-int8_t ijcoord_to_corn_idx(int8_t i, int8_t j);
-int8_t xycoord_to_corn_idx(int16_t *x, int16_t *y);
-void init_corn_table(int8_t conf_side, int8_t conf_center);
+void num2line(struct line_2pts *l, uint8_t dir, uint8_t num);
+
+uint8_t line2line(uint8_t dir1, uint8_t num1,
+ uint8_t dir2, uint8_t num2);