/// <summary>
/// Simulates the gameplay logic for this <see cref="EnemyGroup"/>.
/// </summary>
/// <param name="deltaTime">The elapsed time between this frame and the last frame, in seconds.</param>
public void Update(float deltaTime)
{
GameplayScreen gameplayScreen = MainGame.Context.GetGameScreen <GameplayScreen>(GameScreenType.Gameplay);
if (isStartupAnimation)
{
startupAnimationTimer -= deltaTime;
if (startupAnimationTimer <= 0)
{
startupAnimationTimer = StartupAnimationTime;
renderRowThreshold -= 1;
}
if (renderRowThreshold == 0)
{
isStartupAnimation = false;
gameplayScreen.Unfreeze();
}
}
if (gameplayScreen.IsFrozen)
{
return;
}
timeToMovement -= deltaTime;
if (timeToMovement <= 0)
{
if (canVerticallyMove && IsTouchingHorizontalBounds())
{
movementDirection *= -1;
boundingRectangle.Y += VerticalMovementShift * MainGame.ResolutionScale;
canVerticallyMove = false;
}
else
{
boundingRectangle.X += HorizontalMovementShift * MainGame.ResolutionScale * movementDirection;
canVerticallyMove = true;
}
timeToMovement = GetMovementTime();
animationFrameToggle = !animationFrameToggle;
movementSounds[movementSoundCounter].Play();
movementSoundCounter = (movementSoundCounter + 1) % movementSounds.Length;
}
for (int x = 0; x < GroupWidth; x++)
{
for (int y = GroupHeight - 1; y >= 0; y--)
{
// Only bottom-most enemies in their respective columns can attack
if (!enemyGrid[x, y].Active || y < GroupHeight - 1 && enemyGrid[x, y + 1].Active)
{
continue;
}
Enemy enemy = enemyGrid[x, y];
enemy.AttackTime -= deltaTime;
if (!(enemy.AttackTime <= 0))
{
continue;
}
enemy.AttackTime = GetEnemyAttackTime();
// If this enemy has not attacked since the start of the game, it means that
// the attack time was only generated this frame; hence, let's return and
// turn off the flag.
if (!enemy.HasAttacked)
{
enemy.HasAttacked = true;
return;
}
gameplayScreen.ProjectileController.CreateEnemyProjectile(enemy);
// Since we have the bottom-most enemy that active, we are done looking
// at the current column.
break;
}
}
for (int i = activeExplosions.Count - 1; i >= 0; i--)
{
activeExplosions[i] = new Tuple <Enemy, float>(activeExplosions[i].Item1, activeExplosions[i].Item2 - deltaTime);
if (activeExplosions[i].Item2 <= 0)
{
activeExplosions.RemoveAt(i);
}
}
Enemy bottomMost = GetBottomMostEnemy();
if (GetEnemyWorldRectangle(bottomMost).Bottom > gameplayScreen.BarrierGroup[0].Rectangle.Bottom)
{
gameplayScreen.TriggerGameover();
}
}
