bugUnifont - Bugs: bug #52204, Problems with Ahom

 
 

You are not allowed to post comments on this tracker with your current authentication level.

bug #52204: Problems with Ahom

Submitter:  David Corbett <dscorbett>
Submitted:  Tue 10 Oct 2017 11:55:50 PM UTC
   
 
Category:  None Severity:  3 - Normal
Item Group:  None Status:  Works For Me
Privacy:  Public Assigned to:  None
Open/Closed:  Closed

Sat 11 Aug 2018 06:13:00 AM UTC, comment #3: 

I am marking this as "works for me" because the changes suggested will not render correctly given the shortcomings in the common font rendering engines. In particular, removing combining characters from combining character data files will not have the desired effect in common font rendering engines. If an individual glyph is incorrect, please submit a separate bug report.

Thank you,


Paul Hardy

Paul Hardy <unifoundry>
Group administrator
Mon 30 Jul 2018 03:37:49 AM UTC, comment #2: 

I have gone back to leaving all combining glyphs in combining.dat files, if nothing else because some font rendering engines are making up their own minds about combining glyph placement.  As a consequence, I think this is too tangled a mess for a font that is not a full, high-resolution vector font with intelligent double- and triple-glyph placement.  Because of the limitations inherent in Unifont, further complicated by different rendering engines interpreting (or not interpreting) the combining character information differently, I intend to leave Ahom as it is.  The same holds for Saurashtra.

Paul Hardy <unifoundry>
Group administrator
Sat 14 Oct 2017 08:52:09 PM UTC, comment #1: 

David,

One issue with this is that text editors that contain tables of combining characters will give them zero width; they ignore the font's encoding. So removing a glyph's code point from a combining.txt file will not suffice when it comes to rendering with available applications. This type of spacing that you mention really has to be implemented in a TrueType font with kerning pairs, which Unifont lacks.


Paul Hardy

Paul Hardy <unifoundry>
Group administrator
Tue 10 Oct 2017 11:55:50 PM UTC, original submission:  

Some Ahom vowel signs are doubled and used with other vowel signs, so in Unifont, they overlap themselves and each each other. The solution is to make certain combining marks be spacing. Based on the combinations listed in the Unicode proposal (http://www.unicode.org/L2/L2012/12309r-n4321r.pdf) I think the best set of marks to be spacing is:

  • U+11720 AHOM VOWEL SIGN A
  • U+11721 AHOM VOWEL SIGN AA
  • U+11722 AHOM VOWEL SIGN I
  • U+11723 AHOM VOWEL SIGN II
  • U+11727 AHOM VOWEL SIGN AW
  • U+11729 AHOM VOWEL SIGN AI


U+11726 AHOM VOWEL SIGN E should go on the left side of consonants.

To make room for U+11726, U+1171E AHOM CONSONANT SIGN MEDIAL RA should not reach all the way to the left edge.

To make room for U+11726 and U+1171E, the consonants should be shifted right. This is another reason for U+11720 and U+11721 to be made spacing.

U+1171D AHOM CONSONANT SIGN MEDIAL LA should be shifted right to follow the consonants.

The numbers and U+1173F AHOM SYMBOL VI should be centered.

U+1173C AHOM SIGN SMALL SECTION and U+1173D AHOM SIGN SECTION have too much blank space on the sides: they should be one cell wide.

011700:0000000000000000000000000888055406640444044404440444044400000000
011701:0000000000000000000000000800043004480484050406240418040000000000
011702:000000000000000000080008020801900160010001200110011000E000000000
011703:000000000000000000000000023002D003000210027003900210001000000000
011704:0000000000000000000000000710089008A808A808A808C408C4078200000000
011705:00000000000000000000000001C002200220022002280230023001D000000000
011706:000000000000000000000000022001100110011001100110012000C000000000
011707:00000000000000000000000008580464044404440444044404A4031800000000
011708:000000000000000000000000026001900110011001100110012000C000000000
011709:000000000000000000000000022001100110011001F00110012000C000000000
01170A:00000000000000000000000008480444044404440444044404A4031800000000
01170B:000000000000000000000000042802340224026402A403240224021800000000
01170C:0000000000000000000000000840075804E404440444044404A4031800000000
01170D:000000000000000000380044004C004C004003F80444044404E4031800000000
01170E:000000000000000000000000042C022C0224026402A403280230022000000000
01170F:000000000000000000000000040402040224026402A403280230022000000000
011710:00000000000000000010001008100420044804C4054406480450042000000000
011711:0000000000000000000000000200010001100130015001900110011000000000
011712:0000000000000000003000400888055406640444044404440444044400000000
011713:000000000000000000000000031801E801000100013001C80108000800680070
011714:0000000000000000000000000C00035804E404440444044404A403B800A00040
011715:00000000000000000000000003F80404080208020802080208C207CC00000000
011716:00000000000000000000000007DE0821101110111011101516120E6000000000
011717:000000000000000000000000181C04220442045A045A044C0380004008400780
011718:00000000000000000000000008580464044404440444044404A403B800A00040
011719:00000000000000000000000008480444044404440444044404A403B800A00040
01171D:00000000000000000000000000000000000000000000000000000001040E03F0
01171E:0FFE100120002000200020002000200020002000200020002000200010040FF8
01171F:0000000E00100010000800000000000000000000000000000000000000000000
011720:00000000000808100000100808100000
011721:0000000000006010101010101010100C
011722:00182424241800000000000000000000
011723:0018243C241800000000000000000000
011724:0000000000000000000000000000000000000000000000000000000800080007
011725:00000000000000000000000000000000000000000000000000000008000F0007
011726:000000002000400040004000400040004000C000C00040004000400000000000
011727:00070808083000000000000000000000
011728:0000000000000000000000000000000000000000000000000000000600090006
011729:00182424040830000000000000000000
01172A:0000000001800240018000000000000000000000000000000000000000000000
01172B:0000007800840080004000000000000000000000000000000000000000000000
011730:0000000000000000000000000000000000C00120022004400480030000000000
011731:00000000000000000008001000E0070000700808058804480848308600000000
011732:000000000000000000000000100008000860089009080A080C48083000000000
011733:00000000003000480030000008080408044804C8054806500460044000000000
011734:000000180024003C0024001808080408044804C8054806500460044000000000
011735:00000000000000000000000010600810089009900A900C90089008900010000C
011736:0000000003F80400080008000A300948098009000960089008100810042003C0
011737:000000000000000000000000030004B0044808C80928112810C8000800080004
011738:0000000000000000000000001800258C22524632494A894A8632000200020001
011739:000003E00410080808080988098808F0088008800888087008000408020801F0
01173A:0000000000000000000000003006100210621092111212221242118200000000
01173B:000000000000000C000800082028103011201320152019401180110000000000
01173C:00000000000018080808080808080000
01173D:00000000000066222222222222220000
01173E:000000000FF810042000200022002170208820882088208810500FE000000000
01173F:000000E0010E008800F00100430025002900310021C0012002200420021E0100

011726:-16

Remove from plane01-combining.txt:

011720
011721
011722
011723
011727
011729

The pre-base mark U+11726 should be special-cased in unibmp2hex.

David Corbett <dscorbett>

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by unifoundry (Posted a comment)
  • -email is unavailable- added by dscorbett (Submitted the item)
  •  

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

     

    Follow 2 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2018-08-11 unifoundry StatusNone Works For Me
        Open/ClosedOpen Closed

    Back to the top

    Powered by Savane 3.13-cf05.
    Corresponding source code