Draw text at the specified point on top of existing content, using the
old background color for the foreground (for drawing characters).
This does not wrap text - any overflow will be clipped.
Moves the virtual origin point of the context. This effectively moves the
"draw window" of the context, keeping the size the same and hiding off-
screen drawing.
The CCGraphicsContext class is used to draw onto a surface with various transformations applied on top.