Top Down 2D Animation - Can't seem to get it right

I'm making a 2D top-down game, there are 4 animations

Front Idle
Back Idle

Front Walking
Back Walking

I cannot seem to wrap my head around how to create parameters to run the animations at the proper moments. When I am walking upwards, I want the player to 'Back Walking'. When I stop, the player should 'Back Idle', and the same logic applies to the front walking and front idle.

Could someone help me figure out what parameters I should use and how I should impliment them into my walking script.

Code (CSharp):

1. Vector2 moveInput = new Vector2(Input.GetAxisRaw("Horizontal"), Input.GetAxisRaw("Vertical"));
2.         moveVelocity = moveInput.normalized * speed;
3. rb.velocity = moveVelocity;

 

My Animancer plugin (link in my signature) has some Directional Sprites examples which demonstrate how to implement this sort of thing without needing to create an Animator Controller or mess around with parameters.