T480 Unicode and Fonts
T480
Programmer’s Guide
Page
202
Rev A
100-14362
indicated, but are always spaced in a fixed dot cell provided that the legacy commands
are used. Adding or subtracting space between characters achieves different character
pitches with a fixed character cell size. As each dot has a fixed size and position, only
specific pitches are possible.
Character spacing may also be selected by requesting a print pitch based on characters
pre inch. Once again, the results are not exact.
If the requested spacing is zero, the character spacing will be defined by the character
definition, and will result in variable spacing.
Line spacing
The legacy commands select line spacing as lines per inch. With scalable characters,
the lines per inch is a minimum spacing. If a character is larger then the spacing
between lines, the line spacing will be increased to allow enough room for the characters
on that line.
Selecting character size by points.
In addition to the legacy or classic method of character size selection, the EPIC 3000
allows selection by point size. Point sizes from 4 to 72 points may be selected for both
the horizontal and vertical axes. If a horizontal point size of zero (0) is selected for the
horizontal spacing the characters are printed using variable spacing based on the
character definition, using the vertical point size for the horizontal point size.
To provide fine control over character size, two commands are available, one of which
specifies the size in points, and the other of which specifies the size in ¼-point
increments.
If the font is a stroke font, the boldness of the characters is controlled through variations
in individual stroke width.
Diacritical Marks
It is sometimes required that diacritical marks like accents be placed on characters. The
Unicode standard defines three basic ways to accomplish this.
1) Define a character with the diacritical mark as part of the character
definion.
2) Define combining diacritical marks that may be added to existing
characters.
3) Define diacritical marks as characters that may be positioned and
combined with other characters.
The first is the easiest as the character is addressed as a single character and renders
the character with the the character with the diacritical mark. The second defines a
character with a negative position that places the character over the previous character
