7.4

Table Of Contents

Encoding tables are tables computers use to map keystrokes to font glyphs. Your keystroke generates a numeric code and the

computer consults an encoding table for the Helvetica font. The encoding table tells the computer which glyph is associated

with that numeric code, in this case the glyph for the upper case ‘A’. The computer displays the upper case ‘A’ glyph for the Hel-

vetica font on the screen.

Why have different encoding tables?

The obvious immediate strategy was to extend the ASCII character set. Each character in the standard ASCII character set fits

in a single byte, but it uses only seven of the eight bits in the byte to represent characters. Using the full 8 bits of a byte to rep-

resent a character increased the number of characters you could represent from 128 to 255 and made it possible to represent

many more languages.

Other strategies also developed for multi-byte character sets, such as those for the Chinese, Japanese and Korean languages.

Encoding Tables in PlanetPress Design

Encoding tables can vary across platforms. When you create your documents in PlanetPress Design, you want to ensure that

the input data the document receives maps to the correct glyphs in the output. You use encoding tables to make any necessary

adjustments.

In PlanetPress Design you specify the encoding table you want a given style to use, or you define your own encoding table for

that style. You can rearrange the glyphs in the encoding table, altering the glyph associated with a specific numeric code. You

can also add glyphs to the encoding table from the list of all glyphs in the font. Not all glyphs in a font necessarily appear in an

encoding table.

You also specify an encoding table for the font you select to display the sample data file in the Data Pane.

There are four key points to keep in mind as you work with encoding tables in PlanetPress Design:

1. A font usually contains more glyphs than an encoding table references.

2. Different fonts have different glyphs. If you use two different fonts, there may be differences in the glyphs available in

each.

3. Different encoding tables reference different glyphs and/or may place the same glyphs in different positions. If you use

the same font but a different encoding table, the glyph that represents a given input character may change.

4. You can edit the encoding table a style uses, and adjust both the glyphs the encoding table references and the positions

of those glyphs within the encoding table. You cannot edit the encoding table for the font you use to display the sample

data file.The output of the document always reflects what appears in the data selections on the document page.

Edit the Encoding Table for a Style

The procedures here describe how to edit the encoding table for a style, and how to import an external encoding table for a

style. Editing an encoding table means editing the individual characters that compose it. You set the encoding table that

appears by default in the Style properties dialog box, in the User Options dialog box. See "Set a Default Encoding Table" (page

38).

It is important to understand that when you edit the encoding table for a style, the edits are internal to that style and are not

made to the encoding table itself. Thus the edits you make to an encoding table in one style do not appear in that encoding

table when you view it in another style.

Note that PlanetPress Design saves all the encoding tables the styles in a document use in the PP7 file for that document.

To edit the encoding table for a style:

Fonts and Styles