text: export class Point {
    constructor(x, y) {
      this.x = x;
      this.y = y;
    }
  
    add(dPoint) {
      this.x += dPoint.x;
      this.y += dPoint.y;
      return this;
    }
  
    sub(dPoint) {
      this.x -= dPoint.x;
      this.y -= dPoint.y;
      return this;
    }
  
    scale(c) {
      this.x *= c;
      this.y *= c;
      return this;
    }
  }
  