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

[Jack Chen <jacks_small_world yahoo com>]

 --- "Marcelo E. Magallon" <mmagallo debian org> wrote: 
> 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

So what you said is that the graphic card has its own physical memory
in the card to store 2 buffers without displaying one of them...hmmm,
that's a different architecture of the PC hardware from what I have
studied. Care to enlighten me a little bit?

Jack

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