+ * + * Note: Libraries that perform a bidirectional algorithm and + * reorder strings accordingly are sometimes called "Storage Layout Engines". + * ICU's Bidi and shaping (u_shapeArabic()) APIs can be used at the core of such + * "Storage Layout Engines". + * + *
pErrorCode pointer must be valid
+ * and the value that it points to must not indicate a failure before
+ * the function call. Otherwise, the function returns immediately.
+ * After the function call, the value indicates success or failure.+ * + * The "limit" of a sequence of characters is the position just after their + * last character, i.e., one more than that position.
+ * + * Some of the API functions provide access to "runs". + * Such a "run" is defined as a sequence of characters + * that are at the same embedding level + * after performing the Bidi algorithm.
+ * + * @author Markus W. Scherer + * @version 1.0 + * + * + *
The basic assumptions are:
+ *
+ * \code
+ *#include "unicode/ubidi.h"
+ *
+ *typedef enum {
+ * styleNormal=0, styleSelected=1,
+ * styleBold=2, styleItalics=4,
+ * styleSuper=8, styleSub=16
+ *} Style;
+ *
+ *typedef struct { int32_t limit; Style style; } StyleRun;
+ *
+ *int getTextWidth(const UChar *text, int32_t start, int32_t limit,
+ * const StyleRun *styleRuns, int styleRunCount);
+ *
+ * // set *pLimit and *pStyleRunLimit for a line
+ * // from text[start] and from styleRuns[styleRunStart]
+ * // using ubidi_getLogicalRun(para, ...)
+ *void getLineBreak(const UChar *text, int32_t start, int32_t *pLimit,
+ * UBiDi *para,
+ * const StyleRun *styleRuns, int styleRunStart, int *pStyleRunLimit,
+ * int *pLineWidth);
+ *
+ * // render runs on a line sequentially, always from left to right
+ *
+ * // prepare rendering a new line
+ * void startLine(UBiDiDirection textDirection, int lineWidth);
+ *
+ * // render a run of text and advance to the right by the run width
+ * // the text[start..limit-1] is always in logical order
+ * void renderRun(const UChar *text, int32_t start, int32_t limit,
+ * UBiDiDirection textDirection, Style style);
+ *
+ * // We could compute a cross-product
+ * // from the style runs with the directional runs
+ * // and then reorder it.
+ * // Instead, here we iterate over each run type
+ * // and render the intersections -
+ * // with shortcuts in simple (and common) cases.
+ * // renderParagraph() is the main function.
+ *
+ * // render a directional run with
+ * // (possibly) multiple style runs intersecting with it
+ * void renderDirectionalRun(const UChar *text,
+ * int32_t start, int32_t limit,
+ * UBiDiDirection direction,
+ * const StyleRun *styleRuns, int styleRunCount) {
+ * int i;
+ *
+ * // iterate over style runs
+ * if(direction==UBIDI_LTR) {
+ * int styleLimit;
+ *
+ * for(i=0; ilimit) { styleLimit=limit; }
+ * renderRun(text, start, styleLimit,
+ * direction, styleRun[i].style);
+ * if(styleLimit==limit) { break; }
+ * start=styleLimit;
+ * }
+ * }
+ * } else {
+ * int styleStart;
+ *
+ * for(i=styleRunCount-1; i>=0; --i) {
+ * if(i>0) {
+ * styleStart=styleRun[i-1].limit;
+ * } else {
+ * styleStart=0;
+ * }
+ * if(limit>=styleStart) {
+ * if(styleStart=length
+ *
+ * width=getTextWidth(text, 0, length, styleRuns, styleRunCount);
+ * if(width<=lineWidth) {
+ * // everything fits onto one line
+ *
+ * // prepare rendering a new line from either left or right
+ * startLine(paraLevel, width);
+ *
+ * renderLine(para, text, 0, length,
+ * styleRuns, styleRunCount);
+ * } else {
+ * UBiDi *line;
+ *
+ * // we need to render several lines
+ * line=ubidi_openSized(length, 0, pErrorCode);
+ * if(line!=NULL) {
+ * int32_t start=0, limit;
+ * int styleRunStart=0, styleRunLimit;
+ *
+ * for(;;) {
+ * limit=length;
+ * styleRunLimit=styleRunCount;
+ * getLineBreak(text, start, &limit, para,
+ * styleRuns, styleRunStart, &styleRunLimit,
+ * &width);
+ * ubidi_setLine(para, start, limit, line, pErrorCode);
+ * if(U_SUCCESS(*pErrorCode)) {
+ * // prepare rendering a new line
+ * // from either left or right
+ * startLine(paraLevel, width);
+ *
+ * renderLine(line, text, start, limit,
+ * styleRuns+styleRunStart,
+ * styleRunLimit-styleRunStart);
+ * }
+ * if(limit==length) { break; }
+ * start=limit;
+ * styleRunStart=styleRunLimit-1;
+ * if(start>=styleRuns[styleRunStart].limit) {
+ * ++styleRunStart;
+ * }
+ * }
+ *
+ * ubidi_close(line);
+ * }
+ * }
+ * }
+ *
+ * ubidi_close(para);
+ *}
+ *\endcode
+ *
+ */
+
+/*DOCXX_TAG*/
+/*@{*/
+
+/**
+ * UBiDiLevel is the type of the level values in this
+ * Bidi implementation.
+ * It holds an embedding level and indicates the visual direction
+ * by its bit 0 (even/odd value).
+ *
+ * It can also hold non-level values for the
+ * paraLevel and embeddingLevels
+ * arguments of ubidi_setPara(); there:
+ *
embeddingLevels[]
+ * value indicates whether the using application is
+ * specifying the level of a character to override whatever the
+ * Bidi implementation would resolve it to.paraLevel can be set to the
+ * pseudo-level values UBIDI_DEFAULT_LTR
+ * and UBIDI_DEFAULT_RTL.The related constants are not real, valid level values.
+ * UBIDI_DEFAULT_XXX can be used to specify
+ * a default for the paragraph level for
+ * when the ubidi_setPara() function
+ * shall determine it but there is no
+ * strongly typed character in the input.
+ *
+ * Note that the value for UBIDI_DEFAULT_LTR is even
+ * and the one for UBIDI_DEFAULT_RTL is odd,
+ * just like with normal LTR and RTL level values -
+ * these special values are designed that way. Also, the implementation
+ * assumes that UBIDI_MAX_EXPLICIT_LEVEL is odd.
+ *
+ * @see UBIDI_DEFAULT_LTR
+ * @see UBIDI_DEFAULT_RTL
+ * @see UBIDI_LEVEL_OVERRIDE
+ * @see UBIDI_MAX_EXPLICIT_LEVEL
+ * @stable ICU 2.0
+ */
+typedef uint8_t UBiDiLevel;
+
+/** Paragraph level setting.
+ * + * Constant indicating that the base direction depends on the first strong + * directional character in the text according to the Unicode Bidirectional + * Algorithm. If no strong directional character is present, + * then set the paragraph level to 0 (left-to-right).
+ *
+ * If this value is used in conjunction with reordering modes
+ * UBIDI_REORDER_INVERSE_LIKE_DIRECT or
+ * UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, the text to reorder
+ * is assumed to be visual LTR, and the text after reordering is required
+ * to be the corresponding logical string with appropriate contextual
+ * direction. The direction of the result string will be RTL if either
+ * the righmost or leftmost strong character of the source text is RTL
+ * or Arabic Letter, the direction will be LTR otherwise.
+ *
+ * If reordering option UBIDI_OPTION_INSERT_MARKS is set, an RLM may
+ * be added at the beginning of the result string to ensure round trip
+ * (that the result string, when reordered back to visual, will produce
+ * the original source text).
+ * @see UBIDI_REORDER_INVERSE_LIKE_DIRECT
+ * @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL
+ * @stable ICU 2.0
+ */
+#define UBIDI_DEFAULT_LTR 0xfe
+
+/** Paragraph level setting.
+ * + * Constant indicating that the base direction depends on the first strong + * directional character in the text according to the Unicode Bidirectional + * Algorithm. If no strong directional character is present, + * then set the paragraph level to 1 (right-to-left).
+ *
+ * If this value is used in conjunction with reordering modes
+ * UBIDI_REORDER_INVERSE_LIKE_DIRECT or
+ * UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, the text to reorder
+ * is assumed to be visual LTR, and the text after reordering is required
+ * to be the corresponding logical string with appropriate contextual
+ * direction. The direction of the result string will be RTL if either
+ * the righmost or leftmost strong character of the source text is RTL
+ * or Arabic Letter, or if the text contains no strong character;
+ * the direction will be LTR otherwise.
+ *
+ * If reordering option UBIDI_OPTION_INSERT_MARKS is set, an RLM may
+ * be added at the beginning of the result string to ensure round trip
+ * (that the result string, when reordered back to visual, will produce
+ * the original source text).
+ * @see UBIDI_REORDER_INVERSE_LIKE_DIRECT
+ * @see UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL
+ * @stable ICU 2.0
+ */
+#define UBIDI_DEFAULT_RTL 0xff
+
+/**
+ * Maximum explicit embedding level.
+ * (The maximum resolved level can be up to UBIDI_MAX_EXPLICIT_LEVEL+1).
+ * @stable ICU 2.0
+ */
+#define UBIDI_MAX_EXPLICIT_LEVEL 125
+
+/** Bit flag for level input.
+ * Overrides directional properties.
+ * @stable ICU 2.0
+ */
+#define UBIDI_LEVEL_OVERRIDE 0x80
+
+/**
+ * Special value which can be returned by the mapping functions when a logical
+ * index has no corresponding visual index or vice-versa. This may happen
+ * for the logical-to-visual mapping of a Bidi control when option
+ * #UBIDI_OPTION_REMOVE_CONTROLS is specified. This can also happen
+ * for the visual-to-logical mapping of a Bidi mark (LRM or RLM) inserted
+ * by option #UBIDI_OPTION_INSERT_MARKS.
+ * @see ubidi_getVisualIndex
+ * @see ubidi_getVisualMap
+ * @see ubidi_getLogicalIndex
+ * @see ubidi_getLogicalMap
+ * @stable ICU 3.6
+ */
+#define UBIDI_MAP_NOWHERE (-1)
+
+/**
+ * UBiDiDirection values indicate the text direction.
+ * @stable ICU 2.0
+ */
+enum UBiDiDirection {
+ /** Left-to-right text. This is a 0 value.
+ *
ubidi_getDirection(), it means
+ * that the source string contains no right-to-left characters, or
+ * that the source string is empty and the paragraph level is even.
+ * ubidi_getBaseDirection(), it
+ * means that the first strong character of the source string has
+ * a left-to-right direction.
+ * ubidi_getDirection(), it means
+ * that the source string contains no left-to-right characters, or
+ * that the source string is empty and the paragraph level is odd.
+ * ubidi_getBaseDirection(), it
+ * means that the first strong character of the source string has
+ * a right-to-left direction.
+ * As return value for ubidi_getDirection(), it means
+ * that the source string contains both left-to-right and
+ * right-to-left characters.
+ * @stable ICU 2.0
+ */
+ UBIDI_MIXED,
+ /** No strongly directional text.
+ *
As return value for ubidi_getBaseDirection(), it means
+ * that the source string is missing or empty, or contains neither left-to-right
+ * nor right-to-left characters.
+ * @stable ICU 4.6
+ */
+ UBIDI_NEUTRAL
+};
+
+/** @stable ICU 2.0 */
+typedef enum UBiDiDirection UBiDiDirection;
+
+/**
+ * Forward declaration of the UBiDi structure for the declaration of
+ * the API functions. Its fields are implementation-specific.
+ * This structure holds information about a paragraph (or multiple paragraphs) + * of text with Bidi-algorithm-related details, or about one line of + * such a paragraph.
+ * Reordering can be done on a line, or on one or more paragraphs which are
+ * then interpreted each as one single line.
+ * @stable ICU 2.0
+ */
+struct UBiDi;
+
+/** @stable ICU 2.0 */
+typedef struct UBiDi UBiDi;
+
+/**
+ * Allocate a UBiDi structure.
+ * Such an object is initially empty. It is assigned
+ * the Bidi properties of a piece of text containing one or more paragraphs
+ * by ubidi_setPara()
+ * or the Bidi properties of a line within a paragraph by
+ * ubidi_setLine().
+ * This object can be reused for as long as it is not deallocated
+ * by calling ubidi_close().
+ * ubidi_setPara() and ubidi_setLine() will allocate
+ * additional memory for internal structures as necessary.
+ *
+ * @return An empty UBiDi object.
+ * @stable ICU 2.0
+ */
+U_STABLE UBiDi * U_EXPORT2
+ubidi_open(void);
+
+/**
+ * Allocate a UBiDi structure with preallocated memory
+ * for internal structures.
+ * This function provides a UBiDi object like ubidi_open()
+ * with no arguments, but it also preallocates memory for internal structures
+ * according to the sizings supplied by the caller.
+ * Subsequent functions will not allocate any more memory, and are thus + * guaranteed not to fail because of lack of memory.
+ * The preallocation can be limited to some of the internal memory
+ * by setting some values to 0 here. That means that if, e.g.,
+ * maxRunCount cannot be reasonably predetermined and should not
+ * be set to maxLength (the only failproof value) to avoid
+ * wasting memory, then maxRunCount could be set to 0 here
+ * and the internal structures that are associated with it will be allocated
+ * on demand, just like with ubidi_open().
+ *
+ * @param maxLength is the maximum text or line length that internal memory
+ * will be preallocated for. An attempt to associate this object with a
+ * longer text will fail, unless this value is 0, which leaves the allocation
+ * up to the implementation.
+ *
+ * @param maxRunCount is the maximum anticipated number of same-level runs
+ * that internal memory will be preallocated for. An attempt to access
+ * visual runs on an object that was not preallocated for as many runs
+ * as the text was actually resolved to will fail,
+ * unless this value is 0, which leaves the allocation up to the implementation.
+ * The number of runs depends on the actual text and maybe anywhere between
+ * 1 and maxLength. It is typically small.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return An empty UBiDi object with preallocated memory.
+ * @stable ICU 2.0
+ */
+U_STABLE UBiDi * U_EXPORT2
+ubidi_openSized(int32_t maxLength, int32_t maxRunCount, UErrorCode *pErrorCode);
+
+/**
+ * ubidi_close() must be called to free the memory
+ * associated with a UBiDi object.
+ *
+ * Important:
+ * A parent UBiDi object must not be destroyed or reused if
+ * it still has children.
+ * If a UBiDi object has become the child
+ * of another one (its parent) by calling
+ * ubidi_setLine(), then the child object must
+ * be destroyed (closed) or reused (by calling
+ * ubidi_setPara() or ubidi_setLine())
+ * before the parent object.
+ *
+ * @param pBiDi is a UBiDi object.
+ *
+ * @see ubidi_setPara
+ * @see ubidi_setLine
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_close(UBiDi *pBiDi);
+
+#if U_SHOW_CPLUSPLUS_API
+
+U_NAMESPACE_BEGIN
+
+/**
+ * \class LocalUBiDiPointer
+ * "Smart pointer" class, closes a UBiDi via ubidi_close().
+ * For most methods see the LocalPointerBase base class.
+ *
+ * @see LocalPointerBase
+ * @see LocalPointer
+ * @stable ICU 4.4
+ */
+U_DEFINE_LOCAL_OPEN_POINTER(LocalUBiDiPointer, UBiDi, ubidi_close);
+
+U_NAMESPACE_END
+
+#endif
+
+/**
+ * Modify the operation of the Bidi algorithm such that it
+ * approximates an "inverse Bidi" algorithm. This function
+ * must be called before ubidi_setPara().
+ *
+ *
The normal operation of the Bidi algorithm as described + * in the Unicode Technical Report is to take text stored in logical + * (keyboard, typing) order and to determine the reordering of it for visual + * rendering. + * Some legacy systems store text in visual order, and for operations + * with standard, Unicode-based algorithms, the text needs to be transformed + * to logical order. This is effectively the inverse algorithm of the + * described Bidi algorithm. Note that there is no standard algorithm for + * this "inverse Bidi" and that the current implementation provides only an + * approximation of "inverse Bidi".
+ * + *With isInverse set to TRUE,
+ * this function changes the behavior of some of the subsequent functions
+ * in a way that they can be used for the inverse Bidi algorithm.
+ * Specifically, runs of text with numeric characters will be treated in a
+ * special way and may need to be surrounded with LRM characters when they are
+ * written in reordered sequence.
Output runs should be retrieved using ubidi_getVisualRun().
+ * Since the actual input for "inverse Bidi" is visually ordered text and
+ * ubidi_getVisualRun() gets the reordered runs, these are actually
+ * the runs of the logically ordered output.
Calling this function with argument isInverse set to
+ * TRUE is equivalent to calling
+ * ubidi_setReorderingMode with argument
+ * reorderingMode
+ * set to #UBIDI_REORDER_INVERSE_NUMBERS_AS_L.
+ * Calling this function with argument isInverse set to
+ * FALSE is equivalent to calling
+ * ubidi_setReorderingMode with argument
+ * reorderingMode
+ * set to #UBIDI_REORDER_DEFAULT.
+ *
+ * @param pBiDi is a UBiDi object.
+ *
+ * @param isInverse specifies "forward" or "inverse" Bidi operation.
+ *
+ * @see ubidi_setPara
+ * @see ubidi_writeReordered
+ * @see ubidi_setReorderingMode
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_setInverse(UBiDi *pBiDi, UBool isInverse);
+
+/**
+ * Is this Bidi object set to perform the inverse Bidi algorithm?
+ *
Note: calling this function after setting the reordering mode with
+ * ubidi_setReorderingMode will return TRUE if the
+ * reordering mode was set to #UBIDI_REORDER_INVERSE_NUMBERS_AS_L,
+ * FALSE for all other values.
UBiDi object.
+ * @return TRUE if the Bidi object is set to perform the inverse Bidi algorithm
+ * by handling numbers as L.
+ *
+ * @see ubidi_setInverse
+ * @see ubidi_setReorderingMode
+ * @stable ICU 2.0
+ */
+
+U_STABLE UBool U_EXPORT2
+ubidi_isInverse(UBiDi *pBiDi);
+
+/**
+ * Specify whether block separators must be allocated level zero,
+ * so that successive paragraphs will progress from left to right.
+ * This function must be called before ubidi_setPara().
+ * Paragraph separators (B) may appear in the text. Setting them to level zero
+ * means that all paragraph separators (including one possibly appearing
+ * in the last text position) are kept in the reordered text after the text
+ * that they follow in the source text.
+ * When this feature is not enabled, a paragraph separator at the last
+ * position of the text before reordering will go to the first position
+ * of the reordered text when the paragraph level is odd.
+ *
+ * @param pBiDi is a UBiDi object.
+ *
+ * @param orderParagraphsLTR specifies whether paragraph separators (B) must
+ * receive level 0, so that successive paragraphs progress from left to right.
+ *
+ * @see ubidi_setPara
+ * @stable ICU 3.4
+ */
+U_STABLE void U_EXPORT2
+ubidi_orderParagraphsLTR(UBiDi *pBiDi, UBool orderParagraphsLTR);
+
+/**
+ * Is this Bidi object set to allocate level 0 to block separators so that
+ * successive paragraphs progress from left to right?
+ *
+ * @param pBiDi is a UBiDi object.
+ * @return TRUE if the Bidi object is set to allocate level 0 to block
+ * separators.
+ *
+ * @see ubidi_orderParagraphsLTR
+ * @stable ICU 3.4
+ */
+U_STABLE UBool U_EXPORT2
+ubidi_isOrderParagraphsLTR(UBiDi *pBiDi);
+
+/**
+ * UBiDiReorderingMode values indicate which variant of the Bidi
+ * algorithm to use.
+ *
+ * @see ubidi_setReorderingMode
+ * @stable ICU 3.6
+ */
+typedef enum UBiDiReorderingMode {
+ /** Regular Logical to Visual Bidi algorithm according to Unicode.
+ * This is a 0 value.
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_DEFAULT = 0,
+ /** Logical to Visual algorithm which handles numbers in a way which
+ * mimicks the behavior of Windows XP.
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_NUMBERS_SPECIAL,
+ /** Logical to Visual algorithm grouping numbers with adjacent R characters
+ * (reversible algorithm).
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_GROUP_NUMBERS_WITH_R,
+ /** Reorder runs only to transform a Logical LTR string to the Logical RTL
+ * string with the same display, or vice-versa.#UBIDI_OPTION_INSERT_MARKS, some Bidi controls in the source
+ * text may be removed and other controls may be added to produce the
+ * minimum combination which has the required display.
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_RUNS_ONLY,
+ /** Visual to Logical algorithm which handles numbers like L
+ * (same algorithm as selected by ubidi_setInverse(TRUE).
+ * @see ubidi_setInverse
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_INVERSE_NUMBERS_AS_L,
+ /** Visual to Logical algorithm equivalent to the regular Logical to Visual
+ * algorithm.
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_INVERSE_LIKE_DIRECT,
+ /** Inverse Bidi (Visual to Logical) algorithm for the
+ * UBIDI_REORDER_NUMBERS_SPECIAL Bidi algorithm.
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL,
+ /** Number of values for reordering mode.
+ * @stable ICU 3.6 */
+ UBIDI_REORDER_COUNT
+} UBiDiReorderingMode;
+
+/**
+ * Modify the operation of the Bidi algorithm such that it implements some
+ * variant to the basic Bidi algorithm or approximates an "inverse Bidi"
+ * algorithm, depending on different values of the "reordering mode".
+ * This function must be called before ubidi_setPara(), and stays
+ * in effect until called again with a different argument.
+ *
+ * The normal operation of the Bidi algorithm as described + * in the Unicode Standard Annex #9 is to take text stored in logical + * (keyboard, typing) order and to determine how to reorder it for visual + * rendering.
+ * + *With the reordering mode set to a value other than
+ * #UBIDI_REORDER_DEFAULT, this function changes the behavior of
+ * some of the subsequent functions in a way such that they implement an
+ * inverse Bidi algorithm or some other algorithm variants.
Some legacy systems store text in visual order, and for operations + * with standard, Unicode-based algorithms, the text needs to be transformed + * into logical order. This is effectively the inverse algorithm of the + * described Bidi algorithm. Note that there is no standard algorithm for + * this "inverse Bidi", so a number of variants are implemented here.
+ * + *In other cases, it may be desirable to emulate some variant of the + * Logical to Visual algorithm (e.g. one used in MS Windows), or perform a + * Logical to Logical transformation.
+ * + *#UBIDI_REORDER_DEFAULT,
+ * the standard Bidi Logical to Visual algorithm is applied.#UBIDI_REORDER_NUMBERS_SPECIAL,
+ * the algorithm used to perform Bidi transformations when calling
+ * ubidi_setPara should approximate the algorithm used in
+ * Microsoft Windows XP rather than strictly conform to the Unicode Bidi
+ * algorithm.
+ * #UBIDI_REORDER_GROUP_NUMBERS_WITH_R,
+ * numbers located between LTR text and RTL text are associated with the RTL
+ * text. For instance, an LTR paragraph with content "abc 123 DEF" (where
+ * upper case letters represent RTL characters) will be transformed to
+ * "abc FED 123" (and not "abc 123 FED"), "DEF 123 abc" will be transformed
+ * to "123 FED abc" and "123 FED abc" will be transformed to "DEF 123 abc".
+ * This makes the algorithm reversible and makes it useful when round trip
+ * (from visual to logical and back to visual) must be achieved without
+ * adding LRM characters. However, this is a variation from the standard
+ * Unicode Bidi algorithm.#UBIDI_REORDER_RUNS_ONLY,
+ * a "Logical to Logical" transformation must be performed:
+ * paraLevel
+ * in ubidi_setPara) is even, the source text will be handled as
+ * LTR logical text and will be transformed to the RTL logical text which has
+ * the same LTR visual display.#UBIDI_REORDER_INVERSE_NUMBERS_AS_L, an "inverse Bidi" algorithm
+ * is applied.
+ * Runs of text with numeric characters will be treated like LTR letters and
+ * may need to be surrounded with LRM characters when they are written in
+ * reordered sequence (the option #UBIDI_INSERT_LRM_FOR_NUMERIC can
+ * be used with function ubidi_writeReordered to this end. This
+ * mode is equivalent to calling ubidi_setInverse() with
+ * argument isInverse set to TRUE.#UBIDI_REORDER_INVERSE_LIKE_DIRECT, the "direct" Logical to Visual
+ * Bidi algorithm is used as an approximation of an "inverse Bidi" algorithm.
+ * This mode is similar to mode #UBIDI_REORDER_INVERSE_NUMBERS_AS_L
+ * but is closer to the regular Bidi algorithm.
+ * UBIDI_REORDER_INVERSE_NUMBERS_AS_L.#UBIDI_OPTION_INSERT_MARKS, this mode generally
+ * adds Bidi marks to the output significantly more sparingly than mode
+ * #UBIDI_REORDER_INVERSE_NUMBERS_AS_L with option
+ * #UBIDI_INSERT_LRM_FOR_NUMERIC in calls to
+ * ubidi_writeReordered.#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL, the Logical to Visual
+ * Bidi algorithm used in Windows XP is used as an approximation of an "inverse Bidi" algorithm.
+ * In all the reordering modes specifying an "inverse Bidi" algorithm
+ * (i.e. those with a name starting with UBIDI_REORDER_INVERSE),
+ * output runs should be retrieved using
+ * ubidi_getVisualRun(), and the output text with
+ * ubidi_writeReordered(). The caller should keep in mind that in
+ * "inverse Bidi" modes the input is actually visually ordered text and
+ * reordered output returned by ubidi_getVisualRun() or
+ * ubidi_writeReordered() are actually runs or character string
+ * of logically ordered output.
+ * For all the "inverse Bidi" modes, the source text should not contain
+ * Bidi control characters other than LRM or RLM.
Note that option #UBIDI_OUTPUT_REVERSE of
+ * ubidi_writeReordered has no useful meaning and should not be
+ * used in conjunction with any value of the reordering mode specifying
+ * "inverse Bidi" or with value UBIDI_REORDER_RUNS_ONLY.
+ *
+ * @param pBiDi is a UBiDi object.
+ * @param reorderingMode specifies the required variant of the Bidi algorithm.
+ *
+ * @see UBiDiReorderingMode
+ * @see ubidi_setInverse
+ * @see ubidi_setPara
+ * @see ubidi_writeReordered
+ * @stable ICU 3.6
+ */
+U_STABLE void U_EXPORT2
+ubidi_setReorderingMode(UBiDi *pBiDi, UBiDiReorderingMode reorderingMode);
+
+/**
+ * What is the requested reordering mode for a given Bidi object?
+ *
+ * @param pBiDi is a UBiDi object.
+ * @return the current reordering mode of the Bidi object
+ * @see ubidi_setReorderingMode
+ * @stable ICU 3.6
+ */
+U_STABLE UBiDiReorderingMode U_EXPORT2
+ubidi_getReorderingMode(UBiDi *pBiDi);
+
+/**
+ * UBiDiReorderingOption values indicate which options are
+ * specified to affect the Bidi algorithm.
+ *
+ * @see ubidi_setReorderingOptions
+ * @stable ICU 3.6
+ */
+typedef enum UBiDiReorderingOption {
+ /**
+ * option value for ubidi_setReorderingOptions:
+ * disable all the options which can be set with this function
+ * @see ubidi_setReorderingOptions
+ * @stable ICU 3.6
+ */
+ UBIDI_OPTION_DEFAULT = 0,
+
+ /**
+ * option bit for ubidi_setReorderingOptions:
+ * insert Bidi marks (LRM or RLM) when needed to ensure correct result of
+ * a reordering to a Logical order
+ *
+ *
This option must be set or reset before calling
+ * ubidi_setPara.
This option is significant only with reordering modes which generate + * a result with Logical order, specifically:
+ *#UBIDI_REORDER_RUNS_ONLY#UBIDI_REORDER_INVERSE_NUMBERS_AS_L#UBIDI_REORDER_INVERSE_LIKE_DIRECT#UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIALIf this option is set in conjunction with reordering mode
+ * #UBIDI_REORDER_INVERSE_NUMBERS_AS_L or with calling
+ * ubidi_setInverse(TRUE), it implies
+ * option #UBIDI_INSERT_LRM_FOR_NUMERIC
+ * in calls to function ubidi_writeReordered().
For other reordering modes, a minimum number of LRM or RLM characters
+ * will be added to the source text after reordering it so as to ensure
+ * round trip, i.e. when applying the inverse reordering mode on the
+ * resulting logical text with removal of Bidi marks
+ * (option #UBIDI_OPTION_REMOVE_CONTROLS set before calling
+ * ubidi_setPara() or option #UBIDI_REMOVE_BIDI_CONTROLS
+ * in ubidi_writeReordered), the result will be identical to the
+ * source text in the first transformation.
+ *
+ *
This option will be ignored if specified together with option
+ * #UBIDI_OPTION_REMOVE_CONTROLS. It inhibits option
+ * UBIDI_REMOVE_BIDI_CONTROLS in calls to function
+ * ubidi_writeReordered() and it implies option
+ * #UBIDI_INSERT_LRM_FOR_NUMERIC in calls to function
+ * ubidi_writeReordered() if the reordering mode is
+ * #UBIDI_REORDER_INVERSE_NUMBERS_AS_L.
ubidi_setReorderingOptions:
+ * remove Bidi control characters
+ *
+ * This option must be set or reset before calling
+ * ubidi_setPara.
This option nullifies option #UBIDI_OPTION_INSERT_MARKS.
+ * It inhibits option #UBIDI_INSERT_LRM_FOR_NUMERIC in calls
+ * to function ubidi_writeReordered() and it implies option
+ * #UBIDI_REMOVE_BIDI_CONTROLS in calls to that function.
ubidi_setReorderingOptions:
+ * process the output as part of a stream to be continued
+ *
+ * This option must be set or reset before calling
+ * ubidi_setPara.
This option specifies that the caller is interested in processing large + * text object in parts. + * The results of the successive calls are expected to be concatenated by the + * caller. Only the call for the last part will have this option bit off.
+ * + *When this option bit is on, ubidi_setPara() may process
+ * less than the full source text in order to truncate the text at a meaningful
+ * boundary. The caller should call ubidi_getProcessedLength()
+ * immediately after calling ubidi_setPara() in order to
+ * determine how much of the source text has been processed.
+ * Source text beyond that length should be resubmitted in following calls to
+ * ubidi_setPara. The processed length may be less than
+ * the length of the source text if a character preceding the last character of
+ * the source text constitutes a reasonable boundary (like a block separator)
+ * for text to be continued.
+ * If the last character of the source text constitutes a reasonable
+ * boundary, the whole text will be processed at once.
+ * If nowhere in the source text there exists
+ * such a reasonable boundary, the processed length will be zero.
+ * The caller should check for such an occurrence and do one of the following:
+ *
UBIDI_OPTION_STREAMING.When the UBIDI_OPTION_STREAMING option is used,
+ * it is recommended to call ubidi_orderParagraphsLTR() with
+ * argument orderParagraphsLTR set to TRUE before
+ * calling ubidi_setPara so that later paragraphs may be
+ * concatenated to previous paragraphs on the right.
UBiDi object.
+ * @param reorderingOptions is a combination of zero or more of the following
+ * options:
+ * #UBIDI_OPTION_DEFAULT, #UBIDI_OPTION_INSERT_MARKS,
+ * #UBIDI_OPTION_REMOVE_CONTROLS, #UBIDI_OPTION_STREAMING.
+ *
+ * @see ubidi_getReorderingOptions
+ * @stable ICU 3.6
+ */
+U_STABLE void U_EXPORT2
+ubidi_setReorderingOptions(UBiDi *pBiDi, uint32_t reorderingOptions);
+
+/**
+ * What are the reordering options applied to a given Bidi object?
+ *
+ * @param pBiDi is a UBiDi object.
+ * @return the current reordering options of the Bidi object
+ * @see ubidi_setReorderingOptions
+ * @stable ICU 3.6
+ */
+U_STABLE uint32_t U_EXPORT2
+ubidi_getReorderingOptions(UBiDi *pBiDi);
+
+/**
+ * Set the context before a call to ubidi_setPara().+ * + * ubidi_setPara() computes the left-right directionality for a given piece + * of text which is supplied as one of its arguments. Sometimes this piece + * of text (the "main text") should be considered in context, because text + * appearing before ("prologue") and/or after ("epilogue") the main text + * may affect the result of this computation.
+ * + * This function specifies the prologue and/or the epilogue for the next + * call to ubidi_setPara(). The characters specified as prologue and + * epilogue should not be modified by the calling program until the call + * to ubidi_setPara() has returned. If successive calls to ubidi_setPara() + * all need specification of a context, ubidi_setContext() must be called + * before each call to ubidi_setPara(). In other words, a context is not + * "remembered" after the following successful call to ubidi_setPara().
+ * + * If a call to ubidi_setPara() specifies UBIDI_DEFAULT_LTR or + * UBIDI_DEFAULT_RTL as paraLevel and is preceded by a call to + * ubidi_setContext() which specifies a prologue, the paragraph level will + * be computed taking in consideration the text in the prologue.
+ * + * When ubidi_setPara() is called without a previous call to + * ubidi_setContext, the main text is handled as if preceded and followed + * by strong directional characters at the current paragraph level. + * Calling ubidi_setContext() with specification of a prologue will change + * this behavior by handling the main text as if preceded by the last + * strong character appearing in the prologue, if any. + * Calling ubidi_setContext() with specification of an epilogue will change + * the behavior of ubidi_setPara() by handling the main text as if followed + * by the first strong character or digit appearing in the epilogue, if any.
+ *
+ * Note 1: if ubidi_setContext is called repeatedly without
+ * calling ubidi_setPara, the earlier calls have no effect,
+ * only the last call will be remembered for the next call to
+ * ubidi_setPara.
+ *
+ * Note 2: calling ubidi_setContext(pBiDi, NULL, 0, NULL, 0, &errorCode)
+ * cancels any previous setting of non-empty prologue or epilogue.
+ * The next call to ubidi_setPara() will process no
+ * prologue or epilogue.
+ *
+ * Note 3: users must be aware that even after setting the context
+ * before a call to ubidi_setPara() to perform e.g. a logical to visual
+ * transformation, the resulting string may not be identical to what it
+ * would have been if all the text, including prologue and epilogue, had
+ * been processed together.
+ * Example (upper case letters represent RTL characters):
+ * prologue = "abc DE"
+ * epilogue = none
+ * main text = "FGH xyz"
+ * paraLevel = UBIDI_LTR
+ * display without prologue = "HGF xyz"
+ * ("HGF" is adjacent to "xyz")
+ * display with prologue = "abc HGFED xyz"
+ * ("HGF" is not adjacent to "xyz")
+ *
+ * @param pBiDi is a paragraph UBiDi object.
+ *
+ * @param prologue is a pointer to the text which precedes the text that
+ * will be specified in a coming call to ubidi_setPara().
+ * If there is no prologue to consider, then proLength
+ * must be zero and this pointer can be NULL.
+ *
+ * @param proLength is the length of the prologue; if proLength==-1
+ * then the prologue must be zero-terminated.
+ * Otherwise proLength must be >= 0. If proLength==0, it means
+ * that there is no prologue to consider.
+ *
+ * @param epilogue is a pointer to the text which follows the text that
+ * will be specified in a coming call to ubidi_setPara().
+ * If there is no epilogue to consider, then epiLength
+ * must be zero and this pointer can be NULL.
+ *
+ * @param epiLength is the length of the epilogue; if epiLength==-1
+ * then the epilogue must be zero-terminated.
+ * Otherwise epiLength must be >= 0. If epiLength==0, it means
+ * that there is no epilogue to consider.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @see ubidi_setPara
+ * @stable ICU 4.8
+ */
+U_STABLE void U_EXPORT2
+ubidi_setContext(UBiDi *pBiDi,
+ const UChar *prologue, int32_t proLength,
+ const UChar *epilogue, int32_t epiLength,
+ UErrorCode *pErrorCode);
+
+/**
+ * Perform the Unicode Bidi algorithm. It is defined in the
+ * Unicode Standard Anned #9,
+ * version 13,
+ * also described in The Unicode Standard, Version 4.0 .
+ * + * This function takes a piece of plain text containing one or more paragraphs, + * with or without externally specified embedding levels from styled + * text and computes the left-right-directionality of each character.
+ *
+ * If the entire text is all of the same directionality, 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 can be composed of multiple paragraphs. Occurrence of a block
+ * separator in the text terminates a paragraph, and whatever comes next starts
+ * a new paragraph. The exception to this rule is when a Carriage Return (CR)
+ * is followed by a Line Feed (LF). Both CR and LF are block separators, but
+ * in that case, the pair of characters is considered as terminating the
+ * preceding paragraph, and a new paragraph will be started by a character
+ * coming after the LF.
+ *
+ * @param 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.
+ *
+ * @param text is a pointer to the text that the Bidi algorithm will be performed on.
+ * This pointer is stored in the UBiDi object and can be retrieved
+ * with ubidi_getText().
+ * Note: the text must be (at least) length long.
+ *
+ * @param length is the length of the text; if length==-1 then
+ * the text must be zero-terminated.
+ *
+ * @param paraLevel specifies the default level for the text;
+ * 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 the text contains multiple
+ * paragraphs, the paragraph level shall be determined separately for
+ * each paragraph; if a paragraph does not include any 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.
+ *
+ * @param 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,
+ * with one exception: a level of zero may be specified for a paragraph
+ * separator even if paraLevel>0 when multiple paragraphs
+ * are submitted in the same call to ubidi_setPara().
+ * 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.
+ * Note: the embeddingLevels array must be
+ * at least length long.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_setPara(UBiDi *pBiDi, const UChar *text, int32_t length,
+ UBiDiLevel paraLevel, UBiDiLevel *embeddingLevels,
+ UErrorCode *pErrorCode);
+
+/**
+ * ubidi_setLine() sets a UBiDi to
+ * contain the reordering information, especially the resolved levels,
+ * for all the characters in a line of text. This line of text is
+ * specified by referring to a UBiDi object representing
+ * this information for a piece of text containing one or more paragraphs,
+ * and by specifying a range of indexes in this text.
+ * In the new line object, the indexes will range from 0 to limit-start-1.
+ *
+ * This is used after calling ubidi_setPara()
+ * for a piece of text, and after line-breaking on that text.
+ * It is not necessary if each paragraph is treated as a single line.
+ *
+ * After line-breaking, rules (L1) and (L2) for the treatment of
+ * trailing WS and for reordering are performed on
+ * a UBiDi object that represents a line.
+ *
+ * Important: pLineBiDi shares data with
+ * pParaBiDi.
+ * You must destroy or reuse pLineBiDi before pParaBiDi.
+ * In other words, you must destroy or reuse the UBiDi object for a line
+ * before the object for its parent paragraph.
+ *
+ * The text pointer that was stored in
+ *
+ * @param pBiDi is the paragraph or line
+ *
+ * @param pBiDi is the paragraph
+ *
+ * Note that this function may allocate memory under some
+ * circumstances, unlike
+ * This is especially useful for line-breaking on a paragraph.
+ *
+ * @param pBiDi is the paragraph or line
+ *
+ * Use of
+ *
+ * The value returned may be
+ * When the visual output is altered by using options of
+ *
+ * Note that in right-to-left runs, this mapping places
+ * second surrogates before first ones (which is generally a bad idea)
+ * and combining characters before base characters.
+ * Use of
+ *
+ * The value returned may be
+ * This is the inverse function to
+ * When the visual output is altered by using options of
+ *
+ * Some values in the map may be
+ * When the visual output is altered by using options of
+ *
+ * Note that in right-to-left runs, this mapping places
+ * second surrogates before first ones (which is generally a bad idea)
+ * and combining characters before base characters.
+ * Use of
+ * Some values in the map may be
+ * When the visual output is altered by using options of
+ *
+ * The index map will result in
+ * The index map will result in This option does not imply corresponding adjustment of the index
+ * mappings. This option does not imply corresponding adjustment of the index
+ * mappings. This has the same effect as calling Usually, the function pointer will be propagated to a If a This may be useful for assigning Bidi classes to PUA characters, or
+ * for special application needs. For instance, an application may want to
+ * handle all spaces like L or R characters (according to the base direction)
+ * when creating the visual ordering of logical lines which are part of a report
+ * organized in columns: there should not be interaction between adjacent
+ * cells.
+ *
+ * @param pBiDi is the paragraph pParaBiDi is also copied,
+ * and start is added to it so that it points to the beginning of the
+ * line for this object.
+ *
+ * @param pParaBiDi is the parent paragraph object. It must have been set
+ * by a successful call to ubidi_setPara.
+ *
+ * @param start is the line's first index into the text.
+ *
+ * @param limit is just behind the line's last index into the text
+ * (its last index +1).
+ * It must be 0<=startUBiDi object.
+ *
+ * @return a value of UBIDI_LTR, UBIDI_RTL
+ * or UBIDI_MIXED
+ * that indicates if the entire text
+ * represented by this object is unidirectional,
+ * and which direction, or if it is mixed-directional.
+ * Note - The value UBIDI_NEUTRAL is never returned from this method.
+ *
+ * @see UBiDiDirection
+ * @stable ICU 2.0
+ */
+U_STABLE UBiDiDirection U_EXPORT2
+ubidi_getDirection(const UBiDi *pBiDi);
+
+/**
+ * Gets the base direction of the text provided according
+ * to the Unicode Bidirectional Algorithm. The base direction
+ * is derived from the first character in the string with bidirectional
+ * character type L, R, or AL. If the first such character has type L,
+ * UBIDI_LTR is returned. If the first such character has
+ * type R or AL, UBIDI_RTL is returned. If the string does
+ * not contain any character of these types, then
+ * UBIDI_NEUTRAL is returned.
+ *
+ * This is a lightweight function for use when only the base direction
+ * is needed and no further bidi processing of the text is needed.
+ *
+ * @param text is a pointer to the text whose base
+ * direction is needed.
+ * Note: the text must be (at least) @c length long.
+ *
+ * @param length is the length of the text;
+ * if length==-1 then the text
+ * must be zero-terminated.
+ *
+ * @return UBIDI_LTR, UBIDI_RTL,
+ * UBIDI_NEUTRAL
+ *
+ * @see UBiDiDirection
+ * @stable ICU 4.6
+ */
+U_STABLE UBiDiDirection U_EXPORT2
+ubidi_getBaseDirection(const UChar *text, int32_t length );
+
+/**
+ * Get the pointer to the text.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @return The pointer to the text that the UBiDi object was created for.
+ *
+ * @see ubidi_setPara
+ * @see ubidi_setLine
+ * @stable ICU 2.0
+ */
+U_STABLE const UChar * U_EXPORT2
+ubidi_getText(const UBiDi *pBiDi);
+
+/**
+ * Get the length of the text.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @return The length of the text that the UBiDi object was created for.
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_getLength(const UBiDi *pBiDi);
+
+/**
+ * Get the paragraph level of the text.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @return The paragraph level. If there are multiple paragraphs, their
+ * level may vary if the required paraLevel is UBIDI_DEFAULT_LTR or
+ * UBIDI_DEFAULT_RTL. In that case, the level of the first paragraph
+ * is returned.
+ *
+ * @see UBiDiLevel
+ * @see ubidi_getParagraph
+ * @see ubidi_getParagraphByIndex
+ * @stable ICU 2.0
+ */
+U_STABLE UBiDiLevel U_EXPORT2
+ubidi_getParaLevel(const UBiDi *pBiDi);
+
+/**
+ * Get the number of paragraphs.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @return The number of paragraphs.
+ * @stable ICU 3.4
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_countParagraphs(UBiDi *pBiDi);
+
+/**
+ * Get a paragraph, given a position within the text.
+ * This function returns information about a paragraph.
+ * Note: if the paragraph index is known, it is more efficient to
+ * retrieve the paragraph information using ubidi_getParagraphByIndex().UBiDi object.
+ *
+ * @param charIndex is the index of a character within the text, in the
+ * range [0..ubidi_getProcessedLength(pBiDi)-1].
+ *
+ * @param pParaStart will receive the index of the first character of the
+ * paragraph in the text.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pParaLimit will receive the limit of the paragraph.
+ * The l-value that you point to here may be the
+ * same expression (variable) as the one for
+ * charIndex.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pParaLevel will receive the level of the paragraph.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The index of the paragraph containing the specified position.
+ *
+ * @see ubidi_getProcessedLength
+ * @stable ICU 3.4
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_getParagraph(const UBiDi *pBiDi, int32_t charIndex, int32_t *pParaStart,
+ int32_t *pParaLimit, UBiDiLevel *pParaLevel,
+ UErrorCode *pErrorCode);
+
+/**
+ * Get a paragraph, given the index of this paragraph.
+ *
+ * This function returns information about a paragraph.UBiDi object.
+ *
+ * @param paraIndex is the number of the paragraph, in the
+ * range [0..ubidi_countParagraphs(pBiDi)-1].
+ *
+ * @param pParaStart will receive the index of the first character of the
+ * paragraph in the text.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pParaLimit will receive the limit of the paragraph.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pParaLevel will receive the level of the paragraph.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @stable ICU 3.4
+ */
+U_STABLE void U_EXPORT2
+ubidi_getParagraphByIndex(const UBiDi *pBiDi, int32_t paraIndex,
+ int32_t *pParaStart, int32_t *pParaLimit,
+ UBiDiLevel *pParaLevel, UErrorCode *pErrorCode);
+
+/**
+ * Get the level for one character.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param charIndex the index of a character. It must be in the range
+ * [0..ubidi_getProcessedLength(pBiDi)].
+ *
+ * @return The level for the character at charIndex (0 if charIndex is not
+ * in the valid range).
+ *
+ * @see UBiDiLevel
+ * @see ubidi_getProcessedLength
+ * @stable ICU 2.0
+ */
+U_STABLE UBiDiLevel U_EXPORT2
+ubidi_getLevelAt(const UBiDi *pBiDi, int32_t charIndex);
+
+/**
+ * Get an array of levels for each character.ubidi_getLevelAt().
+ *
+ * @param pBiDi is the paragraph or line UBiDi object, whose
+ * text length must be strictly positive.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The levels array for the text,
+ * or NULL if an error occurs.
+ *
+ * @see UBiDiLevel
+ * @see ubidi_getProcessedLength
+ * @stable ICU 2.0
+ */
+U_STABLE const UBiDiLevel * U_EXPORT2
+ubidi_getLevels(UBiDi *pBiDi, UErrorCode *pErrorCode);
+
+/**
+ * Get a logical run.
+ * This function returns information about a run and is used
+ * to retrieve runs in logical order.UBiDi object.
+ *
+ * @param logicalPosition is a logical position within the source text.
+ *
+ * @param pLogicalLimit will receive the limit of the corresponding run.
+ * The l-value that you point to here may be the
+ * same expression (variable) as the one for
+ * logicalPosition.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @param pLevel will receive the level of the corresponding run.
+ * This pointer can be NULL if this
+ * value is not necessary.
+ *
+ * @see ubidi_getProcessedLength
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_getLogicalRun(const UBiDi *pBiDi, int32_t logicalPosition,
+ int32_t *pLogicalLimit, UBiDiLevel *pLevel);
+
+/**
+ * Get the number of runs.
+ * This function may invoke the actual reordering on the
+ * UBiDi object, after ubidi_setPara()
+ * may have resolved only the levels of the text. Therefore,
+ * ubidi_countRuns() may have to allocate memory,
+ * and may fail doing so.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The number of runs.
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_countRuns(UBiDi *pBiDi, UErrorCode *pErrorCode);
+
+/**
+ * Get one run's logical start, length, and directionality,
+ * which can be 0 for LTR or 1 for RTL.
+ * In an RTL run, the character at the logical start is
+ * visually on the right of the displayed run.
+ * The length is the number of characters in the run.ubidi_countRuns() should be called
+ * before the runs are retrieved.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param runIndex is the number of the run in visual order, in the
+ * range [0..ubidi_countRuns(pBiDi)-1].
+ *
+ * @param pLogicalStart is the first logical character index in the text.
+ * The pointer may be NULL if this index is not needed.
+ *
+ * @param pLength is the number of characters (at least one) in the run.
+ * The pointer may be NULL if this is not needed.
+ *
+ * @return the directionality of the run,
+ * UBIDI_LTR==0 or UBIDI_RTL==1,
+ * never UBIDI_MIXED,
+ * never UBIDI_NEUTRAL.
+ *
+ * @see ubidi_countRuns
+ *
+ * Example:
+ *
+ * \code
+ * int32_t i, count=ubidi_countRuns(pBiDi),
+ * logicalStart, visualIndex=0, length;
+ * for(i=0; i
+ *
+ * Note that in right-to-left runs, code like this places
+ * second surrogates before first ones (which is generally a bad idea)
+ * and combining characters before base characters.
+ * ubidi_writeReordered(), optionally with the
+ * #UBIDI_KEEP_BASE_COMBINING option, can be considered in order
+ * to avoid these issues.
+ * @stable ICU 2.0
+ */
+U_STABLE UBiDiDirection U_EXPORT2
+ubidi_getVisualRun(UBiDi *pBiDi, int32_t runIndex,
+ int32_t *pLogicalStart, int32_t *pLength);
+
+/**
+ * Get the visual position from a logical text position.
+ * If such a mapping is used many times on the same
+ * UBiDi object, then calling
+ * ubidi_getLogicalMap() is more efficient.#UBIDI_MAP_NOWHERE if there is no
+ * visual position because the corresponding text character is a Bidi control
+ * removed from output by the option #UBIDI_OPTION_REMOVE_CONTROLS.
+ * ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
+ * UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
+ * UBIDI_REMOVE_BIDI_CONTROLS, the visual position returned may not
+ * be correct. It is advised to use, when possible, reordering options
+ * such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
+ * ubidi_writeReordered(), optionally with the
+ * #UBIDI_KEEP_BASE_COMBINING option can be considered instead
+ * of using the mapping, in order to avoid these issues.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param logicalIndex is the index of a character in the text.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The visual position of this character.
+ *
+ * @see ubidi_getLogicalMap
+ * @see ubidi_getLogicalIndex
+ * @see ubidi_getProcessedLength
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_getVisualIndex(UBiDi *pBiDi, int32_t logicalIndex, UErrorCode *pErrorCode);
+
+/**
+ * Get the logical text position from a visual position.
+ * If such a mapping is used many times on the same
+ * UBiDi object, then calling
+ * ubidi_getVisualMap() is more efficient.#UBIDI_MAP_NOWHERE if there is no
+ * logical position because the corresponding text character is a Bidi mark
+ * inserted in the output by option #UBIDI_OPTION_INSERT_MARKS.
+ * ubidi_getVisualIndex().
+ * ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
+ * UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
+ * UBIDI_REMOVE_BIDI_CONTROLS, the logical position returned may not
+ * be correct. It is advised to use, when possible, reordering options
+ * such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param visualIndex is the visual position of a character.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The index of this character in the text.
+ *
+ * @see ubidi_getVisualMap
+ * @see ubidi_getVisualIndex
+ * @see ubidi_getResultLength
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_getLogicalIndex(UBiDi *pBiDi, int32_t visualIndex, UErrorCode *pErrorCode);
+
+/**
+ * Get a logical-to-visual index map (array) for the characters in the UBiDi
+ * (paragraph or line) object.
+ * #UBIDI_MAP_NOWHERE if the
+ * corresponding text characters are Bidi controls removed from the visual
+ * output by the option #UBIDI_OPTION_REMOVE_CONTROLS.
+ * ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
+ * UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
+ * UBIDI_REMOVE_BIDI_CONTROLS, the visual positions returned may not
+ * be correct. It is advised to use, when possible, reordering options
+ * such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
+ * ubidi_writeReordered(), optionally with the
+ * #UBIDI_KEEP_BASE_COMBINING option can be considered instead
+ * of using the mapping, in order to avoid these issues.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param indexMap is a pointer to an array of ubidi_getProcessedLength()
+ * indexes which will reflect the reordering of the characters.
+ * If option #UBIDI_OPTION_INSERT_MARKS is set, the number
+ * of elements allocated in indexMap must be no less than
+ * ubidi_getResultLength().
+ * The array does not need to be initialized.
+ * The index map will result in indexMap[logicalIndex]==visualIndex.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @see ubidi_getVisualMap
+ * @see ubidi_getVisualIndex
+ * @see ubidi_getProcessedLength
+ * @see ubidi_getResultLength
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_getLogicalMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
+
+/**
+ * Get a visual-to-logical index map (array) for the characters in the UBiDi
+ * (paragraph or line) object.
+ * #UBIDI_MAP_NOWHERE if the
+ * corresponding text characters are Bidi marks inserted in the visual output
+ * by the option #UBIDI_OPTION_INSERT_MARKS.
+ * ubidi_writeReordered() such as UBIDI_INSERT_LRM_FOR_NUMERIC,
+ * UBIDI_KEEP_BASE_COMBINING, UBIDI_OUTPUT_REVERSE,
+ * UBIDI_REMOVE_BIDI_CONTROLS, the logical positions returned may not
+ * be correct. It is advised to use, when possible, reordering options
+ * such as UBIDI_OPTION_INSERT_MARKS and UBIDI_OPTION_REMOVE_CONTROLS.
+ *
+ * @param pBiDi is the paragraph or line UBiDi object.
+ *
+ * @param indexMap is a pointer to an array of ubidi_getResultLength()
+ * indexes which will reflect the reordering of the characters.
+ * If option #UBIDI_OPTION_REMOVE_CONTROLS is set, the number
+ * of elements allocated in indexMap must be no less than
+ * ubidi_getProcessedLength().
+ * The array does not need to be initialized.
+ * The index map will result in indexMap[visualIndex]==logicalIndex.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @see ubidi_getLogicalMap
+ * @see ubidi_getLogicalIndex
+ * @see ubidi_getProcessedLength
+ * @see ubidi_getResultLength
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_getVisualMap(UBiDi *pBiDi, int32_t *indexMap, UErrorCode *pErrorCode);
+
+/**
+ * This is a convenience function that does not use a UBiDi object.
+ * It is intended to be used for when an application has determined the levels
+ * of objects (character sequences) and just needs to have them reordered (L2).
+ * This is equivalent to using ubidi_getLogicalMap() on a
+ * UBiDi object.
+ *
+ * @param levels is an array with length levels that have been determined by
+ * the application.
+ *
+ * @param length is the number of levels in the array, or, semantically,
+ * the number of objects to be reordered.
+ * It must be length>0.
+ *
+ * @param indexMap is a pointer to an array of length
+ * indexes which will reflect the reordering of the characters.
+ * The array does not need to be initialized.indexMap[logicalIndex]==visualIndex.
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_reorderLogical(const UBiDiLevel *levels, int32_t length, int32_t *indexMap);
+
+/**
+ * This is a convenience function that does not use a UBiDi object.
+ * It is intended to be used for when an application has determined the levels
+ * of objects (character sequences) and just needs to have them reordered (L2).
+ * This is equivalent to using ubidi_getVisualMap() on a
+ * UBiDi object.
+ *
+ * @param levels is an array with length levels that have been determined by
+ * the application.
+ *
+ * @param length is the number of levels in the array, or, semantically,
+ * the number of objects to be reordered.
+ * It must be length>0.
+ *
+ * @param indexMap is a pointer to an array of length
+ * indexes which will reflect the reordering of the characters.
+ * The array does not need to be initialized.indexMap[visualIndex]==logicalIndex.
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_reorderVisual(const UBiDiLevel *levels, int32_t length, int32_t *indexMap);
+
+/**
+ * Invert an index map.
+ * The index mapping of the first map is inverted and written to
+ * the second one.
+ *
+ * @param srcMap is an array with length elements
+ * which defines the original mapping from a source array containing
+ * length elements to a destination array.
+ * Some elements of the source array may have no mapping in the
+ * destination array. In that case, their value will be
+ * the special value UBIDI_MAP_NOWHERE.
+ * All elements must be >=0 or equal to UBIDI_MAP_NOWHERE.
+ * Some elements may have a value >= length, if the
+ * destination array has more elements than the source array.
+ * There must be no duplicate indexes (two or more elements with the
+ * same value except UBIDI_MAP_NOWHERE).
+ *
+ * @param destMap is an array with a number of elements equal to 1 + the highest
+ * value in srcMap.
+ * destMap will be filled with the inverse mapping.
+ * If element with index i in srcMap has a value k different
+ * from UBIDI_MAP_NOWHERE, this means that element i of
+ * the source array maps to element k in the destination array.
+ * The inverse map will have value i in its k-th element.
+ * For all elements of the destination array which do not map to
+ * an element in the source array, the corresponding element in the
+ * inverse map will have a value equal to UBIDI_MAP_NOWHERE.
+ *
+ * @param length is the length of each array.
+ * @see UBIDI_MAP_NOWHERE
+ * @stable ICU 2.0
+ */
+U_STABLE void U_EXPORT2
+ubidi_invertMap(const int32_t *srcMap, int32_t *destMap, int32_t length);
+
+/** option flags for ubidi_writeReordered() */
+
+/**
+ * option bit for ubidi_writeReordered():
+ * keep combining characters after their base characters in RTL runs
+ *
+ * @see ubidi_writeReordered
+ * @stable ICU 2.0
+ */
+#define UBIDI_KEEP_BASE_COMBINING 1
+
+/**
+ * option bit for ubidi_writeReordered():
+ * replace characters with the "mirrored" property in RTL runs
+ * by their mirror-image mappings
+ *
+ * @see ubidi_writeReordered
+ * @stable ICU 2.0
+ */
+#define UBIDI_DO_MIRRORING 2
+
+/**
+ * option bit for ubidi_writeReordered():
+ * surround the run with LRMs if necessary;
+ * this is part of the approximate "inverse Bidi" algorithm
+ *
+ * ubidi_writeReordered()
+ * first without this option, and then calling
+ * ubidi_writeReverse() without mirroring.
+ * Doing this in the same step is faster and avoids a temporary buffer.
+ * An example for using this option is output to a character terminal that
+ * is designed for RTL scripts and stores text in reverse order.ubidi_setPara(). This length may be different from the length
+ * of the source text if option #UBIDI_OPTION_STREAMING
+ * has been set.
+ *
+ * Note that whenever the length of the text affects the execution or the
+ * result of a function, it is the processed length which must be considered,
+ * except for ubidi_setPara (which receives unprocessed source
+ * text) and ubidi_getLength (which returns the original length
+ * of the source text).
+ * In particular, the processed length is the one to consider in the following
+ * cases:
+ *
+ *
+ *
+ * @param pBiDi is the paragraph limit argument of
+ * ubidi_setLinecharIndex argument of
+ * ubidi_getParagraphcharIndex argument of
+ * ubidi_getLevelAtubidi_getLevelslogicalStart argument of
+ * ubidi_getLogicalRunlogicalIndex argument of
+ * ubidi_getVisualIndex*indexMap argument of
+ * ubidi_getLogicalMapubidi_writeReorderedUBiDi object.
+ *
+ * @return The length of the part of the source text processed by
+ * the last call to ubidi_setPara.
+ * @see ubidi_setPara
+ * @see UBIDI_OPTION_STREAMING
+ * @stable ICU 3.6
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_getProcessedLength(const UBiDi *pBiDi);
+
+/**
+ * Get the length of the reordered text resulting from the last call to
+ * ubidi_setPara(). This length may be different from the length
+ * of the source text if option #UBIDI_OPTION_INSERT_MARKS
+ * or option #UBIDI_OPTION_REMOVE_CONTROLS has been set.
+ *
+ * This resulting length is the one to consider in the following cases:
+ *
+ *
+ * Note that this length stays identical to the source text length if
+ * Bidi marks are inserted or removed using option bits of
+ * visualIndex argument of
+ * ubidi_getLogicalIndex*indexMap argument of
+ * ubidi_getVisualMapubidi_writeReordered, or if option
+ * #UBIDI_REORDER_INVERSE_NUMBERS_AS_L has been set.
+ *
+ * @param pBiDi is the paragraph UBiDi object.
+ *
+ * @return The length of the reordered text resulting from
+ * the last call to ubidi_setPara.
+ * @see ubidi_setPara
+ * @see UBIDI_OPTION_INSERT_MARKS
+ * @see UBIDI_OPTION_REMOVE_CONTROLS
+ * @stable ICU 3.6
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_getResultLength(const UBiDi *pBiDi);
+
+U_CDECL_BEGIN
+/**
+ * value returned by UBiDiClassCallback callbacks when
+ * there is no need to override the standard Bidi class for a given code point.
+ * @see UBiDiClassCallback
+ * @stable ICU 3.6
+ */
+#define U_BIDI_CLASS_DEFAULT U_CHAR_DIRECTION_COUNT
+
+/**
+ * Callback type declaration for overriding default Bidi class values with
+ * custom ones.
+ * UBiDi
+ * object by calling the ubidi_setClassCallback() function;
+ * then the callback will be invoked by the UBA implementation any time the
+ * class of a character is to be determined.c if the default class has been overridden, or
+ * #U_BIDI_CLASS_DEFAULT if the standard Bidi class value
+ * for c is to be used.
+ * @see ubidi_setClassCallback
+ * @see ubidi_getClassCallback
+ * @stable ICU 3.6
+ */
+typedef UCharDirection U_CALLCONV
+UBiDiClassCallback(const void *context, UChar32 c);
+
+U_CDECL_END
+
+/**
+ * Retrieve the Bidi class for a given code point.
+ * #UBiDiClassCallback callback is defined and returns a
+ * value other than #U_BIDI_CLASS_DEFAULT, that value is used;
+ * otherwise the default class determination mechanism is invoked.UBiDi object.
+ *
+ * @param c is the code point whose Bidi class must be retrieved.
+ *
+ * @return The Bidi class for character c based
+ * on the given pBiDi instance.
+ * @see UBiDiClassCallback
+ * @stable ICU 3.6
+ */
+U_STABLE UCharDirection U_EXPORT2
+ubidi_getCustomizedClass(UBiDi *pBiDi, UChar32 c);
+
+/**
+ * Set the callback function and callback data used by the UBA
+ * implementation for Bidi class determination.
+ * UBiDi object.
+ *
+ * @param newFn is the new callback function pointer.
+ *
+ * @param newContext is the new callback context pointer. This can be NULL.
+ *
+ * @param oldFn fillin: Returns the old callback function pointer. This can be
+ * NULL.
+ *
+ * @param oldContext fillin: Returns the old callback's context. This can be
+ * NULL.
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @see ubidi_getClassCallback
+ * @stable ICU 3.6
+ */
+U_STABLE void U_EXPORT2
+ubidi_setClassCallback(UBiDi *pBiDi, UBiDiClassCallback *newFn,
+ const void *newContext, UBiDiClassCallback **oldFn,
+ const void **oldContext, UErrorCode *pErrorCode);
+
+/**
+ * Get the current callback function used for Bidi class determination.
+ *
+ * @param pBiDi is the paragraph UBiDi object.
+ *
+ * @param fn fillin: Returns the callback function pointer.
+ *
+ * @param context fillin: Returns the callback's private context.
+ *
+ * @see ubidi_setClassCallback
+ * @stable ICU 3.6
+ */
+U_STABLE void U_EXPORT2
+ubidi_getClassCallback(UBiDi *pBiDi, UBiDiClassCallback **fn, const void **context);
+
+/**
+ * Take a UBiDi object containing the reordering
+ * information for a piece of text (one or more paragraphs) set by
+ * ubidi_setPara() or for a line of text set by
+ * ubidi_setLine() and write a reordered string to the
+ * destination buffer.
+ *
+ * This function preserves the integrity of characters with multiple
+ * code units and (optionally) combining characters.
+ * Characters in RTL runs can be replaced by mirror-image characters
+ * in the destination buffer. Note that "real" mirroring has
+ * to be done in a rendering engine by glyph selection
+ * and that for many "mirrored" characters there are no
+ * Unicode characters as mirror-image equivalents.
+ * There are also options to insert or remove Bidi control
+ * characters; see the description of the destSize
+ * and options parameters and of the option bit flags.
+ *
+ * @param pBiDi A pointer to a UBiDi object that
+ * is set by ubidi_setPara() or
+ * ubidi_setLine() and contains the reordering
+ * information for the text that it was defined for,
+ * as well as a pointer to that text.
+ * The text was aliased (only the pointer was stored
+ * without copying the contents) and must not have been modified
+ * since the ubidi_setPara() call.
+ *
+ * @param dest A pointer to where the reordered text is to be copied.
+ * The source text and dest[destSize]
+ * must not overlap.
+ *
+ * @param destSize The size of the dest buffer,
+ * in number of UChars.
+ * If the UBIDI_INSERT_LRM_FOR_NUMERIC
+ * option is set, then the destination length could be
+ * as large as
+ * ubidi_getLength(pBiDi)+2*ubidi_countRuns(pBiDi).
+ * If the UBIDI_REMOVE_BIDI_CONTROLS option
+ * is set, then the destination length may be less than
+ * ubidi_getLength(pBiDi).
+ * If none of these options is set, then the destination length
+ * will be exactly ubidi_getProcessedLength(pBiDi).
+ *
+ * @param options A bit set of options for the reordering that control
+ * how the reordered text is written.
+ * The options include mirroring the characters on a code
+ * point basis and inserting LRM characters, which is used
+ * especially for transforming visually stored text
+ * to logically stored text (although this is still an
+ * imperfect implementation of an "inverse Bidi" algorithm
+ * because it uses the "forward Bidi" algorithm at its core).
+ * The available options are:
+ * #UBIDI_DO_MIRRORING,
+ * #UBIDI_INSERT_LRM_FOR_NUMERIC,
+ * #UBIDI_KEEP_BASE_COMBINING,
+ * #UBIDI_OUTPUT_REVERSE,
+ * #UBIDI_REMOVE_BIDI_CONTROLS
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The length of the output string.
+ *
+ * @see ubidi_getProcessedLength
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_writeReordered(UBiDi *pBiDi,
+ UChar *dest, int32_t destSize,
+ uint16_t options,
+ UErrorCode *pErrorCode);
+
+/**
+ * Reverse a Right-To-Left run of Unicode text.
+ *
+ * This function preserves the integrity of characters with multiple
+ * code units and (optionally) combining characters.
+ * Characters can be replaced by mirror-image characters
+ * in the destination buffer. Note that "real" mirroring has
+ * to be done in a rendering engine by glyph selection
+ * and that for many "mirrored" characters there are no
+ * Unicode characters as mirror-image equivalents.
+ * There are also options to insert or remove Bidi control
+ * characters.
+ *
+ * This function is the implementation for reversing RTL runs as part
+ * of ubidi_writeReordered(). For detailed descriptions
+ * of the parameters, see there.
+ * Since no Bidi controls are inserted here, the output string length
+ * will never exceed srcLength.
+ *
+ * @see ubidi_writeReordered
+ *
+ * @param src A pointer to the RTL run text.
+ *
+ * @param srcLength The length of the RTL run.
+ *
+ * @param dest A pointer to where the reordered text is to be copied.
+ * src[srcLength] and dest[destSize]
+ * must not overlap.
+ *
+ * @param destSize The size of the dest buffer,
+ * in number of UChars.
+ * If the UBIDI_REMOVE_BIDI_CONTROLS option
+ * is set, then the destination length may be less than
+ * srcLength.
+ * If this option is not set, then the destination length
+ * will be exactly srcLength.
+ *
+ * @param options A bit set of options for the reordering that control
+ * how the reordered text is written.
+ * See the options parameter in ubidi_writeReordered().
+ *
+ * @param pErrorCode must be a valid pointer to an error code value.
+ *
+ * @return The length of the output string.
+ * @stable ICU 2.0
+ */
+U_STABLE int32_t U_EXPORT2
+ubidi_writeReverse(const UChar *src, int32_t srcLength,
+ UChar *dest, int32_t destSize,
+ uint16_t options,
+ UErrorCode *pErrorCode);
+
+/*#define BIDI_SAMPLE_CODE*/
+/*@}*/
+
+#endif