Create: CAES

Performance, on the server tick, plus one balance leak the same code path was causing. An 0.1.1 world loads unchanged and nothing about how the mod is played changes, except that an engine whose air supply cannot keep up now waits instead of stuttering.

• A vessel no longer sweeps its whole volume every tick. Telling a vessel's neighbours that its comparator reading moved means a getBlockEntity and a neighbour update for every block of the multiblock, and the tank changes on every tick an engine runs -- so this ran twenty times a second to publish a number that, measured over 100 ticks of steady compression, changed exactly zero times. It now runs when the reading actually moves. Measured on a 3x3x5 vessel: 4,500 neighbour updates per 100 ticks became none, and about 40us of every tick came back. At the 3x3x32 height cap it is closer to 260us per tick, per vessel.
• An engine whose supply cannot keep up waits instead of stuttering. Dropping out of generating takes the engine's speed to zero, which tears the rotation network down and builds it back -- work that scales with the size of the player's factory, not with this mod. A vessel taking in air more slowly than the engine spent it flipped mode every third tick, thirty times in a hundred. There is now a deadband on the way out, matching the one that already existed between compressing and generating.
• An engine no longer gets air nobody paid for. It used to drain whatever was left when it could not afford a full stroke, and the leftover debt was then forgiven on the way to idle -- on a trickle, an engine ran mostly on air it never bought. It now asks before it takes, and the dregs stay in the vessel until there are enough for a whole stroke.
• Counting the engines on a vessel is cheaper. The scan walks the outward faces directly instead of testing all six faces of every block on the shell and discarding two thirds of them, and it reads a blockstate rather than fetching a block entity. On a 3x3x32 vessel that is 402 blockstate reads in place of 1,548 tests and 402 block entity lookups, ten times a second.
• The Air Engine is drawn by Flywheel like every other rotating block. Create pairs an instanced visual with a block entity renderer for its Steam Engine, its shafts and its flywheels; this mod shipped only the renderer, so every engine in view had both its partials transformed vertex by vertex on the CPU every frame. The renderer stays as the fallback for backends that need it.