Compression, Importer, Working on exporter.

[Trico-Everfire]

I've added the 7.6 compression elements to the exporter for strata source VTFs.

I've also improved the VTF importer to where it now no longer RGBA8888s everything. It now respects alpha (so formats with no alpha channel with become RGB888/161616f) as well As I8 and A8 becoming grayscale. I'm currently working on the exporter respecting the formats gimp supports in it's layers. A critical flaw is that if a format doesn't have an alpha channel or is smaller/greater than ui8 it will either crash the plugin or create corrupt image data. GIMP doesn't really like to share what formats it supports? So I'm trying to figure out how to translate the formats used by the drawables into as close of a match that VTFPP understands.

This plugin could be very useful when it works properly.

[Trico-Everfire]

Non power of 2 VTFs are in fact allowed. The need for power of 2 only was a limitation brought on by VTFLib because of it's unique structure internally. As well as that back in the early 2000s, GPU/CPU hardware did not like non power of two. These days, both GPU and CPUs, even as early as around 2010~ allow for non power of two texture/data to be used. Source has no problems loading these either from the experiments done by the creator of VTFPP.