Font::TTF::Scripts::AP(3pm)

Font::TTF::Scripts::AP(3)

User Contributed Perl Documentation

Font::TTF::Scripts::AP(3)

NAME

Font::TTF::Scripts::AP - Memory representation of a TTFBuilder Attachment Point database (APDB)

SYNOPSIS

 use Font::TTF::Scripts::AP;
 $ap = Font::TTF::Scripts::AP->read_font($ttf_file, $ap_file, %opts);
 $ap->make_classes();

INSTANCE VARIABLES

cmap: Reference to the Microsoft cmap within the "font".
font: Reference to a font structure. "read_font" will cause at least the post, cmap, loca, and name tables to be read in.
glyphs: An array of references to glyph data structures, indexed by glyphID. Stucture elements are:

uni: Array of Unicode scalar values (decimal integers), if any, that map from cmap to this glyph.
gnum: Actual glyph ID from font.
post: Actual Postscript name from font.
name: This element is set by "make_names" or "make_classes" and is the replacement name returned by "make_name".

Note: The "uni", "gnum" and "post" values are based on the "UID", "GID", and "PSName" fields of the APDB. If there are descrepancies between the APDB and the font's internal tables, then for calcuating the above three values, priority is given first to "UID" field, then "PSName" field, and finally "GID".

glyph: Reference to glyph structure read from "font".
line: Line number in APDB where glyph is defined.
points: A hash of references to attachment point structures for this glyph, keyed by attachment point type (aka name). Each AP structure contains

name: The name ("type" in TTFBuilder terminology) of the attachment point
x, y: X and Y coordinates for the attachment point
line: Line number in APDB where this point is defined.

components: Present if the glyph is a composite. Is a reference to an array of component structures. Each component structure includes:

bbox: comma separated list of bounding box coordinates, i.e., "x1, y1, x2, y2"
uni: Unicode scalar value, if any, of the component. (decimal integer)
line: Line number in APDB where this component is defined.

Note: The following instance variables contain the actual text read from the APDB. If there are descrepancies between the APDB and the font, these values may differ from corresponding values given above. Therefore these values should not be used except for diagnostic purposes.

UID: Unicode scalar value, if any, as specified in the APDB. (string of hex digits)
PSName: Postscript name, if any, as specified in the APDB
GID: Glyph id, if any, as specified in the APDB

classes: Created by "make_classes", this is a hash keyed by class name returning an array of GIDs for glyphs that are in the class. Classes are identified by extensions (part after a '.') on the post name of each glyph. For each such extension, two classes are defined. The first is the class of all glyphs that have that extension (class name is the extension). The second is the class of nominal glyphs corresponding to the glyphs with that extension (class name is the extension but with the prefix 'no_').
lists: Created by "make_classes", this is a hash keyed by attachment point name (as modified by "make_point") returning an array of GIDs for glyphs that have the given attachment point.
vecs: If defined, this variable will be updated by "make_classes". It is a hash, keyed by attachment point name (as modified by "make_point") returning a bit vec bit array, indexed by GID, each bit set to 1 if the corresponding glyph has the given attachment point.
ligclasses: Optionally created by "make_classes" if ligatures are requested and they exist. The base forms class is no_code while the ligatures are held in code.
WARNINGS: If "-errorfh" not set, this accumulates any warning or error messages encountered.
cWARNINGS: Count of number of warnings or errors encountered.

METHODS

$ap = Font::TTF::Scripts::AP->read_font ($ttf_file, $ap_file, %opts)

Reads the TrueType font file $ttf_file and the attachment point database (APDB) file $ap_file, and builds a structure to represent the APDB.

Options that may be supplied through the %opts hash include:

-omittedAPs: A list of attachment point types to ignore. Can be a string containing comma- or space-separated names, or a ref to an array of strings.
-strictap: If true, warn about attachment points that do not correspond to appropriate points on the outline of the glyph.
-knownemptyglyphs: If this option is specified, "read_font" will warn if glyphs that should have outlines don't. The option value should be a list of names of glyphs that are known to have no outline (thus shouldn't generate warning). Can be a string containing comma- or space-separated names, or a ref to an array of strings.
-errorfh: A file handle to which warning messages are to be printed. If not supplied, warning messages are accumulated in "WARNINGS".

$ap->add_classfile ($fname, %opts)

Reads the given xml classes description file and stores the info in this ap structure

$ap->make_names

An alternative to "make_classes", this method just creates name records for all the glyphs in the font. That is, for every glyph record in "glyphs", "make_names" invokes "make_name" and saves the result in the "name" element of the glyph.

$ap->make_classes (%opts)

First, for every glyph record in "glyphs", "make_classes" invokes "make_name" followed by, for every attachment point record in "points", "make_point" . This gives sub-classes a chance to convert the names (of glyphs and points) to an alternate form (e.g., as might be useful in building Graphite source.) See GDL.pm for an example.

"make_classes" then builds the "classes" and "lists" instance variables, and updates the "vecs" instance variable (if it is defined).

Options supported are:

-ligatures: Accepts one of two possible values: 'first' or 'last'. First creates ligature classes with the class based on the first element of the ligature and the contents of the class on the rest of the ligature. Last creates classes based on the last element of the ligature, thus grouping all glyphs with the same last ligature element together. Ligature classes are stored in "$self-"{'ligclasses'}>.
Ligature elements are separated by _ in the glyph name. Ligatures are only made if there are corresponding non ligature glyphs in the font. A final .text on the glyph name of a ligature is assumed to be associated with the whole ligature and not just the last element.
-ligtype: If set to 'comp', then treat glyph name extension as part of the final element.

$ap->make_name ($gname, $uni, $glyph)

Given a glyph's name, USV, and a reference to its "glyph" structure, returns a replacement name, e.g., one that might be an acceptable identifier in a programming language. By default this returns $gname, but the function could be overridden when subclassing.

$ap->make_point ($pname, $glyph, \%opts)

Given an an attachment point name and a reference to its "glyph" structure, returns a replacement name, e.g., one that might be an acceptable identifier in a programming language, or undef to indicate the attachment point should be omitted. By default this returns $pname, but the function could be overridden when subclassing.

$opts->{'-ignoredAPs'} can be set to a list of AP names that should be ignored.

$fv->align_glyphs($dat)

Provides one possible way to map glyph names in a new font with an existing project.

Compares the list of glyphs found during "read_font" (the new glyph list) with the list from "parse_volt" in $dat (the old glyph list>, returning an array that provides a mapping between old and new glyph IDs. The array is indexed by old glyph ID and returns the new glyph ID.

This implementation works by "sdiff"ing the two ordered lists of glyph "name"s and then matching them up, first by "name" then by "uni".

perl v5.44.0

NAME

SYNOPSIS

INSTANCE VARIABLES

METHODS

$ap = Font::TTF::Scripts::AP->read_font ($ttf_file, $ap_file, %opts)

$ap->add_classfile ($fname, %opts)

$ap->make_names

$ap->make_classes (%opts)

$ap->make_name ($gname, $uni, $glyph)

$ap->make_point ($pname, $glyph, \%opts)

$fv->align_glyphs($dat)

canon($psname)

$str = $ap->as_xml()

See also

AUTHOR

LICENSING