U_CAPI void U_EXPORT2 ubidi_setPara (UBiDi *pBiDi, const UChar *text, UTextOffset length, UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels, UErrorCode *pErrorCode)

Perform the Unicode BiDi algorithm

Perform the Unicode BiDi algorithm. It is defined in the Unicode Technical Report 9, version 5, also described in The Unicode Standard, Version 3.0 .

This function takes a single plain text paragraph with or without externally specified embedding levels from styled text and computes the left-right-directionality of each character.

If the entire paragraph consists of text of only one direction, then the function may not perform all the steps described by the algorithm, i.e., some levels may not be the same as if all steps were performed. This is not relevant for unidirectional text.
For example, in pure LTR text with numbers the numbers would get a resolved level of 2 higher than the surrounding text according to the algorithm. This implementation may set all resolved levels to the same value in such a case.

The text must be externally split into separate paragraphs (rule P1). Paragraph separators (B) should appear at most at the very end.

Parameters:

pBiDi - A UBiDi object allocated with ubidi_open() which will be set to contain the reordering information, especially the resolved levels for all the characters in text.
text - is a pointer to the single-paragraph text that the BiDi algorithm will be performed on (step (P1) of the algorithm is performed externally). The text must be (at least) length long.
length - is the length of the text; if length==-1 then the text must be zero-terminated.
paraLevel - specifies the default level for the paragraph; it is typically 0 (LTR) or 1 (RTL). If the function shall determine the paragraph level from the text, then paraLevel can be set to either UBIDI_DEFAULT_LTR or UBIDI_DEFAULT_RTL; if there is no strongly typed character, then the desired default is used (0 for LTR or 1 for RTL). Any other value between 0 and UBIDI_MAX_EXPLICIT_LEVEL is also valid, with odd levels indicating RTL.
embeddingLevels - (in) may be used to preset the embedding and override levels, ignoring characters like LRE and PDF in the text. A level overrides the directional property of its corresponding (same index) character if the level has the UBIDI_LEVEL_OVERRIDE bit set.

Except for that bit, it must be paraLevel<=embeddingLevels[]<=UBIDI_MAX_EXPLICIT_LEVEL.

Caution: A copy of this pointer, not of the levels, will be stored in the UBiDi object; the embeddingLevels array must not be deallocated before the UBiDi structure is destroyed or reused, and the embeddingLevels should not be modified to avoid unexpected results on subsequent BiDi operations. However, the ubidi_setPara() and ubidi_setLine() functions may modify some or all of the levels.

After the UBiDi object is reused or destroyed, the caller must take care of the deallocation of the embeddingLevels array.

The embeddingLevels array must be at least length long.
pErrorCode - must be a valid pointer to an error code value, which must not indicate a failure before the function call.

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