js获取点到线段的距离

/** * 获取点到线段的距离 * @param point * @param lineStart * @param lienEnd */ export function getTheDistanceOfAPointLineSegment(point, lineStart, lienEnd) {    if(lineStart.x === lienEnd.x && lineStart.y === lienEnd.y) return Math.sqrt((point.x - lineStart.x) * (point.x - lineStart.x) + (point.y - lineStart.y) * (point.y - lineStart.y));    let r = ((point.x - lineStart.x) * (lienEnd.x - lineStart.x) + (point.y - lineStart.y) * (lienEnd.y - lineStart.y))        / ((lienEnd.x - lineStart.x) * (lienEnd.x - lineStart.x) + (lienEnd.y - lineStart.y) * (lienEnd.y - lineStart.y));    if (r <= 0)return Math.sqrt((point.x - lineStart.x) * (point.x - lineStart.x) + (point.y - lineStart.y) * (point.y - lineStart.y));    if (r >= 1)return Math.sqrt((point.x - lienEnd.x) * (point.x - lienEnd.x) + (point.y - lienEnd.y) * (point.y - lienEnd.y));    let px = lineStart.x + (lienEnd.x - lineStart.x) * r;    let py = lineStart.y + (lienEnd.y - lineStart.y) * r;    return Math.sqrt((point.x-px)*(point.x-px)+(point.y-py)*(point.y-py));}