[Mesa-dev] [PATCH] st/mesa: optionally apply texture swizzle to border color

[Christoph Bumiller]

On 14.04.2013 13:50, Jose Fonseca wrote:
> ----- Original Message -----
>
>> Not to mention the sheer insanity, ugliness and emotional pain incurred
>> when writing that code when it COULD be so easy and simple in the state
>> tracker where you know that textures and samplers are tightly coupled,
>> while in gallium I cannot assume that to be the case.
> Also, will this still be true when Mesa state tracker implements GL_ARB_texture_view ?

I dare say yes. GL texture views do NOT decouple textures from samplers,
they just decouple gallium sampler views from OpenGL textures.

There may be an issue if we wanted (and we don't) to use a single
sampler for all the OpenGL texture views of a single texture. However,
that ONLY works if the shaders are changed as well, and since the
texture/sampler combinations are not predictable, this is a very bad
idea as it would mean frequent shader recompilations.

As to whether there will ever be an OpenGL extension that adds
separation of views and samplers to shaders ... I'm hoping for NV to add
some clause to the spec to solve the border colour trouble, like
forbidding texture swizzle in such cases (and I'm sure AMD would be
inclined to agree).

> Jose