Tileable Perlin noise: each octave wraps its integer grid coordinates
with modulo at the octave's frequency, so gradients at opposite edges
match and the noise field is continuous across the boundary.
Coarse elevation grid interpolation wraps instead of padding boundary
cells. Rivers can flow across world edges. All coordinate access
(get_tile, is_passable, get_viewport) wraps via modulo. Movement,
spawn search, nearby-player detection, and viewport relative positions
all handle the toroidal topology.
1000x1000 tile world generated deterministically from a seed using
layered Perlin noise. Terrain derived from elevation: mountains,
forests, grasslands, sand, water, with rivers traced downhill from
peaks. ANSI-colored viewport centered on player.
Command system with registry/dispatch, 8-direction movement (n/s/e/w
+ diagonals), look/l, quit/q. Players see arrival/departure messages.
Set connect_maxwait=0.5 on telnetlib3 to avoid the 4s CHARSET
negotiation timeout — MUD clients reject CHARSET immediately via MTTS.
