class Bee
{
  float x, y; // Position
  float px, py; // Previous position
  float vx, vy; // Velocity
  float gx, gy; // Gravity
  float friction; // Friction
  Bee()
  {
    reset();
  }
  void reset()
  {
    x = 0;
    y = 0;
    px = 0;
    py = 0;
    vx = 0;
    vy = 0;
    gx = 0;
    gy = 0;
    friction = 1;
  }
  void set_pos(float x, float y)
  {
    this.x = x;
    this.y = y;
  }
  void set_vel(float vel, float dir)
  {
    float[] c = xy_comps(vel, dir);
    vx = c[0];
    vy = c[1];
  }
  void set_grav(float vel, float dir)
  {
    float[] c = xy_comps(vel, dir);
    gx = c[0];
    gy = c[1];
  }
  void step()
  {
    // Previous position
    px = x;
    py = y;
    
    // Gravity
    vx += gx;
    vy += gy;
    
    // Friction
    vx *= friction;
    vy *= friction;
    
    // Position
    x += vx;
    y += vy;
  }
  void draw()
  {
    line(px, py, x, y);
  }
  void display()
  {
    step();
    draw();
  }
}