38 releases (22 breaking)
0.23.0 | Oct 9, 2024 |
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0.21.0 | Aug 6, 2024 |
0.20.0 | Jul 2, 2024 |
0.16.2 | Feb 19, 2024 |
0.2.0 | Jul 21, 2020 |
#1 in Data formats
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fontdb
fontdb
is a simple, in-memory font database with CSS-like queries.
Features
- The database can load fonts from files, directories and raw data (
Vec<u8>
). - The database can match a font using CSS-like queries. See
Database::query
. - The database can try to load system fonts. Currently, this is implemented by scanning predefined directories. The library does not interact with the system API.
- Provides a unique ID for each font face.
Non-goals
-
Advanced font properties querying.
The database provides only storage and matching capabilities. For font properties querying you can use ttf-parser. -
A font fallback mechanism.
This library can be used to implement a font fallback mechanism, but it doesn't implement one. -
Application's global database.
The database doesn't usestatic
, therefore it's up to the caller where it should be stored. -
Font types support other than TrueType.
Font vs Face
A font is a collection of font faces. Therefore, a font face is a subset of a font. A simple font (*.ttf/*.otf) usually contains a single font face, but a font collection (*.ttc) can contain multiple font faces.
fontdb
stores and matches font faces, not fonts.
Therefore, after loading a font collection with 5 faces (for example), the database will be
populated with 5 FaceInfo
objects, all of which will be pointing to the same file or binary data.
Performance
The database performance is largely limited by the storage itself. We are using ttf-parser, so the parsing should not be a bottleneck.
For example, on Mac Book Pro 14 with M1 Pro, it takes just ~24ms to load 1361 font faces.
Safety
The library relies on memory-mapped files, which is inherently unsafe. But since we do not keep the files open it should be perfectly safe.
If you would like to use a persistent memory mapping of the font files,
then you can use the unsafe Database::make_shared_face_data
function.
License
MIT
Dependencies
~2MB
~46K SLoC