private float rotationTicks = 0;

@SubscribeEvent
public void onKeyInput(InputEvent.KeyInputEvent event) {
	EntityPlayer player = mc.thePlayer;

	if(KeyHandler.RIVEN_Z.isPressed()) {
		if(zPressed) return;
		else {
			zPressed = true;	player.moveEntity(-Z_MOVE_DISTANCE*Math.sin(Math.toRadians(player.rotationYawHead))*Math.cos(Math.toRadians(player.rotationPitch)),-Z_MOVE_DISTANCE*Math.sin(Math.toRadians(player.rotationPitch)), Z_MOVE_DISTANCE*Math.cos(Math.toRadians(player.rotationYawHead))*Math.cos(Math.toRadians(player.rotationPitch)));
			float x = player.rotationYaw;
		}
	}
}

@SubscribeEvent(priority = EventPriority.HIGHEST)
public void clientTickEvent(ClientTickEvent event) {
	if(zPressed) {
		System.out.println(zPressed);
		float yaw = mc.thePlayer.rotationYaw;
		rotationTicks += 1F;

		mc.thePlayer.rotationYaw += rotationTicks;
		if(mc.thePlayer.rotationYaw < yaw) {
			rotationTicks += 1F;
			mc.thePlayer.rotationYaw += rotationTicks;
		} else if(mc.thePlayer.rotationYaw == yaw) {
			zPressed = false;
			rotationTicks = 0;
			System.out.println(zPressed);
		}
	}
}