AFM

Section: User Contributed Perl Documentation (3)
Updated: 2021-01-27
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NAME

Font::AFM - Interface to Adobe Font Metrics files

SYNOPSIS

 use Font::AFM;
 $h = new Font::AFM "Helvetica";
 $copyright = $h->Notice;
 $w = $h->Wx->{"aring"};
 $w = $h->stringwidth("Gisle", 10);
 $h->dump;  # for debugging

DESCRIPTION

This module implements the Font::AFM class. Objects of this class are initialised from an AFM (Adobe Font Metrics) file and allow you to obtain information about the font and the metrics of the various glyphs in the font.

All measurements in AFM files are given in terms of units equal to 1/1000 of the scale factor of the font being used. To compute actual sizes in a document, these amounts should be multiplied by (scale factor of font)/1000.

The following methods are available:

$afm = Font::AFM->new($fontname): Object constructor. Takes the name of the font as argument. Croaks if the font can not be found.
$afm->latin1_wx_table(): Returns a 256-element array, where each element contains the width of the corresponding character in the iso-8859-1 character set.
$afm->stringwidth($string, [$fontsize]): Returns the width of the argument string. The string is assumed to be encoded in the iso-8859-1 character set. A second argument can be used to scale the width according to the font size.
$afm->FontName: The name of the font as presented to the PostScript language "findfont" operator, for instance ``Times-Roman''.
$afm->FullName: Unique, human-readable name for an individual font, for instance ``Times Roman''.
$afm->FamilyName: Human-readable name for a group of fonts that are stylistic variants of a single design. All fonts that are members of such a group should have exactly the same "FamilyName". Example of a family name is ``Times''.
$afm->Weight: Human-readable name for the weight, or ``boldness'', attribute of a font. Examples are "Roman", "Bold", "Light".
$afm->ItalicAngle: Angle in degrees counterclockwise from the vertical of the dominant vertical strokes of the font.
$afm->IsFixedPitch: If "true", the font is a fixed-pitch (monospaced) font.
$afm->FontBBox: A string of four numbers giving the lower-left x, lower-left y, upper-right x, and upper-right y of the font bounding box. The font bounding box is the smallest rectangle enclosing the shape that would result if all the characters of the font were placed with their origins coincident, and then painted.
$afm->UnderlinePosition: Recommended distance from the baseline for positioning underline strokes. This number is the y coordinate of the center of the stroke.
$afm->UnderlineThickness: Recommended stroke width for underlining.
$afm->Version: Version number of the font.
$afm->Notice: Trademark or copyright notice, if applicable.
$afm->Comment: Comments found in the AFM file.
$afm->EncodingScheme: The name of the standard encoding scheme for the font. Most Adobe fonts use the "AdobeStandardEncoding". Special fonts might state "FontSpecific".
$afm->CapHeight: Usually the y-value of the top of the capital H.
$afm->XHeight: Typically the y-value of the top of the lowercase x.
$afm->Ascender: Typically the y-value of the top of the lowercase d.
$afm->Descender: Typically the y-value of the bottom of the lowercase p.
$afm->Wx: Returns a hash table that maps from glyph names to the width of that glyph.
$afm->BBox: Returns a hash table that maps from glyph names to bounding box information. The bounding box consist of four numbers: llx, lly, urx, ury.
$afm->dump: Dumps the content of the Font::AFM object to STDOUT. Might sometimes be useful for debugging.

The AFM specification can be found at:

   http://partners.adobe.com/asn/developer/pdfs/tn/5004.AFM_Spec.pdf

ENVIRONMENT

METRICS

Contains the path to search for AFM-files. Format is as for the PATH environment variable. The default path built into this library is:

 /usr/lib/afm:/usr/local/lib/afm:/usr/openwin/lib/fonts/afm/:.

BUGS

Kerning data and composite character data are not yet parsed. Ligature data is not parsed.

COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.