$app->add_event_handler( \&quit_event );
$app->add_move_handler ( \&calculate_laser );
$app->add_show_handler ( \&render_laser );
sub quit_event
{
	my $event = shift;
	my $controller = shift;
	
	$controller->stop if $event->type == SDL_QUIT;
}

sub calculate_laser
{
	# The step is the difference in Time calculated for the next jump
	my ( $step, $app, $t ) = @_;
	$laser += $velocity * $step;
	$phaser += $velocity * $step;
	
	$velocity = -$velocity if $laser > $app->w;
	$velocity = -$velocity if $laser < -20;
}

sub render_laser {
	my ($delta, $app) = @_;

	#draw bg
	$app->draw_rect( [0, 0, $app->w, $app->h ], 0);
	
	$app->draw_rect([$phaser, $app->h/4, 20, 4], [100, 100, 255, 255]);
	$app->draw_rect( [ $laser, $app->h / 2, 20, 4 ], [255, 8, 8, 255] );
	$app->update();
}