HP PCL/PJL reference (PCL 5 Printer Language) - Technical Reference Manual Part II

EN RO, Rotate Coordinate System 19-35
Figure 19-14Angle of rotations
Note The relationship of the X-axis to Y-axis can change as a result of the
scaling point or scaling factor changes, thus changing the direction of
a positive angle of rotation.
The physical location of the pen does not change when you rotate
the coordinate system. The printer updates the pen’s X,Y coordinate
location to reflect the new orientation.
The scaling points P1 and P2 rotate with the coordinate system.
However, they maintain the same X,Y coordinate values as before
the rotation. This means that P1 and P2 can be located outside of
the PCL Picture Frame. Follow the (RO90) or (RO270) commands
with (IP) or (IR) to relocate points P1 and P2 to the lower-left and
upper-right corners of the picture frame.
When the RO command is used, the soft-clip window, if defined, is
also rotated, and any portion that is rotated outside of the picture
frame is clipped to the picture frame boundaries. The soft-clip window
can be set equal to the picture frame by issuing an “IW;” command
(see Figure 19-17).