Optimised, high-performance, multi-threaded rendering pipeline

Mon Nov 28 08:10:57 UTC 2016

We should discuss a new rendering pipeline on the openjfx mailing list. It’s not off topic - it’s an important topic for the future of JavaFX.

> Am 28.11.2016 um 06:54 schrieb Felix Bembrick <felix.bembrick at gmail.com>:
> 
> Sorry Gerrit - you did indeed.
> 
> Maybe you'd also like to participate in the offline discussion (especially now that you don't work for Oracle)?
> 
>> On 28 Nov. 2016, at 16:07, han.solo at icloud.com wrote:
>> 
>> Well I mentioned before that I'm interested too :)
>> 
>> Cheers,
>> 
>> Gerrit
>> 
>> 
>> Am 27. Nov. 2016, 22:58 +0100 schrieb Felix Bembrick <felix.bembrick at gmail.com>:
>>> Well, given that you and Benjamin seem to be the only people interested in it, perhaps we should discuss it offline (so as not to bother Oracle or spam list this)...
>>> 
>>>> On 28 Nov. 2016, at 06:57, Tobias Bley <bley at jpro.io> wrote:
>>>> 
>>>> Where can we read more about your HPR renderer?
>>>> 
>>>> 
>>>> 
>>>> 
>>>>> Am 25.11.2016 um 16:45 schrieb Felix Bembrick <felix.bembrick at gmail.com>:
>>>>> 
>>>>> Short answer? Maybe.
>>>>> 
>>>>> But exactly one more word than any from Oracle ;-)
>>>>> 
>>>>>> On 26 Nov. 2016, at 00:07, Tobias Bley <bley at jpro.io> wrote:
>>>>>> 
>>>>>> A very short answer ;) ….
>>>>>> 
>>>>>> Do you have any URL?
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>>> Am 25.11.2016 um 12:19 schrieb Felix Bembrick <felix.bembrick at gmail.com>:
>>>>>>> 
>>>>>>> Yes.
>>>>>>> 
>>>>>>>> On 25 Nov. 2016, at 21:45, Tobias Bley <bley at jpro.io> wrote:
>>>>>>>> 
>>>>>>>> Hi,
>>>>>>>> 
>>>>>>>> @Felix: Is there any Github project, demo video or trial to test HPR with JavaFX?
>>>>>>>> 
>>>>>>>> Best regards,
>>>>>>>> Tobi
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 
>>>>>>>>> Am 11.11.2016 um 12:08 schrieb Felix Bembrick <felix.bembrick at gmail.com>:
>>>>>>>>> 
>>>>>>>>> Thanks Laurent,
>>>>>>>>> 
>>>>>>>>> That's another thing we discovered: using Java itself in the most performant way can help a lot.
>>>>>>>>> 
>>>>>>>>> It can be tricky, but profiling can often highlight various patterns of object instantiation that show-up red flags and can lead you directly to regions of the code that can be refactored to be significantly more efficient.
>>>>>>>>> 
>>>>>>>>> Also, the often overlooked GC log analysis can lead to similar discoveries and remedies.
>>>>>>>>> 
>>>>>>>>> Blessings,
>>>>>>>>> 
>>>>>>>>> Felix
>>>>>>>>> 
>>>>>>>>>> On 11 Nov. 2016, at 21:55, Laurent Bourgès <bourges.laurent at gmail.com> wrote:
>>>>>>>>>> 
>>>>>>>>>> Hi,
>>>>>>>>>> 
>>>>>>>>>> To optimize Pisces that became the Marlin rasterizer, I carefully avoided any both array allocation (byte/int/float pools) and also reduced array copies or clean up ie only clear dirty parts.
>>>>>>>>>> 
>>>>>>>>>> This approach is generic and could be applied in other critical places of the rendering pipelines.
>>>>>>>>>> 
>>>>>>>>>> FYI here are my fosdem 2016 slides on the Marlin renderer:
>>>>>>>>>> https://bourgesl.github.io/fosdem-2016/slides/fosdem-2016-Marlin.pdf
>>>>>>>>>> 
>>>>>>>>>> Of course I would be happy to share my experience and work with a tiger team on optimizing JavaFX graphics.
>>>>>>>>>> 
>>>>>>>>>> However I would like getting sort of sponsoring for my potential contributions...
>>>>>>>>>> 
>>>>>>>>>> Cheers,
>>>>>>>>>> Laurent
>>>>>>>>>> 
>>>>>>>>>> Le 11 nov. 2016 11:29, "Tobi" <tobi at ultramixer.com> a écrit :
>>>>>>>>>>> 
>>>>>>>>>>> Hi,
>>>>>>>>>>> 
>>>>>>>>>>> thanks Felix, Laurent and Chris for sharing your stuff with the community!
>>>>>>>>>>> 
>>>>>>>>>>> I am happy to see starting a discussion about boosting up the JavaFX rendering performance. I can confirm that the performance of JavaFX scene graph is not there where it should be. So multithreading would be an excellent, but difficult approach.
>>>>>>>>>>> 
>>>>>>>>>>> Felix, concerning your research of other toolkits: Do they all use multithreading or are there any toolkits which use single threading but are faster than JavaFX?
>>>>>>>>>>> 
>>>>>>>>>>> So maybe there are other points than multithreading where we can boost the performance?
>>>>>>>>>>> 
>>>>>>>>>>> 2) your HPR sounds great. Did you already try DemoFX (part 3) benchmark with your HPR?
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> Best regards,
>>>>>>>>>>> Tobi
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>>> Am 10.11.2016 um 19:11 schrieb Felix Bembrick <felix.bembrick at gmail.com>:
>>>>>>>>>>>> 
>>>>>>>>>>>> (Thanks to Kevin for lifting my "awaiting moderation" impasse).
>>>>>>>>>>>> 
>>>>>>>>>>>> So, with all the recent discussions regarding the great contribution by
>>>>>>>>>>>> Laurent Bourgès of MarlinFX, it was suggested that a separate thread be
>>>>>>>>>>>> started to discuss parallelisation of the JavaFX rendering pipeline in
>>>>>>>>>>>> general.
>>>>>>>>>>>> 
>>>>>>>>>>>> As has been correctly pointed-out, converting or modifying the existing
>>>>>>>>>>>> rendering pipeline into a fully multi-threaded and performant beast is
>>>>>>>>>>>> indeed quite a complex task.
>>>>>>>>>>>> 
>>>>>>>>>>>> But, that's exactly what myself and my colleagues have been working on for
>>>>>>>>>>>> about 2 years.
>>>>>>>>>>>> 
>>>>>>>>>>>> The result is what we call the Hyper Rendering Pipeline (HPR).
>>>>>>>>>>>> 
>>>>>>>>>>>> Work on HPR started when we developed FXMark and were (bitterly)
>>>>>>>>>>>> disappointed with the performance of the JavaFX scene graph. Many JavaFX
>>>>>>>>>>>> developers have blogged about the need to dramatically minimise the number
>>>>>>>>>>>> of nodes (especially on embedded devices) in order to achieve even
>>>>>>>>>>>> "acceptable" performance. Often it is the case that most (if not all
>>>>>>>>>>>> rendering) is eventually done in a single Canvas node.
>>>>>>>>>>>> 
>>>>>>>>>>>> Now, as well already know, the JavaFX Canvas does perform very well and the
>>>>>>>>>>>> recent awesome work (DemoFX) by Chris Newland, just for example, shows what
>>>>>>>>>>>> can be done with this one node.
>>>>>>>>>>>> 
>>>>>>>>>>>> But, the majority of the animation plumbing in JavaFX is related to the
>>>>>>>>>>>> scene graph itself and is designed to make use of multiple nodes and node
>>>>>>>>>>>> types. At the moment, the performance of this scene graph is the Achilles
>>>>>>>>>>>> Heel of JavaFX (or at least one of them).
>>>>>>>>>>>> 
>>>>>>>>>>>> Enter HPR.
>>>>>>>>>>>> 
>>>>>>>>>>>> I personally have worked with a number of hardware-accelerated toolkits
>>>>>>>>>>>> over the years and am astounded by just how sluggish the rendering pipeline
>>>>>>>>>>>> for JavaFX is. When I am animating just a couple of hundred nodes using
>>>>>>>>>>>> JavaFX and transitions, I am lucky to get more than about 30 FPS, but on
>>>>>>>>>>>> the same (very powerful) machine, I can use other toolkits to render
>>>>>>>>>>>> thousands of "objects" and achieve frame rates well over 1000 FPS.
>>>>>>>>>>>> 
>>>>>>>>>>>> So, we refactored the entire scene graph rendering pipeline with the
>>>>>>>>>>>> following goals and principles:
>>>>>>>>>>>> 
>>>>>>>>>>>> 1. It is written using JavaFX 9 and Java 9 (but could theoretically be
>>>>>>>>>>>> back-ported to JavaFX 8 though I see no reason to).
>>>>>>>>>>>> 
>>>>>>>>>>>> 2. We analysed how other toolkits had optimised their own rendering
>>>>>>>>>>>> pipelines (especially Qt which has made some significant advances in this
>>>>>>>>>>>> area in recent years). We also analysed recent examples of multi-threaded
>>>>>>>>>>>> rendering using the new Vulkan API.
>>>>>>>>>>>> 
>>>>>>>>>>>> 3. We carefully analysed and determined which parts of the pipeline should
>>>>>>>>>>>> best utilise the CPU and which parts should best utilise the GPU.
>>>>>>>>>>>> 
>>>>>>>>>>>> 4. For those parts most suited to the CPU, we use the advanced concurrency
>>>>>>>>>>>> features of Java 8/9 to maximise parallelisation and throughput by
>>>>>>>>>>>> utilising multiple cores & threads in as an efficient manner as possible.
>>>>>>>>>>>> 
>>>>>>>>>>>> 5. We devoted a large amount of time to optimising the "communication"
>>>>>>>>>>>> between the CPU and GPU to be far less "chatty" and this alone led to some
>>>>>>>>>>>> huge performance gains.
>>>>>>>>>>>> 
>>>>>>>>>>>> 6. We also looked at the structure of the scene graph itself and after
>>>>>>>>>>>> studying products such as OpenSceneGraph, we refactored the JavaFX scene
>>>>>>>>>>>> graph in such a way that it lends itself to optimised rendering much more
>>>>>>>>>>>> easily.
>>>>>>>>>>>> 
>>>>>>>>>>>> 7. This is clearly not a "small" patch. In fact to refer to it as a
>>>>>>>>>>>> "patch" is probably rather inappropriate.
>>>>>>>>>>>> 
>>>>>>>>>>>> The end result is that we now have a fully-functional prototype of HPR and,
>>>>>>>>>>>> already, we are seeing very significant performance improvements.
>>>>>>>>>>>> 
>>>>>>>>>>>> At the minimum, scene graph rendering performance has improved by 500% and,
>>>>>>>>>>>> with judicious and sometimes "tricky" use of caching, we have seen
>>>>>>>>>>>> improvements in performance of 10x or more.
>>>>>>>>>>>> 
>>>>>>>>>>>> And... we are only just *starting* with the performance optimisation phase.
>>>>>>>>>>>> 
>>>>>>>>>>>> The potential for HPR is massive as it opens-up the possibility for the
>>>>>>>>>>>> JavaFX scene graph and the animation/transition infrastructure to be used
>>>>>>>>>>>> for a whole new class of applications including games, advanced
>>>>>>>>>>>> visualisations etc., without having to rely on imperative programming of a
>>>>>>>>>>>> single Canvas node.
>>>>>>>>>>>> 
>>>>>>>>>>>> I believe that HPR, along with tremendous recent developments like JPro and
>>>>>>>>>>>> the outstanding work by Gluon on mobiles and embedded devices, could
>>>>>>>>>>>> position JavaFX to be the best graphics toolkit of any kind in any language
>>>>>>>>>>>> and, be the ONLY *truly* cross-platform graphics technology available.
>>>>>>>>>>>> 
>>>>>>>>>>>> WORA for graphics and UIs is finally within reach!
>>>>>>>>>>>> 
>>>>>>>>>>>> Blessings,
>>>>>>>>>>>> 
>>>>>>>>>>>> Felix
>>>>>>>>>>> 
>>>>>>>> 
>>>>>> 
>>>> 