Withdrawn: 8322619: Parts of SG no longer update during rendering - overlapping - culling - dirty

[Florian Kirmaier]

On Thu, 21 Dec 2023 12:33:52 GMT, Florian Kirmaier <fkirmaier at openjdk.org> wrote:

> In some situations, a part of the SG is no longer rendered.
> I created a test program that showcases this problem.
> 
> Explanation:
> 
> This can happen, when a part of the SG, is covered by another Node.
> In this part, one node is totally covered, and the other node is visible.
> 
> When the totally covered Node is changed, then it is marked dirty and it's parent, recursively until an already dirty node is found.
> Due to the Culling, this totally covered Node is not rendered - with the effect that the tree is never marked as Clean.
> 
> In this state, a Node is Dirty but not It's parent. Based on my CodeReview, this is an invalid state which should never happen.
> 
> In this invalid state, when the other Node is changed, which is visible, then the dirty state is no longer propagated upwards - because the recursive "NGNode.markTreeDirty" algorithm encounters a dirty node early.
> 
> This has the effect, that any SG changes in the visible Node are no longer rendered. Sometimes the situation repairs itself.
> 
> Useful parameters for further investigations:
> -Djavafx.pulseLogger=true
> -Dprism.printrendergraph=true
> -Djavafx.pulseLogger.threshold=0
> 
> PR:
> This PR ensures the dirty flag is set to false of the tree when the culling is used.
> It doesn't seem to break any existing tests - but I'm not sure whether this is the right way to fix it.
> It would be great to have some feedback on this solution - maybe guiding me to a better solution.
> 
> I could write a test, that just does the same thing as the test application, but checks every frame that these nodes are not dirty - but maybe there is a better way to test this.

This pull request has been closed without being integrated.

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PR: https://git.openjdk.org/jfx/pull/1310