[OpenJDK 2D-Dev] X11 uniform scaled wide lines and dashed lines; STROKE_CONTROL in Pisces

[Jim Graham]

Hi Denis,

Also, I've gotten another 20% improvement out of the design with a few 
more tweaks.  (Though I measured the 20% in the stripped down version 
that I'm prototyping with FX so I'm not sure how much of that 20% would 
show up through the layers of the 2D code.  Overall, I've about doubled 
the frame rates of the prototype since your first drop that you checked 
in to the OpenJDK repository.)

How about looking more at the stroking end of the process and I'll dig a 
little more into optimal rasterization code.  I have a lot of experience 
with optimizing rasterizer code (and JNI if it comes to that), but very 
little with the curve manipulations involved in stroking (math is so 
*hard* at my age ;-)...

			...jim

On 11/4/2010 9:20 AM, Clemens Eisserer wrote:
> Hi Denis,
>
>> It's not obvious to me why this happened, so I think now I will put
>> this type of optimization aside and convert to JNI,
>
> I've only followed your discussion with Jim but skipped all the
> in-depth discussion.
>> From my prior experiences usually  JNI is not woth the trouble, if you
> don't have a serious reason why using native code would have
> advantages (like the possibility of using SIMD or when value-types
> would be a huge benefit), it has its own performance pitfalls
> especially if the workload is small and things like Get*ArrayCritical
> cause scalability problems because they have to lock the GC.
>
>> where profiling
>> will be easier (for me - I haven't been able to make OProfile work
>> for java yet).
>
> Have you had a look at the Netbeans profiler? It supports sampling
> based testing to keep the influence of the profiler at a minimum.
>
> Thanks for working on this!
>
> - Clemens