PDF::API2::TTF::Glyph - Holds a single glyph's information
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.
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 | |
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:
There are also a number of arrays indexed by point number
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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:
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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 | |
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 |
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) |
Creates a new glyph setting various instance variables
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.
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.
Writes the glyph data to outfile
Outputs an XML description of the glyph
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.
Updates the bounding box for this glyph according to the points in the glyph
Returns lots of information about a glyph so that the maxp
table can update
itself.
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
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
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
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The instance variables used here are somewhat clunky and inconsistent with the other tables. | |
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Martin Hosken Martin_Hosken@sil.org. See PDF::API2::TTF::Font for copyright and licensing.