/*
 * ARTS 102 - Aesthetics of the Algorithmic Image
 * Johannes Goerz (johannes.goerz@gmail.com)
 * 2005-12-04
 */
 
class Vector {
  float angle,x,y,l;
  
  Vector() {
    
  }

  void init(float _x, float _y) {
    this.x = _x;
    this.y = _y;
    this.l = sqrt( sq(_x) + sq(_y) );
    this.angle = atan2( _y, _x);
  }
  
  void reset() {
    this.init( 0, 0);
  }
  
  float distance( Vector v ) {
    return sqrt( sq(this.x - v.x) + sq(this.y - v.y) );
  }
  
  void add( Vector v ) {
    this.init( this.x + v.x, this.y + v.y );
  }
  
  void sub( Vector v ) {
    this.init( this.x - v.x, this.y - v.y );
  }
  
  void setAngle( float _a ) {
    this.angle = _a;
    this.x = cos( _a ) * this.l;
    this.y = sin( _a ) * this.l;
  }
  
  void setLength( float _l) {
    this.l = _l;
    this.x = cos( this.angle ) * _l;
    this.y = sin( this.angle ) * _l;
  }
  
  void draw( int x, int y ) {
    stroke(255,0,0);
    line(x,y,x+this.x,y+this.y);
    noStroke();
  }
}