Artifacts when resizing the subpasses example

[Axilot]

Hello there,

when playing around with the samples, I noticed an issue within the "subpasses" sample. This issue is only triggered when resizing the window while the program is running. It basically becomes a giant artifact which it never recovers from.

At first I thought, that it had to do with my gpu drivers but it seems to affect both Nvidia aswell as AMD gpu's.

I hope this helps to some extent!
Best regards!

[SaschaWillems]

See #455. That sample is missing proper synchronization. We'll fix this.

[Axilot]

Oh, didn't see that. That makes sense. Thanks for the quick reply!