[cairo] X extensions

[Russell Shaw]

Carl Worth wrote:
> [All my answers regarding cairo below apply only to the xlib backend
> of cairo, and in particular when the X server being used has a recent
> version of the Render extension.]
> 
> On Wed, 10 Aug 2005 01:22:49 +1000, Russell Shaw wrote:
> 
>>Does cairo use Xft for font rendering, or does it render the
>>character glyphs itself?
> 
> Cairo has its own code for text rendering which works very much like
> the code in Xft.
> 
>>What format is the data sent from the client to the server?
>>Ie, is it pdf commands, or something different for graphic
>>primitives?
> 
> For shapes that cairo draws, they are sent as lists of
> trapezoids. Image data is also sent directly for images, masks, and
> text glyphs.

I just found a lot in:

http://www.usenix.org/events/usenix01/freenix01/full_papers/packard/packard_html/

>>Is text rendered on the client side, or the X server?
> 
> The text is rendered on the client side, and the client library
> (cairo) manages a server-side cache of glyph images.
> 
> All of this communication with the X server, (trapezoids, pictures,
> and glyphs), happens through the Render extension, for which you can
> read the protocol description here:
> 
> http://cvs.freedesktop.org/*checkout*/xorg/xc/doc/specs/Render/protocol
> 
> I hope that helps answer your questions.

yes.

> -Carl