X-Git-Url: https://plomlompom.com/repos/?a=blobdiff_plain;f=src%2Fyx_uint16.h;h=f6f90a372dca46c8af4b63a17dcd1e4e3f37bcb6;hb=89c4ab4e0d6d7bb9d51d6714afae52603b465fc0;hp=a8707618cadb8ed1e8309f46ee960d5478962261;hpb=f222ace2f2441b21a3c29741483d8018294820a4;p=plomrogue

diff --git a/src/yx_uint16.h b/src/yx_uint16.h
index a870761..f6f90a3 100644
--- a/src/yx_uint16.h
+++ b/src/yx_uint16.h
@@ -1,10 +1,34 @@
+/* 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