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

19-8 The Configuration and Status Group EN
Using Scaling Effectively
The following sections describe how to combine scaling and P1/P2
concepts to do the following.
z Enlarge or reduce the size of a drawing
z Draw equal-size pictures on the same page.
z Create mirror-imaged pictures
Enlarging or Reducing a Picture
The basic technique for changing a picture’s size is to scale the
printing area defined by P1 and P2, then move the locations of P1
and P2 to define a smaller or larger area. This is especially useful
when you want to print the picture on any portion of the page.
Note Only scaled drawings (those using the SC command) are
enlarged/reduced when the P1/P2 locations change. Use PCL
Picture Frame scaling when importing HP-GL/2 images created
without the SC command (see “Automatically Adjusting the Image
Size” in Chapter 18).
To maintain the proportions of scaled plots, set P1 and P2 to define
an area with the sameaspect ratio as the original scaling rectangle.
For example, if the area defined by P1 and P2 is 3000 x 2000 plotter
units, its aspect ratio is 3:2. To enlarge the plot, set P1 and P2 to
define a larger area that maintains a 3:2 ratio.
The following example illustrates this technique using a square P1/P2
scaling rectangle with a scale of 0 to 10 for both axes. By definition,
a square always has an aspect ratio of 1:1. After drawing a circle
within the scaled area, the locations of P1 and P2 move to form a
new square area that maintains the 1:1 ratio. Note that the circle
printed in the new area is smaller but is proportionately identical.