An opengl regression

Lionel Ulmer lionel.ulmer at
Mon Nov 25 15:40:46 CST 2002

> I did notice and try that (after posting), and it also fixes it. So I 
> guess the issue becomes whether it should also work without double 
> buffering, as that is the default in the sample config file.

Well, before my patch, in one of the X11DRV rewrite, the option got somehow
lost and was enabled by default whatever the value of the entry in the
config file. So that it was working before was a 'feature' :-)

Now let's try to explain the reason of this option : in Windows, you first
create the Window and then only tell it that one wants to do OpenGL drawing
in it (single or double buffered). Now, in X11, if you plan to use a window
to do OpenGL drawings, you first need to be sure that the visual you choose
for it is compatible with OpenGL (ie does it support double buffering ? has
it a stencil buffer ? ...). The problem is that when Wine detects that the
application wants to do double buffered OpenGL drawings in that window, it's
too late as the window was already created with the default visual => hence
the option to have the default visual used by all windows be double buffered.

I do not think putting it as default is such a good idea as it may lead to
performance problems to all the people not using OpenGL... And the gamerz
just have to read the config file (if they know how to read, sometimes we
wonder when doing 'support' on #WineHQ 8-) ).

As to why it's called 'DesktopDoubleBuffered' and not something else, it's
also historic : at the beginnings, OpenGL only worked properly in Desktop
mode :-)

Finally, Alexandre (if you read this :-) ), now that you rewrote most of the
internal Windows handling code (ie with the Wine window == X11 window
stuff), would it be possible to somehow recreate the X11 window when we
detect OpenGL attaching to it and replace the old window in Wine's window
hierarchy ?


		 Lionel Ulmer -

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