TypeTool does not allow you to add OpenType Layout features which are needed to add the "alternates" functionality (or "ligatures"). But Microsoft offers the free Microsoft VOLT app for Windows (
https://www.microsoft.com/typography/volt.mspx ) which can be used to add OpenType Layout features.
Alternatively, you can use the commandline tool makeotf from the Adobe FDK toolkit (AFDKO) to add OpenType Layout features to your font, or you can use TransType 4.0 (
http://new.fontlab.com/font-converter/transtype/ ) to do the same. In both cases, you'll need to write your features using the Adobe FEA syntax* in a plain-text editor such as TextWrangler or Notepad++.
In TypeTool, create glyphs with names such as G.ss01. Generate your font as Type 1 (.pfb). If your font file is named MyFont-Regular.pfb, then save a plain-text file named MyFont-Regular.fea in the same folder. The contents of the file should be something like:
languagesystem latn dflt;
feature ss01 {
sub G by G.ss01;
} ss01;
Use AFDKO makeotf tool:
makeotf -f MyFont-Regular.pfb -fi MyFont-Regular.inf -ff MyFont-Regular.fea -o MyFont-Regular.otf
Or just open your MyFont-Regular.pfb in TransType 4 and generate an OpenType PS .otf font. If MyFont-Regular.fea is in the same folder as the .pfb, TransType will use it to write the OpenType Layout features into the .otf font.
One complication is that in fact, your kerning information should be in the .fea file as well, but when you generate the Type 1 (.pfb), it will be in the .afm file. But it's fairly easy to convert from .afm kerning to .fea kerning by hand:
You'll find your kerning in the .afm file written like this:
StartKernData
StartKernPairs 899
KPX A W -85
KPX A T -75
KPX V A -72
...
KPX quotesingle slash -189
EndKernPairs
EndKernData
Copy all the lines starting with "KPX" into a separate text file, and do a little search-replace so at the end, you have this:
feature kern {
pos A W -85;
pos A T -75;
pos V A -72;
...
pos quotesingle slash -189;
} kern;
You basically need to change each "KPX" to "pos" and add a ";" to each end-of-line.
Then, paste the entire "feature kern" stuff at the end of your MyFont-Regular.fea so in the end you'll have something like:
languagesystem latn dflt;
feature ss01 {
sub G by G.ss01;
} ss01;
feature kern {
pos A W -85;
pos A T -75;
pos V A -72;
...
pos quotesingle slash -189;
} kern;
in your .fea file. Then use makeotf or TransType.
Best,
Adam
*) See
http://ilovetypography.com/OpenType/opentype-features.html and
http://opentypecookbook.com/ on info about the FEA syntax.