/// <summary>
/// Draws a star object from the world.
/// </summary>
private void StarDrawer(object o, PaintEventArgs e)
{
Star s = o as Star;
int starWidth = 45 + Convert.ToInt32(s.GetSize() * 1000);
Rectangle r = new Rectangle(-(starWidth / 2), -(starWidth / 2), starWidth, starWidth);
e.Graphics.DrawImage(starImage, r);
}
/// <summary>
/// Calculates gravity between a ship and a star.
/// </summary>
/// <returns>a Vector2D gravity</returns>
private Vector2D CalculateForce(Ship ship, Star star)
{
// get direction
Vector2D g = star.GetLocation() - ship.GetLocation();
g.Normalize();
// get magnitude
g *= star.GetSize();
return(g);
}