GNLIB                                                   Menu: Non-menu command
==============================================================================
Generates a library of entities for placing in the model.

         1. (CHAR) name of library description file (.lib) (up to 8 chars.)

Description
This command creates libraries of entities from a library description file.
The libraries created can then be used to place the entities in your models.

The libraries are defined in a library description file with a name of up to
eight characters and the extension .LIB.  You may create as many library
description files as you wish.

A library description file contains the list of entities included in one or
more libraries.  There are three types of libraries: symbols (lib), 3D
(lib3d), and openings (libop).

The following is the layout required for a library description file:

          lib=libname
          table1description1
          table2description2
          .
          .
          lib3d=libname
          chair1description1
          .
          .
          libop=libname
          win1<w1>description1
          win2<w2>description2
          win3description3

Each library within the file is headed by a line:

lib=libname     where the library consists of 2D symbols
lib3d=libname   where the library consists of 3D objects
libop=libname   where the library consists of openings

The library name is the name that the system searches for when calling the
library.  The system creates a drawing file (.III and .DDD) for each of the
libraries listed in the library description file, i.e., libname.III and
libname.ddd.

The list following the library name is a list of library elements.  These
elements are ordinary drawing files with extensions .III and .DDD which must
reside either in the working directory or in \ARCALIB.  They will appear in
the graphic menu when the library is called.

You may add a short description after the element name, such as:
         TBL4CHR1  table and 4 chairs (110x60)

where    "TBL4CHR1" is the name of the library element and
         "table and 4 chairs (110x60)" is the description.

The description can be up to 40 characters and will appear above the entity
when viewing this item of the graphic library in more detail.

It is recommended to group objects of the same type within individual
libraries.  For example, all sanitary fitting symbols within one library and
all doors of a specific type within another.  The library is retained by the
system for use in future sessions until it is erased or overwritten.

The following are examples of .LIB files:

     3d.lib

          lib3d=3D_chairs
          CH1   livingroom_chair1
          CH2   livingroom_chair2
          CH3   livingroom_chair3
          CH4   study_deskchair

          lib3d=3D_beds
          BED1  mainbdrm_dblbed
          BED2  childsrm_singlebed

          open.lib

          libop=l$open
          door1<w2> simple door
          dbldoor1double 180cm
          slwindo1  <w1> sliding window
          window1  <w1> simple window
          w-open <w1>
          d-open  <w1>

Note that an `_' in the .LIB file element description will appear as a blank
when it is displayed with the element.  The element description can be updated
using the \edcom command.

After defining the libraries use \gnlib to generate them.

If an object is bad, missing or empty, the system will issue a message.

In order to call a library that you have created, it is necessary to include
it in the pull-down menu.  This is done by editing the .POP file in the
directory \ARCA.

NOTE: Make a backup copy of the .POP file before making any alterations to it.

In the file you will find a section similar to the following:
         %plac.pop
         3-DELEMENTS;@-lib8|jc\drag|;
         SANITARY FITTINGS;@-lib7|jc\drag|;
         WC;@ . . .

The first part of each line, i.e., up to the `;', is what will appear in the
pull-down menu.  This is followed by @-libname, which is the library name as
defined in the .LIB file.  |jc clears the input.  \drag| activates the \drag
command.

If you wish to add your own libraries to the pull-down menu, change the
existing lines or add new lines immediately after the existing ones.  Type a
short description followed by `;@-' and your library name.

After changing the .POP file it is necessary to compile the system or, extract
the new file with the extension .POP (e.g., plac.pop) and place it in the
\ARCA\USERDEF subdirectory.

To compile the system go to the \ARCA directory and type:
         COMPILE

NOTE: If you want to add a few entities to a library, use the \olib command
(option `a') to create a new library.  If you want to add a large number of
entities to an existing element or opening library without losing the existing
elements, make sure you extract all the elements using the \olib command
(option `e').  For all library types, add existing element names and
descriptions to the library definition file.

Using the Symbols Library

The elements in this library must be created in plan view on the xy plane and
at (0,0).

Once an entity has been included in the library, its original drawing file may
be deleted as the entity itself is stored in the library file.

Using the 3D Library

The elements in this library must be created at (0,0,0).

When elements from this library are selected, a reference to the drawing file
is used, therefore the original drawing file must not be deleted.

Using the Openings Libraries

The elements in this library must be created in plan view on the xy plane and
at (0,0).

Openings for placing within walls may be:
    a. fixed size entities
    b. elastic entities stretchable in one direction only (e.g., windows)
    c. elastic entities stretchable in two directions (e.g., door symbols)

When creating an opening, two sets of "control" lines must be added in the
drawing file.  The first set indicates the width of the opening to be cut in
the wall when using the \odrag command.  The second set defines the alignment
of the opening within the wall, e.g., both external faces of the wall.  The
lines must be of line type 4 and line color 1 and will not be seen when the
entity is placed.

In order to make the item an elastic entity in one direction it is necessary
to add "<w1>" after the file name and before the description in the library
description file, e.g., window1 <w1> standard window.  For elastic entities in
two directions add "<w2>" after the file name.

NOTE: When designing elastic openings it is important to bear in mind that the
entity is stretched or shrunk along its original X axis and relative to its
central axis.  It is essential that the basic X dimensions be 1.

Once an opening entity has been included in the library, its original drawing
file may be deleted as the entity itself is stored in the library file.
