Helper class for dealing with points and line segments

line_segment.py

import numpy as np

# https://www.desmos.com/calculator/acagoky1yo

Point2 = np.ndarray  # np.ndarray[2,]

def dist(p1: Point2, p2: Point2):
    return np.linalg.norm(p2 - p1)

class LineSegment:
    def __init__(self, p1: Point2, p2: Point2):
        # Line segment from `p1` to `p2`
        
        self.p1 = p1
        self.p2 = p2

        self.v = p2 - p1  # Direction Vector
        factor = np.linalg.norm(self.v)
        if factor == 0:
            raise ValueError("Cannot make line segment from two coincident points.")
        self.v /= factor

        self.L = self.horiz_dist(self.p2)  # Length of the segment
    
    def perp_dist(self, p: Point2):  # Rename -> perp_dist
        # Perpendicular distance of `p` from the line
        return np.cross(self.v, p - self.p1)
    
    def horiz_dist(self, p: Point2):  
        # Distance from `p1` to the projection of `p` onto the line
        return np.dot(self.v, p - self.p1)

    def parametric(self, horiz_dist: float):  
        # The point `horiz_dist` away from `p1` on the line
        return self.p1 + self.v * horiz_dist