This is a 2D slice viewer for assignment 6.

It takes a single command-line argument, the directory where the smoke0000 etc. files are.

It draws 2D cross-sections through the smoke (much cheaper than a full 3D render). The following
controls operate:

f   full-screen
.   forward one frame
,   backward one frame
>   forward 10 frames
<   backward 10 frames
a   change axis (through which cross-sections are taken)
[   examine a lower numbered slice (one lower than current)
]   examine a higher numbered slice (one higher than current)
s   save screen as hw6_000.ppm etc.

