[OpenJDK Rasterizer] Some questions
Jim.A.Graham at Sun.COM
Tue May 15 17:18:17 PDT 2007
Hopefully you've all had time to read my getting started message. Now
some details on where we might go from here.
We're continuing to work on getting the Pisces renderer into shape to
have it potentially be the long-term replacement for our encumbered
Ductus binary plug, but that effort will take a little more time.
In the meantime, yesterday I hacked up a quick AA rasterizer replacement
just to see if we could get something simple and expedient in place to
disencumber our sources. It is a small piece of code, but it isn't the
best performing alternative. I basically render the path at N times
larger into a Region, similar to the way we turn a Shape into a clipping
Region, and then generate tiles of alpha coverage from the Region at
about the same relative size as the tiles that were generated by the
Ductus code (32x32 pixels at a time).
I can get anywhere from 50% down to 10% of the performance of the Ductus
binary plug with this code at 16x16 oversampling - which is similar
quality to what the encumbered library produces. If I drop it down to
4x4 oversampling the performance gets up to about 30% to 70% of the
binary plug at the expense of some rendering quality. The variations in
performance relate to the complexity of the path and how much area it
What I think I'd like to do at this point is to create a pluggable
interface and use this quick and dirty solution as a temporary open
source plug for AA rendering in order to get our code more buildable
sooner rather than later so that others could start contributing towards
the eventual replacement. It may not have the best performance, but it
doesn't represent a lot of work that may eventually be obsoleted by the
community and it gets us weaned off of the closed sources quicker.
The remaining work then would be to create a "quick and dirty" line
widener that plugs into the rest of our code reasonably well. I can
talk more about that in another message.
Any thoughts on getting this quick and dirty AA plugin out in the public
sources sooner vs. waiting for a replacement that might have more longer
Is anyone out there already looking at AA rendering alternatives that
they want to plug into the OpenJDK sources?
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