Cocos2d: How to create .fnt file for font texture atlas?
Any free bitmap font creation tool?
Now I have all single character image.. and created texture grid in
As far as I know there's no tool that does exactly what you want. Since the .fnt file is simply an XML file you can create it manually.
The most widely used free bitmap font tool that works on Macs is Hiero. I wrote a Hiero tutorial that explains how to install, use and workaround some of its bugs.
Glyph Designer is a far better tool however. It costs $29.99 and is well worth it.
But as far as I know neither tool supports the creation of a fnt file from an existing atlas texture.