Adding Hello Virtual World text overlay

For starters, we're just going to put some text on the screen that you might use for a toast message to the user, or a heads-up display (HUD) with informative content. We're going to implement this incrementally in small steps:

1. Create a simple overlay view with some text.
2. Center it on the screen.
3. Add parallax for stereoscopic viewing.

A simple text overlay

First, we'll add some overlay text in a simple way, not stereoscopically, just text on the screen. This will be our initial implementation of the OverlayView class.

Open the activity_main.xml file, and add the following lines to add an OverlayView to your layout:

<.OverlayView
   android:id="@+id/overlay"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:layout_alignParentLeft="true"
   android:layout_alignParentTop="true" />

Note that we reference the OverlayView class with just .OverlayView. You...