libXrender - documentation?

[Clemens Eisserer]

> 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).
Because xft deals with Glyphs, and for performance/bandwith resons
glyphs are handled in a special manner.
That was what I ment with "(using the XRender*Glyphs functions)".
xftglyphs: XRenderAddGlyphs
xftrender: XRenderCompositeText...

I mentioned Trapezoids only because everthing else AddGlyph and
XPutImage is not really server-side antialiasing, but client-side with
server-side blending. (however for glyphs that doesn't matter, they
are rasterized once client-side, are uploaded and used again and again
by number).

>>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.
I have never used xft by myself, but without RENDER knowledge someone
can see that:
- Probably all functions with *Glyph* inside, are text related
- That there are glyph-sets, to which glyphs can be uploaded and rendered from
- searching the functions in XFT's source.

I know that its not easy, but someone can't expect a step-by-step
tutorial for such low-level stuff.

> 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.
I don't know about opera, but im am pretty (99,5%) sure QT uses Render
- now if Opera uses QT's graphic context for drawing it will
implicitly use it.

> 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.
XFT is more or less a sample implementation, and as far as I know its
not used a lot.
As far as I know QT does its own glyph handling, so does GTK with pango.

- Clemens