- how to compile
  * edit the Makefile to use the correct lib-linking flag for your
    platform. -- uncomment the corresponding line.
  * type make
- how to run
  * nurb_gl1
  * nurb_gl2 in2


-----------
Three routine in C
    1. pcp3.c       -- central (sub)routine  
    2. nurb_gl1.c   -- driver 1: generates 4 nurbs patches on a cube
    3. nurb_gl2.c   -- driver 2: generates a more complex object
    4. drawtri.c    -- supporting file: draw a bezier triangle patch using openGL
    5. rotate.c     -- supporting file: rotate the object in the scene
and one ascii data input file
    6. in2          -- input data to driver 2
