Phaser API Documentation

Description:

This method is only used by Post FX Pipelines and those that extend from them.

This method is called every time the postBatch method is called and is passed a reference to the current render target.

At the very least a Post FX Pipeline should call this.bindAndDraw(renderTarget), however, you can do as much additional processing as you like in this method if you override it from within your own pipelines.