/* src/server/map.c */
#include "map.h"
-#include <stdint.h> /* uint8_t, uint16_t, uint32_t, UINT16_MAX */
+#include <stdint.h> /* uint8_t, int8_t, uint16_t, uint32_t, (U)INT*_(MIN|MAX) */
#include <stdlib.h> /* free() */
+#include <string.h> /* strchr() */
#include "../common/rexit.h" /* exit_err() */
#include "../common/try_malloc.h" /* try_malloc() */
-#include "../common/yx_uint8.h" /* struct yx_uint8 */
+#include "../common/yx_uint8.h" /* yx_uint8 */
#include "rrand.h" /* rrand() */
#include "world.h" /* global world */
+/* Helper to mv_yx_in_dir_legal(). Move "yx" into hex direction "d". */
+static void mv_yx_in_dir(char d, struct yx_uint8 * yx);
+
/* Call this too often with "init" of 0 and the game exits with an error message
* about reaching an iteration limit. An "init" of 1 sets the iteration counter
* to 0. Iteration limit is currently 256 * UINT16_MAX.
+static void mv_yx_in_dir(char d, struct yx_uint8 * yx)
+{
+ if (d == 'e')
+ {
+ yx->x = yx->x + (yx->y % 2);
+ yx->y--;
+ }
+ else if (d == 'd')
+ {
+ yx->x++;
+ }
+ else if (d == 'c')
+ {
+ yx->x = yx->x + (yx->y % 2);
+ yx->y++;
+ }
+ else if (d == 'x')
+ {
+ yx->x = yx->x - !(yx->y % 2);
+ yx->y++;
+ }
+ else if (d == 's')
+ {
+ yx->x--;
+ }
+ else if (d == 'w')
+ {
+ yx->x = yx->x - !(yx->y % 2);
+ yx->y--;
+ }
+}
+
+
+
static uint8_t iter_limit(uint8_t init)
{
static uint32_t i = 0;
-extern uint8_t is_passable(struct yx_uint8 pos)
+extern uint8_t mv_yx_in_dir_legal(char dir, struct yx_uint8 * yx)
{
- uint8_t passable = 0;
- if (pos.x < world.map.length && pos.y < world.map.length)
+ static int8_t wrap_west_east = 0;
+ static int8_t wrap_north_south = 0;
+ if (!yx)
{
- passable = ('.' == world.map.cells[(pos.y * world.map.length) + pos.x]);
+ wrap_west_east = wrap_north_south = 0;
+ return 0;
}
- return passable;
-}
-
-
-
-extern uint16_t yx_to_map_pos(struct yx_uint8 * yx)
-{
- return (yx->y * world.map.length) + yx->x;
+ char * err = "Too much wrapping in mv_yx_in_dir_legal().";
+ exit_err( INT8_MIN == wrap_west_east || INT8_MIN == wrap_north_south
+ || INT8_MAX == wrap_west_east || INT8_MAX == wrap_north_south, err);
+ struct yx_uint8 original;
+ original.y = yx->y;
+ original.x = yx->x;
+ mv_yx_in_dir(dir, yx);
+ if (strchr("edc", dir) && yx->x < original.x)
+ {
+ wrap_west_east++;
+ }
+ else if (strchr("xsw", dir) && yx->x > original.x)
+ {
+ wrap_west_east--;
+ }
+ if (strchr("we", dir) && yx->y > original.y)
+ {
+ wrap_north_south--;
+ }
+ else if (strchr("xc", dir) && yx->y < original.y)
+ {
+ wrap_north_south++;
+ }
+ if ( !((wrap_west_east != 0) + (wrap_north_south != 0))
+ && yx->x < world.map.length && yx->y < world.map.length)
+ {
+ return 1;
+ }
+ return 0;
}