Just for funzies I went back and looked it up – editing kern data was introduced in Glyphr Studio version 1, Beta 5, which was a whole 10 years ago! The reason we put it in is because SVG Fonts supported kern information – and therefore Glyphr Studio had a way to read and write kern data as well. SVG Font is a deprecated format, so there was an extra step of somehow converting your SVG Font to something like an OTF or TTF file. But, with the extra step, it was possible.
We use a library called opentype.js to read and write font files. There has been an uptick in activity on this project, so we are slowly exploring new features and capabilities. Technically, we’re using a branch of a pre-v2 build of opentype.js, so there may be some unexpected bugs that pop up. But! The big news is Glyphr Studio can now read *and write* kern data from OTF files.
For long-forgotten legacy reasons, we used to store the kern’s value as a delta-x for the left character. Which is to say, a positive value would decrease the space between the two characters in a kern pair. This is counter-intuitive, and also not how font files store kern values. The other big change with this version is we flipped how we store that kern value. Starting with v2.5, the kern value can be thought of as an adjustment to the left character’s advance width (or, just an update to the overall advance). That is to say, a negative kern value will decrease the space between the two characters. Even though we made this kinda-breaking change, when you load a Glyphr Studio project file that was last saved before v2.5, Glyphr Studio will loop through all the kern data and invert the value, so that everything is up to date.
Even though this isn’t a huge update to Glyphr Studio’s experience or UI, it does add a feature that has long been an unexpected gap. Glyphr Studio is now able to read and write OTF files, including their Characters, Ligatures, Kern data, and Metadata. OpenType fonts have a ton of other possible features (Variables? Color?), and hopefully the advances in opentype.js will help us bring those to Glyphr Studio.
Thank you!
As always, your input and contributions are the main driving force behind Glyphr Studio. If you have any questions, or have an idea about what we should do next, please drop us a line! mail@glyphrstudio.com