Color highlight where in sigbuffer the ind is, and provide an ind just like an image buffer.  TBD provide a 0-1.0 fractional input, and also make default behaviour stop sampling input when input is disconnected/not dirty (but optionally sample all the time?)
Only update when input is dirty
Thinking about making a node that allows mouse drawing into a buffer, but need better facility to track mouse state
Fractional input is working, but needs to update ind so that drawing will update with it
Now updating ind with fr converted value