+static void
+adj_land_update(int x, int y)
+{
+ int dir, nx, ny, noff;
+
+ assert(own[x][y] != -1);
+
+ for (dir = DIR_FIRST; dir <= DIR_LAST; dir++) {
+ nx = new_x(x + diroff[dir][0]);
+ ny = new_y(y + diroff[dir][1]);
+ noff = XYOFFSET(nx, ny);
+ adj_land[noff] |= 1u << DIR_BACK(dir);
+ }
+}
+