[OpenJDK 2D-Dev] Reporitory, Accalerating blits with EA
Christopher.Campbell at Sun.COM
Tue Jul 15 16:00:04 PDT 2008
On Jul 15, 2008, at 3:28 PM, Clemens Eisserer wrote:
> Hi again,
> - The Xrender-pipeline now is almost able to run common swing
> applications, copyArea and some bugs are still waiting to be killed,
> but more or less it should work after.
> Its only the "hack" release where I tried all the stuff out and I plan
> to rewrite it starting next week or so, but it would be great if I
> could upload it to the OpenJDK repository.
> What should I do to get access to it?
There's an hg repository already set up for your Xrender project:
I'm not sure the process you need to follow to get commit access to it
(maybe you could ask Mark Reinhold about that on a separate alias,
like the discuss alias?). In theory that should be your sandbox (a
child of the jdk7 master repository) as you work to stabilize your new
> - My blit-functions currently are not called if composition with
> extra-alpha is requested, although I have registered my Blits with
> CompositeType.AnyAlpha. Are there further requirements to get this
Do you know which Blit loop is being called in its place? (You can
use -Dsun.java2d.trace=log to get an idea, or you can just step
through the Blit.getFromCache() method.) I suspect there is another,
more specific Blit loop that's already registered that is being found
before the one you registered, but that's just a guess.
> - How does ExtraAlpha influence composition for operators other than
> For now I implement extra-alpha as a 1x1 A8 mask, however although the
> results are consistent when SRC_OVER is used, when SRC is used the
> image gets darker and darker the lower the EA value becomes with
> Xrender, but the RI seems to ignore the the extra-alpha value set.
"Extra alpha" has the same behavior for all AlphaComposite instances.
In a nutshell, the extra alpha value gets logically multiplied with
the source before the actual compositing operation. The
AlphaComposite docs explain this process in great detail (look for the
> Thank you in advance, lg Clemens
> Blog: http://linuxhippy.blogspot.com/
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