fribidi-bidi.h
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/* FriBidi
* fribidi-bidi.h - bidirectional algorithm
*
* Authors:
* Behdad Esfahbod, 2001, 2002, 2004
* Dov Grobgeld, 1999, 2000
*
* Copyright (C) 2004 Sharif FarsiWeb, Inc
* Copyright (C) 2001,2002 Behdad Esfahbod
* Copyright (C) 1999,2000 Dov Grobgeld
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library, in a file named COPYING; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA
*
* For licensing issues, contact <fribidi.license@gmail.com>.
*/
#ifndef _FRIBIDI_BIDI_H
#define _FRIBIDI_BIDI_H
#include "fribidi-common.h"
#include "fribidi-types.h"
#include "fribidi-flags.h"
#include "fribidi-bidi-types.h"
#include "fribidi-begindecls.h"
/* fribidi_get_par_direction - get base paragraph direction
*
* This function finds the base direction of a single paragraph,
* as defined by rule P2 of the Unicode Bidirectional Algorithm available at
* http://www.unicode.org/reports/tr9/#P2.
*
* You typically do not need this function as
* fribidi_get_par_embedding_levels() knows how to compute base direction
* itself, but you may need this to implement a more sophisticated paragraph
* direction handling. Note that you can pass more than a paragraph to this
* function and the direction of the first non-neutral paragraph is returned,
* which is a very good heuristic to set direction of the neutral paragraphs
* at the beginning of text. For other neutral paragraphs, you better use the
* direction of the previous paragraph.
*
* Returns: Base pargraph direction. No weak paragraph direction is returned,
* only LTR, RTL, or ON.
*/
FRIBIDI_ENTRY FriBidiParType fribidi_get_par_direction (
const FriBidiCharType *bidi_types, /* input list of bidi types as returned by
fribidi_get_bidi_types() */
const FriBidiStrIndex len /* input string length */
);
/* fribidi_get_par_embedding_levels_ex - get bidi embedding levels of a paragraph
*
* This function finds the bidi embedding levels of a single paragraph,
* as defined by the Unicode Bidirectional Algorithm available at
* http://www.unicode.org/reports/tr9/. This function implements rules P2 to
* I1 inclusive, and parts 1 to 3 of L1, except for rule X9 which is
* implemented in fribidi_remove_bidi_marks(). Part 4 of L1 is implemented
* in fribidi_reorder_line().
*
* There are a few macros defined in fribidi-bidi-types.h to work with this
* embedding levels.
*
* Returns: Maximum level found plus one, or zero if any error occurred
* (memory allocation failure most probably).
*/
FRIBIDI_ENTRY FriBidiLevel
fribidi_get_par_embedding_levels_ex (
const FriBidiCharType *bidi_types, /* input list of bidi types as returned by
fribidi_get_bidi_types() */
const FriBidiBracketType *bracket_types, /* input list of bracket types as returned by
fribidi_get_bracket_types() */
const FriBidiStrIndex len, /* input string length of the paragraph */
FriBidiParType *pbase_dir, /* requested and resolved paragraph
* base direction */
FriBidiLevel *embedding_levels /* output list of embedding levels */
) FRIBIDI_GNUC_WARN_UNUSED;
/* fribidi_reorder_line - reorder a line of logical string to visual
*
* This function reorders the characters in a line of text from logical to
* final visual order. This function implements part 4 of rule L1, and rules
* L2 and L3 of the Unicode Bidirectional Algorithm available at
* http://www.unicode.org/reports/tr9/#Reordering_Resolved_Levels.
*
* As a side effect it also sets position maps if not NULL.
*
* You should provide the resolved paragraph direction and embedding levels as
* set by fribidi_get_par_embedding_levels(). Also note that the embedding
* levels may change a bit. To be exact, the embedding level of any sequence
* of white space at the end of line is reset to the paragraph embedding level
* (That is part 4 of rule L1).
*
* Note that the bidi types and embedding levels are not reordered. You can
* reorder these (or any other) arrays using the map later. The user is
* responsible to initialize map to something sensible, like an identity
* mapping, or pass NULL if no map is needed.
*
* There is an optional part to this function, which is whether non-spacing
* marks for right-to-left parts of the text should be reordered to come after
* their base characters in the visual string or not. Most rendering engines
* expect this behavior, but console-based systems for example do not like it.
* This is controlled by the FRIBIDI_FLAG_REORDER_NSM flag. The flag is on
* in FRIBIDI_FLAGS_DEFAULT.
*
* Returns: Maximum level found in this line plus one, or zero if any error
* occurred (memory allocation failure most probably).
*/
FRIBIDI_ENTRY FriBidiLevel fribidi_reorder_line (
FriBidiFlags flags, /* reorder flags */
const FriBidiCharType *bidi_types, /* input list of bidi types as returned by
fribidi_get_bidi_types() */
const FriBidiStrIndex len, /* input length of the line */
const FriBidiStrIndex off, /* input offset of the beginning of the line
in the paragraph */
const FriBidiParType base_dir, /* resolved paragraph base direction */
FriBidiLevel *embedding_levels, /* input list of embedding levels,
as returned by
fribidi_get_par_embedding_levels */
FriBidiChar *visual_str, /* visual string to reorder */
FriBidiStrIndex *map /* a map of string indices which is reordered
* to reflect where each glyph ends up. */
) FRIBIDI_GNUC_WARN_UNUSED;
#include "fribidi-enddecls.h"
#endif /* !_FRIBIDI_BIDI_H */
/* Editor directions:
* vim:textwidth=78:tabstop=8:shiftwidth=2:autoindent:cindent
*/