-
-
-/* Return yx_uint16 coordinate one step from coordinate yx in direction dir.
- *
- * If an invalid dir "d" is passed, "yx" remains unchanged.
+/* Return yx_uint16 coordinate one step from "yx" in direction "dir" (east: 'E',
+ * west: 'W', north: 'N', south: 'S'). An invalid dir leaves "yx" unchanged.