Add get_object_center method to misc.gd

misc.gd

@@ -66,3 +66,7 @@ func flat_float(number:float) -> float:
 
 func flat_float_int(number:float) -> int:
 	return int(number)
+
+# Get object center
+func get_object_center(child_size:float,parent_size:float) -> float:
+	return parent_size/2-child_size/2