Fwd: allowShmPixmaps

[Clemens Eisserer]

Hi Mark,

Its always JNI_TRUE when it is called from within the X11 pipeline,
but when called from the XRender pipeline (
Java_sun_java2d_xr_XRSurfaceData_initIDs ) SHMPixmaps are disabled.

The reason is that SHMPixmaps are ususally a bad if you would like
them accalerated by the driver, because they cause pixmaps to be bound
to system-memory usually - however the X11 pipeline relies on it for
good performance when mixing server/client rendering.
However SHMPixmaps are not supported by EXA based drivers and the
latest NVidia beta release also disables them by default, so usually
we won't get them anyway ;)

By the way, I intend to rewrite the whole MaskBuffer stuff soon, as
well as large amounts of the C code.
I am not really used to C, so sorry if the code is quite ugly in some cases.

- Clemens