/// <summary>
/// Updates the Photon's position and graphics state
/// </summary>
/// <param name="elapsedTime">The time elapsed between the previous and current frame</param>
public override void Update(float elapsedTime)
{
//Get the vector to the player
toPlayer = player.GetPosition() - this.position;
//determine how to chase the player
if (homing)
{
//Photon 1st fired and if player is far away
if (toPlayer.LengthSquared() > 3000)
{
//chase the player
toPlayer.Normalize();
this.position += toPlayer * elapsedTime * this.velocity;
}
else //Become a dummy and go straight
{
homing = false;
lastPlayerPosition = toPlayer;
}
}
else //When near the player
{
lastPlayerPosition.Normalize();
this.position += elapsedTime * lastPlayerPosition * this.velocity;
}
//Update the Photon graphics state
UpdatePhotonState(elapsedTime);
}
/// <summary>
/// Creates a new bullet that will travel towards the Player's current position.
/// </summary>
/// <param name="id">Id for the bullet.</param>
/// <param name="content">ContentManager to load content with.</param>
/// <param name="position">Starting position for the bullet.</param>
public ToPlayerBullet(uint id, ContentManager content, Vector2 position)
: base(id)
{
this.spriteSheet = content.Load <Texture2D>(SPRITESHEET);
this.spriteBounds = SPRITEBOUNDS;
this.position = position;
//Fire at the Player.
PlayerShip Player = ScrollingShooterGame.Game.Player;
Vector2 positionVector = Player.GetPosition() - position;
positionVector.Normalize();
this.velocity = positionVector * VELOCITY;
}
