# NAME

PDF::API2::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 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->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.

# BUGS

None known

# AUTHOR

Martin Hosken Martin_Hosken@sil.org. See PDF::API2::TTF::Font for copyright and licensing.