Binary vs Compiled ?

[MacEachaidh]

HI all,
I'm trying to learn Fontlab 5 by practising on cleaning up and expanding freeware TTF fonts from the web.  I'm not rebadging these as my own or redistributing them as my work, just using them as exercise files, so I don't think I'm breaching any copyright.

Anyway, my point is that when I go to generate the file, Fontlab comes up with a dialogue box asking if I want to use the Binary or Compiled data in the OpenType tables.  I've looked in both the Fontlab manual and in Leslie Cabarga's book on Fontlab, and neither makes any mention (that I can find) of this dialogue box.  So the questions I have, if anyone can help with them please, are these:

1)  Why is Fontlab generating an OpenType table in this font, when I haven't entered any OpenType information and, as far as I can tell, the OpenType options aren't invoked ?  (I do realise that I have a fair bit yet to learn, so I'm trying not to make assumptions -- I just don't understand where this dialogue comes from, and with no mention of it in the documentation, I don't know what it means.)

2)  What do the two options actually mean ?  And what is the effect, and consequences, of each choice ?

Thanks for any help you can offer.

[Der FontMeister]

All I can think of is this font you are opening has some OTF data in it. Try the same steps with a new empty font with a circle in one of the slots.

Jimmy G.

[MacEachaidh]

G'day JG,
Thanks for the response.

You're right in what (at least I assume) you were asking:  a new font, with nothing in it but a simple circle as one of the glyphs, doesn't invoke that dialogue box.

So what you're saying -- that the font must have some OT code in it -- certainly makes sense to me.  But (forgive me if I'm being a dummy !) I can't see where the OT data has been placed.  In the Font Info, on the "TrueType-specific settings" page, the "Use default export options" checkbox is ticked.  (I think that happens by default, doesn't it ?)  In the "Binary and custom tables" page, there's only a "TT native hinting" listed, no OT table.  Is there somewhere else I should be looking ?

Also, assuming I *do* want it to be an OTF at some point, how do I answer the question in the original dialogue box ?  Should I choose "Binary" or "Compiled" ?

[Der FontMeister]

OTFs have various tables associated with them (see www.microsoft.com/typography) and I suspect that the font in question had such a table and you were unaware of it.

When generating OTFs you can use the "compiled" option in order to compile all these tables in to the font.

Jimmy G.

[MacEachaidh]

So what happens if I choose "Binary" ?

That's the bit I'm not clear on -- and that isn't even mentioned in the manual.  What do "Binary" and "Compiled" mean in this context ?

What difference do they each make in the final font and how it performs  ?

[Eigi]

If you open an OpenType Font with Opentype layout tables these tables will be decompiled to readable text, which ist displayed in the OpenType window. A binary version of these tables is also stored in the VFB file.
If you want to generate a new font from this VFB file you can decide which version you want to put in your font. If you have made any changes to the OpenType layout features you have to put the new compiled tables in the font. In the other case you can use the original binary version.

Use of the binary version is important if the original font contains OpenType layouot features which can't be generated by FontLab e.g. mark positioning for complex scripts.