[9fans] Attempt at making 3D graphics library

[Pietro Gagliardi]

Hello. I realized that that last /usr/glenda/bin/rc/pull focused on a  
rewrite to the system libraries. I decided to start writing a library  
to convert 3D coordinates to 2D coordinates based on the data at  
http://www.shade.ca/getarticle.asp?i=11. You can find it at /n/ 
sources/contrib/pietro/3d.bundle. It contains: 3d.h (the header),  
3d.c (the library itself), and 3dtest.c (a test program). The test  
program doesn't seem to work right. It looks like the 2D coordinates  
are way off the charts - the x coordinates are between 500 and 600  
for xyz=(5,5,5)! I wonder... This makes the line a stub in the center  
of a 1024x768 screen. Plus, the threadmain crashes on threadexitsall.  
What's going on?