X-Git-Url: https://plomlompom.com/repos/?a=blobdiff_plain;f=src%2Fyx_uint16.h;h=eb951a7fd895d959046d3e5078a1ddaed71e74ac;hb=35cdeffc062d3d87f1526bbff10c401b56b1345a;hp=a8707618cadb8ed1e8309f46ee960d5478962261;hpb=f222ace2f2441b21a3c29741483d8018294820a4;p=plomrogue

diff --git a/src/yx_uint16.h b/src/yx_uint16.h
index a870761..eb951a7 100644
--- a/src/yx_uint16.h
+++ b/src/yx_uint16.h
@@ -1,10 +1,35 @@
+/*  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>
+
+/* Coordinates for maps of max. 65536x65536 cells. */
+struct yx_uint16
+{
+    uint16_t y;
+    uint16_t x;
+};
+
+/* This encodes directions. */
+
+enum dir
+{
+    NORTH = 1,
+    EAST  = 2,
+    SOUTH = 3,
+    WEST  = 4
+};
+
+/* 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);
+/* 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