Complex Script Functionality: Difference between revisions

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===Tibetan Script Rendering Examples:===
===Tibetan Script Rendering Examples:===  
 
This relates to [http://bugs.scribus.net/view.php?id=4452 Bug 0004452: No support for Tibetan Script]


====1. Test of ccmp feature used for Decomposition (GSUB lookup type 2):====
====1. Test of ccmp feature used for Decomposition (GSUB lookup type 2):====

Revision as of 10:08, 29 July 2008

Things we require for testing Complex Script Functionality

  • Sample text files encoded in UTF8
  • Sample screenshots of Scribus 1.3.3. or 1.3.4cvs rendering these incorrectly.
  • Sample fonts that we can get that are freely available that have the ability to be used for DTP.
  • Sample screenshots of any application rendering the same text correctly

An important point to note is we need comparable information. Same texts, same fonts etc and screenshots (png or tiff please) of said texts and fonts. --Cbradney 18:40, 25 Feb 2005 (UTC)

  • Other usefull contribution would be mapping of the languages you're interested in with its script/lang pair in OpenType Font style.

example : French:latn:FRA

To help, you can have a look at http://www.microsoft.com/typography/developers/OpenType/scripttags.aspx for script tags and http://www.microsoft.com/typography/developers/OpenType/languagetags.aspx for lang tags. --Pmarchand 13:46, 8 April 2007 (CEST)

Please try to only list the best fonts for each script for use in printed publications. (Not screen/web fonts).

Arabic & Urdu

Font: Free fonts for Arabic / Urdu are available by Crulp and by PakType. Licensing is GPL at PakType and Crulp has also very loose license.

Bengali

Font:


Language, Script & Language System tags:

  • Assamese:beng:ASM
  • Bengali:beng:BEN

Open Type features used for Bengali script


Screenshots:


Please expand this section

Devanagari

The Devanagari script is used for writing many languages in India and Nepal including Sanskrit, Hindi and Nepali.

Fonts:

  • Chandas - Devanagari Unicode Open Type font with 4347 glyphs: 325 half-forms, 960 half-forms context-variations, 2743 ligature-signs. It is designed especially for Vedic and Classical Sanskrit but can also be used for Hindi, Nepali and other modern Indian languages. The font includes Vedic accents and many additional signs and so provides maximal support for Devanagari script. GPL License.

Language, Script & Language System tags:

  • Bhojpuri:deva:BHO
  • Hindi:deva:HIN
  • Marathi:deva:MAR
  • Nepali:deva:NEP
  • Sanskrit:deva:SAN

OpenType features used for Devanagari script

Screenshots:

Please expand this section

Gujarati

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Kannada

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Khmer

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Lao

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Malayalam

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Myanmar

Please expand this section

Font:


Language, Script & Language System tags:

  • Burmese:mymr:BRM

OpenType Features used for Myanmar script:



Screenshots:

Oriya

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Sinhala

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Tamil

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Telugu

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Thai

  • Please expand this section

Fonts:


Language, Script & Language System tags:


Screenshots:

Tibetan & Dzongkha

Fonts for Tibetan Script:

Jomolhari, a free Tibetan script font suitable for publishing is available from Jomolhari font - OFL License. The font was originaly designed for publishing traditional Buddhist texts in Classical Tibetan (chos skad) - but can also be used for modern Tibetan, Dzongkha and Ladakhi text. The font works well in OO.org 2.4.x & Inkscape.

Language Script & Language System tags:

  • Tibetan:tibt:TIB
  • Dzongkha:tibt:DZN
  • Ladakhi:tibt:LDK

OpenType Features

The following OpenType features should be processed to support Tibetan script:

  • ccmp - Glyph Composition / Decomposition (Composition = GSUB lookup type 4 & Decomposition = GSUB lookup type 2).
  • blws - Below-base Substitutions (GSUB lookup type 4)
  • abvs - Above-base Substitutions (GSUB lookup type 4)
  • calt - Contextual Alternates (GSUB lookup type 6)
  • blwm - Below-base Mark Positioning (GPOS lookup type 4,5)
  • abvm - Above-base Mark Positioning (GPOS lookup type 4,5)
  • kern - Kerning - (GPOS lookup type 2 or 8)

Note: The current version of the Jomolhari font uses only ccmp, blws, abvs, calt, and kern features. In kern only GPOS lookup type 2 (pair-adjustment) is used in this font ~ so this is the only kind of GPOS lookup used.


Tibetan Script Rendering Examples:

1. Test of ccmp feature used for Decomposition (GSUB lookup type 2):

The string U+0F43 U+0F77 (གྷཷ) should render: Tibetan-0F430F77-a.png

However, in Scribus, U+0F43 U+0F77 currently renders like this: Tibetan-0F430F77-b.png

In this case, the ccmp feature should decompose U+0F77 into seperate glyph components to go below and above the glyph for the base character (U+0F43)


2. Test of ccmp feature used for Composition (GSUB lookup type 4):

The string U+0F42 U+0FB7 U+0F0B U+0F4C U+0FB7 U+0F0B U+0F51 U+0FB7 U+0F0B U+0F56 U+0FB7 U+0F0B U+0F5B U+0FB7 U+0F0B U+0F40 U+0FB5 (གྷ་ཌྷ་དྷ་བྷ་ཛྷ་ཀྵ) should render as follows:

2a. Correct Rendering in MSWord 2003

However, in Scribus, that string currently renders like this:

2b.Rendering in Scribus

In this case if ccmp feature is being applied ligatures should be properly composed.

Furthermore, the strings U+0F42 U+0FB7 U+0F0B U+0F4C U+0FB7 U+0F0B U+0F51 U+0FB7 U+0F0B U+0F56 U+0FB7 U+0F0B U+0F5B U+0FB7 U+0F0B U+0F40 U+0FB5 (གྷ་ཌྷ་དྷ་བྷ་ཛྷ་ཀྵ) and U+0F43 U+0F0B U+0F4D U+0F0B U+0F52 U+0F0B U+0F57 U+0F0B U+0F5C U+0F0B U+0F69 (གྷ་ཌྷ་དྷ་བྷ་ཛྷ་ཀྵ) should render identically as they are canonically equivalent. (U+0F42 U+0FB7 = U+0F43; U+0F4C U+0FB7 = U+0F4D; U+0F51 U+0FB7 = U+0F52; U+0F5B U+0FB7 = U+0F5C; and U+0F40 U+0FB5 = U+0F69.)

3. Test of blws feature (GSUB lookup type 4)

3a. Correct Rendering in OO.org

Test string consists of the folowing Unicode characters:
U+0F62 U+0F0B U+0F62 U+0F90 U+0F0B U+0F62 U+0F90 U+0FB1 U+0F0B U+0F62 U+0F90 U+0FB1 U+0F74 U+0F62 U+0F92 U+0F0B U+0F62 U+0F92 U+0FB1 U+0F0B U+0F62 U+0F92 U+0FB1 U+0F74 U+0F0D (ར་རྐ་རྐྱ་རྐྱུརྒ་རྒྱ་རྒྱུ།) and U+0F66 U+0F0B U+0F66 U+0FA6 U+0F0B U+0F66 U+0FA6 U+0FB2 U+0F0B U+0F66 U+0FA6 U+0FB2 U+0F74 U+0F0B U+0F66 U+0FA8 U+0F0B U+0F66 U+0FA8 U+0FB2 U+0F0B U+0F66 U+0FA8 U+0FB2 U+0F74 U+0F0D (ས་སྦ་སྦྲ་སྦྲུ་སྨ་སྨྲ་སྨྲུ།)

3b. Rendering in Scribus

4. Test of abvs feature (GSUB lookup type 4)