HP 4 FAMILY - Manual (Page 49)

Logical Operations With the introduction of the HP LaserJet 4ML printer the
print model was expanded to include logical operations.
The basic print model defines how a pattern, source image,
and destination image are applied to each other using the
print model’s transparent and opaque modes to produce a
resulting image (refer to the PCL 5 Printer Language
Technical Reference Manual for detailed information about
the basic print model operation). The Logical Operations
(?*l#O) command can apply logical functions (e.g., AND,
OR, XOR, NOT) to any of these operands except
transparency, which must be specified first.
The print model process consists of the following steps:
1. Specify source and/or pattern transparency modes, if
desired.
2. Specify the logical operation (or use the default).
3. Define the desired operands (source, destination,
pattern).
Definitions
Source: The source image may be one of the following:
HP-GL/2 primitives
Rules
Characters
Raster images (single plane mask or multiplane color)
Destination: The destination image contains whatever is
currently defined on the page. It includes any images
placed through previous operations.
Pattern or Texture: The pattern is defined by Current
Pattern (?*v#T). The terms pattern and texture are used
interchangeably in this section.
Printer-Specific Differences 2-13