-/* Returns message: "Trouble in ".parent." with ".child."." (try_*() helper) */
-extern char * trouble_msg(char * parent, char * child);
-
-/* Wrappers to malloc(), calloc() from function called "f" calling exit_err()
- * with trouble_msg() error message if necessary.
+/* Return 16-bit number pseudo-randomly generated via Linear Congruential
+ * Generator algorithm with some proven constants. Use instead of rand() to
+ * ensure portability of the same pseudo-randomness across systems.
*/
+extern uint16_t rrand();
+
+/* Wrappers to malloc(), calloc() from function "f"; exit_trouble() on error. */
extern void * try_malloc(size_t size, char * f);
extern void * try_calloc(size_t nmemb, size_t size, char * f);
-
-
-/* Check if tempfile "path" exists, and if so, exit with explanation that. */
-extern void check_tempfile(char * path);
-
/* If one and only one of files at "p1", "p2" exists, fail with explanation. */
extern void check_files_xor(char * p1, char * p2);
-
+/* Check if tempfile "path" exists, and if so, exit with explanation that. */
+extern void check_tempfile(char * path);
/* Save / load / unload (free) / reload interface configuration data. */
extern void save_interface_conf();
extern void unload_interface_conf();
extern void reload_interface_conf();
-
-
-/* Update game log by appending "text", or by appending a "." if "text" is the
- * same as the last one passed.
- */
+/* Append "text" to game log, or a "." if "text" is the same as the last one. */
extern void update_log(char * text);
-
-
-/* Return the offset necessary to center a map of "mapsize" on position "pos" in
- * a frame of "framesize.
- */
-extern uint16_t center_offset(uint16_t pos,
+/* Return offset nto center map of "mapsize" on "position" in "framesize". */
+extern uint16_t center_offset(uint16_t position,
uint16_t mapsize, uint16_t framesize);
-
-
-/* Record last player "action" in game record file "record, increment the game
- * turn and trigger enemy movement.
- */
+/* Record "action" in record file, do all movements until player's next turn. */
extern void turn_over(char action);
-
-
/* Save or load current game data to / from file "savefile". */
extern void save_game();
extern void load_game();
-
-
-/* Return a random position on the map "map" that is passable (as determined by
- * is_passable().
- */
+/* Return random passable (as by is_passable()) position on "map". */
extern struct yx_uint16 find_passable_pos(struct Map * map);
-
-
-/* Navigate (as far as possible) up (dir=='u') or (else) down in player's
- * inventory selection.
- */
+/* Move world.inventory_sel up ("dir"="u") or down (else) as far as possible. */
extern void nav_inventory(char dir);