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Operation (Compaq Tru64 UNIX)
7–6 PowerStorm 300 AGP and 300/350 PCI Graphics Controllers
7.3.1.2 Indirect Contexts, GLXPixmaps, and the Software Renderer
The following section only concerns those who run applications that require GLXPixmap
rendering support. Most applications do not fall into this category. Where GLXPixmaps
are used for multi-buffering, they should be replaced by OpenGL double-buffering if
possible. But if your application requires GLXPixmap support, this section describes how
to enable it.
Follow these steps to enable a generic software OpenGL renderer for indirect rendering
contexts in the X server, opposed to the hardware-accelerated driver:
1.
Login to the system as root. Ensure that no other user is currently working locally at
the X console or connected remotely to the X server. You may choose to reboot the
system in single-user mode before continuing.
2.
Edit the file
/var/X11/Xserver.conf. Save a backup copy.
3.
Find the line containing PowerStorm 300/350 X server command-line arguments.
Search for the text “
PowerStorm 300/350 Server args start” and proceed to
the next line where the arguments reside.
4.
Append a
–I argument to the list if one is not already present. This indicates the
beginning of device-dependent arguments.
5.
Append the
–riGLXuseSWindirect argument to the list as follows:
! PowerStorm 300/350 Server args start
-pn –su –bs –nice –2 –I –riGLXuseSWindirect
! PowerStorm 300/350 Server args end
6.
Save your changes to the /var/X11/Xserver.conf file.
7.
Restart the server:
> /sbin/init.d/xlogin restart
To disable the synchronization, follow these same steps, but remove the
-riGLXuseSWindirect argument. If no other device-dependent arguments are present,
you may also remove the
–I flag from the end of the list.
In addition, you must indicate to the client library that indirect rendering contexts are
allowed. Set the ALLOWINDIRECT environment variable in your application’s
environment before running it, as shown (assuming a csh compatible shell):
> setenv ALLOWINDIRECT
In most cases, the performance of indirect rendering contexts and the generic software
renderer does not come close to that of hardware-accelerated direct rendering. Therefore
its use is only recommended when GLXPixmap support is an absolute requirement.