Re: [linux-opengl-base] [oglbase-discuss] Re: draft spec for GL_EXT_get_proc_address

[Michael I Gold]

At 01:59 PM 9/9/99 -0600, Thomas Roell wrote:

>>     Also note that the returned pointer is only valid when the current
>> context is the same as the context to which the GL was connected when
>> the pointer was obtained.
>
>What is the rationale for this constraint ? 

Consider the Windows model, which may or may not apply here.  Not all
Visuals are supported by the same DLL, some are from the ICD and others are
from opengl32.dll (e.g. rendering to bitmap, printer, or if someone
explicitly wants to use the generic software renderer).  If two
implementations support the same extension, they each have a function with
the same name in their respective DLL's.  It would be bad to call a.dll's
entry point when bound to b.dll.  Not sure if an analogous scenario can
occur in Linux (multimon perhaps) but its a good idea to plan ahead.

>Would this imply what for every context that is created a seperate
>pointer had to be queried ? 

Technically, the same ptr should work for any compatible context, where I'd
define compatible as sharing the same Visual.