Re: Changes 2009-07-15/16 in branch?

[James Cloos]

>>>>> "Richard" == Richard Stallman <address@hidden> writes:

Richard> Is it hard to implement background transparency on X?

Not too hard.  A number of terminal apps do it.

The X server needs to support the XCOMPOSITE extension, a compositing
manager must be running (akin to a window manager, but it is responsible
for blending the clients' windows together on top of the root window
based on how they are stacked and on their per-pixel alpha values) and
the client needs to use an x11 visual with an alpha channel.

Normally the last is a 32 bit 8/8/8/8 ARGB visual (8 bits each of Alpha,
Red, Green and Blue), but colour spaces like 2/10/10/10 ARGB are possible.

Anyone running the latest versions of the popular gnu-on-linux dists on
recent hardware is probably using a suitable setup for transparent windows.

To add transparent support to a client, you just need to use a suitable
visual and include the alpha bits in each colour.

I know that rxvt-unicode (http://software.schmorp.de/) gnome-terminal
and KDE's terminal all have transparency support and are all Freely
licensed.  Any of them should provide a more precise recipe for
supporting translucent windows on X11.

-JimC
-- 
James Cloos <address@hidden>         OpenPGP: 1024D/ED7DAEA6