Re: [GtkGLExt] X crash in double mode

[Michalis Kamburelis <michalis camelot homedns org>]

Alex Queiroz wrote:
> Hallo,
>
>        I'm basically using the logo.cc demo as a guide, but my
> application fails when I request a double-buffered mode. The error
> message from Gdk is:
>
> === BEGIN ===
> The program 'orbis' received an X Window System error.
> This probably reflects a bug in the program.
> The error was 'BadColor (invalid Colormap parameter)'.
>   (Details: serial 360 error_code 12 request_code 1 minor_code 0)
>   (Note to programmers: normally, X errors are reported asynchronously;
>    that is, you will receive the error a while after causing it.
>    To debug your program, run it with the --sync command line
>    option to change this behavior. You can then get a meaningful
>    backtrace from your debugger if you break on the gdk_x_error() function.)
> === END ===
>
>      If a request a single-buffered mode the application starts ok.
> Has anybody seen this before?

Are you requesting some additional OpenGL buffers, e.g. stencil or 
accumulation buffer ? Or maybe you're requesting some unusually large 
color depth ? Depending on your graphic card and OpenGL implementation 
you may not be able to get double-buffered visuals if you request such 
additional buffers (especially with large bits, i.e. pixel size). If 
you're under XWindows, you can use `glxinfo' program to check if what 
you request is available.

Note that the error message you show, "BadColor (invalid Colormap 
parameter)", doesn't suggest the above explanation. But the symptoms 
that you describe (program runs with single buffer, doesn't run with 
double buffer) would suggest the above explanation.

Michalis