Fade in/Fade out of a window with XRender and Xcomposite

[Pierre Nicolas-Nicolaz]

Hello,


I'm trying to understand how to make a fade in/fade out of a window
with the Xrender and Xcomposite extension. From all that i had been
able to read over the internet, to do a fade in, i should render the
window (that will appear) off-screen with XComposite, then draw it on
the screen while playing with the alpha channel brought by the XRender
extension ?


As you can see, it's really unclear in my mind, and i do not really
success neither to find any good docs on those two extensions, nor to
understand the few code examples that I can find over the Internet
(they are full of obscure functions like "XRenderFillRectangle" ?!).


So, can anyone give me a good link on how to do things like this, or
explain me how to use XRender/XComposite extension please ?



Thanks a lot,
Nanar Duff.