Sorry, I just resent it to Jonathan Lim, but may be any others are
interested in too.
Gerd
---------- Forwarded message ----------
Date: Thu, 16 May 2002 09:13:36 +0200 (CEST)
From: Gerd Sussner <sussner@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
To: Jonathan Lim <jlim@xxxxxxx>
Subject: Re: Overlay Bugfix and $PREFIX-patch
> Your fix does this:
>
> glXGetConfig(XtDisplay(parent), vis, GLX_TRANSPARENT_INDEX_VALUE_EXT,
> &index);
> overlaySceneMgr->setBackgroundIndex(index);
>
> setBackgroundIndex() sets the color that is used to clear the background in
> color index mode. The default value is black (index 0) as described in the
> SoSceneManager man page. I'm not sure if this is the same thing as
> transparency.
hi jonathan,
as far as i understood the code, the overlay widget lies above the actual
render area. to see anything in the render area, the overlay widget needs
to be transparent by default (except you are drawing something in it, like
the jackInTheBox :-) ). clearing the background means to fill the whole
plane with one color. this means that filling the overlay plane with a
non-transparent color (say black), you won't see anything from the render
area, because it is covered by an opaque black plane.
i hope this helps to diminish your doubts.
gerd
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