jdwglib Technical Specifications

Overview

The Java DWG Library (jdwglib) is a Java libray designed for reading, handling and
writing drawing files in the Autodesk DWG format. This document is the design
specification for the classes, methods and algorithms implemented in the Java DWG
Library.

jdwglib has two different parts, first for DWG file accesing, and second for DWG file
handling. The part for accesing DWG files support the reading of DWG files and in
future versions we hope that writing of DWG files will be supported too. The part for
handling DWG files is designed for managing DWG complex objects like polylines or
blocks with the objective that the spatial position and the attributes of DWG objects
will be definitive and no one operation is required for obtaining the same results
that Autocad.

The detailed documentation of the class hierarchy and methods will be presented in the
form of JavaDoc for the source code.


Other resources

- Pythoncad DWG Library by Art Haas (www.pythoncad.org). The part of jdwglib that reads
  DWG files is a port of this library with an object oriented model added.

- The AutoCAD R13/R14/R2000 DWG File Specification by the OpenDWG Alliance. This is the
  public specification of the DWG format obtained using reverse engineering methods by
  the OpenDWG Alliance (www.opendwg.org).


Design goals

The design of jdwglib is intended to fulfil the following goals:

- jdwglib must return the definitive set of DWG objects. Geometric and
  non geometric attributes of these objects will be enough for its correct and complete
  representation.

- The jdwglib interface must be easy to use, even by someone that hasn't advanced
  CAD knowledge.

- jdwglib will be fast enough to be used in a production environment.

- The algorithms and code used in jdwglib will be clear and well-structured, to
  facilitate understanding by other developers.


Object model

The package javacad.util contains some general classes that are useful for handling
DWG objects and other objects in a GIS environment. Their use is described in the
JavaDoc documentation.

The package jdwglib contains the classes for reading and managing DWG files and its
objects. Their use is described in the JavaDoc documentation.