SYNOPSIS

#include <fribidi.h>

void fribidi_join_arabic
(
       const FriBidiCharType *bidi_types,

       const FriBidiStrIndex len,

       const FriBidiLevel *embedding_levels,

       FriBidiArabicProp *ar_props

);

PARAMETERS

const FriBidiCharType *bidi_types

Input list of bidi types as returned by fribidi_get_bidi_types().

Possible values for a const FriBidiCharType are as follows:

FRIBIDI_TYPE_LTR

Left-To-Right letter.

FRIBIDI_TYPE_RTL

Right-To-Left letter.

FRIBIDI_TYPE_AL

Arabic Letter.

FRIBIDI_TYPE_EN

European Numeral.

FRIBIDI_TYPE_AN

Arabic Numeral.

FRIBIDI_TYPE_ES

European number Separator.

FRIBIDI_TYPE_ET

European number Terminator.

FRIBIDI_TYPE_CS

Common Separator.

FRIBIDI_TYPE_NSM

Non Spacing Mark.

FRIBIDI_TYPE_BN

Boundary Neutral.

FRIBIDI_TYPE_BS

Block Separator.

FRIBIDI_TYPE_SS

Segment Separator.

FRIBIDI_TYPE_WS

WhiteSpace.

FRIBIDI_TYPE_ON

Other Neutral.

FRIBIDI_TYPE_LRE

Left-to-Right Embedding.

FRIBIDI_TYPE_RLE

Right-to-Left Embedding.

FRIBIDI_TYPE_LRO

Left-to-Right Override.

FRIBIDI_TYPE_RLO

Right-to-Left Override.

FRIBIDI_TYPE_PDF

Pop Directional Flag.

const FriBidiStrIndex len

Input string length.

const FriBidiLevel *embedding_levels

Input list of embedding levels, as returned by fribidi_get_par_embedding_levels.

FriBidiArabicProp *ar_props

Arabic properties to analyze, initilized by joining types, as returned by fribidi_get_joining_types.

DESCRIPTION

This function does the Arabic joining algorithm. Means, given Arabic joining types of the characters in ar_props (don't worry, FriBidiJoiningType can be casted to FriBidiArabicProp automagically), this function modifies this properties to grasp the effect of neighboring characters. You probably need this information later to do Arabic shaping.

This function implements rules R1 to R7 inclusive (all rules) of the Arabic Cursive Joining algorithm of the Unicode standard as available at http://www.unicode.org/versions/Unicode4.0.0/ch08.pdf#G7462. It also interacts correctly with the bidirection algorithm as defined in Section
3.5 Shaping of the Unicode Bidirectional Algorithm available at http://www.unicode.org/reports/tr9/#Shaping.

There are a few macros defined in fribidi-joining-types.h for querying the Arabic properties computed by this function.