[Xorg] Question about X Server Internal

[Amir Bukhari]

On Sun, 2004-08-22 at 01:00, Vladimir Dergachev wrote:

> Most accelerated drivers do not access framebuffer directly, just cause 
> the card to perform the corresponding operation.
> 
that is right when XAA is used but I would like to understand cfb code
(actually how it access the framebuffer).
> >
> > 2- is there a different between XImage and Pixmap?
> 
> AFAIK, XImage is a structure that is used for exchanging image data with 
> Xserver (using, for example, shared memory).
> 
> Pixmap is an area you can draw to. In particular, pixmaps can be allocated 
> directly in video memory.
> 
> The difference comes from the fact that XImage structure is located in 
> your application virtual memory, but pixmap is located in Xserver virtual 
> memory.
> 
> The Pixmap value that your application has is just a handle used to tell 
> Xserver which pixmap you are using.
> 

I have read that pixmap has no colormap and alone it does not define a
complete image but I can copy pixmap to a window, thus it will be
displayed on screen, this made confusion!

-Amir