We render pack man at twice the size that we want on screen,
which is the native resolution of the asset file.
The maze is upscaled.
We then project everything onto a view which is applies
the scale factor.
This patches also dectect the appropriate scale on OSX.
This required a bit of objective C (scaling.mm),
but students should not look at this file and there
is a comment in that direction.
Scalling.cpp provides the default implementation
for other platforms.
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