Is there a way to make switch/case using Vector3?

Question

What i want to do is to detect each side when my character(ThirdPerSonController) touch a cube. In fact my main goal is to detect when my player is standing on the cube surface on top. This is my script:

using UnityEngine;
using System.Collections;

public class Test : MonoBehaviour {

    void OnCollisionEnter(Collision collision)
    {
        ContactPoint contact = collision.contacts[0];
        Vector3 normal = contact.normal;
        Vector3 inverseNormal = transform.InverseTransformDirection(normal);
        Vector3 roundNormal = RoundVector3(inverseNormal);

        ReturnSide(roundNormal);
    }

    Vector3 RoundVector3(Vector3 convertThis)
    {
        int x = (int)Mathf.Round(convertThis.x);
        int y = (int)Mathf.Round(convertThis.y);
        int z = (int)Mathf.Round(convertThis.z);
        Vector3 returnVector = new Vector3(x, y, z);
        return returnVector;
    }



void ReturnSide(Vector3 side)
{
    string output = null;
    switch (side)
    {
        case Vector3.down:
            output = "Down";
            break;
        case Vector3.up:
            output = "Up";
            break;
        case Vector3.back:
            output = "Back";
            break;
        case Vector3.forward:
            output = "Front";
            break;
        case Vector3.left:
            output = "Left";
            break;
        case Vector3.right:
            output = "Right";
            break;
    }
    Debug.Log(output + " was hit.");
}

// Use this for initialization
void Start () {

    }

    // Update is called once per frame
    void Update () {

    }
}

I'm getting error on the line:

switch (side)

Severity Code Description Project File Line Suppression State Error CS0151 A switch expression or case label must be a bool, char, string, integral, enum, or corresponding nullable type test.cs 33 Active

Answer 1

With C# 7, you can do this. You case use the when statement:

https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/switch#the-case-statement-and-the-when-clause

So, for example, if you wanted to know which side of a cube is clicked, you can use something like this:

void OnMouseDown()
{
    RaycastHit hit;
    Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
    if (Physics.Raycast(ray, out hit, Mathf.Infinity))
    {
        switch (hit.normal)
        {
                case Vector3 v when v.Equals(Vector3.up):
                    Debug.Log("Up");
                    break;
                case Vector3 v when v.Equals(Vector3.left):
                    Debug.Log("Left");
                    break;
                case Vector3 v when v.Equals(Vector3.back):
                    Debug.Log("Back");
                    break;
        }
    }
}

I'm not sure about the efficiency of this method. YMMV.

Answer 2

No, there is no way to make a switch/case using Vector3.

"A switch expression or case label must be a bool, char, string, integral, enum or corresponding nullable type."