individual wagon extents

[orwell96]

According to semver standard, increasing the major version number means incompatible changes.
Main points:

• Rework the collision system again:
  • Give each individual wagon values about its extents, and calculate occupied nodesfor each wagon individually
  • do not make coupling dependent on collision
    -> api to allow for different train / wagon sizes
• DB trains with greater extents: 3x4m, using the above api
  will need new platform nodes and at least 2 nodes space between rails -> breaking compatibility with existing builds
• redo the ttrain placement item and prepare api for trains with trucks
• ... power lines
• ... outside train display (using font of large display mod from gpcf)
  Possibly: add larger rails 1435mm, use for all new trains and label the others "small track"

[lemon-melon]

Regarding platform nodes, I would prefer just using moreblocks:

• there's much more choice
  • it works with more nodes
  • you can add slopes for the ends of platforms (if you want slopes)
  • you can use the different shapes/sizes to get a platform that closely follows a diagonal track
• it would avoid duplicating work between moreblocks and advtrains

Problems are:

• you don't get the yellow line
  • but it should be easy to replace from somewhere (edit: e.g. StreetsMod, or possibly using moreblocks on a yellow-coloured block)
• more importantly, advtrains doesn't drive past moreblocks nodes which are next to the track
  • it might be complicated to calculate the position of moreblocks nodes, and whether they obstruct the train
  • it could be easier to just treat moreblocks nodes as not obstructing
    • edit: adding fields.groups.not_blocking_trains = 1 at the start of stairsplus:register_all in moreblocks/stairsplus/init.lua does this

Also, half-height platforms look better sometimes because they aren't too high compared to the train, but it's also difficult to place things (like benches) on them. Perhaps instead there could be a half-height track (i.e. raised by 0.5 m), so the platform can use normal blocks? This would probably fit in with whenever you decide to add more sloping track.

[orwell96]

I might rework all models so that the door heights match better with the nodes

[gpcf]

make the trains fit in existing 3m wide tunnels, so they're like 2.9m wide and 4m high. Just add new platform nodes to adapt to this. This would make infrastructure migration a lot easier, but trains would still be more realistic, since trains are normally about 3 meters wide.

[orwell96]

^^
Right, this is what I'm aiming for. The problem is that rails that only have a single node of space between them will become useless.