Positioning of Diacritic Marks when doing Optical Metrics
Posted: Tue Jan 30, 2018 11:25 pm
A change which was introduced in FC 11 was that if a composite glyph has the 'use this glyphs metrics' flag set then Optical Metrics will not change the bearings of that glyph, the glyph will continue to use the bearings of the base glyph.
This was a very welcome change and FC 11 is better for having it, but there is a consequence to this behaviour.
If the base glyph has its left side bearing adjusted then this moves the relative position of any diacritic marks used with that base glyph in composite glyphs.
For example consider the letter 'A', if optical metrics decides to adjust the position of 'A' by 30 then this will be like the 'Â' character having its circumflex moved by -30.
This means that after performing an Optical Metrics operation one has to go through the font adjusting the positions of many of the diacritic marks.
It would be nice if when performing an Optical Metrics operation if a character has its left side bearing adjusted and that character is used in a composite with the 'use this glyphs metrics' flag set then the same horizontal adjustment should be applied to any other glyphs (diacritic marks) used with that base character in a composite glyph.
This was a very welcome change and FC 11 is better for having it, but there is a consequence to this behaviour.
If the base glyph has its left side bearing adjusted then this moves the relative position of any diacritic marks used with that base glyph in composite glyphs.
For example consider the letter 'A', if optical metrics decides to adjust the position of 'A' by 30 then this will be like the 'Â' character having its circumflex moved by -30.
This means that after performing an Optical Metrics operation one has to go through the font adjusting the positions of many of the diacritic marks.
It would be nice if when performing an Optical Metrics operation if a character has its left side bearing adjusted and that character is used in a composite with the 'use this glyphs metrics' flag set then the same horizontal adjustment should be applied to any other glyphs (diacritic marks) used with that base character in a composite glyph.