private Task ChaseStart(State from)
{
PatrolState patrolState = (PatrolState)from;
if (patrolState == null)
{
throw new InvalidOperationException("ChaseState can only be entered from PatrolState");
}
ChaseState chaseState = stateMachine.GetCurrentState <ChaseState>();
if (chaseState == null)
{
throw new InvalidOperationException("ChaseStart can only be used with ChaseState");
}
chaseState.ChaseTarget = patrolState.ChaseTarget;
chaseState.ChaseColliderTarget = patrolState.ChaseColliderTarget;
return(Task.FromResult(0));
}
private void ChaseUpdate()
{
Drone.Alerted = true;
ChaseState chaseState = stateMachine.GetCurrentState <ChaseState>();
if (chaseState == null)
{
throw new InvalidOperationException("ChaseUpdate can only be used with ChaseState");
}
if (chaseState.ChaseTarget == null)
{
// Stop chasing
stateMachine.SwitchTo(PatrolState.Name);
return;
}
IDestructible destructible = Utils.GetDestructible(chaseState.ChaseTarget);
if (destructible == null)
{
throw new InvalidOperationException("ChaseTarget can only target IDestructibles");
}
if (destructible.IsDead)
{
// Stop chasing
stateMachine.SwitchTo(PatrolState.Name);
return;
}
// Check if still overlapping
bool withinRange = false;
foreach (var collision in alertZoneTrigger.Collisions)
{
var targetCollider = collision.ColliderA.Entity != alertZoneTrigger.Entity
? collision.ColliderA
: collision.ColliderB;
if (targetCollider == chaseState.ChaseColliderTarget)
{
withinRange = true;
break;
}
}
if (!withinRange)
{
// Stop chasing
stateMachine.SwitchTo(PatrolState.Name);
return;
}
// Recalculate path to player?
Vector3 actualTargetPos = chaseState.ChaseTarget.Transform.WorldMatrix.TranslationVector;
var source = Entity.Transform.WorldMatrix.TranslationVector;
var target = actualTargetPos;
source.Y = 1.5f;
target.Y = 1.5f;
Vector3 aimDir = target - source;
float distToTarget = aimDir.Length();
aimDir.Normalize();
var playerTargeted = Drone.UpdateHeadRotation(aimDir);
// Process move step
if (chaseState.MoveOperation != null)
{
if (!chaseState.MoveOperation.MoveNext())
{
chaseState.MoveOperation = null;
}
}
bool hasLineOfSight = CheckLineOfSight(Entity, chaseState.ChaseColliderTarget);
if (hasLineOfSight)
{
if (distToTarget < 6.0f)
{
// No longer need to move, player is in line of sight, and drone is pretty close
chaseState.MoveOperation = null;
Drone.SetMovement(Vector3.Zero);
}
if (playerTargeted)
{
// Shoot the player
Drone.Weapon?.TryShoot(chaseState.ChaseTarget);
}
}
// Update path towards player when either not moving or
// the current path would end up too far from the player
float targetDistance = (actualTargetPos - chaseState.CurrentChaseTargetPosition).Length();
if (chaseState.MoveOperation == null || targetDistance > 1.0f)
{
chaseState.CurrentChaseTargetPosition = chaseState.ChaseTarget.Transform.WorldMatrix.TranslationVector;
chaseState.MoveOperation = Move(chaseState.CurrentChaseTargetPosition);
}
}
