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((app) => {
    const showSplashScreen = () => {};
    const hideSplashScreen = () => {};
    const showProgress = (progress) => {};
    app.on("preload:start", showSplashScreen);
    app.on("preload:progress", showProgress);
    app.on("start", hideSplashScreen);
});
```
- Defined in framework/script.js:47