Yeah, DXT1 looks fine to me, all together it came out about half the size of the original png with mipmapping on board, so, yay! Thanks a lot.

if you have an atlas texture with no textures right or left to it, you can tile the texture horizontally using the atlas texture without creating new polygons Ah, thanks, I didn't know that, and that explains why so often there are triangles that extend off the right side of the file. They do somet...

Sweet, thanks!

Oh, nice, that came out smaller than the original png file!

And yeah, it looks like flightgear does do mipmapping, but apparently not with this texture, this is coming from sort of a side project within flightgear, called osm2city.

Okay, I found the DDS plugin for gimp and installed it, seems to work fine. Should I use compression on it? If so, which one?

Sure, here's the texture:

http://chriscalef.com/files/atlas_facades.png

Thanks for the help! They probably don't use mipmaps in flightgear, I'll find out though.

Any idea how much would be a lot? And would it be affecting performance in any other way? I'd rather not have to define my own mipmapping unless the cost is significant, because I'm lazy and don't like to work.

Yeah, png.

I didn't create it, so I don't know why it has to be 16384, I expect the FlightGear artists just kept making it bigger and sticking more textures onto the bottom of it. It's only 256 pixels wide.