GCL stands for Geometry Construction Language. GCL is a description language developed for geometrical IT educational materials in Flash. The syntax of GCL is based on XML, which makes it highly readable. Furthermore, the specifications of GCL are open, allowing for a great level of extensibility. The user can add original extensions to the language.
GCL Editor is a visual tool for creating and saving GCL data. It is also possible to create GCL data in any text editor. GCL Viewer is a viewer for GCL data. The most important characteristics of GCL Editor are as follows:
• Supports Flash, which is widely used in e-textbooks
• Visual expression (supports colors, animations, etc.)
• Supports drawing figures (the figures cannot be saved)
The current version of GCL Viewer has been created using Flash, which is available on most computers nowadays. A GCL viewer may be implemented in other languages as well, so five or 10 years later different implementations may be in use.
This manual introduces the functions of GCL that can be used in GCL Editor. GCL has additional functions. Creating GCL files that use these functions requires a text editor.
The following section explains the basics of GCL Editor. Section 3 describes the usage of each drawing tool. Finally, Section 4 shows the usage of the display tools.