class Line {

  Node a,b;
  String name;
  
  Line(Node a, Node b) {
    if (a != null && b != null) {
      if (a.x <= b.x) {
        this.a=a; this.b=b;
      }
      else {
        this.a=b; this.b=a;
      }
    }
    if (a != null) {
      a.lines.addElement(this);
    }
    if (b != null) {
      b.lines.addElement(this);
    }
    name = "";
  }
  
  void draw() {
    line(a.x,a.y,b.x,b.y);
  }
  
  float angle() {
    return atan2(b.y-a.y,b.x-a.x);
  }
  
  float length() {
    // TODO check != 0
    return sqrt(sq(b.y-a.y)+sq(b.x-a.x));
  }
  
  float distance(Node c) {
    float u = ( ((c.x-a.x)*(b.x-a.x)) + ((c.y-a.y)*(b.y-a.y)) ) / (sq(b.y-a.y)+sq(b.x-a.x));
    float x = a.x + (u * (b.x-a.x));
    float y = a.y + (u * (b.y-a.y));
    float d = c.distance(new Node(x,y));
    //if (keyPressed) println(d);
    return d;
  }
  
  boolean mouseOver() {
    return distance(new Node(mouseX,mouseY)) < 7.5;
  }
  
}