[Buildroot] [PATCH 3/6] package/mesa3d: is a full-openGL provider if X.org is present

[Yann E. MORIN <yann.morin.1998@free.fr>]

Paul, All,

On 2014-04-01 22:14 +0200, Paul Cercueil spake thusly:
> On 01/04/2014 20:14, Yann E. MORIN wrote:
> >I have to admit I am a bit lost in all this mess... :-(
> 
> It works like this: regular OpenGL only works with DRI drivers, and DRI
> drivers are only usable under X11.
> Which means that all DRI drivers should depend on XORG7 (even the swrast
> one), and they should all select OpenGL.
> 
> Gallium drivers are meant to be used with EGL and OpenGL ES, and only some
> of them can be used under X11 using a DRI compatibility layer (for instance,
> "nouveau" in Mesa is both a Gallium and a DRI driver). But they should also
> all work fine without X11, and will support Wayland, which is not the case
> for DRI drivers.

OK, you managed to confuse me yet a bit more! :-)

So, to sum-up our discussion on IRC, so everyone can follow:

  - mesa3d has two types of drivers: Gallium drivers, and DRI drivers

  - Gallium drivers provide EGL and GLES

  - DRI drivers provide full-openGL, and also EGL and GLES

  - for a specific chip, there are two drivers: one Gallium and one DRI

  - some drivers have a DRI wrapper over a Gallium driver, wrapper that
    provides DRI via the Gallium driver

  - X11 needs a DRI driver

  - Gallium are used for non-X11 display (eg. directfb, a wayland
    compositor...)

Is the above a proper summary of what you explained me on IRC?

I'll wait for your reply before I lay out my proposal for fixing mesa3d
support in Buildroot, because if any of the above is wrong, my prioposal
would be wrong.

Regards,
Yann E. MORIN.

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