Improvements for Noto Sans Syloti Nagri

[Sagir8453]

Defect Report

Many characters in the Noto sans Syloti Nagri font are wrong or not in order.

Font

NotoSansSylotiNagri-Regular.ttf.

Where the font came from, and when

Site: https://noto-website-2.storage.googleapis.com/pkgs/NotoSansSylotiNagti-hinted.zip
Date: 2019-03-25

Font Version

The current one available on GitHub.

Issue

As shown in the image below, some characters need improvements. An alternative glyph for the character "A" is needed, the alternative form is more common and less confusing with the character "RO". The shape of the character "I" should be improved, the top part.
Now the consonants.
"TTHO" should be like "6" as in the image. The "DDHO" should also look different. The "DO" 's bottom part should be longer. The "DHO" should have an alternative form. The "NO"'s front part should be connected little bit billow from the top of the vertical line. The "BHO" should be improved, it looks too similar to the "NO" in the current font. The "LO" should have an alternative form. The "SHO" also needs improvements.
Now the diacritics.
The "E", "DVISVARA" and the top part of the vowel sign "OO" should be separated from the horizontal line. And the "U" diacitic should be separate from the letters and it should be longer also.
The "DU" (DO + U diacitic) should be like in the image.
Will talk about the conjunct consonants issue later when they are supported.

Screenshot

Syloti Nagri alphabet from manuscripts. The letter "ddo" is missing here.

A font that I'm making. It's currently in alpha state. Will try to post an improved version later.

Base of my font.

Another manuscript page.

The "DU"

[PaulHanslow]

@Sagir8453 This is a comment about the upcoming changes to Noto Sans Syloti Nagri, showing examples of what's changed . The second part of this comment is about questions I've had where I'm unsure and require answers. I wish to note that showing individual graphemes for what needs addressing/changing makes it easier to assess what's being talked about rather than images involving a group of characters. Also, it would be helpful to have characters referred to by unicode values than naming convention like 'SHO' and 'BHO'. Conjuncts are easier to identify and locate by using uniXXXX_uniXXXX (eg. 'DU' would be written as 'uniA816_uniA825'). Thanks

Changes yet to be uploaded

1. A (U+A800) alt zig-zag form added
   As per your note, the zig-zag form would become the default with the straight barred version becoming the alt form. Advise otherwise if this is incorrect.
   

2. I (U+A801) redesigned
   Top part of I redesigned with additional loop structure.
   

3. TTHO (U+A811) redesigned
   Old form had hard junction at the bottom of the main stem. Redesign's counter form has been closed to avoid ambiguity with DDHO (U+A813).
   

4. DDHO (U+A813) redesigned
   Old form has a hard junction at the bottom of the main stem. Redesign has the main stem curving into the upward stroke. The overall 'loop' shape has been vertically lowered to avoid ambiguity with TTHO (U+A811). Sangri8453's version of DDHO and TTHO has the main stem curving towards the left before curving upward. Google Noto version has been kept straight to better harmonise with the overall design, which is more rigid than calligraphic.
   

5. DHO (U+A817) alt form added
   

6. NO (U+A818) redesigned
   Stroke now meets the main vertical stem at a lower position rather than at the inflection point of the top-stroke and stem.
   

7. BHO (U+A81C) redesigned
   BHO looked too similar to NO (U+A818) before the redesign.
   

8. VOWEL SIGN U (U+A825) tests
   The VOWEL SIGN U has been lengthened to the left. How this vowel attaches to base shapes has also been checked (see image).
   

---

QUESTIONS

1. LO (U+A81F) alt form
   How should this alt form look. Am I correct in assuming it is this grapheme from the image you attached?
   

2. DU (DO + U diacritic) (uniA816_uniA825)
   Am I correct in that it is the character that looks like this?

DU is tricky in that I'm prioritising avoiding clashes with adjacent characters, which limits the length of the DU's out-stroke. The image below shows character pairs which I believe are too close to each other (coloured light blue) when the tail stroke is made long.

Please inform me if character sequences occur where uniA816_uniA825 is followed by characters with the VOWEL SIGN U (U+A825). If so, I'll do more extensive clashing tests. Clashes are marked pink with close clashes marked light blue.

3. You state LO (U+A81F) should have alt form. What does this look like (please show an isolated pictogram of this alt form).
   

4. You state SHO needs improvements but not in what manner. Is SHO a conjunct? An isolated pictogram of this letter as well as its unicode properties would be helpful (ie uniXXXX_uniXXXX if it's a conjunct).

5. The following omissions are mentioned in another Open Issue for Noto Sans Syloti Nagri but I'm unsure how these two conjuncts should look. Please advise.
   

6. I'm yet to update any conjunct which features a base shape that's been changed. The plan is complete the conjuncts after finishing this round of updates.

[PaulHanslow]

@simoncozens A new commit has been pushed to improve Syloti Nagri. Please read the following to understand what's been altered:

• A (U+A800) alt form added, called /uniA800.alt. It is the zig zag version.
• I (U+A801) redesigned to have a '3' like structure, rather than a '2' like structure.
• TTHO (U+A811) redesigned. Sharp junction in SW corner made softer. Outlines refined also.
• DDHO (U+A813) redesigned. Shape altered to avoid ambiguity with /uniA811.
• NO (U+A818) redesigned. Curve connects to main vertical stem rather than top line.
• BHO (U+A81C) redesigned to avoid ambiguity with NO (U+ A818).
• LO (U+A81F) alt form added, called /A81F.alt. Features the 'squiggle' in the centre left position. @Sagir8453's images showed a similar alt form and he requested this alt form be added.
• DO (U+A816)'s bottom curve made longer and extended further rightward. Anchor4 moved to accommodate this shape change.
• OO (U+A827) was requested to be disconnected from the top-line. This was previously don by you.
• DVISVARA (U+A802). Same as above. Done by you.
• E (U+A826). Same as above. Done by you.
• DHO (U+A817) alt for added, called /uniA817.alt.

Major changes

• VOWEL SIGN U (U+A825) design has been drastically altered. This diacritic was connected to each base character. It's now been redesigned to not connect. The outline has also been lengthened. Due to this shape change, an anchor (ie. anchor5) has been added to ALL base characters to allow better positioning of the VOWEL SIGN U on every base character. Previously, anchor4 defined the GPOS of VOWEL SIGN U (U+A825) and ALTERNATE HASANTA (U+A82C), and altering anchor4 would have affected both marks. Instead Anchor5 was added to solely allow independent positioning of VOWEL SIGN U.

Image below shows the vowel sign on all bases and ligated forms:

• DU ligature [DO + U] (/A816uniA825) drastically updated. uniA816uniA825's out-stroke has been extended as far as possible to avoid clashing with adjacent characters. Creating 3 versions of this ligature was considered— short tail, medium tail, and long tail—but doing so would require contextually substituting which one of the previous 3 forms fits best with the proceeding character to avoid clashes. Instead, one version of /uniA816uniA825 has been designed to accommodate all situations. In short, the tail has been lengthened considerably but nothing as long as what's found in manuscripts. This character has no Anchor5 as it's uncertain if DUU occurs and I'm unsure how the U diacritic would be positioned given the length of DU's tail.

The following is an image of possible clashes when the prior character supports the U (i.e BASE + U, followed by DU). Uncertain if this text chain ever occurs. Pink shows clashes, blue shows characters too close to one another.

Further notes

• SHO was listed as needing improvements but uncertain what character this is. Need further comment from @Sagir8453 if 'SHO' is a typo. If not, please show the grapheme of this character so it can be improved.

• Ligature NO + DO (/uniA818uniA816) has been updated as it was straightforward. Please note, this character doesn't include an Anchor5 as I don't know how U would be positioned given the length of /uniA818uniA816's tail.

The following ligatures remain unaltered (marked red in Glyphs source):

I believe most of the required updates for the ligatures involves transposing the updated above to their ligated forms. Yet I'm holding off on doing so for now. Will action shortly.

[PaulHanslow]

@Sagir8453, the plan is to update the conjuncts and I'm requesting your help to do so. The current design of the conjuncts follows what was established in the Syloti base form—which have now been updated. If updating the conjuncts is a simple matter of rolling the new changes into the conjuncts then it's an easy task. However, if the conjuncts' designs drastically differ let me know as I'd love your help.

All following conjuncts haven't been updated.