I have recently purchased Quadraat Sans for use on a website and noticed it has some buggy hinting in Cyrillic glyphs at 17 px size. And I am just not going to use a different size.
That is, horizontal stems of letters "э", "з", "є", "н" are pixel lower than they should be — a really crucial detail in a Cyrillic font. And it ruins this font.
So I want to correct TrueType hinting of those letters. I know it's kinda illegal to do that, but that's not stealing a font or making a copycat and selling it. Just want to fix the bugs.
I have never dealt with hinting. So I had googled a lot, found some tutorials, but most of them are soo difficult to understand. TrueType hinting seems to be a mysterious process even for some of the authors of those tutorials.
As you can see from the image, I managed to correct the "н" with delta-hinting. It was a pain for me to figure it out how (and why) to hint that "н" without distorting the glyph at other ppems, though the letter has such an easy shape.
Now that I know, that to do delta hints I have to set other hints, I struggle to do it with "э", "з", "є"
I would appreciate any help, any single word of advice a whole lot.
All I want is to bring that stem one pixel up at 17 ppem without distorting glyphs' shapes at other ppems.