private void UpdatePlayerShots(GameTime gameTime)
{
// if we are allowed to fire, add a shot to the list
if (InputManager.ControlState.Fire && gameTime.TotalGameTime.TotalMilliseconds - lastTime > 500)
{
// create a new shot over the ship
PlayerShot ps = new PlayerShot(this.contentManager);
ps.Position.X = (player.Position.X + player.Width / 2) - ps.Width / 2;
ps.Position.Y = player.Position.Y - ps.Height;
playerShots.Add(ps);
lastTime = gameTime.TotalGameTime.TotalMilliseconds;
AlienAttackGame.AudioManager.PlayCue(AudioManager.Cue.PlayerShot);
}
// enumerate the player shots on the screen
for (int i = 0; i < playerShots.Count; i++)
{
PlayerShot playerShot = playerShots[i];
playerShot.Update(gameTime);
// if it's off the top of the screen, remove it from the list
if (playerShot.Position.Y + playerShot.Height < 0)
{
playerShots.RemoveAt(i);
playerShot = null;
}
}
}
public bool HandlePlayerShotCollision(PlayerShot playerShot)
{
for (int y = 0; y < EnemyRows; y++)
{
for (int x = 0; x < EnemyCols; x++)
{
// if a player shot hit an enemy, destroy the enemy
if (enemies[y, x] != null && CheckCollision(playerShot, enemies[y, x]))
{
Explosion explosion = new Explosion(this.Content);
explosion.Position = enemies[y, x].Position;
explosions.Add(explosion);
enemies[y, x] = null;
return(true);
}
}
}
return(false);
}
private void HandleCollisions(GameTime gameTime)
{
// see if a player shot hit an enemy
for (int i = 0; i < playerShots.Count; i++)
{
PlayerShot playerShot = playerShots[i];
// check the shot and see if it it collided with an enemy
if (playerShot != null && enemyGroup.HandlePlayerShotCollision(playerShots[i]))
{
// remove the shot, add the score
playerShots.RemoveAt(i);
score += 100;
AlienAttackGame.AudioManager.PlayCue(AudioManager.Cue.Explosion);
}
}
// see if an enemy shot hit the player
if (player != null && enemyGroup.HandleEnemyShotCollision(player))
{
// blow up the player
playerExplosion = new Explosion(this.contentManager);
playerExplosion.Position = player.Position;
player = null;
AlienAttackGame.AudioManager.PlayCue(AudioManager.Cue.Explosion);
}
// see if an enemy hit the player directly
if (player != null && enemyGroup.HandleEnemyPlayerCollision(player))
{
// blow up the player
playerExplosion = new Explosion(this.contentManager);
playerExplosion.Position = player.Position;
player = null;
AlienAttackGame.AudioManager.PlayCue(AudioManager.Cue.Explosion);
loseGame = true;
}
// if the player explosion animation is running, update it
if (playerExplosion != null)
{
// if this is the last frame
if (playerExplosion.Update(gameTime) && !loseGame)
{
// remove it
playerExplosion = null;
// we lose if we have no lives left
if (lives == 0)
{
loseGame = true;
}
else
{
// subract 1 life and reset the board
lives--;
enemyGroup.Reset();
playerShots.Clear();
player = new Player(this.contentManager);
}
}
}
}