Steve Byrne wrote:
> Scott Murray <[EMAIL PROTECTED]> writes:
>
> >
> > On Tue, 8 Jun 1999, Bob Cadenza wrote:
> >
> > [snip]
> > > For images this is almost 5 times as slow in jdk1.2. You can even see
> > > it, the benchmark even redraws itself noticably slow.
> >
> > You can chalk that difference up to the addition of Java2D in JDK 1.2.
> > Check out the number 1 bug in Bug Parade, #4185726. Sadly, Sun seem to
> > be dragging their heels on fixing this problem.
>
> Scott's right -- it's the integration of 2D that's causing the problem. I
> don't know that "dragging the heels" is actually correct: I know they've
> applied some very bright minds to the problem, and made quite a bit of
> improvement (this was before 1.2 first came out), but that it was getting
> harder and harder to find doable performance wins. I think that if I were to
> design it, I'd try to make it so that if you weren't using any of the 2D
> features, the overhead that you'd pay would be minimal, and only when you
> started turning on matrix transformation or any of the other cool 2D effects
> would you have to take a performance hit.
>
> Steve
Well I think your only partially right. True java2D is everywhere but.
Done correctly the rendering pipeline should have a small
effect on aliased line drawing and solid fills.
Plus trying to run two pipelines will be very very messy and end up hurting the
performance of both.
Second the root problem is if you want to run any sort of advanced graphics you
need to have direct access to the
frame buffer and any available acceleration. That the real problem it
practically impossible to write a good high speed
2D graphics pipeline on top of "strait" X11. You should be using DGA for the
backside of the pipeline.
In the Sun sources they provide hooks for this but its not clear to me that
there used I found no refrence to libsunwjdga.so in the 1.2v1 linux port.
Until your running on DGA I would not even consider other options for java2D.
I haven't looked at the latest release but I've pretty much given up on 1.2 on
Linux.
Maybe you can talk to Sun at Java One and get them to open up just a bit. Just
being able to do a build off diffs would help a lot !
Mike
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