## moveSignedDistanceFromFractionGeneric MethodProtected

Generic algorithm to search for point at signed distance from a fractional startPoint.

• This will work for well for smooth curves.
• Curves with tangent or other low-order-derivative discontinuities may need to implement specialized algorithms.
• We need to find an endFraction which is the end-of-interval (usually upper) limit of integration of the tangent magnitude from startFraction to endFraction
• That integral is a function of endFraction.
• The derivative of that integral with respect to end fraction is the tangent magnitude at end fraction.
• Use that function and (easily evaluated!) derivative for a Newton iteration
• TO ALL WHO HAVE FUZZY MEMORIES OF CALCULUS CLASS: "The derivative of the integral wrt upper limit is the value of the integrand there" is the
``````fundamental theorem of integral calculus !!! The fundamental theorem is not just an abstraction !!! It is being used
here in its barest possible form !!!``````
• See https://en.wikipedia.org/wiki/Fundamental_theorem_of_calculus

moveSignedDistanceFromFractionGeneric(startFraction: number, signedDistance: number, allowExtension: boolean, result?: CurveLocationDetail):

Parameter Type Description
startFraction number
signedDistance number
allowExtension boolean
result CurveLocationDetail

### Defined in

Last Updated: 08 January, 2020