EGL_MESA_choose_display version 1

Jon Smirl jonsmirl at
Wed Jun 15 12:27:27 PDT 2005

On 6/15/05, Adam Jackson <ajax at> wrote:
> From version 9 of EGL_MESA_screen_surface:
>     EGLBoolean eglGetScreensMESA(EGLDisplay dpy, EGLScreenMesa *screens,
>                                  EGLint screens_size, EGLint *num_screens);
> If we're doing one screen per display then why do we even have this call and
> why did you fight so hard [1] to make screen handles opaque and dynamic?  If
> you do one EGLDisplay per screen then *num_screens will always be 1, won't
> it?

I'm just making one screen per display in my drivers. I'm designing my
drivers to be able to split a single card between two users, other
driver developers may not want to do that. Nothing in EGL is forcing
this model onto other driver writers.

Now that I think about it, since I have one screen per display it is
ok to use display/0, display/1, etc. From my side I think in terms of
screens and I forgot that there was a 1:1 correspondence.

> This is why having a "screen" transport in eglChooseDisplayMESA is
> fundamentally wrong.  Screens are not the objects we're trying to address
> here.
> [1] - See the version 6 and version 7 threads:

Jon Smirl
jonsmirl at

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