* The eyes will always 'face' the direction that the snake is
* moving.
*
* Vertical lines indicate that it's facing North or South, and
* Horizontal lines indicate that it's facing East or West.
*
* Additionally, the eyes will be closer to whichever edge it's
* facing.
*
* Drawing the eyes is fairly simple, but is a bit difficult to
* explain. The basic process is this:
*
* First, we add (or subtract) EYE_SMALL_INSET to or from the
* side of the tile representing the direction we're facing. This
* will be constant for both eyes, and is represented by the
* variable 'baseX' or 'baseY' (depending on orientation).
*
* Next, we add (or subtract) EYE_LARGE_INSET to and from the two
* neighboring directions (Example; East and West if we're facing
* north).
*
* Finally, we draw a line from the base offset that is EYE_LENGTH
* pixels in length at whatever the offset is from the neighboring
* directions.