Re: [GtkGLExt] What's the difference between GtkGlExt's own buffer-swapping and Gdk's ...

["Marcelo E. Magallon" <mmagallo debian org>]

On Tue, Sep 14, 2004 at 05:54:11PM -0400, Jack Chen wrote:

 > Thank you. Though I think even OpenGL has to copy data, too. After
 > all, only the graphic card's memory address in RAM is for updating
 > the screen, right? Then you would still have to 'copy' data in the
 > buffer to that address. I just don't know the internals of OpenGL and
 > GTK+ to know which routine is faster. (sigh...)

 Not necessarely.  The hardware has a real chance of implementing this
 as a buffer flip instead of a buffer copy.  And even in that case, a
 buffer copy in the graphics card is probably faster than a copy from
 main memory to graphics memory.

 For software-based implementations I think there might be a difference
 in favor of OpenGL because a buffer swap is a common operation, so the
 chances are that this is well optimized.  I don't know GDK internals
 well enough to make a guess at how efficient this operation could be in
 GDK.

 Marcelo