texassemble support to compress DDS to BC formats

[Georgiks]

Hi, would it be possible to add BC compression functionality to texassemble directly?
Right now, when we want to create compressed cubemap texture, we have to first use texassemble to create a DDS texture with uncompressed format, and right after that use texconv to convert the cubemap DDS to compressed BC format.

If we could specify BC output format directly on texassemble, we would not need texconv at all.

[walbourn]

I was mostly trying to keep the tool a bit simpler, but I'll take a look.

[walbourn]

The original design here was to produce complex DDS files without mips or compression, then have texconv invoked to do the remainder of the processing. I believe at a minimum, your request would require both mip-map generation -and- block compression support.