[ft-devel] Autohinter only works for unrotated text

[Thomas Geier]

Dear mailinglist,

 

it appears, that it’s not possible to let freetype autohint rotated text.

After looking through the source, I’ve found out, that autohinting is only

allowed for „no transforms except simple slants“.

This is around ftobjs.c line 500 in function FT_Load_Glyph(…).

 

My question is why this ist he case. I understand that it

Would be tricky (and maybe totally different) to hint for rotations like

30° or something. In our application we’re only dealing with rotations of 90°

steps, though.

 

We have disabled autohinting for now to ensure all text looking the same. Another

solution could be to rotate the glyphs by hand in our application, though this an overhead

in computation since I suppose it would be better to just render the glyphs rotated.

Unfortunately performance is an issue for us.

 

I’m not looking for a solution, just some information about why the autohinter currently only

works for unrotated text.

 

Best regards and thank you for your reply,

Thomas