Inside Macintosh: Text /

Chapter 4 - Font Manager / Font Manager Reference

Data Structures

The Font Family Kerning Table Record

The font family kerning table record, which is part of the font family resource, contains a number of kerning subtable entries, with different subtables for different stylistic variations. The table record, of data type KernTable, consists of a count of the entries in the table and is followed by the entry records.

TYPE KernTable = 
RECORD
   numKerns:   Integer;    {number of subtable entries}
   {kernPairs: ARRAY[0..n] of KernEntry}
END;

Each kerning subtable record entry, of data type KernEntry, contains kerning pair records for a specific stylistic variation of the font family. It is followed by the kerning pair records.

TYPE KernEntry =
RECORD
   kernStyle:  Integer; {kern style}
   kernLength: Integer; {entry length}
   {kernRec:   ARRAY[0..n] of kernPair}
                        {the kerning data records}
END;

Each kerning pair record, of data type KernPair, specifies a kerning value for a pair of glyphs. Each glyph in the pair is specified by its ASCII character code.

TYPE KernPair =
RECORD
   kernFirst:  CHAR;    {Code of 1st character of kerned pair}
   kernSecond: CHAR;    {Code of 2nd character of kerned pair}
   kernWidth:  Integer; {kerning value in 1pt fixed format}
END;

The fields of the kerning table, kerning subtable entry, and kerning pair records are described in the section "The Font Family Kerning Table," beginning on page 4-99.