constructor(v1, v2) {

    this.a = v1;

    this.b = v2;

    this.trias = [];

  }

​

  isAEnd(p) {

    if (p == this.a || p == this.b) return true;

    return false;

  }

​

  hasCommon(l) {

    return this.isAEnd(l.a) || this.isAEnd(l.b);

  }

​

  calcValue(p) {

    let m = (this.b.y - this.a.y) / (this.b.x - this.a.x);

    let ans = p.y - this.a.y - m * (p.x - this.a.x);

    return ans;

  }

​

  onSameSide(p1, p2) {

    return this.calcValue(p1) * this.calcValue(p2) > 0;

  }

​

  delete(tr) {

    for (let i = 0; i < this.trias.length; ++i)

      if (this.trias[i].Tr == tr) {

        this.trias.splice(i, 1);

      }

  }

​

  length() {

    return Math.sqrt(

      Math.pow(this.a.x - this.b.x, 2) + Math.pow(this.a.y - this.b.y, 2)

    );

  }

​

  isStable() {

    if (this.trias.length == 1) return true;

    let sum = 0;

    for (let tr of this.trias) sum += tr.Tr.angles[tr.side];

    return sum < Math.PI;

  }

​

  display() {

    line(this.a.x, this.a.y, this.b.x, this.b.y);

  }

}

​