Table Directory
The Table Directory is an index to the tables in a TrueType font.
Requirements
- A TTF file must contain exactly one Table Directory.
- The Table Directory must appear at the beginning of the TTF file.
- The offsets in the Table Directory must be measured from the start of the TTF file.
- The table tags must be in ASCII alphabetical order (case-sensitive).
- TrueType tables should be long-aligned; that is, each table should begin on a 4-byte boundary. On many RISC processors, such as those commonly used in printers, failure to long-align tables can significantly slow down access and rendering of the font.
- All tables should be recorded in the table directory with their actual length. Any extra space after a table and before the next long-word boundary should be padded with zeros.
Recommendations
- None additional to TTF spec.