Description of HP-GL, HP-GL/2, and HP RTL

HP-GL is a pen plotter control command developed by Hewlett-Packard (HP). HP-GL was originally a command system for controlling HP plotters, but it is now used by many CAD applications and plotters as the most standard command.

HP-GL/2 is a raster plotter control command developed by HP.

Unlike HP-GL, which was developed based on pen plotters, HP-GL/2 provides advanced drawing functions that assume raster plotters are included.

Furthermore, HP-GL/2 provides the following extended functions, which are not provided by HP-GL:

• Drastically reduces the output data volume by the vector-drawing instruction-compressing function, and significantly shortens the computer waiting time.

• Supports color data and allows printing in color or grey scale.

• Data containing both vector data and image data can be printed at high speeds since HP-GL/2 can be switched to HP RTL by using a command.

• Diversified solid fill (color, grey scale, pattern, etc.) is available.

• Various settings (width, line caps, line joins, etc.) using a virtual pen can be specified.

HP RTL is a graphic language developed for drawing image data (bit map).

Image data is a figure composed of dots. When image data is combined with a figure that is composed of lines drawn using a normal plotter, brilliant and expressive drawing can be achieved.

HP RTL allows drawing at high speeds by compressing image data, which tends to become large, for transmission.