• Digitizing Letterforms
• Font Engine
• Instructing Fonts
• Graphics State
• Instruction Set
• Font Tables
• • About AAT
  • Special Tables
  • 'acnt'
  • 'ankr'
  • 'avar'
  • 'bdat'
  • 'bhed'
  • 'bloc'
  • 'bsln'
  • 'cmap'
  • 'cvar'
  • 'cvt '
  • 'EBSC'
  • 'fdsc'
  • 'feat'
  • 'fmtx'
  • 'fond'
  • 'fpgm'
  • 'fvar'
  • 'gasp'
  • 'gcid'
  • 'glyf'
  • 'gvar'
  • 'hdmx'
  • 'head'
  • 'hhea'
  • 'hmtx'
  • 'just'
  • 'kern'
  • 'kerx'
  • 'lcar'
  • 'loca'
  • 'ltag'
  • 'maxp'
  • 'meta'
  • 'mort'
  • 'morx'
  • 'name'
  • 'opbd'
  • 'OS/2'
  • 'post'
  • 'prep'
  • 'prop'
  • 'sbix'
  • 'trak'
  • 'vhea'
  • 'vmtx'
  • 'xref'
  • 'Zapf'
• Instruction Set Summary
• Glyph Mappings
• Converting Outlines
• Font Feature Registry

The 'bhed' table

General table information

The 'bhed' table contains global information about a bitmap font. It records such facts as the font version number, the creation and modification dates, revision number and basic typographic data that applies to the font as a whole. This includes a specification of the font bounding box, the direction in which the font's glyphs are most likely to be written and other information about the placement of glyphs in the em square. The checksum is used to verify the integrity of the data in the font. It can also be used to distinguish between two similar fonts.

The 'bhed' table is byte-for-byte identical with the 'head' (font header) table. OS X uses the presence of a 'bhed' table as a flag that a font doesn't have any glyph outlines but only embedded bitmaps. For more information on the fields in a 'bhed' table and their values, see the documentation for the 'head' (font header) table.

Platform-specific Information

This table is used in OS X to signal the presence of a bitmap-only font. It is required if a font has no outlines. If a font does have outlines, then there should be no 'bhed' table.

Dependencies

If a 'bhed' table is present in a font, the font must also have 'bdat' and 'bloc' tables. The font must have no 'head' or 'glyf' tables.

Field dependencies between the 'bhed' table's fields and other tables are described in the documentation for the 'head' (font header) table.