We are used to use the texture parameter for all util draw calls,
but AMD seems to have a bug where they use the sampler parameter
of stage 0 if no sampler is bound to the used stage.
So as workaround (and a bit as nicer code), we now use sampler
objects everywhere.
This drops the "feature" to load level 0 from the custom texture
and all other levels from the native one if the size matches.
But in my opinion, when a custom texture only provide one level,
no more should be used at all.
degasus