From 18a352f2ebb3c1bb7f6be02f9d8af700aab6ea80 Mon Sep 17 00:00:00 2001 From: r12a Date: Tue, 26 Sep 2017 12:50:43 +0100 Subject: [PATCH] Rewrite of "Vertical arrangements of characters" Additional changes along the lines of https://github.com/w3c/ilreq/issues/25 --- index.html | 81 +++++++++++++++++++++++++++++++----------------------- 1 file changed, 47 insertions(+), 34 deletions(-) diff --git a/index.html b/index.html index 1b039bb..bff4a06 100644 --- a/index.html +++ b/index.html @@ -97,11 +97,15 @@ }; + - +

This document describes the basic requirements for Indic script layout and text support on the Web and in Digital Publications. These requirements provide information for Web technologies such as CSS, HTML, and SVG about how to support users of Indic scripts. The current document focuses on Devanagari, but there are plans to widen the scope to encompass additional Indian scripts as time goes on.

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This document describes the basic requirements for Indic script layout and text support on the Web and in eBooks. These requirements provide information for Web technologies such as CSS, HTML and SVG about how to support users of Indic scripts. The current document focuses on Devanagari, but there are plans to widen the scope to encompass additional Indian scripts as time goes on.

The editor's draft of this document is being developed by the Indic Layout Task Force, part of the W3C Internationalization Interest Group. It is published by the Internationalization Working Group. The end target for this document is a Working Group Note.

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If you wish to make comments regarding this document, please raise them as github issues. Only send comments by email if you are unable to raise issues on github (see links below). All comments are welcome.

To make it easier to track comments, please raise separate issues or emails for each comment, and point to the section you are commenting on  using a URL for the dated version of the document.

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Canonical & Compatible Equivalence

shows the canonical equivalence:

Canonical equivalence in Hindi
Canonical Equivalence
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Unicode Code charts – Devanagari & Devanagari Extended

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Indic orthographic syllable boundaries

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Various example use cases of ABNF based Indic orthographic syllable definiti

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Typographic units

There are two syllables in this word: SA+VIRAMA+KA+UU and LA. Note, however, that there are three Unicode grapheme clusters here: SA+VIRAMA, KA+UU and LA.

Styling is done on the basis of the whole orthographic syllable, not the first character, nor even the first grapheme.

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Guiding principles of Line breaking for Indian languages

Rule 5: Breaking should not be allowed at numerical values such as currency values, year etc. e.g.

“100.00” or “10,000”, nor in “12:59”

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Alignment of Initial letter of Indic scripts with hanging baseline

The part from the hanging baseline and the ascent of the Initial letter may follow the following mechanism, where n = h/2:

Rule for hanging baseline
Rule of Indic script with hanging baseline
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In Indic scripts that have a hanging baseline, the top alignment point is the hanging baseline, and the bottom alignment point is the text-after-edge, and the hanging baselines of both the initial letter and first line of text should be aligned.

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Letter Spacing

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Vertical arrangements of characters

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In vertical arrangement of characters writing each character on a new line may not be suitable in Indian languages. The vertical arrangements of characters are sometimes used in Indian texts. In order to form correct arrangements, it is preferred to follow tailored grapheme cluster approach. - Variations of vertical arrangement of the characters in Hindi is represent below :

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Variations in vertical arrangements

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Example of Vertical arrangements in Hindi -
Variations in vertical arrangements
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The above example shows two variation of the word in order to differentiate the correct and wrong representation of the word. The segmentation of the vertical arrangements should follow the Indic syllabic definition.Given below the example 'स्वागतम्' that follows rule 2 and rule 3 of Indic orthographic syllable definition: - - +

Vertical arrangements of characters are sometimes used in Indian texts. Rather than writing each character on a new line, line-breaks should normally leave orthographic syllables intact.

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✔️❌ ✔️❌
व
क्ता		व
क्
ता		 श
क्ति		श
क्
ति
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Vertical alignment based on orthographic syllable boundaries.
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स्वा CHCv- Rule 2
गC - Rule 2
तC - Rule 2
म्CH - Rule 3
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Segmentation of vertically-set text using Indic syllable rules.
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Collation

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Collation

Collation is one of the most important features for Indic languages . It determines the order in which a given culture indexes its characters. This is best seen in a dictionary sorting order where for easy search words are sorted and arranged in a specific order. Within a given script, each allo-script may have a different sort-order. Thus in Hindi the conjunct glyph क्ष is sorted along with क , since the first letter of that conjunct is क and on a similar principle ज्ञ is sorted along with ज . The same is not the case with Marathi and Nepali which admit a different sort order.

Different scripts admit different sort orders and for all high end NLP applications. Sorting is @@ -1306,7 +1319,7 @@

Collation

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Contributors

Sanat Hansda Visva-Bharati University, Santiniketan, W.B - +

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