GL framebuffer fetch behavior

Mike Blumenkrantz <[email protected]> Wed, 23 Apr 2025 12:24:22 -0400

Newsgroups	gmane.comp.video.mesa3d.devel
Message-ID	<CAHwmOzcC-ztrCaui3N-Dp=ycZ_2D0rJzC98_C3y95cTuYMGzZg@mail.gmail.com>

Hi,

An issue recently came up in the GL working group: what is the robustness
behavior of framebuffer fetch? For example, if a framebuffer attachment
format is R8_UNORM, what are the YZW components which get read back?

If people from all the drivers (besides panfrost) which support this
extension could reply with the expected behavior on their hardware, that
would be helpful.


Thanks,
Mike