## Description:
Add a rail network to handle train stations/railroad between structures.
Changes:
- `RailNetwork` is responsible for the train station graph. Use it to
connect new `TrainStations`
- A `RailRoad` connects two `TrainStation`
- No loop possible in the rail network
- Train stations handles its railroads
- Added a layer to draw the railroads under the structures
#### Clusters
- To speed up computations, each `TrainStation` references its own
cluster
- A cluster is a list of `TrainStation` connected with each other,
created by the `RailNetwork` when connecting the station
- Train stations spawn trains randomly depending on its current cluster
size
- A `TrainStation` decides randomly of the train destination by picking
one from the cluster
#### Production building:
- Added a factory which has no gameplay impact currently. _To be
discussed._
#### Train stops:
- When a train reaches a factory, it's filled with a "cargo". The loaded
trains has no impact currently. _To be discussed._
- When a train reaches a city, the player earn 10k gold
- When a train reaches a port, it sends a new tradeship if possible
- If a destination/source is destroyed, the train & railroad are deleted
too
https://github.com/user-attachments/assets/42375c17-9e04-4a42-98d0-708c81ffd609https://github.com/user-attachments/assets/fbecdb53-a516-4df8-87fb-1f9a62c4efa0
## Please complete the following:
- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors
## Please put your Discord username so you can be contacted if a bug or
regression is found:
IngloriousTom
---------
Co-authored-by: Scott Anderson <scottanderson@users.noreply.github.com>
DevelopingTom