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10 years ago by mdkess

I'm implementing doors in my game, and the logic is basically "if the player presses 'e' and they are facing and reasonably close to a door, open that door."

Right now I am using getEntitiesByType(EntityDoor), and doing the check by hand. I would like to be able to do something like CollisionMap.trace, and extend say a 1xN pixel "hand" in front of the character, but does such a thing exist?

After this, I'm going to implement an EntityChest, which is similar - player presses 'e', and if they are overlapping a chest, the chest opens. So I think it'll be another "getEntitiesByType(EntityChest)" and checking each one for overlap.

So anyway, I have it working, I'm just not sure if it's optimal. Any tips?

// in player.js
var doors =;
if (doors) {
	for (var i = 0; i < doors.length; ++i)  {
		var dist = this.distanceTo(doors[i]);
		if (dist <= this.size.x + 0.0001)  {
			// logic for opening the door, depending on direction player is facing etc.
var chests =;
// ...

10 years ago by Cavalier

You may want to allow for a bigger distance between the player and the door.
As fas as I know, that is the only way to check if an entity is close to another, getting all entities of said type and doing a this.distanceTo()

Now, if all doors always open from the same side (for instance, always with the player going up), all you'll need is a simple animation check
if (player.currentAnim == player.anim['up']) {
 //open door

Now, if each door has a different, or multiple directions from which it can be opened, you'll have to define it among its variables:
door = ig.Entity.extend({
opensFromSouth = true,
opensFromEast = false,
opensFromWest = false,
opensFromNorth = false,
// could also be an array
opensFrom: ['left','right'],

Personally, I'd do it like this:
distanceToOpen: 5,
if (ig.input.pressed('E')) {
var doors =;
  for (var i = 0; i < doors.length; i++)  {
      if (this.distanceTo(doors[i] < this.distanceToOpen) )  {
          if (doors[i].opensFromSouth) { //repeat for other directions
            if (this.currentAnim = this.anims['up'])  {
              //open up!!

EDIT: You can also try using this.touches(door) if you want to make sure the player is actually touching the door instead of checking the distance

10 years ago by Xatruch

you could also just add a boolean to open the door when the player collides with the door.

// door.js
EntityDoor = ig.Entity.extend({

 checkAgainst: ig.Entity.TYPE.A,

 check: function( other ) {
  if( other instanceof EntityPlayer ) {
   other.canOpenDoor = true;

// on player.js
EntityPlayer = ig.Entity.extend({

  type: ig.Entity.TYPE.A,
  update: function() {
   if( this.canOpenDoor && ig.input.pressed( 'E' ) {
    // opening door logic.
   this.canOpenDoor = false;

10 years ago by mdkess

Apologies for the delay in replying, life took over! Thank you all for your responses.

I think my way is right. The distance feels natural, and I think that the collision check is good - but I want the player to be able to open it while standing still next to the door. Context is, this is a platformer. I'll post a demo in a few weeks.
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