4dt3 is a Skel2K-based program to represent 4-dimensional tic-tac-toe as
it would appear projected onto our three space.

Using the program:

Changing the display

The display can easily be rotated by moving the mouse in the desired
direction of rotation.  The display can be rotated along the axis moving
away from the observer by holding down either the first or third mouse
button.  Zooming in can be accomplished by utilizing the second mouse
button, and zooming out is accomplished by holding SHIFT+the second
mouse button.

Fly-mode is engaged by pressing space.  In fly mode, moving the mouse
instead alters the angle of the camera.  All mouse buttons perform the
same tasks as in regular mode, which can be returned to with another
press of the space bar.

W may be pressed to toggle whether the help text is present, while E
toggles the presence of the vectors pointing near the middle cube.

The hypercube is initially stacked so that it appears to be one cube.
One may change the projection of the four dimensions so that it is
possible to see the other cubes.  This is accomplished by selecting x,
y, or z directions, and pressing the corresponding key (X for x
direction, etc.).  Shift will reverse the change in coordinates (so
SHIFT-X would reduce the projection in the x direction).  For faster
movement, B, N, or M may be pressed, with each key corresponding to the
x, y, and z direction respectively.

Inputting pieces: The colored cube indicates the active cell.  The color
of the cube indicates whose turn it is (the first player is blue, the
second player is red).  Moving this selector around is accomplished by
using the number pad (make sure Num Lock is engaged).
			   _           _
			  |\    /|\    /|
			    \    |    /
			     7   8   9
			      \  |  /
			       \ | /
				\|/
			   <-4---*---6->
				/|\
			       / | \
			      /  |  \
			     1   2   3
			    /    |    \
			  |/_   \|/   _\|
Each number on the same line increases or decreases along the same
direction.  For instance, 4 and 6 change along the x-direction (4
decreases, 6 increases), while 9 and 1 increase and decrease along the
w-direction.  It is probably not easiest to think about the numbers as
moving along specific coordinates, as it can get very confusing.

When the selector is on the desired square, pressing 5 will place the
corresponding piece there.

Winning the game:

The game is won when a line of 5 is created among any combination of the
four dimensions.  So it could be constrained into one dimension, or use
all four.  The program notifies the user of a win by printing out a
mesasge and highlighting the winning pieces.
