Copyright (c) 2012 Kevin Wellwood
All rights reserved.
This source code is distributed under the Modified BSD License. For terms and
conditions, see license.txt.
A Renderer is a member of the Game View system and is responsible for
drawing a Window widget to the screen. Only one renderer exists per
application. It implements the Process interface to draw on a tick when
the specified framerate allows. The renderer uses double-buffering for
updating frames.
Create a Renderer object that draws 'win' to 'display' at a maximum
frequency of 'fps'. For best performance, do not attach the Renderer to
a Process_Manager running at a frequency less than 'fps'; it's best if
the Process is ticked at the same frequency, or a multiple of it.