Fix texture format selection. ChooseTextureFormat is supposed to select the
hardware format of the texture, and SetTexImages is supposed to use the
format selected by ChooseTextureFormat. However, both routines were making
their choices based on the texture's BaseFormat. This is wrong.
ChooseTextureFormat uses BaseFormat and SetTexImages uses
TexFormat->MesaFormat.
Once SetTexImages was fixed to use the right format values,
ChooseTextureFormat was cleaned up. It now uses the few available texture
formats supported by the i810 in a smarter way. This should improve the
quality of LUMINANCE, LUMINANCE_ALPHA, and INTENSITY textures.
I tested this by cycling through all the texture formats in demos/texenv and
tests/yuvsquare.
Attempt to fix the issue reported by Alan Grimes with DRM_RADEON_TEXTURE
erroring out when it shouldn't. The errno could be changed by usleep() between
the ioctl call and the loop check, if a signal was received. This could cause
an EAGAIN return from the DRM_RADEON_TEXTURE ioctl to not loop again.
Instead of checking errno, check thevalue of ret itself, since it is a saved
(and sign-flipped) copy of errno from the ioctl call.
Enable ARB_texture_compression. The code has been in place for a long time,
but, for whatever reason, the extension wasn't enabled.
Add some comments to i810ChooseTextureFormat. There's some strangeness with
i810 texture formats.