Does Xorg'x XRender implementation support "better-than-bilinear" interpolation?

[Pierre-Loup A. Griffais]

On 09/11/2012 10:43 AM, Søren Sandmann wrote:
> "Pierre-Loup A. Griffais"<pgriffais at nvidia.com>  writes:
>
>> I'm not very familiar with bicubic interpolation, but couldn't it be
>> achieved using the 'convolution' filter with the adequate kernel?
>> (possibly in several passes at different scales). AFAIK 'convolution'
>> is always provided and often accelerated.
>
> The convolution filter in Render only allows one phase of the filter to
> be used, so the quality of bicubic interpolation implemented that way
> would be terrible.
>
> As an aside, a bunch of code could be deleted if we removed the ability
> for drivers to provide their own filters. As far as I know, no driver
> has ever done this. I have an old branch here:

One of the items of my (long) list of things to do is to expose anisotropic 
filtering to RENDER, so it'd be cool if that didn't get removed.

Thanks,
  - Pierre-Loup

>
>      http://cgit.freedesktop.org/~sandmann/xserver/log/?h=filters
>
> that could probably be resurrected.
>
>
> Soren