-/* yx_uint16.h
+/* yx_uint16.h
*
- * Structs and routines for coordinates and movement in 2-dimensional space
- * (such as the ncurses screen and game maps).
+ * Structs and routines for coordinates and movement in 2-dimensional space
+ * (such as the ncurses screen and game maps).
*/
#ifndef YX_UINT16_H
#define YX_UINT16_H
-#include <stdint.h>
+
+
+#include <stdint.h> /* for uint8_t, uint16_t */
+
+
/* Coordinates for maps of max. 65536x65536 cells. */
struct yx_uint16
uint16_t x;
};
-/* This encodes directions. */
+
+/* Directions available for movement. */
enum dir
{
NORTH = 1,
- EAST = 2,
- SOUTH = 3,
- WEST = 4
+ EAST,
+ SOUTH,
+ WEST
};
-/* Return 1 if two yx_uint16 coordinates a and b are equal, else 0. */
-extern char yx_uint16_cmp(struct yx_uint16 a, struct yx_uint16 b);
-/* Return yx_uint16 coordinate one step from coordinate yx in direction dir. */
+
+/* Return 1 if two yx_uint16 coordinates at "a" and "b" are equal, else 0. */
+extern uint8_t yx_uint16_cmp(struct yx_uint16 * a, struct yx_uint16 * b);
+
+
+
+/* Return yx_uint16 coordinate one step from coordinate yx in direction dir.
+ *
+ * If an invalid dir "d" is passed, "yx" remains unchanged.
+ */
extern struct yx_uint16 mv_yx_in_dir(enum dir d, struct yx_uint16 yx);
+
+
#endif