ufo2ft
ufo2ft ("UFO to FontTools") is a fork of ufo2fdk whose goal is to generate OpenType font binaries from UFOs without the FDK dependency.
The library provides two functions, compileOTF and compileTTF,
which work exactly the same way:
from defcon import Font
from ufo2ft import compileOTF
ufo = Font('MyFont-Regular.ufo')
otf = compileOTF(ufo)
otf.save('MyFont-Regular.otf')In most cases, the behavior of ufo2ft should match that of ufo2fdk, whose documentation is retained below (and hopefully is still accurate).
Naming Data
As with any OpenType compiler, you have to set the font naming data to a particular standard for your naming to be set correctly. In ufo2fdk, you can get away with setting two naming attributes in your font.info object for simple fonts:
- familyName: The name for your family. For example, "My Garamond".
- styleName: The style name for this particular font. For example, "Display Light Italic"
ufo2fdk will create all of the other naming data based on thse two
fields. If you want to use the fully automatic naming system, all of the
other name attributes should be set to None in your font. However,
if you want to override the automated system at any level, you can
specify particular naming attributes and ufo2fdk will honor your
settings. You don't have to set all of the attributes, just the ones
you don't want to be automated. For example, in the family "My Garamond"
you have eight weights. It would be nice to style map the italics to the
romans for each weight. To do this, in the individual romans and
italics, you need to set the style mapping data. This is done through
the styleMapFamilyName and styleMapStyleName attributes. In each
of your roman and italic pairs you would do this:
My Garamond-Light.ufo
- familyName = "My Garamond"
- styleName = "Light"
- styleMapFamilyName = "My Garamond Display Light"
- styleMapStyleName = "regular"
My Garamond-Light Italic.ufo
- familyName = "My Garamond"
- styleName = "Display Light Italic"
- styleMapFamilyName = "My Garamond Display Light"
- styleMapStyleName = "italic"
My Garamond-Book.ufo
- familyName = "My Garamond"
- styleName = "Book"
- styleMapFamilyName = "My Garamond Display Book"
- styleMapStyleName = "regular"
My Garamond-Book Italic.ufo
- familyName = "My Garamond"
- styleName = "Display Book Italic"
- styleMapFamilyName = "My Garamond Display Book"
- styleMapStyleName = "italic"
etc.
Additionally, if you have defined any naming data, or any data for that matter, in table definitions within your font's features that data will be honored.
Feature generation
If your font's features do not contain kerning/mark/mkmk features, ufo2ft will create them based on your font's kerning/anchor data.
In addition to
Adobe OpenType feature files,
ufo2ft also supports the
MTI/Monotype format.
For example, a GPOS table in this format would be stored within the UFO at
data/com.github.googlei18n.ufo2ft.mtiFeatures/GPOS.mti.
Fallbacks
Most of the fallbacks have static values. To see what is set for these,
look at fontInfoData.py in the source code.
In some cases, the fallback values are dynamically generated from other data in the info object. These are handled internally with functions.
Merging TTX
If the UFO data directory has a com.github.fonttools.ttx folder with TTX
files ending with .ttx, these will be merged in the generated font.
The index TTX (generated when using using ttx -s) is not required.
Color fonts
ufo2ft supports building COLR and CPAL tables.
If there is com.github.googlei18n.ufo2ft.colorPalettes key in font lib, and
com.github.googlei18n.ufo2ft.colorLayerMapping key in the font or
in any of the glyphs lib, then ufo2ft will build CPAL table from the color
palettes, and COLR table from the color layers.
colorPalettes is a array of palettes, each palette is a array of colors and
each color is a array of floats representing RGBA colors. For example:
<key>com.github.googlei18n.ufo2ft.colorPalettes</key>
<array>
<array>
<array>
<real>0.26</real>
<real>0.0</real>
<real>0.23</real>
<real>1.0</real>
</array>
<array>
<real>0.86</real>
<real>0.73</real>
<real>0.28</real>
<real>1.0</real>
</array>
</array>
</array>colorLayerMapping is a array of color layers, each color layer is a array of
layer name and palette color index. It is a per-glyph key, but if present in
the font lib then it will be used for all glyphs that lack it. For example:
<key>com.github.googlei18n.ufo2ft.colorLayerMapping</key>
<array>
<array>
<string>color.1</string>
<integer>1</integer>
</array>
<array>
<string>color.2</string>
<integer>0</integer>
</array>
</array>With these this key present, ufo2ft will copy the color layers into individual
glyphs and setup COLR table.
Alternatively, if the color layers are already separate UFO glyphs, the
com.github.googlei18n.ufo2ft.colorLayers font lib key can be used. It uses
a table keyed by base glyph, and the value is an array of color layers, each
color layer is an array of glyph name and palette color index. For example:
<key>com.github.googlei18n.ufo2ft.colorLayers</key>
<dict>
<key>alef-ar</key>
<array>
<array>
<string>alef-ar.color0</string>
<integer>2</integer>
</array>
</array>
<key>alefHamzaabove-ar</key>
<array>
<array>
<string>alefHamzaabove-ar.color0</string>
<integer>1</integer>
</array>
<array>
<string>alefHamzaabove-ar.color1</string>
<integer>2</integer>
</array>
</array>
<dict>