Contour Direction - Does it matter?

pablohoney77's picture

I'm asking because i don't know the answer (obviously), but does it matter which way your contours run? I have been under the impression that black contours should run clockwise while the white parts should run counterclockwise? does it really matter? i know the main thing is that the black and white contours run in opposite directions. anyhow part of my confusion comes from the diagram here:
i had to give you the translated version because i think it adds humor to the text, and i'm all for humor! anyhow, anyone know a "definitive" answer to this question?

eolson's picture

Paul -

I can never remember, and to an extent it doesn't matter until...
You generate the file.

Before generating (in FL) go to Transform > Contour > Reverse All.
Then choose "set counterclockwise (Type 1) direction".
Or TrueType etc.
I hope this helps.

aquatoad's picture

To use your words. Black is counterclockwise. White is clockwise.
- or -
Outermost outline is counterclockwise. Alternate as you move in.
(same thing said differently)

Eric, you mean I don't have to go through glyph by glyph and double check? No wonder computers were invented. :-)


matteson's picture

One funny thing I've noticed in FontLab is that if you Merge Contours (Ctrl + F10), the direction of them has to be the same. If they run in opposite directions, the contours don't merge, they intersect, and there's a lot of tedious clean-up.

It took me eight months, but I finally figured that out ;-)

pablohoney77's picture

Okay i looked this up in the FontLab instruction manual last night and aparrently my thinking was correct if i were working with a TT font. But for T1 fonts the direction is reversed. Does anyone care to explain why this is the case?

hrant's picture

> Does anyone care to explain why this is the case?

Yes, please!


komitlak's picture

It is easy to remember with rime:

Truetype, black on right.

If you follow the conture's direction in TT font the black surface is allways on your right side.

It is the opposite with Postscript fonts. For more info see the Adobe's free online book abouth the postscript language.


blairyo's picture

The Fontographer method is described here;

In brief, outer paths move clockwise and the inner paths (in letters such as A and O) move in an anti-clockwise direction. A small arrow in FOG

pablohoney77's picture

yes, but why??? why counterclockwise in Postscript and clockwise in TT??? (It's probably some reason i wouldn't understand anyway, but it'd be nice to know)

Thomas Phinney's picture

PostScript AFAIK because they had to pick one. There may be some reason from previous graphics languages, I don't know.

I have been told that TrueType did it the other way just to be different from PostScript; I don't know if that's actually true, though.


Syndicate content Syndicate content