Looking for XRender examples
Helge Bahmann
hcb at chaoticmind.net
Mon Dec 10 22:28:39 PST 2007
Am Montag, 10. Dezember 2007 20:20 schrieb Clemens Eisserer:
> Hello Helge,
>
> Thanks a lot for uploading the documentation, also for the not
> directly XRender related presentations. It really made it much easier
> to start with :)
>
> Just because I am curious: Is that teaching material used in a couse,
> and if yes, how is it called?
yes it is teaching material; it is the introduction into a multimedia course,
specifically multimedia in the x window system (which is what my research
project is about)
> One of the things which quite confuse me is how the problem of
> antialiased polygons is solved, if the are composed of several
> trapezoids ... however I've to look at cairo's source ^^
well the basic idea usually is... slice your polygon vertically at every node
point, then step through the segments top to bottom; it is easy to see that
the resulting shapes will always be trapezoids or triangles
if you manage to slice up your shape exactly at pixel boundaries, you can
composite the segments directly to the target surface (because they do not
overlap); otherwise you may need an intermediate mask (PictOpDisjointOver)
Best regards
--
Mathematicians stand on each other's shoulders while computer scientists stand
on each other's toes.
-- Richard Hamming
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