader