sample overlay colormap configuration/setting code needed

[Dr d b karron]

Pardon this second request, but I can't see my original post from last
night;

I seem to have a mental block about allocating Xcolormaps; I don't
understand how they are allocated, how you
write and read them. I have some sample code for reading the color map; it
works fine for the default root window colormap;
when I try to read any other colormaps the colors are packed all in red and
some in blue, nothing in green; How do you use the
colormap mask ?

Is there RGB transparent overlays ? I don't see any thing other than a
single transparent visual with a colorindex; no rgb transparent color seems
to be
available thought you can spec one out; That would be the best way to manage
the overlay;

Can I ask for a popup visual ? What layer is this ? The main buffer is layer
0, the overlay is +1, the underlay is -1, but none are
indicated on the glxinfo listing. What layer is the popup planes ? None seem
to be offered on my octane 2 with V12 graphics (high end).
What is the situation with these unusual visuals ?

What does a stereo buffer do differently ? It is just an additional pair of
buffers for each eye ? You render to Left then right, then swap buffer pairs
?

I don't understand how to create a overlay window; do you do a
XCreateColormap with an default global colormap inherited from the root
window
and an AllocNone ? What does AllocNone mean ?

Then you do a XCreateColormap or XSetWMColormapWindows ? The examples in the
InfoSearch web site are for colormaps and overlays
are contradictory on this point;

I have been futzing around with this experimenting; who has code to setup an
overlay colormap and populate it explicatively; perhaps read and unload it;
If the overlays have a default colormap is there a set of default values
already inherited for these colormaps ?

dr. konfused