cardboard profile generation

cardboard.js

"use strict";

var ProtoBuf = require("protobufjs")

  // to and from URL-safe variant of base64 encoding
  function base64ToUrl(s) {
    return s.replace(/\+/g, '-').replace(/\//g, '_').replace(/\=+$/, '');
  }

  function base64FromUrl(s) {
    s = s + '==='.slice(0, [0, 3, 2, 1][s.length % 4]);
    return s.replace(/-/g, '+').replace(/_/g, '/');
  }

  var PARAMS_URI_PREFIX = 'http://www.sitesinvr.com/qrcode/index.html?';

  ProtoBuf.load('CardboardDevice.proto').then(function(root) {

	var DeviceParams = root.lookupType("DeviceParams");

  function paramsToUri(params) {
    var msg = DeviceParams.create(params);
    var buf = DeviceParams.encode(msg).finish()
    var dream = new Buffer("9a9160100801120a0d0000000015f4fdd43c1800", "hex")
    var fin = Buffer.concat([buf, dream])
    return PARAMS_URI_PREFIX + base64ToUrl(fin.toString("base64"));
  }

  // TODO: support Cardboard v1 URI (i.e. default params)
  function uriToParamsProto(uri) {
    if (uri.substring(0, PARAMS_URI_PREFIX.length) !== PARAMS_URI_PREFIX) {
      return;
    }
    var base64_msg = base64FromUrl(uri.substring(PARAMS_URI_PREFIX.length));
    // TODO: round numeric values
    let buf = new Buffer(base64_msg, "base64")
    return DeviceParams.decode(buf);
  }

  // Returns plain object having only properties of interest.
  function uriToParams(uri) {
    var source = uriToParamsProto(uri), dest = {}, k;
    for (k in source) {
      if (source.hasOwnProperty(k)) {
        dest[k] = source[k];
      }
    }
    return dest;
  }

var cfg = {}
cfg.vendor = "Baofeng"
cfg.model = "Mengjing"
cfg.screenToLensDistance = "0.041"
cfg.interLensDistance = 0.062
cfg.leftEyeFieldOfViewAngles = 
[ 48.85536575317383,
  48.85536575317383,
  48.85536575317383,
  48.85536575317383 ]
cfg.trayToLensDistance = 0.037 
cfg.distortionCoefficients = [ 0.24498000741004944, 0.4219900071620941 ]
cfg.hasMagnet= false
cfg.verticalAlignment = 0
cfg.primaryButton = 0

console.info(cfg)
console.info(paramsToUri(cfg))
  });