+/* 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
-struct yx_uint16 {
- uint16_t y;
- uint16_t x; };
+#include <stdint.h> /* for uint8_t, uint16_t */
+
+
+
+/* Coordinates for maps of max. 65536x65536 cells. */
+struct yx_uint16
+{
+ uint16_t y;
+ uint16_t x;
+};
+
+
+
+/* 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 "yx" in direction "dir" (east: 'E',
+ * west: 'W', north: 'N', south: 'S'). If "dir" is invalid or would wrap the
+ * move around the edge of a 2^16x2^16 cells field, "yx" remains unchanged.
+ */
+extern struct yx_uint16 mv_yx_in_dir(char dir, struct yx_uint16 yx);
+
-extern char yx_uint16_cmp (struct yx_uint16, struct yx_uint16);
#endif