@technobuddha/library/src/normalize-line-segment.ts

A large library of useful functions

import { type LineSegment } from './@types/geometry.ts';

/**
 * Returns a {@link LineSegment} where the point with the higher y-coordinate is always the starting point (x0, y0).
 * If the original line's y1 is greater than y0, the line is returned as-is.
 * Otherwise, the start and end points are swapped.
 * @param line - The line segment to process.
 * @returns A {@link LineSegment} with the topmost point as the starting point.
 * @group Geometry
 * @category Line Segment
 */
export function normalizeLineSegment(line: LineSegment): LineSegment {
  return line.y1 > line.y0 ? line : { x0: line.x1, y0: line.y1, x1: line.x0, y1: line.y0 };
}