How do I lock facing of a top-down player on key down but still have 8 Dir movement?

Hello everyone, I am creating a top-down shooter. I am wondering how do I lock the facing of the player but still retain 8 DIR movement? In this instance WASD are the controls and the SPACEBAR (when DOWN) would lock the angle the player is currently facing and allow the player to still move in 8 DIR but only face 1 DIR.

Any help appreciated.

'Set angle' overrides any angle changes from 8 direction.