Changing station rating calculation

[Casual tycooner]

I'd like to change the way station ratings are calculated, how should I go about it?
editing the source code directly doesn't sound like the most sustainable idea

[Eddi]

station rating can be modded via station rating callback (NML version), however, this makes it incompatible with industry NewGRFs, i think.

[Casual tycooner]

That looks good, it doesn't quite override everything but it's a solid start, I'm not familiar with the format of the files/folders, is there a template I can use to get started?

[Eddi]

i'd probably start with the generic NML tutorial (which doesn't do anything you want, but it should get you familiar with the basic concepts), and then look at existing industry sets. i think FIRS includes a custom rating calculation, where it flat out sets 100% rating for everything. although FIRS code may be difficult to follow, since it builds up the NML code from templates during the compile, you might need to look at some intermediate compile output to see something you can reuse in a pure NML environment.

[Casual tycooner]

I took a look at FIRS, it's certainly big.
Looks like it's to tutorial land for me, any other tips are welcome in the meantime

[3iff]

Take a look at viewtopic.php?t=74856

It's something I wrote, borrowed (very heavily) from Firs. Hope it helps.
If you can say what you wish to achieve perhaps we can point you in the right direction.