The class PIXIApp is the main entry point to create a new PIXI Application.
It inherits from PIXI.Application, set meaningfull defaults, creates a scene and
a stage and provides some helper methods to load resources, get the size of
the app...
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The pattern to create a new application is:
<ol>
<li>Create a new PIXIApp Object</li>
<li>Call the setup() method</li>
<li>Call the run() method</li>
</ol>
These three steps are required. The constructor has been split into these three parts in order to have the greatest possible flexibility in complex applications.
The setup() method creates a default scene. This can be overwritten with a spezialized setup() method to create a scatter container, for example.