A custom rail planner

[mrudat]

It would probably be useful to have a scripted rail planner to play with different methods for laying rail as suggested here. Automatic Belt Planner looks like it might be a good place to start from.

It seems that you would want to optionally:

• avoid trees - perhaps pick path that kills the least number of trees
• avoid rocks
• avoid cliffs

It would ideally be able to do all that FARL can do, in addition to just laying rail.

So:

• the ability to lay signals, LHD/RHD or two-way rail
  • specification of the distance between signals, possibly by number of cars, rather than in tiles.
• the ability to lay parallel track (for LHD/RHD), specifying distance between rails
• the ability to route power poles
  • support for arbitrary power poles; perhaps like Outpost Planner, with the ability to specify the power pole by holding one, and clicking a button in the GUI
• also place ghosts for walls and concrete? Perhaps a separate planner for that?

Distance between rails should probably be optionally enforced; in theory you only care about distance between rails at the start and end of a length of track with no intersections, as it's only necessary to have a specific track separation to make use of specific intersection blueprints, and it is easiest to change track separation when going around a corner or moving the parallel tracks sideways; provided that there is at least one corner between start and end, you can change track separation by one without having to have a large odd-looking section of track.