Forums » Help » "Chasing" CPU's

Is there any way to make CPU's chase the player?

Yes.

The algorithm is called A*, it works well in 2D games, dunno if it'll be any good for a platform game though.
I learned about it from here:
http://bostongamejams.com/akihabara-tutorials/akihabara-tutorial-part-5-enemy-ai
when I experimented with another framework.

Thank you!

I'm pretty new to coding thus I'm not sure how to do this properly.

I got this in my enemy.js entity:

	update: function() {
		
		var player = this.getEntitiesByType( EntityPlayer )[0];
		if( player ) {
			//What here?
		}
		
		var xdir = this.flip ? -1 : 1;
		this.vel.x = this.speed * xdir;
		
		this.parent();
	},

I think I have to use update, but what should I put inside the if-brackets?

You could get the angle to your target entity (the player in this case) and set the velocity of the entity to move torwards it:

var angle = this.angleTo( player );
this.vel.x = Math.cos(angle) * this.speed;
this.vel.y = Math.sin(angle) * this.speed;

Please try to state your questions a bit more explicit in the future. Guessing what you want to achieve is no fun :)

Thank you!

update: function() {
		
		var player = this.getEntitiesByType( EntityPlayer )[0];
		var angle = this.angleTo( player );
		this.vel.x = Math.cos(angle) * this.speed;
		this.vel.y = Math.sin(angle) * this.speed;
		
		this.parent();
	},

This is what I have right now, yet the game just stops loading at 90%, without any error message/etc.. Where could be the problem?

There should be an error in your console if it doesn't load completely.
Hard to say what's wrong if you only present a short snippet of source.
Two wild guesses:

+ The dependency to EntityPlayer is not defined (see requires method)
+ The player hasn't spawned yet. Trying to develop defensive is always a good idea:

update: function() {
        
        var player = this.getEntitiesByType( EntityPlayer )[0];
        if (player) {   
                var angle = this.angleTo( player );
                this.vel.x = Math.cos(angle) * this.speed;
                this.vel.y = Math.sin(angle) * this.speed;
        }
        
        this.parent();
    },

But it hasn't to be one of that...

Btw: The getEntitiesByType method is a member of the Game Object ... won't work on an Entity...

        var player = ig.game.getEntitiesByType( EntityPlayer )[0];

Just use the Devtools with the console ... all of that above will show errors in the console.