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

EN Drawing Polygons 21-15
If you multiply 512 points by 8 bytes per point, the result is 4096 bytes
(4 Kbytes). That means the minimum your printer can store in the
polygon buffer is 4 Kbytes. That is the worst case, however. Unless
the printer has a substantial amount of fonts, macros, or graphics
already downloaded into user memory, you can put much more into
the polygon buffer. As we just calculated, for every 4 Kbytes of extra
unused user memory, the polygon buffer can store 512 more points.
You can see how in most cases there is little chance of a polygon
buffer overflow, especially with the addition of optional printer
memory.
The following formula explains how to calculate the buffer space used
by a polygon:
number of points in polygon × 8 = buffer space consumed by polygon''
Counting the Points in a Polygon
The starting pen location and each subsequent point define a
polygon. As shown in the following illustration, a rectangle is
defined by five points, not four. This is because the starting
location is counted again as the ending location.
Figure 21-10