A suggestion to write CTL languages like Arabic, Devanagari...

[Distill7]

There are two types of scripts, simple scripts like Latin and Cyrillic where you can place each character next to the other, and Complex Scripts where you need:

·         Bidirectional text, from RTL and some LTR text inside it.

·         The shape of character changes depending on the character before or after it like Arabic.

·         Re-ordering of display of characters from the one you typed them in like Devanagari.

To write CTL you need to use a text shaping engine that reads the characters case by case and extracts the correct glyph from the font and determines the order of their display.

There is currently 3 major text shaping engines:

·         Core Text for macOS

·         Uniscribe used with Universal shaping Engine and DirectWrite for MS Windows

·         Pango with Harfbuzz, open source text engine used in Linux, Chrome OS, PlayStation..

An important thing is that a software can use a text shaping engine either directly or via an intermediary toolkit that translates the text shaping engine into the software engine.

I watched a special video about HarfBuzz, I was shocked that in order to produce a usable text shaping engine, you’ll need to test on huge amounts of text and search for errors and correct it case by case (the mentioned notes were to improve HarfBuzz and not to create in the first place).

I believe a representative of Affinity has mentioned that Affinity apps use their own text engine, and that adding CTL languages take a lot of time to implement, that they have decided to give other features a priority.

What I’m suggesting, is that instead of re-inventing the wheel, why don’t you just use one of the pre-established text engines via a toolkit, for example Harfbuzz is open source and you can use it free of charge.

Also HarfBuzz is under MIT license, you can incorporate it any proprietary software as long as you mention that it was used it and a copy of the copyright. Affinity software doesn’t need to be under MIT, only the HarfBuzz part of it. I own an old copy of DrawPlus, and it mentions a GPL license for a lot of its components, so this is not new for Serif.

[kenmcd]

The move to Harfbuzz in LibreOffice for Windows has severely damaged the text quality.
And it looks like it is not going to be fixed anytime soon.
Harfbuzz has its own set of issues and limitations.

Core Text also has its own set of limitations and issues it causes in LibreOffice.
The worst being it trying to cram all fonts into its predefined weights.
Fonts just disappear and are simply unavailable for use.

There is a reason all the major advanced desktop publishing applications create their own text rendering engines.

[Distill7]

But waiting to create a new text engine will take a lot of time and Serif is not even considering it.

Also Adobe has two option, "Adobe paragraph composer" and "Adobe world-ready paragraph composer", why doesn't Affinity try to do the same, using their text engine for Latin/Cyrillic text shaping, and using a toolkit to work with another text engine for Complex scripts, This will make the software usable for billions of people until they develop their own solution.

[fde101]

12 hours ago, toutou123 said:

But waiting to create a new text engine will take a lot of time and Serif is not even considering it.

Seems to me they've already done it, it simply doesn't have full functionality yet.

[Distill7]

11 minutes ago, fde101 said:

Seems to me they've already done it, it simply doesn't have full functionality yet.

How did you find that they've already done a new text engine for Complex Text?

[fde101]

1 minute ago, toutou123 said:

How did you find that they've already done a new text engine for Complex Text?

They keep telling us they are using their own text engine, not Apple's... that has been repeated in multiple places over the forum.

[Distill7]

18 minutes ago, fde101 said:

They keep telling us they are using their own text engine, not Apple's... that has been repeated in multiple places over the forum.

I know that they use their own text engine, it just supports simple text like Latin and Cyrillic, it doesn't support complex text like Arabic and Devanagari, I'm talking about them using the help of other engines to support those languages.

[Distill7]

Does any affinity developer have a comment on using HarfBuzz?

[dominik]

3 minutes ago, toutou123 said:

Does any affinity developer have a comment on using HarfBuzz?

Maybe they are a little busy right now for the initial release of APub in a couple of days?  

d.

[fde101]

They do not normally comment on feature requests.