I actually don't know what you want to achieve with "is_active".
InputEventScreenTouch has an attribute "pressed". Maybe use that?
There's also the attribute index which indicate which "#paralleltouch" that specific event is for. So when touching with two fingers there maybe overlapping touchevents pressed=true -> pressed=false with different index values. Maybe save the index of the first pressed=true event and only react to pressed=false when the event index matches or something similar.
You save any event from input for use in process. Maybe you should save only InputEventScreenTouch events (put evt=... inside the if). And maybe only save the position.