@@ -245,8 +245,8 @@ static uint NPFSlopeCost(AyStarNode *cur
/* Get the height on both sides of the tile edge.
* Avoid testing the height on the tile-center. This will fail for halftile-foundations.
*/
int z1 = GetSlopePixelZ(x1 + dx4, y1 + dy4);
int z2 = GetSlopePixelZ(x2 - dx4, y2 - dy4);
int z1 = GetSlopePixelZ(x1 + dx4, y1 + dy4, true);
int z2 = GetSlopePixelZ(x2 - dx4, y2 - dy4, true);
if (z2 - z1 > 1) {
/* Slope up */