It’s almost as if the old position is removed after the new one is drawn. So a slow moving marker almost completely disappears.
But it only happens on Windows. How can I fix this or, what’s best way of doing this, it seems to be a Windows version bug.
Looking at the DSPDemo, I see the whole waveform is being repainted on a timer, by using JUCE_ENABLE_REPAINT_DEBUGGING.
There is no way I can do that - it’s too time consuming.