Flip x when direction of the movement changed in Unity

Question

What is the easiest and the most efficient way to flip x of the SpriteRenderer when direction of the movement changed in Unity?

I use Input.GetAxis() in order to get user input. When it returns 0 I would like to do nothing, when it returns positive number I would like to have x flipped in SpriteRenderer in one side and when number returned is negative another side.

So far I come up with a solution of using a variable which will be keeping the info about to which side the player is turned and flip x if necessary. But I am sure that this is not an efficient way to do it and even not a convenient one since my code will tend to become a lot bigger and messier.

Answer 1

I suggest do not bind the flipping procedure to the Input since it is directly relevant to the moving direction of the body (Input may not change the body's moving duration in some specific occasions). Do it by simply checking the velocity vector of the rigidBody2D.

It can be simply done by 2 ways:

-Either you can check in the moving object's Update() loop by simply writing:

if(rigidbody2D.velocity.x >= 0){
   spriteRenderer.flipX = false;
}
else {
   spriteRenderer.flipX = true;
}

- Or you can do the same check whatever the function changes the velocity of the body that you are moving.

You can also simplify the code into one line, if you want less lines like the following:

spriteRenderer.flipX = rigidBody2D.velocity.x < 0 ? true : false;