| ... | ... | @@ -3,9 +3,10 @@ _How to lay out, shape, and render text in complex or mixed scripts._ |
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Table of Contents
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- [Overview](#overview)
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- [General Process](#general-process)
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* [Text in Standard Scripts](#text-in-standard-scripts)
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* [Text in Complex Scripts](#text-in-complex-scripts)
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- [APIs for Text Processing](#apis-for-text-processing)
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* [New APIs Conforming to Unicode 12.0](#new-apis-conforming-to-unicode-120)
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* [Processing Text in Standard Scripts](#processing-text-in-standard-scripts)
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* [Processing Text in Complex Scripts](#processing-text-in-complex-scripts)
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- [Internals](#internals)
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- [Restrictions](#restrictions)
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| ... | ... | @@ -78,9 +79,57 @@ The situation becomes more complicated when we process a text in |
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`mixed scripts`. That is, the text contains characters from different
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scripts, for example, Latin, Arabic, and Chinese.
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## General Process
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### Text in Standard Scripts
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## APIs for Text Processing
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### New APIs Conforming to Unicode 12.0
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- New types:
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1. `Uchar32`: the Unicode code point value of a Unicode character.
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1. `Achar32`: the abstract character index value under a certain
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charset/encoding. Under Unicode charset or encodings, the
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abstract character index value will be identical to the Unicode
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code point, i.e., Achar32 is equivalent to Uchar32 under this
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situation.
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1. `Glyph32`: the glyph index value in a device font. Note that
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a Glyph32 value is always bound to a specific logfont object.
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- New functions to determine the Unicode character properties:
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1. `UCharGetCategory` for getting the general category of
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a Unicode character.
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1. `UCharGetBreakType` for getting the breaking type of
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a Unicode character.
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1. `UStrGetBreaks` for getting the breaking types of
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a Unicode string.
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1. `UCharGetBidiType` for getting the bidi type of
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a Unicode character.
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1. `UStrGetBidiTypes` for getting the bidi types of a Unicode
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character string.
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1. `UCharGetBracketType` for getting the bracketed character of a
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Uchar32 character.
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1. `UStrGetBracketTypes` for getting the bracketed characters of a
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Uchar32 string.
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1. `UCharGetMirror` for getting the mirrored character of a Uchar32
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character.
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1. `UCharGetJoiningType` for getting the joining type of a Uchar32
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character.
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1. `UStrGetJoiningTypes` for getting the joining types of a Uchar32
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string.
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1. `UBidiGetParagraphDir` for getting the base paragraph direction
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of a single paragraph.
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1. `UBidiGetParagraphEmbeddingLevels` for getting the bidi embedding
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levels of a paragraph.
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1. `UBidiReorderLine`, `UBidiShapeMirroring`, `UBidiJoinArabic`,
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` UBidiShapeArabic`, and `UBidiShape` for doing bidi-aware
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mirroring, joining, and shaping.
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1. `UCharGetScriptType` for getting the script type of a Uchar32
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character.
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MiniGUI also provides some utilities/helpers for Unicode character
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conversion, such as from lower case to upper case, single width to
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full width. Please see MiniGUI API reference document for the detailed
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description.
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### Processing Text in Standard Scripts
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If you can determine the text to process is in standard scripts, you
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can still to use MiniGUI GDI functions (`TextOut`, `DrawText` and so on)
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| ... | ... | @@ -88,7 +137,7 @@ to show the text. For more information, please refer to: |
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<http://www.minigui.com/doc-api-ref-minigui-sa-4.0.0/html/group__text__output__fns.html>
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### Text in Complex Scripts
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### Processing Text in Complex Scripts
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Before dealing with the bidirectional algorithm and the glyph shaping,
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we first need to divide the text into paragraphs and get the relevant
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| ... | ... | @@ -218,9 +267,8 @@ please refer to: |
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Note that, the white space rule, character transformation rule, word breaking rule,
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line breaking policy, and layout flags used by the new APIs conform
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to the CSS Text Module Level 3 specification:
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<https://www.w3.org/TR/css-text-3/>
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to the specifications of [CSS Text Module Level 3]
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and [CSS Writing Modes Level 3].
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## Internals
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| ... | ... | @@ -268,3 +316,5 @@ flag is supported, and the basic shaping engine can not support scripts |
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which need to re-position the glyphs, such as Indic, Tibetan. For this
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purpose, you must use the complex shaping engine with OpenType fonts.
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[CSS Text Module Level 3]: https://www.w3.org/TR/css-text-3/
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[CSS Writing Modes Level 3]: https://www.w3.org/TR/css-writing-modes-3/ |
