Yes, that's what I normally observe and when you increase the load on the graphics pipeline this is eventually slowed down when a frame rate of 60FPS cannot be maintained anymore.

Now on my Mac I observe a very strange behavior under certain conditions where the visible frame updates drop to something like 1FPS but the AnimationTimer is still running with something like 30FPS. So, what I would like to know is whether such a behavior is normal according to the design or whether this is a potential bug. I have not yet observed this behavior on Windows.

Michael

Am 03.01.17 um 15:30 schrieb Kevin Rushforth:
A running AnimationTimer class will cause pulses to be scheduled continuously, but they should still be limited to no more often than 1/60 sec (unless you are overriding it with system properties).

-- Kevin


Markus KARG wrote:
Merry Christmas,

my personal observation when performaning an EU-fundet power consumption study 
was that once an (even no-op implementation!) AnimationTimer was registered, 
the CPU load increased by several percent _permanently_ on our lab machine. In 
contrast, with key frame animation, the CPU load stayed at zero percent but 
showed scattered peaks. Unfortunately I cannot tell you the actual 
JavaFX-internal reason for sure, but I assume that AnimationTimer is called at 
maximum possible CPU speed (i. e. more or less an endless loop) while the 
animation classes update only once per _pulse_ (i e. more or less 60 FPS).

It feels like (but this might be a false detection of mine; I did not check the source 
code) as the pure _registering_ of an AnimationTimer would enable JavaFX to actually run 
some JavaFX-internal code "undelayed", while _just_ using animation classes do 
not run that same code before the next _pulse_ (possible by using timer interrupts set to 
the next 1/60s).

It would be great if the JavaFX team could confirm this difference between 
AnimationTimer and animation classes?

-Markus

-----Original Message-----
From: openjfx-dev [mailto:openjfx-dev-boun...@openjdk.java.net] On Behalf Of 
Michael Paus
Sent: Samstag, 24. Dezember 2016 10:21
To:openjfx-dev@openjdk.java.net
Subject: Re: AnimationTimer and actual frame rate

Many thanks again.

Am 23.12.16 um 18:18 schrieb Markus KARG:
I assume it is OK for you to use internal APIs?
Of course it is :-)
   Then you could go with:

com.sun.javafx.perf.PerformanceTracker.getSceneTracker(scene)

and let a timer fire one per second to request tracker.getAverageFPS().
I'll give that a try as soon as my family lets me.
Beware not to use any AnimationTimer handlers, as it will reduce FPS, even if 
the handler method is short.
Is the AnimationTimer handler more critical in this respect than any of the 
built-in animations?
-Markus

-----Original Message-----
From: openjfx-dev [mailto:openjfx-dev-boun...@openjdk.java.net] On
Behalf Of Michael Paus
Sent: Freitag, 23. Dezember 2016 17:04
To:openjfx-dev@openjdk.java.net
Subject: Re: AnimationTimer and actual frame rate

Thank you. That explains a lot of what I am observing but it also makes me 
wonder how you could effectively measure the actual frame rate because that's 
what you are normally interested in.
Michael

Am 23.12.16 um 09:15 schrieb Markus KARG:
AnimationTimer is fired once per "planned" frame (i. e. running at maximum possible FPS), 
not per "actually rendered" frame. JavaFX contains a lot of optimizations. For example, a 
boolean property animated over time to switch from false to true will only imply a single 
modification, hence only one frame is actually rendered.
-Markus

-----Original Message-----
From: openjfx-dev [mailto:openjfx-dev-boun...@openjdk.java.net] On
Behalf Of Michael Paus
Sent: Donnerstag, 22. Dezember 2016 17:29
To:openjfx-dev@openjdk.java.net
Subject: AnimationTimer and actual frame rate

Hi all,

for quite a while now I am observing a strange behavior when running
some

JavaFX graphics tests. The scenario is very simple. I am running some
animation

which puts some load onto the graphics engine and I am trying to
measure the

frame rate via an instance of an AnimationTimer. When I increase the
load high

enough I reach a point where the indicated frame rate is just 60FPS
or even a bit

lower but the observed frame rate on screen has already dropped to
something

like 1-2 FPS. So what I observe is that the AnimationTimer is running
much faster

than the updates of the graphics. How can that be? Does anybody have
an explanation

under which circumstances this can happen? Or is this behavior a bug which I 
should report?

Just some puzzle for the boring Christmas holidays :-)

Merry Christmas to all of you

Michael

PS: My system is a MacBook Pro with NVidia graphic card.






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