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PDF::API2::Basic::TTF::Glyph(3pUser Contributed Perl DocumentatiPDF::API2::Basic::TTF::Glyph(3pm)
NAME
PDF::API2::Basic::TTF::Glyph - Holds a single glyph's information
DESCRIPTION
This is a single glyph description as held in a TT font. On creation only its header is
read. Thus you can get the bounding box of each glyph without having to read all the other
information.
INSTANCE VARIABLES
In addition to the named variables in a glyph header ("xMin" etc.), there are also all
capital instance variables for holding working information, mostly from the location
table.
The standard attributes each glyph has are:
numberOfContours
xMin
yMin
xMax
yMax
There are also other, derived, instance variables for each glyph which are read when the
whole glyph is read (via "read_dat"):
instLen
Number of bytes in the hinting instructions (Warning this variable is deprecated, use
"length($g-"{'hints'})> instead).
hints
The string containing the hinting code for the glyph
In addition there are other attribute like instance variables for simple glyphs:
For each contour there is:
endPoints
An array of endpoints for each contour in the glyph. There are "numberOfContours"
contours in a glyph. The number of points in a glyph is equal to the highest
endpoint of a contour.
There are also a number of arrays indexed by point number
flags
The flags associated with reading this point. The flags for a point are
recalculated for a point when it is "update"d. Thus the flags are not very useful.
The only important bit is bit 0 which indicates whether the point is an 'on' curve
point, or an 'off' curve point.
x The absolute x co-ordinate of the point.
y The absolute y co-ordinate of the point
For composite glyphs there are other variables
metric
This holds the component number (not its glyph number) of the component from which the
metrics for this glyph should be taken.
comps
This is an array of hashes for each component. Each hash has a number of elements:
glyph
The glyph number of the glyph which comprises this component of the composite.
args
An array of two arguments which may be an x, y co-ordinate or two attachment
points (one on the base glyph the other on the component). See flags for details.
flag
The flag for this component
scale
A 4 number array for component scaling. This allows stretching, rotating, etc.
Note that scaling applies to placement co-ordinates (rather than attachment
points) before locating rather than after.
numPoints
This is a generated value which contains the number of components read in for this
compound glyph.
The private instance variables are:
INFILE (P)
The input file form which to read any information
LOC (P)
Location relative to the start of the glyf table in the read file
BASE (P)
The location of the glyf table in the read file
LEN (P)
This is the number of bytes required by the glyph. It should be kept up to date by
calling the "update" method whenever any of the glyph content changes.
OUTLOC (P)
Location relative to the start of the glyf table. This variable is only active whilst
the output process is going on. It is used to inform the location table where the
glyph's location is, since the glyf table is output before the loca table due to
alphabetical ordering.
OUTLEN (P)
This indicates the length of the glyph data when it is output. This more accurately
reflects the internal memory form than the "LEN" variable which only reflects the read
file length. The "OUTLEN" variable is only set after calling "out" or "out_dat".
Editing
If you want to edit a glyph in some way, then you should read_dat the glyph, then make
your changes and then update the glyph or set the $g->{' isdirty'} variable. It is the
application's duty to ensure that the following instance variables are correct, from which
update will calculate the rest, including the bounding box information.
numPoints
numberOfContours
endPoints
x, y, flags (only flags bit 0)
instLen
hints
For components, the numPoints, x, y, endPoints & flags are not required but the following
information is required for each component.
flag (bits 2, 10, 11, 12)
glyph
args
scale
metric (glyph instance variable)
METHODS
PDF::API2::Basic::TTF::Glyph->new(%parms)
Creates a new glyph setting various instance variables
$g->read
Reads the header component of the glyph (bounding box, etc.) and also the glyph content,
but into a data field rather than breaking it down into its constituent structures. Use
read_dat for this.
$g->read_dat
Reads the contents of the glyph (components and curves, etc.) from the memory store "DAT"
into structures within the object. Then, to indicate where the master form of the data is,
it deletes the "DAT" instance variable.
$g->out($fh)
Writes the glyph data to outfile
$g->out_xml($context, $depth)
Outputs an XML description of the glyph
$g->update
Generates a "$self-"{'DAT'}> from the internal structures, if the data has been read into
structures in the first place. If you are building a glyph from scratch you will need to
set the instance variable ' read' to 2 (or something > 1) for the update to work.
$g->update_bbox
Updates the bounding box for this glyph according to the points in the glyph
$g->maxInfo
Returns lots of information about a glyph so that the "maxp" table can update itself.
$g->empty
Empties the glyph of all information to the level of not having been read. Useful for
saving memory in apps with many glyphs being read
$g->get_points
This method creates point information for a compound glyph. The information is stored in
the same place as if the glyph was not a compound, but since numberOfContours is negative,
the glyph is still marked as being a compound
$g->get_refs
Returns an array of all the glyph ids that are used to make up this glyph. That is all the
compounds and their references and so on. If this glyph is not a compound, then returns an
empty array
BUGS
o The instance variables used here are somewhat clunky and inconsistent with the other
tables.
o "update" doesn't re-calculate the bounding box or "numberOfContours".
AUTHOR
Martin Hosken Martin_Hosken AT sil.org. See PDF::API2::Basic::TTF::Font for copyright and
licensing.
perl v5.10.0 2005-11-16 PDF::API2::Basic::TTF::Glyph(3pm)
Generated by $Id: phpMan.php,v 4.49 2006/02/26 13:18:18 chedong Exp $ Author: Che Dong
On Apache
Under GNU General Public License
2012-05-24 23:31 @38.107.179.237 Crawled by CCBot/1.0 (+http://www.commoncrawl.org/bot.html)