blob: 9ba0d92c87d822fdf06a2eebd4aedd59e07f31df [file] [log] [blame]
Name Strings
Kyle Brenneman, NVIDIA, kbrenneman at
Kyle Brenneman
Adam Jackson
Andy Ritger
Robert Morell
Arthur Huillet
Martin Peres
Last Modified Date: March 8, 2016
Revision: 1
OpenGL Extension #482
GLX version 1.3 is required.
This specification is written against the wording of the GLX 1.4
This extension allows the vendor-neutral GLX client library,
libglvnd, to determine which vendor-specific driver is needed to
support a given GLX drawable or X11 screen.
This GLX extension is not intended to be used directly by
applications. Instead, it is intended to be used by the GLX client
IP Status
No known IP claims.
New Procedures and Functions
New Types
New Tokens
Accepted by the <name> parameter of glXQueryServerString:
Additions to Chapter 3 of the GLX 1.4 Specification
(Functions and Errors)
[Modify Section 3.3.2, GLX Versioning]
[Replace the 2nd sentence of the 5th paragraph with the following]
"The possible values for <name> and the format of the strings is the
same as for glXGetClientString. <name> may also be
[Add the following paragraph to the end of the section]
"If <name> is GLX_VENDOR_NAMES_EXT, then the returned string is a
space-separated sequence of vendor names. The names are in order of
preference, with the most preferred vendor first."
[Modify Section 3.3.6, Querying Attributes]
[Replace the 2nd sentence of the 1st paragraph with the following]
"<attribute> must be set to one of GLX_WIDTH, GLX_HEIGHT,
[Add the following paragraph just before the last of the section]
"If <attribute> is GLX_SCREEN, then <value> will be the screen
number that the drawable was created on."
GLX Protocol
This extension does not add any new requests. The
GLX_VENDOR_NAMES_EXT enum is used with the existing
glXQueryServerString request, and GLX_SCREEN is added to the
attributes in the glXGetDrawableAttributes reply.
1) Should GLX_VENDOR_NAMES_EXT contain a single vendor name or a
list of names?
RESOLVED: Allow a list of names.
Allowing multiple names would allow for multiple client-side
vendor libraries that work with a single server-side driver.
With only a single name, selecting between multiple client
drivers would require some form of additional configuration.
For example, some vendors may have both a proprietary
client-side vendor library and an open source vendor library
that work with the same server-side driver. In that case, the
server would return the names for both of the vendor libraries.
The client would then try loading each vendor library as
described below in Issue 3.
2) What order should the vendor names be returned in?
RESOLVED: If there are multiple vendor names, then the client
should use the names earlier in the list in preference to names
later in the list.
Specifically, the GLX client library will try to load and use
each vendor name, in the order that the server lists them. It
will stop when it finds the first vendor that works.
3) How are vendor names defined and interpreted?
RESOLVED: The vendor names for a screen are defined based on the
server's GLX implementation. Typically, a server will simply
send the name of the driver that controls the screen.
The GLX client library is responsible for translating the vendor
name to a vendor library name. The details of the translation
are part of the interface between the vendor library and the GLX
client library, and so are not defined in this specification.
4) Does the vendor name list need a new enum? Could it be appended
to the GLX_VENDOR string instead?
RESOLVED: Use a new enum. The vendor-specific part of the
GLX_VENDOR string is by definition arbitrary, even if in
practice every most if not all GLX implementatinos leave it
In addition, using a new enum also makes parsing the string much
easier. The client can simply pass the unmodified string to
strtok or strtok_r.
5) Do we need to define the interaction with GLX_SGIX_pbuffer?
RESOLVED. No. Any client or server that implements this
extension will already support GLX 1.3, so using
glXQueryDrawable to look up a screen number is sufficient.
There's no harm if a server includes a GLX_SCREEN attribute in
its GetDrawableAttributesSGIX reply, so a server is still free
to use the same codepath for GetDrawableAttributesSGIX and
6) Do we want to add GLX_SCREEN to the list of fbconfig attributes
as well?
RESOLVED: No. Adding GLX_SCREEN to glXGetFBConfigAttrib would be
redundant, because a client can already find the screen number
for a GLXFBConfig using glXGetVisualFromFBConfig and indirectly
using glXGetFBConfigs.
Revision History
1. 8 March 2016
- Initial draft.