Dumping the rendering process in JavaFX

Jim Graham james.graham at oracle.com
Fri Nov 14 01:29:57 UTC 2014

Some pie in the sky observations about the background here...

Note that there was a fine line there that had to be evaluated.  Many of 
the printing detection changes were basically just "Oh, look, I have a 
new ResourceFactory now, that probably means new Textures", but it was 
tempered with "One might think to permanently shift over to the 
resources from this new factory, but if we're just printing, we are 
probably going to switch right back to a screen factory so any permanent 
changes of internal state are likely unwarranted".  On the other hand, 
sometimes when you print a scene, it was specially created just for the 
printing process so the initial ResourceFactory it sees is likely the 
only one it will ever see (and then the tree will be tossed).

It would be nice if we could generalize this or switch the way we manage 
resource states in the NGNode tree so that this was both flexible for 
switching seamlessly to a new resource factory/pool and flexibly dealt 
with the temporary/permanent nature of why those differences might come 
up (in other words, dynamically use and cache new resources without 
alienating or losing track of old ones unless that old pipeline/RF is 
going away).

Right now there aren't any on-screen related changes that might require 
us to permanently switch pipelines/resource factories (not entirely sure 
about management of D3D resources when we lose access to the screen, 
though) and printing is really the only use case where we ever even see 
a new ResourceFactory.  But, who knows what the future may bring and 
making assumptions about the RF being a constant throughout the app life 
cycle are not necessarily the best implementation practice in the long 

Have fun!  ;)


On 11/13/14 3:15 PM, Phil Race wrote:
> Basically for printing we had to detect that we were printing and use a
> non-cached texture.
> If you look for references to "PrinterGraphics" you might find some of
> them.
> Canvas is one place we had to deal with this. There are at least one or
> two others.
> Doing anything like only this via public API is probably an
> insurmountable challenge.
> -phil.
> On 11/13/14 2:49 PM, Kevin Rushforth wrote:
>> You could take a look at what JavaFX internally does for printing,
>> which is similar to what you are trying to do. It also forces the J2D
>> pipeline and had to deal with this issue. You likely won't be able to
>> do it without modifying FX internals, though, which is what printing
>> does in a few places.
>> -- Kevin
>> Herve Girod wrote:
>>> Hello,
>>> I think that more than one year ago, I asked if it was possible to
>>> dump the
>>> JavaFX rendering process. More than one year later, I (or we, for I am
>>> speaking on behalf of my project) are almost there. We use this in a
>>> library for a "JavaFX to any format you want" converter. For example
>>> we are
>>> currently able to convert a live JavaFX image to a PowerPoint slider
>>> (using
>>> POI), or we also could do the same with a WMF / EMF / SVG image, keeping
>>> the vector content of course.
>>> What we did is hacking the J2DPrismGraphics class to render it in a
>>> custom
>>> Graphics2D context which in turn can be a PPT / SVG / WMF / or EMF
>>> serializer.
>>> Our use case is the use of JavaFX in an Editor (no it's not a JavaFX
>>> Editor, we edit graphic specifications for an avionics standard called
>>> ARINC 661), and the ability to produce another Vector format with
>>> exactly
>>> the same UI.
>>> It works very well, except that of course we had to hack a few JavaFX
>>> core
>>> classes to do that (obviously J2DPrismGraphics was not designed to allow
>>> this). We did not recompile the core library, it's just separate classes
>>> which uses com.sun classes when possible, or we used
>>> PrivilegedActions when
>>> a method we needed was package protected.
>>> But we have still a big problem (I think that it might be the only one,
>>> except for the fact that our solution is an ugly hack, as you can see):
>>> There is still one case where our solution does not work: Textures.
>>> In fact
>>> we would have been able to convert JavaFX textures to BufferedImages
>>> if we
>>> could use the Java2D-based Texture class, but of course as we did
>>> nothing
>>> special, we encounter a D3D Texture (for example on Windows) which we
>>> don't
>>> know how to deal with.
>>> Which leads me to my two questions:
>>> - Is there a programmatic way (even a contorted one) to force JavaFX
>>> to use
>>> our own specific Pipeline (the idea is to be able to do this temporarily
>>> when serializing the JavaFX content, so without having to use command
>>> line
>>> argument)
>>> - I think that it could be very useful to have a neutral and JavaFX -
>>> supported way for developers to use their own Pipeline, even if it was
>>> limited and with a lower than average performance. Being able to convert
>>> from / to the JavaFX format is something that can be very useful.
>>> Hervé

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