poc-igeom/src/app/components/line-segment-component/models/line-segment-model.js

import { GeometricObject } from "../../../core/models/objects/geometric-object";
import { IntersectionModel } from "../../intersection-component/models/intersection-model";
export class LineSegmentModel extends GeometricObject {
  constructor(pointA, pointB, label) {
    super();
    this.pointA = pointA;
    this.pointB = pointB;
    this.setLabel(label);
  }
  getStraight() {
    const aX = this.pointA.posX;
    const aY = this.pointA.posY;
    const bX = this.pointB.posX;
    const bY = this.pointB.posY;
    const a = bY - aY;
    const b = aX - bX;
    const c = a * aX + b * aY;
    return [a, b, c];
  }
  getIntersection(lineSegment) {
    const r = this.getStraight();
    const s = lineSegment.getStraight();
    const a1 = r[0];
    const b1 = r[1];
    const c1 = r[2];
    const a2 = s[0];
    const b2 = s[1];
    const c2 = s[2];
    const determinant = a1 * b2 - a2 * b1;
    if (determinant == 0) {
      return new IntersectionModel(
        Number.MAX_SAFE_INTEGER,
        Number.MAX_SAFE_INTEGER,
        undefined,
        this,
        lineSegment
      );
    } else {
      const x = (b2 * c1 - b1 * c2) / determinant;
      const y = (a1 * c2 - a2 * c1) / determinant;
      return new IntersectionModel(x, y, undefined, this, lineSegment);
    }
  }
}