/// <summary>
/// Computes the acceleration, velocity, and position of the passed in ship
/// </summary>
public void MotionForShips(Ship ship)
{
// if the ship isn't alive, just skip it
if (!ship.IsAlive())
{
return;
}
// handle left turn command
if (ship.TurnLeft)
{
ship.GetDirection().Rotate(-turningRate);
ship.TurnLeft = false;
}
// handle right turn command
else if (ship.TurnRight)
{
ship.GetDirection().Rotate(turningRate);
ship.TurnRight = false;
}
// spawn a projectile if projectile command has been given
if (ship.FireProjectile)
{
Projectile p = new Projectile(ship.GetID(), projectileID++, ship.GetLocation(), ship.GetDirection());
AddProjectile(p);
ship.FireProjectile = false;
ship.ResetFireTimer();
// we just fired a projectile, increment total number of fired projectiles
ship.ShotsFired++;
}
//get a zero vector
Vector2D acceleration = new Vector2D(0.0, 0.0);
//compute the acceleration caused by the star
foreach (Star star in stars.Values)
{
Vector2D g = star.GetLocation() - ship.GetLocation();
g.Normalize();
acceleration = acceleration + g * star.GetMass();
}
if (ship.HasThrust())
{
//compute the acceleration due to thrust
Vector2D t = new Vector2D(ship.GetDirection());
t = t * engineStrength;
acceleration = acceleration + t;
}
// recalculate velocity and location
ship.SetVelocity(ship.GetVelocity() + acceleration);
ship.SetLocation(ship.GetVelocity() + ship.GetLocation());
// check to see if ship is off screen
Wraparound(ship);
// check for collisions with any star
foreach (Star star in stars.Values)
{
CollisionWithAStar(ship, star);
}
// check for collisions with any projectiles
foreach (Projectile proj in projectiles.Values)
{
CollisionWithAProjectile(ship, proj);
}
ship.IncrementFireTimer();
}