networked-aframe/src/utils.js

A web framework for building multi-user virtual reality experiences.

/* global NAF, THREE */

module.exports.whenEntityLoaded = function(entity, callback) {
  if (entity.hasLoaded) { callback(); }
  entity.addEventListener('loaded', function () {
    callback();
  });
}

module.exports.createHtmlNodeFromString = function(str) {
  var div = document.createElement('div');
  div.innerHTML = str;
  var child = div.firstChild;
  return child;
}

module.exports.getCreator = function(el) {
  var components = el.components;
  if (components['networked']) {
    return components['networked'].data.creator;
  }
  return null;
}

module.exports.getNetworkOwner = function(el) {
  var components = el.components;
  if (components['networked']) {
    return components['networked'].data.owner;
  }
  return null;
}

module.exports.getNetworkId = function(el) {
  var components = el.components;
  if (components['networked']) {
    return components['networked'].data.networkId;
  }
  return null;
}

module.exports.now = function() {
  return Date.now();
};

module.exports.createNetworkId = function() {
  return Math.random().toString(36).substring(2, 9);
};

/**
 * Find the closest ancestor (including the passed in entity) that has a `networked` component
 * @param {ANode} entity - Entity to begin the search on
 * @returns {Promise<ANode>} An promise that resolves to an entity with a `networked` component
 */
function getNetworkedEntity(entity) {
  return new Promise((resolve, reject) => {
    let curEntity = entity;

    while(curEntity && curEntity.components && !curEntity.components.networked) {
      curEntity = curEntity.parentNode;
    }

    if (!curEntity || !curEntity.components || !curEntity.components.networked) {
      return reject("Entity does not have and is not a child of an entity with the [networked] component ");
    }

    if (curEntity.hasLoaded) {
      resolve(curEntity);
    } else {
      curEntity.addEventListener("instantiated", () => {
        resolve(curEntity);
      }, { once: true });
    }
  });
}

module.exports.getNetworkedEntity = getNetworkedEntity;

module.exports.takeOwnership = function(entity) {
  let curEntity = entity;

  while(curEntity && curEntity.components && !curEntity.components.networked) {
    curEntity = curEntity.parentNode;
  }

  if (!curEntity || !curEntity.components || !curEntity.components.networked) {
    throw new Error("Entity does not have and is not a child of an entity with the [networked] component ");
  }

  return curEntity.components.networked.takeOwnership();
};

module.exports.isMine = function(entity) {
  let curEntity = entity;

  while(curEntity && curEntity.components && !curEntity.components.networked) {
    curEntity = curEntity.parentNode;
  }

  if (!curEntity || !curEntity.components || !curEntity.components.networked) {
    throw new Error("Entity does not have and is not a child of an entity with the [networked] component ");
  }

  // When remote networked entities are initially created, there's a frame delay before they are completely instantiated.
  // On that frame, data is undefined in aframe lower than 1.6.0 so we can't check the owner. In this instance we assume that the user is not the owner of the entity.
  // That's not an issue anymore with aframe 1.6.0, this.data can't be undefined and is initialized to an empty object for a multi properties component.
  if (!curEntity.components.networked.data) {
    return false;
  }

  return curEntity.components.networked.data.owner === NAF.clientId;
};

module.exports.almostEqualVec3 = function(u, v, epsilon) {
  return Math.abs(u.x-v.x)<epsilon && Math.abs(u.y-v.y)<epsilon && Math.abs(u.z-v.z)<epsilon;
};

module.exports.vectorRequiresUpdate = epsilon => {
  return () => {
    let prev = null;

    return curr => {
      if (prev === null) {
        prev = new THREE.Vector3(curr.x, curr.y, curr.z);
        return true;
      } else if (!NAF.utils.almostEqualVec3(prev, curr, epsilon)) {
        prev.copy(curr);
        return true;
      }

      return false;
    };
  };
};