libXrender - documentation?

[Charles Lindsey]

In <194f62550901220554g1a3d981boc00c0d484ffbc9b4 at mail.gmail.com> Clemens Eisserer <linuxhippy at gmail.com> writes:

>Most likely I will write some XRender documentation as part of my
>bachelor thesis.

>> In a subsequent thread "2D antialiasing?" on this list, I was bemoaning
>> the fact that antialiasing by that method would waste huge amounts of
>> bandwidth if the client were separated from the Xserver by some slow
>> network, and someone claimed to me, offlist, that Xrender provided
>> server-side antialiasing.
>>
>> So I wanted to verify that claim. Now that this list has pointed me to
>> Keith Packard's "The X Rendering Extension", I have done a quick scan of
>> that, but can still find no mention of antialiasing. Moreover, that
>> describes the protocol, rather than the libXrender interface that is more
>> conveniently used to access it,
>Yes, that was me ;)

>Antialiasing is usually done by transferring the geometry you intend
>to render into a mask-pixmap, this can be done with:
>- XPutImage (client-side geometry rasterization)
>- XRenderAddTraps

>and doing a composite operation with that mask.

>or by using an implicit mask with:
>- XRenderCompositeTrapezoids

I can't see any such calls of XRender* functions in the bits of xft that I
have been looking at (notably in xftcore.c).

>However as far as I know xft already has a XRender aware backend
>(using the XRender*Glyphs functions), as well as legacy support for
>pre-xrender servers.

For sure the Opera/QT combination is not doing anything like that - all
the calls that actually pass glyphs to/from the server use good ol' Xlib.
Though there is evidence that xft does use Xrender elsewhere in its
workings.

But who is actually responsible for the development/maintenance of xft?
For sure they do not seem to hang around on this list, though I gather
they are within the overall Xorg structure somewhere.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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