     This       is       the       README       file        for        XSurface.
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~   (c)1993-1995   Robert  Manners  and
     Dominick Layfield.

     XSurface is a program that allows the creation and manipulation of  objects
     formed  from  bicubic  Bezier  patches.  It was written as a joint 3rd year
     project for the Engineering and Computer  Science  Part  I  course  at  the
     University of Oxford.

     The executable is "xsurface".  This version of XSurface was developed under
     X11R5. The application has also been extensively tested under X11R6.

     Various stored objects may be found in the "surf"  directory,  including  a
     README file with brief descriptions.

     This software is distributed under the terms  of  the  GNU  General  Public
     Licence. Please see the file COPYING for details.

     Installation ~~~~~~~~~~~~

     If you have got hold of a binary distribution of XSurface for your  system,
     you  should  simply  be  able  to  run the xsurface executable `as is'.  No
     further  configuration  should  be  required.  If  there   is   no   binary
     distribution  for  your  machine,  or  the  binary  you have will not work,
     (perhaps due to a mis-match in shared libraries) obtain the source version,
     and proceed as follows:

     Un-tar all the source files. Either modify the Makefile for your system, by
     hand,  or  run  `xmkmf'  to build a Makefile using the information from the
     Imakefile. Then run `make' to build the executable.

     There are a few options which  may  be  enabled  or  disabled  by  defining
     symbols in the Imakefile / Makefile. Please examine the source, if you want
     to play with these!

     Quick User guide ~~~~~~~~~~~~~~~~

     XSurface has three main display windows.  One, "Bezier  Surface",  shows  a
     straight line approximation to the surface.  Another, "Control Polyhedron",
     shows  the  control  points  that  define  the  object.   The  final   one,
     "Connectivity", shows the connections between the component Bezier patches.

     At any time, only control points in the selected patch may  be  moved.  The
     selected patch is shown as a filled square in the connectivity diagram, and
     its control points as filled circles in the control display.  A  patch  may
     be selected by clicking inside its square in the connectivity diagram.

     Control points may be moved by dragging them with the mouse.  Motion  along
     the  line  of  sight  may be accomplished by holding shift down at the same
     time.

     The viewpoint may be changed by dragging in the Bezier window. Holding down
     shift whilst dragging alters the viewing distance.

     Patches may be created or deleted by shift-clicking in the  relevant  place
     in the connectivity window. Patches may be joined by dragging from one edge
     to another.

     For more information please obtain the complete User Guide, see below.

     Hardware ~~~~~~~~

     XSurface was originally written on SPARC hardware running SunOS.   XSurface
     has  also  been  found  to  run  successfully  on a PC running Linux, a VAX
     running Ultrix, and an SGI Indigo running Irix.

     It should run on all UNIX X installations. Please let me know if  it  works
     (or does not work) for you!

     Documentation ~~~~~~~~~~~~~

     The release of Xsurface  available  on  most  ftp  sites  has  very  little
     documentation...  If you feel that you need more user documentation, please
     mail me at the address below. I can send you a full user  guide.  Extensive
     documentation  on  the  usage  of  the  application and on the mathematical
     theory underlying it is available by email. If there is much demand, I  can
     make these documents available by ftp.

     Enjoy!

      ************************************************************************ *
     If  you wish to comment on the software, heap praise on the authors, or * *
     complain about bugs, please mail :                                     *  *
     *               *                                    rjm@swift.eng.ox.ac.uk
     *                                                                         *
     *  * Any suggestions, improvements and general feedback will be appreciated
     *
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