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IDProjectCategoryView StatusLast Update
0015490ScribusTypographypublic2023-11-16 11:18
ReporterMZaske Assigned To 
Status newResolutionopen 
PlatformallOSallOS Versionall
Product Version1.5.4.svn 
Summary0015490: Give users access to the OpenType feature "Contextual Alternates" (calt)
Description"Contextual Alternates" are no longer an obscure nice feature. When you do an advanced search on for "OpenType features" "contains" "Contextual Alternates" the search will yield over 1000 fonts, where the designer has made an extra effort to include (sell) such alternate glyphs.

In Scribus they are not available. One typography-blog is giving the advice to access such "extra glyphs" via the inbuilt character palette (for InDesign and Xpress) but the "insert > glyph" palette in Scribus does not even show any glyphs which are "extra" or aka "unmapped".

If you want to see how to realize a palette which can/does show all glyphs, even the unmapped ones, there is the open-source tool fontmatrix ( where you might find details.

Workaround for now:
Contextual Alternates are supported in XeteX (XeLateX), so if a user desperately needs to create text-frames with such Contextual Alternates he can configure a new set of render frames for the xetex-engine and then use a syntax like this to make it happen:
I have done this yesterday, so can confirm it works. But getting into Latex and then XeLateX is beyond many Scribus users.

If you want to read about "Contextual Alternates" and OpenType Features as a wider context, here is a nice summary, including calt:

I quote a bit from the other Martin:
"Substitute — depending on the context!

In the previous examples, the substitution of a glyph took place when the triggering glyph was used, no matter what. Now let’s look at a feature where the substitution only takes place when additional criteria are met: contextual features.

Contextual features have opened up a whole new spectrum of possibilities, enabling you to define very individual rules on how glyph variants are triggered. They have allowed quite complex typographic ideas to be tunred into working fonts. You’ll find them extensively applied in script typefaces such as Liza (by Underware) or Studio Lettering (by House Industries) where letter variants are used depending on which glyph precedes/follows, keeping the flow within the words going. Another use for the contextual features are fonts that loop through letter variants like FF Trixie HD (by LettError) or FF Duper (by Martin Wenzel). "

I do not know the amount of work it will take to realize this feature, but we should not leave this to InDesign alone. I tested this also on XARA Designer Pro X and could not activate the feature, altough it does have a button for the "simpler OpenType features", just like Scribus.

Thank you for considering this request. I will send a note to the user e-mail list and will also hear their feedback.
Tagsopentype, text frames, typography



2018-11-19 16:56

reporter   ~0045647

I have not looked at the GUI code, but with the OpenType work already done in 1.5.3 I would expect this to be a relatively straighforward change. I for one would love to see an GUI that allows selecting Contextual Alternates.

Issue History

Date Modified Username Field Change
2018-11-19 12:09 MZaske New Issue
2018-11-19 12:09 MZaske Tag Attached: opentype
2018-11-19 12:09 MZaske Tag Attached: text frames
2018-11-19 12:09 MZaske Tag Attached: typography
2018-11-19 12:27 jghali Summary Please give users access to the OpenType feature "Contextual Alternates" (calt) => Give users access to the OpenType feature "Contextual Alternates" (calt)
2018-11-19 16:56 bertd2 Note Added: 0045647