Galactic perimeter

The galactic perimeter is the outer limit of the playable galaxy. UNIVMAX sets its radius in sectors, while UNIVWRAP determines whether a ship crossing an edge wraps to the opposite side or is repelled. The default is a repelling perimeter.

Classic Galactic Empire

In the default non-wrapping galaxy, crossing an outer edge stops the ship, sets its crossed coordinate to UNIVMAX - 2 (or the corresponding negative coordinate), and applies the configured TELEDAM collision damage. This is a fixed landing coordinate, not a distance measured back from the point of impact: a fast ship that overshoots the edge still lands at the same position as a slow ship. The ship's heading is left unchanged. It must be steered away before resuming travel, although NPC navigation may eventually choose a new course.

The X and Y boundaries are handled independently. A ship crossing both in one movement update can receive two collision messages and two damage applications. Classic also tests against +UNIVMAX rather than the far edge of that positive-numbered sector. Consequently, with UNIVMAX 300, sector 300 has no usable width: the effective galaxy is 600 by 600 sectors rather than the intended 601 by 601. These boundary and corner problems are detailed in Classic bug: Galactic perimeter edge errors.

With UNIVWRAP enabled, classic instead shifts each crossed coordinate to the opposite edge without collision damage. Its original boundary arithmetic has the same missing-positive-sector problem, including a wrap span of 600 rather than 601 sectors at the default radius.

ge-next

ge-next 0.1 corrected the galaxy's limits and wrapping span. At the default radius of 300, sectors -300 through 300 are fully playable on each axis, giving a 601 by 601 galaxy. With wrapping enabled, crossing an edge brings the ship to the corresponding position on the opposite side; it does not trigger a repelling collision.

For a non-wrapping collision, ge-next still stops the ship and applies boundary damage to a player, but the bounce grows with impact speed. The crossed coordinate is placed at UNIVMAX - 2 - floor(speed / 1000) on the positive side, or its negative counterpart; speed / 1000 is the ship's warp speed. For example, a warp-10 ship reaching the positive edge of a radius-300 galaxy is placed at coordinate 288. The ship is also rotated toward the center of sector 0 0, giving it an inward heading before it accelerates again. NPCs are stopped and pointed inward rather than repeatedly following an outward heading into the boundary.

A corner crossing corrects both coordinates but triggers the collision routine only once, so it does not double the player's damage or warning. ge-next's SCAN RA and SCAN LO maps also mark areas wholly beyond the galaxy with blue-highlighted dots. This makes the edge visible on a scan before a ship reaches it.

Small galaxies and ge-arena

ge-next 0.3.2 capped the speed-derived part of the bounce at one third of UNIVMAX, with a minimum cap of one sector unit. In a normal-sized galaxy this leaves ordinary collisions unchanged. In a small galaxy, such as a ge-arena match, it prevents a high-speed collision from placing the ship beyond the opposite perimeter and causing another immediate bounce. A radius-10 galaxy, for example, caps that part of the bounce at 3: even at warp 30, a collision with the positive edge places that coordinate at 5, not beyond the opposite edge. This shared correction also protects any small ge-next galaxy configured by a sysop.

ge-arena's separate staging and tiebreaker rule confines active players to sector 0 0 until combat is allowed or for the duration of the tiebreaker. Crossing that sector boundary uses a repulsion penalty, but it is not the outer galactic perimeter. The outer perimeter's wrapping or repelling behavior remains controlled by UNIVWRAP when players can travel through the galaxy.

Classic Galactic Empire

ge-next

Small galaxies and ge-arena

See also