Filter view flickers (shows sine wave)

[pdesaulniers]

How to reproduce:

• Go in Addsynth
• Go in Filter
• Click on the General section a few times

This makes a sine wave flash on screen, which is annoying.

The issue also occurs when switching tabs at the bottom (filter => frequency => filter)

I could also reproduce this in the Padsynth filter section, but not in Subsynth.

Formant filter is not affected.

I've noticed that onExtern in VisFilter is called all the time when clicking on the sections. This doesn't apply to the filter in Subsynth, though.

[fundamental]

Sounds like either there's something going on with how osc-bridge caches values which are float vectors, or there's something going on with the visualization delaying the first rendering to the first animation frame even if it has the data it needs and is being forced to do the first draw frame.