Kapitel 9

AutoCad III: Zugriff auf geometrische Einheiten und die System Umgebung

9.1 AutoCad Database

AutoLisp provides a set of functions to access and modify graphic entities and their properties. Additionally, some other functions provide direct access to input devices like keyboard, digitizer, and output devices like screen. These functions are specific to AutoLisp and are not part of the standard LISP programming language.

Drawing entities created as part of any AutoCad drawing are stored internally in a database of information. Whenever you perform any operation- addition of a new entity, modification of an entity, or deletion of an entity, the drawing database is updated with new information. To access this database, AutoLisp provides two special data types, called entity names and selection sets.

9.2 Entity Access

9.2.1 Entity Name Functions

9.2.2 Entity Data Functions