JEP submitted: Update Java2D to use the Marlin Renderer as the default Graphics Rasterizer
bourges.laurent at gmail.com
Tue Sep 1 08:26:18 UTC 2015
Here are my comments:
2015-08-31 17:29 GMT+02:00 gerard ziemski <gerard.ziemski at oracle.com>:
> It's very exciting to see that we're addressing the performance issues of
> our currently existing Pisces 2D engine.
Thanks for your interest. FYI I am working on Marlin (improving Pisces) for
2 years and since march 2015, I am working with Jim Graham & Phil race to
its openjdk integration as a standalone pure java renderer to add it easily
into OpenJDK 9 asap.
> I'm not sure how detailed we want to have the JEP, but the following are
> the issues I would love to see the JEP go into a bit more detail:
> #1 In the "Success Metrics" we say "significantly outperforms", but we're
> not committing to any hard numbers - do we have an expectation on how much
> better the new engine will be, that can be stated? Especially since we
> claim that the development version already meets this goal?
We deliberately gave no numbers: Marlin is already faster than Pisces in
all Map rendering benchmarks I made and often as fast or faster than ductus
(closed source's Oracle JDK renderer):
=> my goal is to achieve at least ductus's single-threaded performance but
with very good scalability.
FYI here is a comparison report made in february 2015 (Marlin 0.5.6) before
starting the integration process:
These benchmark results use my MapBench tool that perform map rendering
> #2 What is the expected CPU usage allowed when scaling up in a
> multi-threaded environment - 2 threads probably do not mean 2x performance?
> Is Merlin allowed to use all threads, or does it have a limit on how many
> will be used? Can/should this be controlled via some sort of a runtime flag
> available to developers?
Marlin has a very low memory footprint (low GC overhead) and uses a
rendering context per thread => it does perform any thread management but
is purely thread safe (ThreadLocal storage).
MT support means that Marlin supports well parallel rendering requests like
in a map web server: each server thread can perform Graphics2D rendering
(using Marlin) on its own BufferedImage at maximum performance.
> #3 Is Merlin's quality and accuracy high enough that it could one day
> replace the font rendered as well?
It is still not good enough for font rendering: mainly 8x8 supersampling
with proper subpixel alignment.
However, I expect in the future to implement Exact Pixel Coverage (like
freetype or agg) that would provide higher accuracy.
> #4 Is Merlin performing well on both desktop and mobile platforms? Is such
> platform separation still needed?
I only made benchmarks on desktop platforms.
> #5 Would it be helpful to find an external use case scenario, in addition
> to the internal ones (ie. Pisces and Ductus), such as the performance of
> Adobe's Flash to compare Merlin's performance?
Why not ?
FYI, I developped also a map rendering benchmark tool to perform both
regression tests and benchmarks on real-application datasets provided as
serialized drawing commands.
I could improve it to use other input formats (or just convert them) to
let us perform comparisons with other benchmark tools.
> #6 In the "Alternatives" section, shouldn't we at least mention a GPU
> based 2D rendering?
However, I do not know any RenderingEngine implementation based on GPU yet.
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