Re: Swapping Double Buffers?

[Federico Mena Quintero <federico nuclecu unam mx>]

>  Don't get me wrong, I have double buffering without flicker. I just
>  want to eliminate the useless (in my case) copy operation from the
>  offscreen to onscreen buffer.

You will always need to copy from system memory to video memory.  You
cannot avoid this, since you are not in control of the frame buffer.

However, X does support a double buffer extension.  Check the X docs
to see how to use it.

(In most cases I don't think it is necessary; painting to a pixmap and
later copying that to a window works pretty well).

>  Does the GTK+ drawing area widget use MITSHM internally in its
>  implementation? I'd hate to get that low level myself. If not,
>  perhaps that capability could be encapsulated by the widget.

No.  GtkDrawingArea is just a blank Gdk window.

GdkRGB and GdkImage do use MITSHM if it is available for blasting data
to a drawable.

  Federico