How to stop jumping again when character is in air (double jump)?

Question

I'm using touch inputs in my game to control the character. I would like to know how to disable my character from jumping again in the air.

if (FingerTouchy.phase == TouchPhase.Ended)
                {
       charcter.transform.Translate(Vector2.up * speed * Time.deltaTime);
       float jumpForce = 250;
                        charcter.GetComponent<Rigidbody2D>().AddForce(new Vector2(0, jumpForce));

                    }

Update

Im using Collision Detection

void OnCollisionEnter (Collision col)
    {
        if(col.gameObject.tag == "Ground")
        {
            grounded = true;

        }
    }

And checking if charcter is grounded

if(FingerTouchy.phase == TouchPhase.Ended)
            {

                    float jumpForce=250;
                    if (grounded)
                        continue;
                    charcter.transform.Translate(Vector2.up * speed * Time.deltaTime);
                    charcter.GetComponent<Rigidbody2D>().AddForce(new Vector2(0,jumpForce));
                        grounded=false;

                }

using collision/collision2d doesn't work too.

Answer 1

I've handling ground status with raycast.

I declare a global grounded variable and use it to check if my character can jump.

In the fixed update of my character controller, i call my groundedUpdater().

void GroundedUpdater ()
{
    grounded = false; //Set to false every frame by default
    RaycastHit2D[] hit;
    hit = Physics2D.RaycastAll (transform.position, Vector2.down, 0.6f);
    // you can increase RaycastLength and adjust direction for your case
    foreach (var hited  in hit) {
        if (hited.collider.gameObject == gameObject) //Ignore my character
            continue;
        // Don't forget to add tag to your ground
        if (hited.collider.gameObject.tag == "Ground") { //Change it to match ground tag
            grounded = true;
        }
    }
}

And where i handle inputs i do this

if (Input.GetKeyDown (KeyCode.UpArrow)) {
        if (grounded) { // can jump
            rig.AddForce (Vector3.up * jumpPower, ForceMode2D.Impulse);
            grounded = false; //Avoid direct double jump
        }
    }

Answer 2

Checking the game object's velocity in y axis.

if (FingerTouchy.phase == TouchPhase.Ended && charcter.GetComponent<Rigidbody2D>().velocity.y==0)
                {
       charcter.transform.Translate(Vector2.up * speed * Time.deltaTime);
       float jumpForce = 250;
    charcter.GetComponent<Rigidbody2D>().AddForce(new Vector2(0, jumpForce));

                    }

This just works fine.

Let me know if this has any drawbacks.

Answer 3

if (FingerTouchy.phase == TouchPhase.Ended)
    {
        float jumpForce = 250;
        if (playerIsGrounded)
            charcter.transform.Translate(Vector2.up * speed * Time.deltaTime);
            charcter.GetComponent<Rigidbody2D>().AddForce(new Vector2(0, jumpForce));

    }

In the grounded check code :

void OnTriggerEnter(coll Collider)
{
    if (coll.tag == "Ground")
        playerIsGrounded = true;
}

void OnTriggerLeave(coll Collider)
{
    if(coll.tag == "Ground")
        playerIsGrounded = false;
}

---

Haven't used unity in a while but I think it's something like this?

Answer 4

To do that, make a script name Ground. Attach Rigidbody2D to Ground and mark it as Kinematic. Assuming that your character has "Player" tag. Now time to use some delegate stuff.

A simple definition of delegate that delegate is use to notify other class on an event, even if that other class don't have any instance of first class. In other words, delegate does broadcast a message, then all other classes whichever wants to receive that broadcast, just set a listener in it.

For example, class A has an specific event. class B and class C wants to get notify when that specific even occurs in class A without having an instance of class A.

So similarly you can use delegate keeping a good structure of code.

using UnityEngine;
using System.Collections;

public class Ground : MonoBehaviour
{
    public delegate void OnCharacterLandedDelegate();
    public static event OnCharacterLandedDelegate OnCharacterLandedListener;
    // Use this for initialization
    void Start ()
    {

    }

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

    }

    void OnCollisionEnter2D(Collision2D col)
    {
        if (col.gameObject.tag == "Player")
        {
            if (OnCharacterLandedListener != null)
                OnCharacterLandedListener();
        }
    }
}

Now in the script where you are handling touch. Add these lines of code.

bool _shouldJump = true;
void OnEnable()
{
    Ground.OnCharacterLandedListener += EnableJump;
}

void OnDisable()
{
    Ground.OnCharacterLandedListener -= EnableJump;
}

void EnableJump()
{
    _shouldJump = true;
}

Somewhere in your code,

if(FingerTouchy.phase == TouchPhase.Ended)
{
    //charcter.transform.Translate(Vector2.up * speed * Time.deltaTime);
    Jump();
}

void Jump()
{
    if (!_shouldJump)
        return;
    _shouldJump = false;
    float jumpForce=250;
    charcter.GetComponent<Rigidbody2D>().AddForce(new Vector2(0,jumpForce));
}

Answer 5

The easiest way is to use the Boolean variable. Make it true if the character on the ground else make it false. If it is true then only add the force to the character.

Ex:

First check the player is on the ground.

This code snippet goes on ground GameObject.

void OnCollisionEnter2D(Collision2D col)
    {
        if (col.gameObject.tag == "Player")
        {
            if (OnCharacterLandedListener != null)
                OnCharacterLandedListener();
               new PlayerScript().canJump=true;// if player on the ground
        }
    }

Your input action

This code snippet goes to the Player gameobject.

   [HideInspector]   //Don't show  this field in the inspector.
    public bool canJump=false;  

        if(FingerTouchy.phase == TouchPhase.Ended)
        {
            //charcter.transform.Translate(Vector2.up * speed * Time.deltaTime);
            if(canJump)
                Jump();
        }

        void Jump()
        {
            if (!_shouldJump)
                return;
             _shouldJump = false;
             float jumpForce=250;
             charcter.GetComponent<Rigidbody2D>().AddForce(new Vector2(0,jumpForce));
             canJump=false; // if not on the ground
        }

Answer 6

Since I mis understood, I would use a part of @HamzaHasan 's answer, but I would not use AddForce.

I advice to not use Addforce to let a character jump/move because this is not ment for character movement, this is more or less used for explosion that give a "force" to your body, or space ships floating movement. I would advice using transform.Translate(Vector3.up * speed * Time.deltaTime, Space.World);. Where vector.3 defines the direction this could be;

• Vector3.left
• Vector3.right
• Vector3.up
• Vector3.down