+/* yx_uint16.h
+ *
+ * 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>
-#define NORTH 1
-#define EAST 2
-#define SOUTH 3
-#define WEST 4
-struct yx_uint16 {
- uint16_t y;
- uint16_t x; };
+#include <stdint.h> /* for uint16_t */
+
+
+
+/* Coordinates for maps of max. 65536x65536 cells. */
+struct yx_uint16
+{
+ uint16_t y;
+ uint16_t x;
+};
+
+/* Directions available for movement. */
+enum dir
+{
+ NORTH = 1,
+ 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);
-extern char yx_uint16_cmp (struct yx_uint16, struct yx_uint16);
-struct yx_uint16 mv_yx_in_dir (char, struct yx_uint16);
+/* Return yx_uint16 coordinate one step from coordinate yx in direction dir. */
+extern struct yx_uint16 mv_yx_in_dir(enum dir d, struct yx_uint16 yx);
#endif