                            *********************
                              glVIS version 1.5
                            *********************

============================================================================
    Introduction
============================================================================

  glVIS is a PVS (Potentially Visible Set) builder specially designed to be
used with OpenGL ports of the DOOM game engine. It extends the "GL-Friendly
Nodes" with a new lump named "GL_PVS". Basicly it's a subsector accept table
designed for rendering engine to skip the subsectors that can't be visible
from viewer's subsector. PVS is added to both versions of "GL Nodes".
  If "GL Nodes" are in wad file, glVIS will also perform building of REJECT
lump. You can disable this with -noreject option.
  Currently only Vavoom uses PVS. Other source ports will ignore it.

============================================================================
    Using glVIS
============================================================================

  To create PVS for a wad file (e.g. FOO.WAD) first you must create
"GL-Friendly Nodes" with glBSP (see link below). Then simply type:

    glvis foo.wad

  glVIS first searches for a GWA file. If it finds it, it will work with it.
Otherwise it assumes that wad file contains "GL Nodes" and will work with
wad file. glVIS will save old file with extension .~gw for .gwa file or .~wa
for a .wad file.

============================================================================
    Option Descriptions
============================================================================

The following options are recognised:

    -s            silent mode, doesn't print any messages

    -f            fast mode, only some simple tests are performed

    -v            verbose mode

    -t#           specify test level 0-2

    -m<LEVELNAME> specifies a level to process, can be used multiple times.
                  This option can be used to specify non-standard map names.

    -noreject     don't build reject

============================================================================
    Status
============================================================================

  The current version of glVIS is 1.5. It has been tested and known to work
on numerous large wads, including Ultimate DOOM, DOOM II, Heretic, Hexen,
Strife, Batman Doom, Hacx.
  NOTE: glVIS is very expensive, complete vis data for a large wad can take
several hours.

============================================================================
    Compiling glVIS
============================================================================

  glVIS has been written with portability in mind. It is purely ANSI C++.
  glVIS has been known to compile and work on the following platforms:

    * Windows 98 with DJGPP 2.03.

    * Windows 98 with Borland C++ 5.5

    * GNU/Linux

  The "Makefile" makefile is for DOS, Linux and other UN*X type OSes. Simply
typing `make' should create the `glvis' executable. Currently there is no
automatic installation, just copy the glvis executable to where you want it.

============================================================================
    Copyright
============================================================================

  glVIS is Copyright (C) 2000-2004 Janis Legzdinsh. glVIS is now based on
Quake's vis utility.
  All trademarks are the propriety of their owners.

============================================================================
    License
============================================================================

  glVIS is under the GNU General Public License (GPL). See the file `COPYING'
for the full text.

============================================================================
    Contact
============================================================================

  Questions, bug reports, suggestsions, etc... about glVIS should be sent to:
    vavoom@vavoom-engine.com

============================================================================
    Links
============================================================================

  The homepage for glVIS can be found here:
    http://www.vavoom-engine.com/glvis.php

  The homepage for glBSP can be found here:
    http://glbsp.sourceforge.net/

  The "GL Friendly Nodes" specifications can be found here:
    http://glbsp.sourceforge.net/glnodes.html

  The Vavoom homepage can be found here:
    http://www.vavoom-engine.com/

============================================================================
    Acknowledgements
============================================================================

  Andrew Apted for glBSP.

  id Software for Doom, Quake and releasing the source code.

  Raven Software for Heretic and Hexen and releasing the source code.

  ... and everyone else who deserves it !
