Max Content <- Additional Metrics <-Ranges <- Font

[Tom Sherlock]

Does anyone know how i can activate the Additional Metrics area?

I'm trying to change the Max Content to 3 so that i can use ligatures with my kerning.



Thanks

[Bhikkhu Pesala]

I like easy questions.

Just change the version to 2 or 3.

I think I should set the MaxContent value to 3 for my fonts as they have ligatures like ffi and ffl.

The maximum length of a target glyph context for any feature in this font. For example, a font which has only a pair kerning feature should set this field to 2. If the font also has a ligature feature in which the glyph sequence 'f f i' is substituted by the ligature 'ffi', then this field should be set to 3. This field could be useful to sophisticated line-breaking engines in determining how far they should look ahead to test whether something could change that effects the line breaking. For chaining contextual lookups, the length of the string (covered glyph) + (input sequence) + (lookahead sequence) should be considered.

Maybe you can tell us more about the significance of the MaxContent value?

[Tom Sherlock]

I like easy questions.

Just change the version to 2 or 3.

I think I should set the MaxContent value to 3 for my fonts as they have ligatures like ffi and ffl.

The maximum length of a target glyph context for any feature in this font. For example, a font which has only a pair kerning feature should set this field to 2. If the font also has a ligature feature in which the glyph sequence 'f f i' is substituted by the ligature 'ffi', then this field should be set to 3. This field could be useful to sophisticated line-breaking engines in determining how far they should look ahead to test whether something could change that effects the line breaking. For chaining contextual lookups, the length of the string (covered glyph) + (input sequence) + (lookahead sequence) should be considered.

Maybe you can tell us more about the significance of the MaxContent value?

Unfortunately it is not that easy. If you have another look at the graphic in my previous posting you will notice that the Additional Metrics section is all greyed out, inactive, ineditable

I am unable to change the value of MaxContext. My question is, therefore, how do i activate the MaxContext control so that i may change the value from 2 to 3.

As far as the significance of the MaxContext. Based on your quote of Erwin above, it is my understanding that if i want to be able to have in a way a kerning of three glyphs (first glyph +ligature glyph + second glyph) i would need the MaxContext value to be three.

My understanding may be incorrect. In which case i am open to other suggestions as to how I may connect two glyph (two letters) with a ligature without having to assign a key for that ligature.

[Bhikkhu Pesala]

The option is greyed out because the version is set to 1.

Just change the version to 2 or 3.

[Bhikkhu Pesala]

My understanding may be incorrect. In which case i am open to other suggestions as to how I may connect two glyph (two letters) with a ligature without having to assign a key for that ligature.

I am not sure what you're trying to accomplish, but I wouldn't be surprised if your understanding is incorrect.

To connect two glyphs as a ligature automatically you must use an OpenType feature called GSUB (Glyph Substitution), which FontCreator does not support. You can add GSUBs with VOLT or with OpenType Compiler.

See Adding OpenType Features

When the user types "difficult" the OpenType GSUB feature changes that to "difficult" — is that what you want, or something similar?

[Bhikkhu Pesala]

As I understand the effect of MaxCount it might affect how the line breaks. With MaxCount = 0-2 it might break like this:

diff-
icult
but with MaxCount = 3 it would only break like this:
diffi-
cult
or
di-
fficult

[Tom Sherlock]

The option is greyed out because the version is set to 1.

Just change the version to 2 or 3.

Oh, Ok. I got it now. I didn't realize that you were referring to a different property actually called version. I was completely focused on the bottom of the Ranges panel.

Thanks.

[Tom Sherlock]

My understanding may be incorrect. In which case i am open to other suggestions as to how I may connect two glyph (two letters) with a ligature without having to assign a key for that ligature.

I am not sure what you're trying to accomplish, but I wouldn't be surprised if your understanding is incorrect.

To connect two glyphs as a ligature automatically you must use an OpenType feature called GSUB (Glyph Substitution), which FontCreator does not support. You can add GSUBs with VOLT or with OpenType Compiler.

See Adding OpenType Features

When the user types "difficult" the OpenType GSUB feature changes that to "difficult" — is that what you want, or something similar?

So in other words, Font Creator will support the presentation of ligature, but not support the creation of said ligature.

I understand that ligature is used to connect at least two glyphs. Through kerning I am able to space two glyphs in such a way that they look connected. The font i am creating is made up of letter connected as scripted letters are connected. So i want to take glyph and glyph and have them appear as .

And you say that GSUB will do this for me? I will check it out.

Thanks.

[Bhikkhu Pesala]

Don't forget that most applications don't support OpenType features. If you plan to use it only in Wrod I think the ligatures will work, but not everywhere. OpenOffice doesn't yet support them, for example.