+struct cell *level_cell(struct level *lvl, int cx, int cy);
+
+void upd_vis(struct level *lvl, struct player *p);
+
+void cell_to_pos(struct level *lvl, int cx, int cy, int32_t *px, int32_t *py);
+void pos_to_cell(struct level *lvl, int32_t px, int32_t py, int *cx, int *cy);
+