Index: trunk/src/thermal.c
===================================================================
--- trunk/src/thermal.c	(revision 13565)
+++ trunk/src/thermal.c	(revision 13566)
@@ -412,10 +412,11 @@
 	pcb_polyarea_t *ptmp, *p;
 	double fact = 0.5, fact_ortho=0.75;
 	pcb_coord_t cx, cy;
-	double px, py, x, y, dx, dy, vx, vy, nx, ny, mx, my, len;
+	double px, py, x, y, dx, dy, vx, vy, nx, ny, mx, my, len, cl2;
 	int go, first = 1;
 
 	clr -= 2;
+	cl2 = (double)clr * (double)clr;
 
 	/* iterate over the vectors of the contour */
 	for(go = pcb_poly_vect_first(it, &cx, &cy); go; go = pcb_poly_vect_next(it, &cx, &cy)) {
@@ -426,6 +427,10 @@
 			first = 0;
 		}
 
+		/* skip points too dense */
+		if (pcb_distance2(x, y, px, py) < cl2)
+			continue;
+
 		dx = x - px;
 		dy = y - py;
 		mx = (x+px)/2.0;
@@ -479,9 +484,11 @@
 {
 	pcb_polyarea_t *ptmp, *p;
 	pcb_coord_t cx, cy, x2c, y2c;
-	double px, py, x, y, dx, dy, vx, vy, nx, ny, mx, my, len, x2, y2, vx2, vy2, len2, dx2, dy2;
+	double px, py, x, y, dx, dy, vx, vy, nx, ny, mx, my, len, x2, y2, vx2, vy2, len2, dx2, dy2, cl2;
 	int go, first = 1;
 
+	cl2 = (double)clr * (double)clr;
+
 	/* iterate over the vectors of the contour */
 	for(go = pcb_poly_vect_first(it, &cx, &cy); go; go = pcb_poly_vect_next(it, &cx, &cy)) {
 		x = cx; y = cy;
@@ -494,6 +501,10 @@
 		if ((x == px) && (y == py))
 			continue;
 
+		/* skip points too dense */
+		if (pcb_distance2(x, y, px, py) < cl2)
+			continue;
+
 		dx = x - px;
 		dy = y - py;