Re: [Fontforge-users] correct direction and removeoverlap

[George W. <gw...@si...>]

On Sun, 2007-12-23 at 13:20, Qianqian Fang wrote:
> I used to use a (fairly) recent version fontforge (200709) to
> create my CJK fonts. This process involves overlap removal,
> outline simplification and ttf generation. As George warned
> before, the RemoveOverlap seems to produce problematic
> outlines, however, after some experiments, I found that a
> followed CorrectDirection() can resolve the issue in most cases.
> 
> Yesterday I synchronized my copy to the cvs version, and I
> realized that my CorrectDirection trick did not work anymore.
Neither Remove Overlap nor Correct Direction have changed recently.

The problem is that Correct Direction is not a meaningful command to
apply to a glyph with intersections. Correct direction works by saying
that external contours go clockwise, one level internal contours go
counter-clockwise, etc.

If two contours intersect there is no way to determine whether one is
internal or external.

If the trick has worked in the past you have been lucky. That's all. Now
you aren't.