Function createLoadingScreen

createLoadingScreen(callback: CreateScreenCallback): void
Handles the creation of the loading screen of the application. A script can subscribe to the events of a AppBase to show a loading screen, progress bar etc. In order for this to work you need to set the project's loading screen script to the script that calls this method.
Parameters
- callback: CreateScreenCallback
  A function which can set up and tear down a customized loading screen.
Returns void
Example
```
pc.script.createLoadingScreen(function (app) {
    var showSplashScreen = function () {};
    var hideSplashScreen = function () {};
    var showProgress = function (progress) {};
    app.on("preload:start", showSplashScreen);
    app.on("preload:progress", showProgress);
    app.on("start", hideSplashScreen);
});
```
- Defined in framework/script.js:56