i would like to set the double arrow spacing by belt color.

That looks like it'd require quite a bunch of changes in the code, in order to display the proper sprite for each type of belt instead of doing the same function.

And you'd also need a whole new spritesheet for green belts arrows if you want the quadruple arrow spacing.

Yep. We need to create a new sprite for the quadruple arrow spacing. The turbo ( green ) belt looks bad even with double arrow spacing.

The code part should be easy, we would need to add the logic in get_belt_animation function.

Maybe the "beltdata" in the data.lua file could have an "arrow" parameter that denotes if it's single, double or quadruple, which then could be plugged in the get_belt_animation_set function to grab the proper sprites as needed.
I'll see if I can get something done, including for the arrow spritesheet image, but don't expect anything soon...

I'm not a coder, I just found an old mod and uploaded it to the mod portal to play with friends who like it too. Added your lines to the code, thank you. I do not know what to do with the animation of green belts.

I'm not a coder, I just found an old mod and uploaded it to the mod portal to play with friends who like it too. Added your lines to the code, thank you. I do not know what to do with the animation of green belts.

Hey no problems man. Thx for reuploading this btw

If you fork this mod, let me know, and I'll install it for myself.

Just letting you guys know: I forked the mod and fixed the arrow spacing for turbo belts. :)
It should all work fine for vanilla, I'll roll out compat options later.
Try it out here!

Cool! Thanks!