Canvas clip problems

Richard Bair richard.bair at
Sat Jun 1 17:55:18 PDT 2013

"Cheese" (the smear) should never be possible. It means that the clip used on the device is wrong for some reason, and therefore some area of the screen was not being repainted that needed to be. In Swing (or Android or any other immediate mode API) it is possible that your app could have a bug that causes this, but with the scene graph the responsibility is with JFX not to mess up the dirty regions.

My guess is this is related to the other issue you already filed about the "z order" rendering issue (which is also related to the clip being wrong). It might be worth putting the link to the screencast on that bug report.


On Jun 1, 2013, at 3:21 PM, Daniel Zwolenski <zonski at> wrote:

> Here is one I can't reproduce in smaller code.
> You can see that when the enemies start off the canvas they end up leaving
> a smear behind. When they leave the canvas at the other end they also
> smear.
> I suspect it's something to do with the clipping code used in the game but
> I haven't been able to narrow it down (and this area I was a bit flaky on
> and I think Richard did the starting setup for).
> It's probably a case of clipping properly, but should this sort of
> behaviour be even possible to occur?
> p.s. thanks for the Camtasia tips - nice product.

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