HP 5961-0509 HP-GL/2 Coordinate System, Coordinate System to Match the PCL System in Chapter

The HP-GL/2 Coordinate System

Both PCL and HP-GL/2 use a Cartesian Coordinate System. The Cartesian coordinate system is a grid formed by two perpendicular axes, usually called the X-axis and Y-axis (refer to Figure 17-4). The intersection of the axes is called the origin of the system and has a location of (0,0). The default HP-GL/2 coordinate system is different than the PCL coordinate system; +Y is down in PCL and up in HP-GL/2. In addition, the default origin is at the lower left in HP-GL/2 and at the upper left in PCL.

Note	The HP-GL/2 coordinate system can be set up to match the PCL
	coordinate system. See the example entitled “Adapting the HP-GL/2
	Coordinate System to Match the PCL System” in Chapter 19.

Figure 17-4 The HP-GL/2 Coordinate System

To locate any point on the grid (the printing area within the PCL Picture Frame), move from the origin a number of units along the X-axis, then move a number of units parallel to the Y-axis. The number of units you move matches a coordinate location. Each point is designated by the combination of its X-coordinate and Y-coordinate, known as an X,Y coordinate pair. In , positive X values are plotted to the right of the origin, and positive Y values are plotted above the origin.

EN The HP-GL/2 Coordinate System 17-15