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DWRITE_SCRIPT_PROPERTIES structure (dwrite_1.h)

  • Article

The DWRITE_SCRIPT_PROPERTIES structure specifies script properties for caret navigation and justification.

Syntax

struct DWRITE_SCRIPT_PROPERTIES {
  UINT32 isoScriptCode;
  UINT32 isoScriptNumber;
  UINT32 clusterLookahead;
  UINT32 justificationCharacter;
  UINT32 restrictCaretToClusters : 1;
  UINT32 usesWordDividers : 1;
  UINT32 isDiscreteWriting : 1;
  UINT32 isBlockWriting : 1;
  UINT32 isDistributedWithinCluster : 1;
  UINT32 isConnectedWriting : 1;
  UINT32 isCursiveWriting : 1;
  UINT32 reserved : 25;
};

Members

isoScriptCode

The standardized four character code for the given script.

Note  These only include the general Unicode scripts, not any additional ISO 15924 scripts for bibliographic distinction.
 

isoScriptNumber

The standardized numeric code, ranging 0-999.

clusterLookahead

Number of characters to estimate look-ahead for complex scripts. Latin and all Kana are generally 1. Indic scripts are up to 15, and most others are 8.

Note  Combining marks and variation selectors can produce clusters that are longer than these look-aheads, so this estimate is considered typical language use. Diacritics must be tested explicitly separately.
 

justificationCharacter

Appropriate character to elongate the given script for justification. For example:

  • Arabic - U+0640 Tatweel
  • Ogham - U+1680 Ogham Space Mark

restrictCaretToClusters

Restrict the caret to whole clusters, like Thai and Devanagari. Scripts such as Arabic by default allow navigation between clusters. Others like Thai always navigate across whole clusters.

usesWordDividers

The language uses dividers between words, such as spaces between Latin or the Ethiopic wordspace. Examples include Latin, Greek, Devanagari, and Ethiopic. Chinese, Korean, and Thai are excluded.

isDiscreteWriting

The characters are discrete units from each other. This includes both block scripts and clustered scripts. Examples include Latin, Greek, Cyrillic, Hebrew, Chinese, and Thai.

isBlockWriting

The language is a block script, expanding between characters. Examples include Chinese, Japanese, Korean, and Bopomofo.

isDistributedWithinCluster

The language is justified within glyph clusters, not just between glyph clusters, such as the character sequence of Thai Lu and Sara Am (U+E026, U+E033), which form a single cluster but still expand between them. Examples include Thai, Lao, and Khmer.

isConnectedWriting

The script's clusters are connected to each other (such as the baseline-linked Devanagari), and no separation is added between characters.

Note  Cursively linked scripts like Arabic are also connected (but not all connected scripts are cursive).
 
Examples include Devanagari, Arabic, Syriac, Bengala, Gurmukhi, and Ogham. Latin, Chinese, and Thaana are excluded.

isCursiveWriting

The script is naturally cursive (Arabic and Syriac), meaning it uses other justification methods like kashida extension rather than inter-character spacing.

Note   Although other scripts like Latin and Japanese might actually support handwritten cursive forms, they are not considered cursive scripts.
 
Examples include Arabic, Syriac, and Mongolian. Thaana, Devanagari, Latin, and Chinese are excluded.

reserved

Reserved

Requirements

Requirement Value
Minimum supported client Windows 8 and Platform Update for Windows 7 [desktop apps only]
Minimum supported server Windows Server 2012 and Platform Update for Windows Server 2008 R2 [desktop apps only]
Header dwrite_1.h

See also

IDWriteTextAnalyzer1::GetScriptProperties