/// <summary>
/// Creates a Circle to represent the attack radius of the AI. If the Position Component of the
/// AI's target is within this Circle, then the AI is in range.
/// </summary>
/// <param name="entID">The Entity to check range for.</param>
/// <param name="AI">AI component of the Entity to check range for.</param>
/// <param name="pos">Position component of the Entity to check range for.</param>
protected void CheckRange(ulong entID, CAI AI, CPosition pos)
{
Circle attackRadius = SwinGame.CreateCircle(pos.Centre.X, pos.Centre.Y, AI.Range + (pos.Width / 2));
CPosition targetPos = World.GetComponent <CPosition>(AI.TargetID);
AI.IsInRange = SwinGame.CircleRectCollision(attackRadius, targetPos.Rect);
}
/// <summary>
/// Evaluates the Player AI's current position against the positions of each Enemy Entity.
/// The Enemy which is closest to the Player AI becomes the Player AI's target.
/// </summary>
/// <param name="playerAI">The Player AI Entity's AI Component.</param>
/// <param name="playerPos">The Player AI Entity's Position Component.</param>
private void GetClosestTarget(CAI playerAI, CPosition playerPos)
{
/// <summary>
/// How far away the Enemy Entity is on the x-axis.
/// </summary>
float xOffset;
/// <summary>
/// How far away the Enemy Entity is on the y-axis.
/// </summary>
float yOffset;
/// <summary>
/// The direct diagonal distance from the Enemy Entity.
/// </summary>
float distance;
/// <summary>
/// The Enemy Entity closest to the Player AI. This will become the AI's target.
/// </summary>
ulong closestTarget;
/// <summary>
/// Represents the Entities to be considered as targets and their distance from the Player AI.
/// </summary>
Dictionary <ulong, float> _targetDistances = new Dictionary <ulong, float>();
foreach (KeyValuePair <ulong, Point2D> enemy in _enemyPositions)
{
xOffset = enemy.Value.X - playerPos.X;
yOffset = enemy.Value.Y - playerPos.Y;
distance = (float)Math.Sqrt((xOffset * xOffset) + (yOffset * yOffset));
//Only consider Entities which are in range for the AI to attack.
if (distance <= playerAI.Range)
{
_targetDistances.Add(enemy.Key, distance);
}
}
//If there are targets to consider.
if (_targetDistances.Count > 0)
{
/// <summary>
/// Returns the corresponding key for the smallest value in the dictionary.
/// </summary>
closestTarget = _targetDistances.Aggregate((l, r) => l.Value < r.Value ? l : r).Key;
playerAI.TargetID = closestTarget;
playerAI.HasTarget = true;
}
}
/// <summary>
/// Checks the Game Time against the last time the AI attacked. If the time difference is greater
/// than the attack cooldown of the AI, then the AI is ready to attack and their Attack animation begins.
/// </summary>
/// <param name="entID">Ent identifier.</param>
protected void CheckCooldown(ulong entID)
{
CAI AI = World.GetComponent <CAI>(entID);
AI.AttackIsReady = World.GameTime - AI.LastAttackTime >= AI.Cooldown;
if (AI.AttackIsReady)
{
/// <summary>
/// Begin the Attack animation for the AI
/// </summary>
CAnimation anim = World.GetComponent <CAnimation>(entID);
SwinGame.AssignAnimation(anim.Anim, "Attack", anim.AnimScript);
}
}
/// <summary>
/// Performs an Attack for the specified Entity. The Entity's
/// attack Type is evaluated and the appropriate attack is performed.
/// </summary>
/// <param name="entID">The Attacking Entity.</param>
/// <typeparam name="T">The Team the Entity belongs to.</typeparam>
protected void Attack <T>(ulong entID) where T : CTeam
{
CAI AI = World.GetComponent <CAI>(entID);
CDamage damage;
CPosition pos;
CPosition targetPos;
/// <summary>
/// The AI has just attacked, so its cooldown is started.
/// </summary>
AI.LastAttackTime = World.GameTime;
AI.AttackIsReady = false;
/// <summary>
/// If the Attack Type is Melee, register an attack with the Damage System.
/// If the Attack Type is Gun, create an Arrow Entity to travel towards the Target.
/// </summary>
switch (AI.AttackType)
{
case AttackType.Melee:
{
/// <summary>
/// The System where Attacks are registered.
/// </summary>
DamageSystem damageSystem = World.GetSystem <DamageSystem>();
damage = World.GetComponent <CDamage>(entID);
damageSystem.RegisterAttack(AI.TargetID, damage.Damage);
break;
}
case AttackType.Bow:
{
pos = World.GetComponent <CPosition>(entID);
CBow bow = World.GetComponent <CBow>(entID);
targetPos = World.GetComponent <CPosition>(AI.TargetID);
EntityFactory.CreateArrow <T>(pos.Centre.X, pos.Centre.Y, bow, targetPos);
break;
}
}
}
