0 glyph to a mode 1 glyph. An opposite offset is applied during a mode 1 to mode 0 glyph transition. This scheme easily accommodates two writing directions. Historically, fonts had 128 or 256 code points. Today, Unicode allows for over one million code points. Fonts can conceivably contain thousands of glyphs, some of which should be written left-to-right, some right-to-left, and some top-to-bottom. Such multi-directional writing requires creative use of DWIDTH1 and SWIDTH1 for each glyph. In addition to keywords added for international support, version 2.2 adds the "CONTENTVERSION" declaration. This keyword is followed by an integer to indicate the version number of the font. For more detailed information, consult the version 2.2 specification. X Window Properties X Window font utilities support several properties that can be specified in the STARTPROPERTIES section of a BDF file. A generic BDF file is in ASCII encoding. X Window properties are specified using ISO 8859-1 encoding, which is an extension of ASCII. These properties include: CAP_HEIGHT integer—the height above the baseline of a capital letter (See Cap height). COPYRIGHT string—a copyright statement. DEFAULT_CHAR positive—the default character (glyph) to display for an undefined glyph. FACE_NAME string—the name of the face for this font. FONT string—the X Window name of the font. FONT_ASCENT integer—the height above the baseline, for line spacing calculation. FONT_DESCENT integer—the descender below the baseline, for line spacing calculation. FONT_VERSION string—the version of the font. FOUNDRY string FAMILY_NAME string—the font family name. NOTICE string—a general comment. POINT_SIZE integer—See Point (typography). If it is not separately specified, EMspace = round(POINT_SIZE/10), ENspace = round(POINT_SIZE/20), and THINspace = round(POINT_SIZE/30). RESOLUTION_X positive RESOLUTION_Y positive SLANT string -- "R" is Roman, "I" is Italic, "O" is Oblique, "RI" is Reverse Italic, "RO" is Reverse Oblique, "OT" is Other and a number indicates polymorphic slant capability. WEIGHT_NAME string—the weight of this font ("Bold" and "Normal" are typical, though there is no set enumeration). X_HEIGHT integer—the height above the baseline of a lower-case 'x' (See x-height). ...where "integer" is a natural number, "positive" is a positive number (of value 1 or higher), and "string" is an ISO 8859-1 character string. Notes References External links Adobe Glyph Bitmap Distribution Format (BDF) Specification, version 2.2 Font formats X Window System