X Logical Font Description

X logical font description (XLFD) is a font standard used by the X Window System. It is intended to support:

  • unique, descriptive font names that support simple pattern matching
  • multiple font vendors, arbitrary character sets, and encodings
  • naming and instancing of scalable and polymorphic fonts
  • transformations and subsetting of fonts
  • independence of X server and operating or file system implementations
  • arbitrarily complex font matching or substitution
  • extensibility

One prominent XLFD convention is to refer to individual fonts including any variations using their unique FontName. It comprises a sequence of fourteen hyphen-prefixed, X-registered fields:

  1. FOUNDRY: Type foundry - vendor or supplier of this font
  2. FAMILY_NAME: Typeface family
  3. WEIGHT_NAME: Weight of type
  4. SLANT: Slant (upright, italic, oblique, reverse italic, reverse oblique, or "other")
  5. SETWIDTH_NAME: Proportionate width (e.g. normal, condensed, narrow, expanded/double-wide)
  6. ADD_STYLE_NAME: Additional style (e.g. (Sans) Serif, Informal, Decorated)
  7. PIXEL_SIZE: Size of characters, in pixels; 0 (Zero) means a scalable font
  8. POINT_SIZE: Size of characters, in tenths of points
  9. RESOLUTION_X: Horizontal resolution in dots per inch (DPI), for which the font was designed
  10. RESOLUTION_Y: Vertical resolution, in DPI
  11. SPACING: monospaced, proportional, or "character cell"
  12. AVERAGE_WIDTH: Average width of characters of this font; 0 means scalable font
  13. CHARSET_REGISTRY: Registry defining this character set
  14. CHARSET_ENCODING: Registry's character encoding scheme for this set

The following sample is for a 75-dpi, 12-point, Charter font:

-bitstream-charter-medium-r-normal--12-120-75-75-p-68-iso8859-1

(which also tells the font source that the client is interested only in characters 65, 70, and 80-90.)

Famous quotes containing the words logical, font and/or description:

    “The sensual and spiritual are linked together by a mysterious bond, sensed by our emotions, though hidden from our eyes. To this double nature of the visible and invisible world—to the profound longing for the latter, coupled with the feeling of the sweet necessity for the former, we owe all sound and logical systems of philosophy, truly based on the immutable principles of our nature, just as from the same source arise the most senseless enthusiasms.”
    —Karl Wilhelm Von Humboldt (1767–1835)

    “Le corps, l’amour, la mort, ces trois ne font qu’un.”
    —Thomas Mann (1875–1955)

    “It [Egypt] has more wonders in it than any other country in the world and provides more works that defy description than any other place.”
    —Herodotus (c. 484–424 B.C.)