I know that GL 3.x requires that the RGB10_A2 format is supported for textures and renderbuffers.
However, I’ve found that I’m unable to create default framebuffers with RGB10_A2 on NVIDIA cards. That is, I can’t get a pixel format that uses RGB10_A2. Is it just that NVIDIA cards can’t handle using such formats for the default framebuffer (ATI cards are supposed to be able to do this), or is it something else?
It probably only shows up when you have a 10-bit display attached via a DisplayPort connection. You’ll also need a Quadro card. Here’s NVIDIA document on it.
I have used this format for offscreen FBOs successfully.
Maybe its just that RGB10_A2 is a non-displayable format on nVidia, so you can’t use it for windows (thats what you refer to by ‘default’ framebuffer, don’t you?).
On FireGL/FirePro cards, you can enable 10bit formats in the chaos control center, but I have never tried to open a displayed window in this format.
I’ve been able to create RGB10A2 on Nvidia as a displayable format, but it was on a Quadro. I was able to do it with only a DVI cable used also. So it may just require a Quadro.