[X3D-Public] Fwd: [FreeWRL-develop] 3D philosophical question

[Russ Kinter]

> > But, from another point of view, it is sending an event tied to an
> > object that no longer exists.

The key is this statement. 
This POV is illusionary because the object DID exist at that particular
discrete timestamp. The call to removeChildren happens at a different
timestamp. 

EAI is relatively slow, that's why you shouldn't try to do animations with
it.
That slowness produces different timestamps, therefore since this is a
"philosophical" question, I'll paraphrase Heraclitus and say "You can't
produce the same event in an EAI scene twice" -that is unless it's WorldView
leaking more memory than a Timothy Leary lecture.

Russ Kinter




> -----Original Message-----
> From: x3d-public-bounces at web3d.org [mailto:x3d-public-bounces at web3d.org]
> On Behalf Of John A. Stewart
> Sent: Sunday, September 26, 2010 12:10 PM
> To: X3D Graphics public mailing list
> Subject: [X3D-Public] Fwd: [FreeWRL-develop] 3D philosophical question
> 
> Dear X3D people;
> 
> A FreeWRL user, using the EAI interface, has a conundrum that, on the
> surface at least, would affect not only EAI, but SAI and Javascript
> deletion of nodes.
> 
> I don't know the answer to the question, does anyone on this list have an
> opinion?
> 
> Here is the users' question:
> 
> > Amongst the actions that happens in my world via the EAI is an 'object
> > delete' event.
> >
> > It happens in the following sequence:
> > mouse over, EAI app gets event
> > mouse click, EAI app gets the request
> > EAI app sees the object should be deleted
> > EAI app sends a remove children request, (and removes the object from
> > its internal tables)
> >
> > Now comes the conundrum:
> >
> > Obviously, from one point of view, the mouse is no longer over the
> > disappeared object, and therefore FreeWRL is quite entitled to send a
> > mouse exit event; this is what FreeWRL currently does.
> >
> > But, from another point of view, it is sending an event tied to an
> > object that no longer exists.
> >
> > I can program round this; but which is the correct behaviour for
> > FreeWRL in this corner case  ?
> >
> > At the moment I avoid the problem by ignoring the 'dangling pointer'
> > but I might miss a genuine problem.
> 
> 
> -----------------------------------------------------------
> John A. Stewart
> alex.stewart at crc.ca
> 
> Network Systems and Technologies -
>         Systemes et technologies des reseaux
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