index.js

/*
mostly copied from
https://stackoverflow.com/questions/41968142/aframe-emitting-custom-events-between-components
*/
/* global AFRAME */

if (typeof AFRAME === 'undefined') {
  throw new Error('Component attempted to register before AFRAME was available.');
}

var lastPos = {x: 0, y:0, z:0};
var lastRot = {x: 0, y:0, z:0};

/* look for significant rotation, 0.1 degree or more
so as to not take up too much CPU power */
function diffPosRot(currentPos, currentRot, accuracy) {
  var val = Object.keys(currentPos).map(function(key){
    if (key) {
      if (currentPos[key].toFixed(accuracy) != lastPos[key].toFixed(accuracy)) {
        lastPos[key] = currentPos[key];
        return true;
      }
      if (currentRot[key].toFixed(accuracy) != lastRot[key].toFixed(accuracy)) {
        lastRot[key] = currentRot[key];
        return true;
      }
    }
  });
  for (var i = 0; i < val.length; i++){
    if (val[i] == true) {
	return true;
    }
  }
  return false;
  /*
  for (key in currentPos) {
  if (currentRot[key].toFixed(1) == lastRot[key].toFixed(1)) {
  return false;
  }
  }*/
}
/**
* Camera Listener component for A-Frame.
*/
AFRAME.registerComponent('camera-listener', {
  schema: {
    dataEl: {type: 'selector'},
    /* maybe pos and rot are unnecessary as they can be
    queried directly */
    position: {type: 'vec3'},
    rotation: {type: 'vec3'}
  },

  /**
  * Set if component needs multiple instancing.
  */
  multiple: false,

  tick: function () {
    var cameraEl = this.el.sceneEl.camera.el;
    var pos = cameraEl.getAttribute('position');
    var rot = cameraEl.getAttribute('rotation');
      if (diffPosRot(pos, rot, 2)) {
      this.data.dataEl.emit('camera-moved', {value: {position: pos, rotation: rot}});
    }
  },

  /**
  * Called once when component is attached. Generally for initial setup.
  */
  init: function () {
    this.data.dataEl = this.el;
  },

  /**
  * Called when component is attached and when component data changes.
  * Generally modifies the entity based on the data.
  */
  updateSchema: function (d) {
  },

  /**
  * Called when a component is removed (e.g., via removeAttribute).
  * Generally undoes all modifications to the entity.
  */
  remove: function () { },

  /**
  * Called on each scene tick.
  */
  // tick: function (t) { },

  /**
  * Called when entity pauses.
  * Use to stop or remove any dynamic or background behavior such as events.
  */
  pause: function () { },

  /**
  * Called when entity resumes.
  * Use to continue or add any dynamic or background behavior such as events.
  */
  play: function () { }
});