phpman > perldoc > Font::TTF::OS_2

NAME
    Font::TTF::OS_2 - the OS/2 table in a TTF font

DESCRIPTION
    The OS/2 table has two versions and forms, one an extension of the other. This module supports
    both forms and the switching between them.

INSTANCE VARIABLES
    No other variables than those in table and those in the standard:

        Version
        xAvgCharWidth
        usWeightClass
        usWidthClass
        fsType
        ySubscriptXSize
        ySubScriptYSize
        ySubscriptXOffset
        ySubscriptYOffset
        ySuperscriptXSize
        ySuperscriptYSize
        ySuperscriptXOffset
        ySuperscriptYOffset
        yStrikeoutSize
        yStrikeoutPosition
        sFamilyClass
        bFamilyType
        bSerifStyle
        bWeight
        bProportion
        bContrast
        bStrokeVariation
        bArmStyle
        bLetterform
        bMidline
        bXheight
        ulUnicodeRange1
        ulUnicodeRange2
        ulUnicodeRange3
        ulUnicodeRange4
        achVendID
        fsSelection
        usFirstCharIndex
        usLastCharIndex
        sTypoAscender
        sTypoDescender
        sTypoLineGap
        usWinAscent
        usWinDescent
        ulCodePageRange1
        ulCodePageRange2
        xHeight
        CapHeight
        defaultChar
        breakChar
        maxLookups

    Notice that versions 0, 1, 2 & 3 of the table are supported. Notice also that the Panose
    variable has been broken down into its elements.

METHODS
  $t->read
    Reads in the various values from disk (see details of OS/2 table)

  $t->out($fh)
    Writes the table to a file either from memory or by copying.

  $t->XML_element($context, $depth, $key, $value)
    Tidies up the hex values to output them in hex

  $t->XML_end($context, $tag, %attrs)
    Now handle them on the way back in

  $t->minsize()
    Returns the minimum size this table can be. If it is smaller than this, then the table must be
    bad and should be deleted or whatever.

  $t->update
    Updates the OS/2 table by getting information from other sources:

    Updates the "firstChar" and "lastChar" values based on the MS table in the cmap.

    Updates the sTypoAscender, sTypoDescender & sTypoLineGap to be the same values as Ascender,
    Descender and Linegap from the hhea table (assuming it is dirty) and also sets usWinAscent to be
    the sum of Ascender+Linegap and usWinDescent to be the negative of Descender.

  $t->guessRangeBits (\%map, [$cp_threshold, [%u_threshold]])
    Set the ulCodePageRange and ulUnicodeRange fields based on characters actually present in the
    font.

    %map is a hash keyed by USV returning non-zero for characters present (e.g. use {'val'} a from
    Unicode cmap).

    The two optional parameters are percentage of characters within the codepage or unicode range
    that need to be present to constitute coverage. A threshold of 0 causes corresponding range bits
    to be set if any characters are present at all, while a negative value causes the corresponding
    range bits to be unchanged. Defaults are 50 and 0, respectively.

    For codepage bits, the threshold is percentage of characters between 0xC0 and 0xFF that need to
    be present to constitute coverage). For codepages other than 1252, characters (e.g.,
    punctuation) that are defined identically to cp1252 are ignored for the purposes of this
    percentage calculation. Looks only for SBCS codepages, not DBCS.

    For Unicode range bits that represent multiple ranges, e.g., bit 29 represents:

      Latin Extended Additional  1E00-1EFF
      Latin Extended-C           2C60-2C7F
      Latin Extended-D           A720-A7FF

    the bit will be set if any of these ranges meet the threshold requirement.

BUGS
    None known

AUTHOR
    Martin Hosken <http://scripts.sil.org/FontUtils>.

LICENSING
    Copyright (c) 1998-2016, SIL International (http://www.sil.org)

    This module is released under the terms of the Artistic License 2.0. For details, see the full
    text of the license in the file LICENSE.