Crouching In a 2D game

Help & Support
1

Hello! I am here seeking advice once again on coding. I want to implement a crouching mechanic in my game, however, whenever I launch to playtest, I keep getting an error. Could someone please assist me.

Code of Interest Below:

 if(this.keyboard.isPressed(pc.KEY_SHIFT))
        
        if( !this.crouching){
            this.crouching = true;
            
            this.entity.collision.height = 1;

            this.entity.rigidbody.enabled = false;
            this.entity.rigidbody.enabled = true;            
            
        }else{
            this.crouching = false;
            
            this.entity.collision.height = 2;

            this.entity.rigidbody.enabled = false;
            this.entity.rigidbody.enabled = true;   
        
        }

Error Received: Cannot read properties of undefined (reading ‘isPressed’)

2

Hi @Overbaked_Prod,

try updating your if statement to:

this.app.keyboard.isPressed(pc.KEY_SHIFT)

The app object is where you can find the keyboard object and its various methods.

Check out this part of the user manual for more examples:

https://developer.playcanvas.com/en/tutorials/keyboard-input/

2 Likes
3

Hello, I used the code you suggested below and now get this error.

Cannot read properties of undefined (reading ‘keyboard’)

I am completely stumped on how to figure this out as the if statement is formated same as everything else in the code.

4

Hi @Overbaked_Prod! Can you share your project or script please?

5

Here is the entirety of the script, my good sir.

var Heyehyey = pc.createScript('heyehyey');

// initialize code called once per entity
Heyehyey.prototype.initialize = function() {
     this.entity.collision.on('collisionstart', this.onCollisionStart, this);
};

// update code called every frame
Heyehyey.prototype.update = function(dt) {
       if(this.app.keyboard.isPressed(pc.KEY_D)){
    this.entity.rigidbody.applyForce(0,0,5000);}
    
       if(this.app.keyboard.isPressed(pc.KEY_A)){
    this.entity.rigidbody.applyForce(0,0,-2000);} 
    
    //Jumping
    var canJump = false;
    var from = this.entity.getPosition();
    var to = new pc.Vec3(from.x, from.y - this.entity.getLocalScale().y, from.z);
    var result = this.app.systems.rigidbody.raycastFirst(from, to);
    var toLeftSide = new pc.Vec3(from.x - this.entity.getLocalScale().x, from.y, from.z);
    var resultLeftSide = this.app.systems.rigidbody.raycastFirst(from, toLeftSide);
    var toRightSide = new pc.Vec3(from.x + this.entity.getLocalScale().x, from.y, from.z);
    var resultRightSide = this.app.systems.rigidbody.raycastFirst(from, toRightSide);
    var airborne = false;
    var dash = this.app.keyboard.wasPressed(pc.KEY_SPACE);
    var jump = this.app.keyboard.wasPressed(pc.KEY_W);
    var onGround = false;
    var crouching =false;
    
    Heyehyey.prototype.onCollisionStart = function(result){
    if(result.other.tags.has('ground')){
      onGround = true;  
    }
        else
            {
                onGround = false;
}
    

};
    if(result || resultLeftSide || resultRightSide)
    {
        canJump = true;
        airborne = false;
    }
    else
    {
        canJump = false;
        airborne = true;
    }
    
    
    if(this.app.keyboard.wasPressed(pc.KEY_W) && canJump)
    {
        if(resultLeftSide && !result)
            this.entity.rigidbody.applyImpulse(0,1500,1000);
        else if(resultRightSide && !result)
            this.entity.rigidbody.applyImpulse(0,1500,-1000);
        else if(result)
            this.entity.rigidbody.applyImpulse(0,1500,0);
    }

    
};

 this.app.keyboard.isPressed(pc.KEY_SHIFT);
        
        if( !this.crouching){
            this.crouching = true;
            
            this.entity.collision.height = 1;

            this.entity.rigidbody.enabled = false;
            this.entity.rigidbody.enabled = true;            
            
        }else{
            this.crouching = false;
            
            this.entity.collision.height = 2;

            this.entity.rigidbody.enabled = false;
            this.entity.rigidbody.enabled = true;   
        
        }
6

You have some code outside the update function and you have your collision start function inside the update function. In the script below I fixed some problems that I have found.

var Heyehyey = pc.createScript('heyehyey');

// initialize code called once per entity
Heyehyey.prototype.initialize = function() {
     this.entity.collision.on('collisionstart', this.onCollisionStart, this);
};

// UPDATE FUNCTION
// update code called every frame
Heyehyey.prototype.update = function(dt) {
       if(this.app.keyboard.isPressed(pc.KEY_D)){
    this.entity.rigidbody.applyForce(0,0,5000);}
    
       if(this.app.keyboard.isPressed(pc.KEY_A)){
    this.entity.rigidbody.applyForce(0,0,-2000);} 
    
    //Jumping
    var canJump = false;
    var from = this.entity.getPosition();
    var to = new pc.Vec3(from.x, from.y - this.entity.getLocalScale().y, from.z);
    var result = this.app.systems.rigidbody.raycastFirst(from, to);
    var toLeftSide = new pc.Vec3(from.x - this.entity.getLocalScale().x, from.y, from.z);
    var resultLeftSide = this.app.systems.rigidbody.raycastFirst(from, toLeftSide);
    var toRightSide = new pc.Vec3(from.x + this.entity.getLocalScale().x, from.y, from.z);
    var resultRightSide = this.app.systems.rigidbody.raycastFirst(from, toRightSide);
    var airborne = false;
    var dash = this.app.keyboard.wasPressed(pc.KEY_SPACE);
    var jump = this.app.keyboard.wasPressed(pc.KEY_W);
    var onGround = false;
    var crouching =false;
    
    if(result || resultLeftSide || resultRightSide)
    {
        canJump = true;
        airborne = false;
    }
    else
    {
        canJump = false;
        airborne = true;
    }
    
    
    if(this.app.keyboard.wasPressed(pc.KEY_W) && canJump)
    {
        if(resultLeftSide && !result)
            this.entity.rigidbody.applyImpulse(0,1500,1000);
        else if(resultRightSide && !result)
            this.entity.rigidbody.applyImpulse(0,1500,-1000);
        else if(result)
            this.entity.rigidbody.applyImpulse(0,1500,0);
    }

 if (this.app.keyboard.isPressed(pc.KEY_SHIFT)) {
        
        if( !this.crouching){
            this.crouching = true;
            
            this.entity.collision.height = 1;

            this.entity.rigidbody.enabled = false;
            this.entity.rigidbody.enabled = true;            
            
        }else{
            this.crouching = false;
            
            this.entity.collision.height = 2;

            this.entity.rigidbody.enabled = false;
            this.entity.rigidbody.enabled = true;   
        
        }
}

// END FUNCTION
};

// COLLISION START FUNCTION
Heyehyey.prototype.onCollisionStart = function(result){
    if(result.other.tags.has('ground')){
      onGround = true;  
    }
        else
            {
                onGround = false;
}
    
// END FUNCTION
};