public void Update(double time_elapsed)
{
this.TimeElapsed = time_elapsed;
//calculate the combined force from each steering behavior in the
//vehicle's list
Vector2 steeringForce = steering.Calculate();
//Acceleration = Force/Mass
Vector2 acceleration = steeringForce * (float)(1 / mass);
//update velocity
velocity += acceleration * (float)time_elapsed;
//make sure vehicle does not exceed maximum velocity
Helper2.Truncate(ref velocity, maxSpeed);
//update the position
position += velocity * (float)time_elapsed;
//update the heading if the vehicle has a non zero velocity
if (velocity.LengthSq() > 0.00000001)
{
heading = Vector2.Normalize(velocity);
side = Helper2.Perp(heading);
}
//treat the screen as a toroid
Helper2.WrapRound(ref position, world.cxClient, world.cyClient);
}
public Vehicle(GameWorld world, Vector2 position, float rotation, Vector2 velocity, float mass)
{
this.world = world;
this.position = position;
this.heading = new Vector2((float)+Math.Sin(rotation), (float)-Math.Cos(rotation));
this.side = Helper2.Perp(this.heading);
steering = new SteeringBehavior(this);
this.mass = mass;
this.maxSpeed = 150.0f;
this.maxForce = 2.0f * SteeringBehavior.steeringForceTweaker;
}