LibreDWG

LibreDWG is a free C library to read and write DWG files.  This program is
part of the GNU project, released under the aegis of GNU.  It is licensed
under the terms of the GNU General Public License version 3 (or at you option
any later version).

DWG is a file format created in the 70's for the emerging CAD applications.
Currently it is the native file format of AutoCAD, a proprietary CAD program 
developed by AutoDesk.

LibreDWG is a fork from LibDWG due to its usage of Esperanto, which we think
is not the best strategy for a free software project which aims to get lots of
contributors.  LibreDWG is written in English.  Since we forked LibDWG (May
16, 2009), its development seems to have been inactive.  At the moment
(September 25, 2009) our decoder is almost done.  We are reaching 100% read
support in our data structures parser but we still need a test suite.  Among
the example applications we wrote using LibreDWG is an initial SVG conversion
tool. Please contact us if you can help.

The program dwg_ps (in examples/) reads DWG and outputs Postscript; it
depends on pslib: <http://pslib.sourceforge.net>.  In many GNU/Linux
distributions, this is available by installing the pslib-dev package.
If the configure script does not find pslib, dwg_ps will not be built.

Sometimes we hang on our IRC channel which is #libredwg at irc.freenode.net
If you don't find us there, please email the package maintainers:

Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
Rodrigo Rodrigues da Silva <pitanga@members.fsf.org>

If you are looking for general information about the project, check our website:
http://www.gnu.org/software/libredwg

== Building and installing the library ==

You need the following dependencies:
- Basic development tools (gcc, autoconf and libtool)
- SWIG 1.7+
- TeXinfo
- Python development headers (debian: python-dev; yum: python-devel)

See INSTALL for generic instructions.  Basically, you do:

$ ./autogen.sh (if you checked out the source code from git)
$ ./configure [options]
$ make
$ make check    # optional but strongly encouraged while LibreDWG is alpha
$ make install

This builds and installs various files in the "installation dirs":
  $libdir     ($exec_prefix/lib)   -- library files (libredwg.*)
  $includedir ($prefix/include)    -- dwg.h
  $infodir    ($datarootdir/info)  -- LibreDWG.info

Use "./configure --help" to see a full list of options you can use to
customize the installation dirs.  Other options recognized by configure are:

  --enable-trace

    NB: This is an experimental feature that is not in its final form.

    Enable runtime tracing (default: no).  When enabled, the environment
    variable LIBREDWG_TRACE is consulted on the first decode/encode attempt.
    Its value is an integer: 0 (no output) through 9 (full verbosity).

  --enable-write
  
    NB: This is an experimental feature that is not in its under construction, so its highly unstable.
    
    Enable write support (default: no). When enabled you activate the write
    support for the dwg format.

== Example usage of the library ==

The examples directory contains some application code that uses our lib:

* load_dwg.c -- This is a skeleton code.  Look there if you want to have a
  quickly glance on how to use the library.

* dwg_ps.c -- Opens a DWG file and outputs an PostScript file.  This code
  depends on the PSlib library.  On Debian-based systems this is usually
  available as a package named pslib-dev

* testSVG.c -- Opens a DWG file and outputs an SVG (Scalable Vector Graphics)
  file.  SVG is a W3C standard for 2d vector graphics.  You can open these
  files on several free software tools.  We recomend Inkscape, a free software
  vector graphics editor.  The testSVG.c program will not handle 3d content
  from DWG since SVG only supports 2-dimensional images.

* get_bmp.c -- Extracts the bmp thumbnail of a dwg file when it is available.

* rewrite.c -- Load, rewrite and try to re-read a existing dwg file. Just for writing test. Still failing (as in 08/2010) 

/*****************************************************************************/
/*  LibreDWG - free implementation of the DWG file format                    */
/*                                                                           */
/*  Copyright (C) 2009, 2010 Free Software Foundation, Inc.                  */
/*                                                                           */
/*  This library is free software, licensed under the terms of the GNU       */
/*  General Public License as published by the Free Software Foundation,     */
/*  either version 3 of the License, or (at your option) any later version.  */
/*  You should have received a copy of the GNU General Public License        */
/*  along with this program.  If not, see <http://www.gnu.org/licenses/>.    */
/*****************************************************************************/