[Mesa-dev] [PATCH] drisw: Fix drawable creation against non-default screens

[Adam Jackson]

On 1/3/12 3:48 PM, Ian Romanick wrote:
> On 01/03/2012 11:40 AM, Adam Jackson wrote:
>> There's no reason to only force the visual to be on the default screen,
>> and in fact good reason not to.
>
> Is the visual ID enough information to uniquely identify it? I may be
> mistaken (and horribly ignorant in this area), but I thought the visual
> ID namespace was per-screen, not per-display.

Practically, yes.  VIDs and XIDs happen to use the same allocator in the 
sample implementation (and every vendor server I've seen) which means 
they're unique and not namespaced by screen.

According to the protocol spec, visuals may be listed for more than one 
depth or [1] more than one screen.  But that's fine: the visual ID will 
uniquely identify the capabilities of a given visual, and if it happens 
to be valid for multiple screens, awesome.  The requirement then is that 
visuals present on multiple screens actually _be_ compatible, but that's 
a server issue.

[1] - this is just "or" in the spec; it's not clear whether it's meant 
to be ^^ or ||, but || is probably the conservative interpretation.

- ajax