-static void perturb_point_mid(int x1, int x2, int x3, int x4,
- int xmid, int ymid, int rough, int depth_max)
+static void perturb_point_mid(POSITION x1, POSITION x2, POSITION x3, POSITION x4, POSITION xmid, POSITION ymid, POSITION rough, POSITION depth_max)