Combined request for train/rails/pathfinder read access

[Godmave]

LuaTrain: pathfinder stats
- path_rails_to_destination - number of rails to the current destination
- (opt) path_blocks_to_destination - array of RailBlock tables

LuaEntity type="train-stop"
- connected_rail

LuaEntity type="rail"
- rail_blocks - table with one or two RailBlock tables

RailBlock table
- block-number
- length in rails
- number of trains in this block (in most cases 0 or 1, so could even be train_in_block => LuaTrain or nil)
- array of bordering rail-signals

(opt) direct pathfinder access
LuaPathfinder.path(LuaEntity:startRail, LuaEntity:endRail) or LuaPathfinder.path(LuaTrain:train, LuaEntity:endRail)
- path_distance
- pathed_blocks

[eradicator]

LuaEntity type="train-stop"
- connected_rail

Oh yes. Having to guess this by direction is so ugly.

[Aidiakapi]

LuaEntity type="train-stop"
- connected_rail

Would this be the piece of rail that the train stop is connected to, or piece of rail where a train which is stopped at the train stop, would actually stop (the rail before).

LuaEntity type="rail"
- rail_blocks - table with one or two RailBlock tables

Every piece of rail is exclusively part of one block.

RailBlock table
- block-number
- length in rails
- number of trains in this block (in most cases 0 or 1, so could even be train_in_block => LuaTrain or nil)
- array of bordering rail-signals

Distinction between signals that enter the block, and leave the block is important.
There could be multiple trains in a block.
Length of the rail doesn't make much sense, since it wouldn't know length along which path in the block. (Every block can have multiple paths.)

[Godmave]

LuaEntity type="train-stop"
- connected_rail

Would this be the piece of rail that the train stop is connected to, or piece of rail where a train which is stopped at the train stop, would actually stop (the rail before).

You should know that better than anyone else, since you wrote the code to search for it in the can_spawn_train function

RailBlock table
- block-number
- length in rails
- number of trains in this block (in most cases 0 or 1, so could even be train_in_block => LuaTrain or nil)
- array of bordering rail-signals

Distinction between signals that enter the block, and leave the block is important.

Ok

There could be multiple trains in a block.

Ok

Length of the rail doesn't make much sense, since it wouldn't know length along which path in the block. (Every block can have multiple paths.)

Yeah, like we discussed in discord, this one makes no sense then.

[Rseding91]

What's the utility of being able to find rail paths through script? The rail path finder is built specifically for trains so it expects a front rail + direction of search, back rail + direction of search, and list of rail ends to path to (rail + direction of travel) and a source train the path will be used for.

[Godmave]

The utility for me was for the teleportation part of the clusterio mod I am working on. And I would effectively only need the currently calculated distance to destination from the pathfinder.
Since I can not show a map view of trains on other instances, I wanted at least to show a progress bar for the distance a train has still to go until it reaches the next teleport station (distance left in relation to total distance).

Another possible thing would have been to say: this train is approaching the teleport station, is less than train length away, and there is nothing between it and the station, so speed it up until it is just before the station (where it has to stop since I can not dismantle moving stuff).
This would give the teleport a nice effect. I could even apply an overlaying effect on top of the train (most likely this will require a mod for the graphics). A flash or something, to hide that the train stops before getting teleported.

The finding of the attached rails and following its path is needed to make sure the destination station is free and there is no train in the way of the teleport.
Being able to easily access those information without having to scan an area and guess around with directions, would be nice. Especially the part for finding signals.

Here is the current version of trying to do that (written by Aidiakapi):
https://github.com/Godmave/factorioClus ... g.lua#L377

I think Aidiakapi even made a lot more stuff that would definitely be faster in c++ than lua.