/// <summary>Updates the position and orientation of all sprites on each timer tick.</summary>
/// <param name="sender">The timer.</param>
/// <param name="e">Event args.</param>
private void UpdateSpritesOnTimerTick(object sender, EventArgs e)
{
if (_timer != null)
{
if (_sprites != null)
{
// Update each sprite
for (int i = _sprites.Count - 1; i >= 0; --i)
{
// Update the sprite
ImageSprite s = _sprites[i];
s.Update();
// If it's left the visible range, remove it from the list so we don't
// need to deal with it any more
Rectangle bounds = ClientRectangle;
if (s.Location.X > bounds.Right + s.Image.Width || s.Location.X < -s.Image.Width ||
s.Location.Y > bounds.Bottom + s.Image.Width || s.Location.Y < -s.Image.Width)
{
_sprites.RemoveAt(i);
s.Dispose();
}
}
// If there are no sprites left, stop the timer; we're done.
if (_sprites.Count == 0)
{
_timer.Stop(); // stop but don't delete, as _timer is used as a marker
}
// Refresh the window
Invalidate();
}
}
}
