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Font::TTF::OS_2(3pm)  User Contributed Perl Documentation Font::TTF::OS_2(3pm)

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.

perl v5.34.0                      2022-06-14              Font::TTF::OS_2(3pm)

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