Engine trails

Trails are done.  Positions are tracked in memory, but most of the work calculating the trail shape is done in shaders.
I’ve given enemy ships trails too.  Zooming out when there are a lot of them around is now more interesting looking.
Obviously the blue trail coming from the yellow/red flames of the player ship doesn’t make much sense, and neither does having the trail coming from the middle of the ship, but those are relatively minor things.
Note those ugly spiky things that happen when the player makes really sharp turns, also seen in many other games.  Getting rid of those is pretty difficult, and probably not worthwhile.  Instead, I’ll just manage it with the point update rate and trail width.
For next time: some kind of system for generating stuff to do at planets.  Trading?  Quests?  Base building?  Something.  This will probably involve building some sort of real UI, which is bound to be a major project.  Just building the UI for the emitter program took a while, and that wasn’t exactly user friendly stuff.

ver19