///<summary>
///steering behavior constructor
///</summary>
///<param name="agent"></param>
public Steering(BotEntity agent)
{
_bot = agent;
Flags = 0;
_weightSeparation = GameManager.GameManager.Instance.Parameters.SeparationWeight;
_weightWander = GameManager.GameManager.Instance.Parameters.WanderWeight;
_weightWallAvoidance = GameManager.GameManager.Instance.Parameters.WallAvoidanceWeight;
_viewDistance = GameManager.GameManager.Instance.Parameters.ViewDistance;
_wallDetectionFeelerLength = GameManager.GameManager.Instance.Parameters.WallDetectionFeelerLength;
Feelers = new List<Vector2>(3);
_deceleration = Decelerations.Normal;
TargetAgent1 = null;
TargetAgent2 = null;
_wanderDistance = WANDER_DIST;
_wanderJitter = WANDER_JITTER_PER_SEC;
_wanderRadius = WANDER_RAD;
_weightSeek = GameManager.GameManager.Instance.Parameters.SeekWeight;
_weightArrive = GameManager.GameManager.Instance.Parameters.ArriveWeight;
CellSpaceIsOn = true;
SummingMethod = SummingMethods.Prioritized;
//stuff for the wander behavior
float theta = RandomUtil.RandomFloat()*(float) Math.PI*2.0f;
//create a vector to a target position on the wander circle
WanderTarget = new Vector2(WanderRadius*(float) Math.Cos(theta),
WanderRadius*(float) Math.Sin(theta));
}
///<summary>
///This behavior is similar to seek but it attempts to arrive at the
///target with a zero velocity
///</summary>
///<param name="target"></param>
///<param name="deceleration"></param>
///<returns></returns>
public Vector2 Arrive(Vector2 target, Decelerations deceleration)
{
Vector2 toTarget = target - Bot.Position;
//calculate the distance to the target
float dist = toTarget.Length();
if (dist > 0)
{
//because Decelerations is enumerated as an int, this value is
//required to provide fine tweaking of the deceleration..
const float decelerationTweaker = 0.3f; //TODO: should be a parameter
//calculate the speed required to reach the target given the
//desired deceleration
float speed = dist/((float) deceleration*decelerationTweaker);
//make sure the velocity does not exceed the max
speed = Math.Min(speed, Bot.MaxSpeed);
//from here proceed just like Seek except we don't need to
//normalize the toTarget vector because we have already gone
//to the trouble of calculating its length: dist.
Vector2 desiredVelocity = toTarget*speed/dist;
return (desiredVelocity - Bot.Velocity);
}
return Vector2.Zero;
}
