vfb2ufo3 0.6.1

UFO converter for Windows FontLab 5.2

VFB2UFO3

Description

Multiple master-compatible Unified Font Object (UFO) version 3 font writer API for Windows FontLab 5.2

VFB2UFO3 is primarily intended to create scaled UFO instances from a > 1000 UPM multiple master FontLab .vfb font with PostScript outlines for use with the AFDKO tools for creating binary fonts while still working with Windows FontLab 5.2. The most significant non-trivial change that will occur in export is the renaming of kerning glyph groups (FontLab classes). Providing a .flc (FontLab-class) file can speed up conversion significantly when font groups are not identifiable as first/second from their name. All glyph hints/links are ignored. A batch command can be created for use with psautohint, which supports hinting outlines with decimal coordinates.

Installation

This package may be installed via PyPi:

pip install vfb2ufo3

Alternatively, the latest release .zip may be downloaded, unzipped, and added to your FontLab Macros folder as shown:

[user folder]
`-- Documents
    `-- Fontlab
        `-- Studio 5
            `-- Macros
                `-- System
                    `-- Modules
                        `-- vfb2ufo3
                            `-- __init__.py
                            `-- core.pyd
                            `-- designspace.pyd
                            `-- fdk.pyd
                            `-- fea.pyd
                            `-- fontinfo.pyd
                            `-- glif.pyd
                            `-- groups.pyd
                            `-- kern.pyd
                            `-- mark.pyd
                            `-- plist.pyd
                            `-- tools.pyd
                            `-- user.py
                            `-- vfb.pyd

Requirements

This package has no dependencies outside of the standard library. It is written in Cython and in Python 3 syntax where it is natively supported by Cython. The submodules are compiled into .pyd extension modules. To recompile the submodules, the PyPi cython package and a compiler for Cython to utilize during extension module compilation will be required.

Optional

• cython
  pip install cython
  https://github.com/cython/cython

• Minimalist GNU for Window (MinGW)
  http://www.mingw.org
  http://winlibs.com

• AFDKO
  pip install afdko
  https://github.com/adobe-type-tools/afdko

Functionality

UFO output is produced without changes to the source font. The source font will be copied and UFOs will be created from the copy. If the font is multiple master, instances will be generated from the copy. If a specific layer or instance_values are not provided for a multiple master source font, a UFO will be generated for each master in the font.

Fonts with a large number of glyphs benefit greatly from supplying additional glyph names to be optimized when removing overlaps (glyphs_optimize_names) and/or glyph names and suffixes which can be omitted from the final UFO instance (glyphs_omit_names, glyphs_omit_suffixes). See GLYPHS OPTIONS below.

Generated instances/layers can be saved and/or left open after generation via the vfb_save and vfb_close options. If vfb_save is set to True, the resulting .vfb instance will be updated during UFO creation. This includes glyph outline changes (overlap removal and decomposition).

All path options must be absolute paths; folder and file paths which are not absolute will be ignored. The default output path is the user's Desktop.

A dictionary of attributes may be suppled via the instance_attributes option. These attributes should consist of keys from the UFO specification and they must match the data type in the specification. Not all fontinfo attributes are configurable; please see CONFIGURABLE_ATTRS in the fontinfo.pxi source file for a list of attributes which will be checked and updated to the UFO(s) during creation.

-------------------------------------------------------------------------------
EXAMPLE UFO GENERATION SCRIPT
-------------------------------------------------------------------------------
#FLM: write ufo
# coding: utf-8
from __future__ import absolute_import, unicode_literals

import os

from vfb2ufo3 import write_ufo

user_profile_folder = os.environ['USERPROFILE']
output_path = os.path.join(user_profile_folder, 'Documents', 'test_font')

instances = [
	0,
	200,
	400,
	650,
	1000,
	]
names = [
	'Thin',
	'Light',
	'Regular',
	'SemiBold',
	'Bold',
	]
attributes = [
	{'openTypeOS2WeightClass': 200},
	{'openTypeOS2WeightClass': 300},
	{'openTypeOS2WeightClass': 400},
	{'openTypeOS2WeightClass': 600},
	{'openTypeOS2WeightClass': 700},
	]

write_ufo(
	output_path=output_path,
	instance_values=instances,
	instance_names=names,
	instance_attributes=attributes,
	glyphs_decompose=True,
	glyphs_remove_overlaps=True,
	)

-------------------------------------------------------------------------------

Scale options

By default, the target UPM for UFO output is 1000. For a UPM other than 1000, say 2048, it should be set via the scale_to_upm option. The value from the scale_to_upm option is ignored if it is lower than 1000. Scaling can be turned off by setting scale_auto to False; this does not reduce conversion times.

All scaling operations are performed independently from FontLab; if the .vfb instance(s)/master copy are being saved, the .vfb font and glyph values will be the original un-scaled values.

Instance options

When creating instances from a multiple master source font, lists of values, names (optional), and attributes (optional) should be provided to generate instance UFOs from the master font.

If the source is a multiple master font and a list of instance values is not provided, a UFO for each master will be created.

For multiple master fonts, the instance values list should be values in tuple- or list-form with a value for each axis. For single-axis fonts, if the list values are numerical, the values will be converted to single-element lists:

2-axis font

• instance_values = [[0, 1000], [200, 1000]]

• instance_values = [(0, 1000), (200, 1000)]

1-axis font

• instance_values = [[0], [200]]

• instance_values = [(0,), (200,)]

• instance_values = [0, 200] becomes [[0], [200]]

If the optional lists of names and/or attributes are provided in addition to a list of values, they must be of the same length as the values list. A ValueError will be raised if the lengths do not match, since this will likely produce undesirable results:

Correct:

instance_values = [(0, 1000), (200, 1000)]
instance_names = ['Light Display', 'Regular Display']

Incorrect (ValueError):

instance_values = [(0, 1000), (200, 1000)]
instance_names = ['Light Display']

Glyph options

Glyph scaling is independent from the .vfb instance itself; if the .vfb instance is being saved, the glyphs in the .vfb will remain un-scaled.

Glyph decomposition and overlap removal is optional and occurs after instances are generated. This option is intended for final output when a binary font will be created from the UFO.

By default, when decomposing and removing overlaps from glyph outlines for export, GLIF files for glyphs containing components will be built using contours from each component's base contours.

When decomposing only, the optimization outlined above will be used for all glyphs containing components.

The generated .vfb instance(s) will leave components in component-form.

To disable the optimizations outlined above, set the glyphs_optimize option to False.

Omit glyphs from instance

• A list of glyph suffixes and/or glyph names can be supplied that should be omitted from the instance UFO via the glyphs_omit_suffixes and glyphs_omit_names options, respectively.

Optimize glyph name and code point lists

• If removing overlaps, the default list of code points for glyphs to be constructed in the above manner is composed of glyphs that normally have no overlapping components. The list is located in the ufo.pxi source file with the character representations for these code points shown below.

• The code points from the default code point list can be shown by running the vfb2ufo3.show_default_optimize_code_points() function. The code points will print to the FontLab output window and can then be copied into a text editor and edited as needed.

• A user-supplied code point list (glyphs_optimize_code_points) can be a list of '0x00ac'-format strings, integers in hexadecimal-form (0x00ac), or numeric integers (172); values which cannot be converted to an integer will raise a ValueError. Only the first code point in each glyph's list of code points (FontLab unicodes attribute) is checked for code point set membership.

• A user-supplied glyph name list (glyphs_optimize_names) can be supplied to supplement the code point list for glyphs. Any glyphs containing components that do not overlap should be added to this list.

• Small case variants of the code points in the code point list will be also added to code point list assuming they end with .sc, .smcp, or .c2sc suffixes.

OPTIMIZE_CODE_POINTS

Latin
À Á Â Ã Ä Ā Ă Ǣ Ǽ Ȁ Ȃ Ǎ Ȧ
Ḇ
Ć Ĉ Ċ Č
Ď Ḍ Ḏ Ḓ
È É Ê Ë Ē Ĕ Ė Ė Ȅ Ȇ
Ĝ Ğ Ġ Ģ Ḡ Ǧ Ǵ
Ĥ Ḥ Ḫ
Ì Í Ĩ Ī Ĭ İ Î Ï Ȉ Ȋ Ǐ
Ĵ
Ķ Ḳ Ḵ
Ĺ Ļ Ľ Ŀ Ḷ Ḹ Ḻ Ḽ
Ḿ Ṁ Ṃ
Ñ Ń Ņ Ň Ṅ Ṇ Ṉ Ṋ Ǹ
Ò Ó Ô Õ Ö Ō Ŏ Ő Ȍ Ȏ Ȯ Ǒ
Ŗ Ř Ŕ Ṙ Ṛ Ṝ Ṟ Ȑ Ȓ
Ś Ŝ Ş Ș Š Ṣ
Ţ Ț Ť Ṭ Ṯ Ṱ
Ũ Ū Ŭ Ů Ű Ù Ú Û Ü Ȕ Ȗ Ǔ Ǖ Ǘ Ǚ Ǜ
Ṿ
Ŵ Ẁ Ẃ Ẅ Ẇ
Ẋ Ẍ
Ŷ Ÿ Ý Ẏ Ȳ
Ź Ż Ž Ẑ Ẓ Ẕ
IJ LJ NJ Lj Nj
DZ DŽ Dz Dž
à á â ã ä ā ă ǣ ǽ ȁ ȃ ǎ ȧ
ḇ
ć ĉ ċ č
ď ḍ ḏ ḓ
è é ê ë ē ĕ ė ě ȅ ȇ
ĝ ğ ġ ģ ḡ ǧ ǵ
ĥ ẖ ḥ ḫ
ì í ĩ ī ĭ î ï ȉ ȋ ǐ
ĵ ǰ
ķ ḳ ḵ
ĺ ļ ľ ŀ ḷ ḹ ḻ ḽ
ḿ ṁ ṃ
ń ņ ň ʼn ñ ṅ ṇ ṉ ṋ ǹ
ò ó ō ŏ ő ô õ ö ȍ ȏ ȯ ǒ
ŗ ř ŕ ṙ ṛ ṝ ṟ ȑ ȓ
ś ŝ ş ș š ṣ
ţ ț ť ṭ ṯ ṱ
ũ ū ŭ ů ű ù ú û ü ȕ ȗ ǔ ǖ ǘ ǚ ǜ
ṿ
ŵ ẁ ẃ ẅ ẇ
ẋ ẍ
ý ÿ ŷ ẏ ȳ
ź ż ž ẑ ẓ ẕ
ij lj nj
dz dž

Cyrillic
Ѓ Ќ Ѝ Й Ӣ Ӥ Ў Ӝ Ӂ Ѐ Ё Ӗ Ӟ Ѷ Ә Ӛ Ѕ І Ї Ј Ӑ Ӓ Ӕ Ӧ Ӯ Ӱ Ӳ Ӵ Ӹ Ӏ Ӏ
ѓ ќ ѝ й ӣ ӥ ў ӝ ӂ ѐ ё ӗ ӟ ѷ ә ӛ ѕ і ї ј ӑ ӓ ӕ ӧ ӯ ӱ ӳ ӵ ӹ

Greek Mono- and Polytonic
Ἀ Ἁ Ἂ Ἃ Ἄ Ἅ Ἆ Ἇ ᾈ ᾉ ᾊ ᾋ ᾌ ᾍ ᾎ ᾏ Ᾰ Ᾱ Ὰ Ά ᾼ
Ἐ Ἑ Ἒ Ἓ Ἔ Ἕ Ὲ Έ
Ἠ Ἡ Ἢ Ἣ Ἤ Ἥ Ἦ Ἧ ᾘ ᾙ ᾚ ᾛ ᾜ ᾝ ᾞ ᾟ Ὴ Ή ῌ
Ἰ Ἱ Ἲ Ἳ Ἴ Ἵ Ἶ Ἷ Ῐ Ῑ Ὶ Ί
Ὀ Ὁ Ὂ Ὃ Ὄ Ὅ Ὸ Ό
Ῥ
Ὑ Ὓ Ὕ Ὗ Ῠ Ῡ Ὺ Ύ
Ὠ Ὡ Ὢ Ὣ Ὤ Ὥ Ὦ Ὧ ᾨ ᾩ ᾪ ᾫ ᾬ ᾭ ᾮ ᾯ Ὼ Ώ ῼ
ἀ ἁ ἂ ἃ ἄ ἅ ἆ ἇ ᾀ ᾁ ᾂ ᾃ ᾄ ᾅ ᾆ ᾇ ᾰ ᾱ ᾲ ᾳ ᾴ ᾶ ᾷ ὰ ά
ἐ ἑ ἒ ἓ ἔ ἕ ὲ έ
ἠ ἡ ἢ ἣ ἤ ἥ ἦ ἧ ᾐ ᾑ ᾒ ᾓ ᾔ ᾕ ᾖ ᾗ ῂ ῃ ῄ ῆ ῇ ὴ ή
ἰ ἱ ἲ ἳ ἴ ἵ ἶ ἷ ῐ ῑ ῒ ΐ ῖ ῗ ὶ ί
ὀ ὁ ὂ ὃ ὄ ὅ ὸ ό
ῤ ῥ
ὐ ὑ ὒ ὓ ὔ ὕ ὖ ὗ ῠ ῡ ῢ ΰ ὺ ύ ῦ ῧ
ὠ ὡ ὢ ὣ ὤ ὥ ὦ ὧ ᾠ ᾡ ᾢ ᾣ ᾤ ᾥ ᾦ ᾧ ῲ ῳ ῴ ῶ ῷ ὼ ώ

Features options

Font groups can be added to the features.fea file on export by setting features_import_groups to True. The font's features are neither formatted nor checked for correctness. Users are responsible for moving referenced feature files from include() statements to the chosen output directory. Also see KERN FEATURE OPTIONS and MARK FEATURE OPTIONS below for kern and mark feature options.

Kern feature options

Kern values will be scaled in parity with the output UFO. This scaling is independent from the created .vfb instance. A minimum value can be set using kern_min_value. This value should be a positive integer and when set, all kern values (negative and positive) not above the threshold will be omitted from the kern feature.

By default, the kern feature from the master font is not included in the features.fea file. To include the kern feature from the master font, kern_feature_passthrough should be set to True.

An external feature file with a kern feature can be imported to the font features using the kern_feature_file_path option, which expects a path to a text file with the .fea extension.

By default, a new kern feature is generated for each instance. Setting kern_feature_generate to False will turn this off. The kern feature generation will add subtables and a lookup as necessary. This is not particularly elegant, and so far, no checks are made to guarantee a working kern feature. Any remaining subtable overflows may be due to glyph(s) being in more than one kern group of the same side; however overflows can also be caused by issues from one or more GPOS features located earlier in the feature list.

Mark feature options

A mark feature can be generated on export by setting mark_feature_generate to True. A list of anchor names to omit (mark_anchors_omit) or a list of anchor names to include (mark_anchors_include) can be supplied to fine-tune the mark feature output.

Group options

Providing a FontLab-class file (.flc) or groups.plist speeds up UFO creation time significantly when the group names are not named using first and second group identifiers (see groups_flc_path and groups_plist_path options). Group names in the .flc file do not have match any specific formatting (e.g. MMK_R_<key glyph>, public.kern2.<key glyph>).

When not using either a .flc or groups.plist file, group names will be checked for UFO3-style group identifiers (public.kern1.<key glyph>, public.kern2.<key glyph>), MetricsMachine-style identifiers (MMK_L_<key glyph>, MMK_R_<key glyph>), and the simpler _L and _R identifier suffixes. Groups which either have no kerning or are not identifiable using their name will be identified as first/second using FontLab's built-in GetClassLeft/GetClassRight methods.

If the export_flc option is set to True, a FontLab-class file (.flc) will be generated with group names matching those of the generated UFOs. This file will be located in the same directory as the generated UFO(s).

The kern_ignore_no_kerning option can be set to True to ignore groups which have no kerning pairs. This may be desirable if making a binary font from the UFO. This option has no effect when using an imported .flc or groups.plist file.

FontLab kern classes without a key glyph in a provided .flc file or in the master font's kern classes will have the first glyph in the FontLab class marked as the key glyph and it will be noted in the output console. If there is more than one glyph marked as a key glyph, the first marked glyph is considered the key glyph. These key glyph operations may affect the kerning. An imported groups.plist infers that the glyph in the group name is the key glyph.

Kern group naming recommendations

Typical FontLab-style kerning groups:
_A: A' Agrave Aacute Acircumflex Atilde Adieresis Aring...
_A_r: A' AE Agrave Aacute Acircumflex Atilde Adieresis Aring...

Recommended naming for FontLab-style kerning groups:
_public.kern1.A: A' Agrave Aacute Acircumflex Atilde Adieresis Aring...
_public.kern2.A: A' AE Agrave Aacute Acircumflex Atilde Adieresis Aring...

Final output (UFO group plist):
<key>public.kern1.A</key>
<array>
	<string>A</string>
	<string>Agrave</string>
	<string>Aacute</string>
	<string>Acircumflex</string>
	<string>Atilde</string>
	<string>Adieresis</string>
	<string>Aring</string>
	...
</array>

<key>public.kern2.A</key>
<array>
	<string>A</string>
	<string>AE</string>
	<string>Agrave</string>
	<string>Aacute</string>
	<string>Acircumflex</string>
	<string>Atilde</string>
	<string>Adieresis</string>
	<string>Aring</string>
	...
</array>

AFDKO options

The OS/2, hhea, head, and name tables will be added to the features file. The name table entry strings will be formatted according to OpenType Feature File Specification § 9.e. Any strings unable to be formatted fully for each platform's specific encoding restriction (Windows -- UTF-8, Macintosh -- Mac OS Roman) will be formatted to their nearest ASCII equivalent rather than omitting any un-encodable characters. The standard library unicodedata module is used for any entries meeting this criteria.

GlyphOrderAndAliasDB (GOADB) and FontMenuNameDB files can be generated for use with MakeOTF. The GOADB can be provided (afdko_makeotf_GOADB_path), derived from the .vfb's original encoding, or the order of the source font.

Optionally, the first 256 glyphs can be filled from the Windows-1252 or Mac OS Roman code pages (afdko_makeotf_GOADB_win1252, afdko_makeotf_GOADB_macos_roman). The first character of a generated GOADB file will always start with the .notdef glyph. If a GOADB file is provided, it is not checked for correctness. Commands to run MakeOTF for each generated instance separately or all instances as a batch using the options afdko_makeotf_cmd and afdko_makeotf_batch_cmd, respectively.

There are several explicit keyword options to enable specific MakeOTF switches. For those not available via a keyword option, they should be defined as a list of strings and passed to the afdko_makeotf_args option.

psautohint options

psautohint can be utilized for generating glyph hints after UFO generation. Commands to run psautohint for each generated instance separately or all instances as a batch using the options psautohint_cmd and psautohint_batch_cmd, respectively. The default options are -d (write decimal (float) hint coordinates) and -w (write hints directly to the .glif lib for each glyph).

UFOZ options

UFO instances can be written as a .ufoz archive. If you are planning on any file transfer operations after creation, transferring a single .ufoz file is much quicker than the large number of small text files in the generated UFO instance(s), especially when transferring through USB. By default, archives are written in compressed mode. Compression can be turned off by setting ufoz_compress to False.

.designspace font options

A .designspace document can be created in place of individual UFO instances. A UFO for each master will be generated and the instances will be described in the .designspace document. A default instance can be described with the designspace_default option. This value must be a list or tuple with a value for each axis in the font. If glyphs_omit_list or glyphs_omit_suffixes_list lists are provided, the glyphs will remain in the source UFOs and a glyph mute rule for each glyph to be omitted will be added for each instance.

Benchmarks

For reference, testing was performed on a Windows 10 machine with an Intel Xeon E5 1650v3 @ 3.5 GHz CPU and a solid-state hard drive.

Times are per-instance (±.5 sec) and do not include time to load and parse user options, then copy the original font and prepare the copy for conversion to the UFO format. This prep time increases when not providing a FontLab-class or groups.plist file.

The ufoz option will reduce times by 0 - 0.5 sec.

Test (~3200 glyphs @ 10,000 UPM -> 1,000 UPM), <10 sec

flc_path = <path to .flc file>

vfb2ufo3.write_ufo(
	glyphs_decompose=True,
	glyphs_remove_overlaps=True,
	groups_flc_path=flc_path,
	)

Test (~2900 glyphs @ 10,000 UPM -> 1,000 UPM), ≈9 sec

flc_path = <path to .flc file>
glyphs_omit_list = [
	<glyph names to be omitted go here>
	]
glyphs_omit_suffixes_list = [
	<glyph name suffixes to be omitted go here>
	]

vfb2ufo3.write_ufo(
	glyphs_decompose=True,
	glyphs_remove_overlaps=True,
	glyphs_omit_list=glyphs_omit_list,
	glyphs_omit_suffixes_list=glyphs_omit_suffixes_list,
	groups_flc_path=flc_path,
	)

Test (~2900 glyphs @ 10,000 UPM -> 1,000 UPM), ≈7 sec

flc_path = <path to .flc file>
glyphs_optimize_names = [
	<glyph names with no overlapping components go here>
	]
glyphs_omit_list = [
	<glyph names to be omitted go here>
	]
glyphs_omit_suffixes_list = [
	<glyph name suffixes to be omitted go here>
	]

vfb2ufo3.write_ufo(
	glyphs_decompose=True,
	glyphs_remove_overlaps=True,
	glyphs_optimize_names=glyphs_optimize_names,
	glyphs_omit_list=glyphs_omit_list,
	glyphs_omit_suffixes_list=glyphs_omit_suffixes_list,
	groups_flc_path=flc_path,
	)

Test (~2900 glyphs @ 10,000 UPM -> 1,000 UPM), ≈4 sec

flc_path = <path to .flc file>
vfb2ufo3.write_ufo(
	glyphs_decompose=True,
	groups_flc_path=flc_path,
	)

Test (~2900 glyphs @ 10,000 UPM -> 1,000 UPM), ≈3-4 sec

flc_path = <path to .flc file>
glyphs_omit_list = [
	<glyph names to be omitted go here>
	]
glyphs_omit_suffixes_list = [
	<glyph name suffixes to be omitted go here>
	]

vfb2ufo3.write_ufo(
	glyphs_decompose=True,
	glyphs_omit_list=glyphs_omit_list,
	glyphs_omit_suffixes_list=glyphs_omit_suffixes_list,
	groups_flc_path=flc_path,
	)

Test (~3200 glyphs @ 10,000 UPM -> 1,000 UPM), ≈3-4 sec

flc_path = <path to .flc file>

vfb2ufo3.write_ufo(
	groups_flc_path=flc_path,
	)

Notes

Generally, no assumptions are made about the correctness of the input. When adfko_makeotf_release mode is set, glyph name errors will raise an exception and UFO generation will not continue. Glyph name checks are made prior to building instances. Other errors in the original font will likely be passed through to the UFO.

Author

Jameson R Spires

License

This package is available under the MIT License

Version history

• version 0.6.1
  small corrections

• version 0.6.0
  small fix for single-master font builds
  small changes to several source files
  glif.pyx has been rewritten in C++ as much as possible

• version 0.5.2
  small change to groups.pyx
  re-added link to known working GCC compiler

• version 0.5.1
  majority of code base rewritten
  support for UFO3 specification only
  considerable improvement in UFO creation times
  corrected UFOZ build structure
  removed hint operations, added psautohint batch command options
  improved option handling
  improved group conversion
  native kern and mark feature generation

• version 0.3.1
  updated sample script

• version 0.3.0
  additional documentation
  slight improvement in glif and .glif file creation times
  added sample benchmark times

• version 0.2.0
  minor formatting
  change to plistlib for groups.plist import
  removed commented lines in __init__.py
  added futures package as a required package
  added module to PyPi

• version 0.1.0
  initial release