Alternate BG Should be definable

[MjnMixael]

Not sure the best way to go about this, but the old UI allowed for setting an alternate BG image for the background per mission. This data is supplied by the mission file if the author includes it and it looks something like this.

#Command Briefing

$Background 640: commandbrief.pcx
$Background 1024: 2_CommandBriefB_Demo.png

We should provide similar functionality here and at the briefing screen at a minimum. If it's easy, might as well throw in Fiction and Debrief while we're at it.

[asarium]

Would you want the briefing UI to use the same files specified in the mission?

How would we handle scaling in that case. Since that was a big part of the new UI it would be good to also consider how we want to do that.

For the implementation I think this should be pretty reasonable. It would need an API to get the file names but other than that nothing special. Just replacing the backup image URL of the correct element.

[MjnMixael]

Good question. I would think since the new UI is going to require any mod that had a custom UI to basically remake it all, that it would be fine to get the images from the mission file the same way. Whoever uses this feature will need to provide an appropriately sized image. I assume the other option would be a special cfg or something with mission names and replacement backgrounds?

As for scaling, normal CSS has a property to define the behavior. I don't see that property in the RCSS documents, but it's got to have something defined. If I had to guess it will either stretch or tile the background image automatically.

[asarium]

Seems like a sensible way to implement this. I'll see when I get to this...