Short question, is that pointOnPath() function for expressions also available for scripting somehow? The only chance I see is by creating an layer with that expression and harvesting the result.
And an associated question: Is it possible via expression or script to get the opposite of that pointOnPath() function. You feed in a specific Point or a vertex number of a path and get the percentage where the point sits in that path. I am trying to write an approximation function to achieve that, but dont really get it to work so that it doesnt fail when working with specific paths where the path intersects.