Filter Mix - draw on FilterDisplay

[DanH]

So I'm looking at ways to draw a filter's mix in a FilterDisplay tile, which should interpolate between the filter curve and a flat line.... Short of getting Claude Code to hack away at the Hise codebase to implement a mix control onto the stock filters, I'm looking at drawing all the filters on a panel fresh (they don't need to be exact mathematical models) but this will take a long time to iron out the quirks. I also had a look at the SNEX filter graph getPlotValue() API but I need confirmation that a mix control could be included here - @Christoph-Hart ?