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fribidi-bidi.c
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fribidi-bidi.c
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/* FriBidi
* fribidi-bidi.c - bidirectional algorithm
*
* Authors:
* Behdad Esfahbod, 2001, 2002, 2004
* Dov Grobgeld, 1999, 2000, 2017
*
* Copyright (C) 2004 Sharif FarsiWeb, Inc
* Copyright (C) 2001,2002 Behdad Esfahbod
* Copyright (C) 1999,2000,2017 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>.
*/
#include "common.h"
#include <fribidi-bidi.h>
#include <fribidi-mirroring.h>
#include <fribidi-brackets.h>
#include <fribidi-unicode.h>
#include "bidi-types.h"
#include "run.h"
/*
* This file implements most of Unicode Standard Annex #9, Tracking Number 13.
*/
#ifndef MAX
# define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif /* !MAX */
/* Some convenience macros */
#define RL_TYPE(list) ((list)->type)
#define RL_LEN(list) ((list)->len)
#define RL_LEVEL(list) ((list)->level)
/* "Within this scope, bidirectional types EN and AN are treated as R" */
#define RL_TYPE_AN_EN_AS_RTL(list) ( \
(((list)->type == FRIBIDI_TYPE_AN) || ((list)->type == FRIBIDI_TYPE_EN) | ((list)->type == FRIBIDI_TYPE_RTL)) ? FRIBIDI_TYPE_RTL : (list)->type)
#define RL_BRACKET_TYPE(list) ((list)->bracket_type)
#define RL_ISOLATE_LEVEL(list) ((list)->isolate_level)
#define LOCAL_BRACKET_SIZE 16
/* Pairing nodes are used for holding a pair of open/close brackets as
described in BD16. */
struct _FriBidiPairingNodeStruct {
FriBidiRun *open;
FriBidiRun *close;
struct _FriBidiPairingNodeStruct *next;
};
typedef struct _FriBidiPairingNodeStruct FriBidiPairingNode;
static FriBidiRun *
merge_with_prev (
FriBidiRun *second
)
{
FriBidiRun *first;
fribidi_assert (second);
fribidi_assert (second->next);
first = second->prev;
fribidi_assert (first);
first->next = second->next;
first->next->prev = first;
RL_LEN (first) += RL_LEN (second);
if (second->next_isolate)
second->next_isolate->prev_isolate = first;
first->next_isolate = second->next_isolate;
fribidi_free (second);
return first;
}
static void
compact_list (
FriBidiRun *list
)
{
fribidi_assert (list);
if (list->next)
for_run_list (list, list)
if (RL_TYPE (list->prev) == RL_TYPE (list)
&& RL_LEVEL (list->prev) == RL_LEVEL (list)
&& RL_BRACKET_TYPE(list) == FRIBIDI_NO_BRACKET /* Don't join brackets! */
&& RL_BRACKET_TYPE(list->prev) == FRIBIDI_NO_BRACKET
)
list = merge_with_prev (list);
}
static void
compact_neutrals (
FriBidiRun *list
)
{
fribidi_assert (list);
if (list->next)
{
for_run_list (list, list)
{
if (RL_LEVEL (list->prev) == RL_LEVEL (list)
&&
((RL_TYPE (list->prev) == RL_TYPE (list)
|| (FRIBIDI_IS_NEUTRAL (RL_TYPE (list->prev))
&& FRIBIDI_IS_NEUTRAL (RL_TYPE (list)))))
&& RL_BRACKET_TYPE(list) == FRIBIDI_NO_BRACKET /* Don't join brackets! */
&& RL_BRACKET_TYPE(list->prev) == FRIBIDI_NO_BRACKET
)
list = merge_with_prev (list);
}
}
}
/* Search for an adjacent run in the forward or backward direction.
It uses the next_isolate and prev_isolate run for short circuited searching.
*/
/* The static sentinel is used to signal the end of an isolating
sequence */
static FriBidiRun sentinel = { NULL, NULL, 0,0, FRIBIDI_TYPE_SENTINEL, -1,-1,FRIBIDI_NO_BRACKET, NULL, NULL };
static FriBidiRun *get_adjacent_run(FriBidiRun *list, fribidi_boolean forward, fribidi_boolean skip_neutral)
{
FriBidiRun *ppp = forward ? list->next_isolate : list->prev_isolate;
if (!ppp)
return &sentinel;
while (ppp)
{
FriBidiCharType ppp_type = RL_TYPE (ppp);
if (ppp_type == FRIBIDI_TYPE_SENTINEL)
break;
/* Note that when sweeping forward we continue one run
beyond the PDI to see what lies behind. When looking
backwards, this is not necessary as the leading isolate
run has already been assigned the resolved level. */
if (ppp->isolate_level > list->isolate_level /* <- How can this be true? */
|| (forward && ppp_type == FRIBIDI_TYPE_PDI)
|| (skip_neutral && !FRIBIDI_IS_STRONG(ppp_type)))
{
ppp = forward ? ppp->next_isolate : ppp->prev_isolate;
if (!ppp)
ppp = &sentinel;
continue;
}
break;
}
return ppp;
}
#ifdef DEBUG
/*======================================================================
* For debugging, define some functions for printing the types and the
* levels.
*----------------------------------------------------------------------*/
static char char_from_level_array[] = {
'$', /* -1 == FRIBIDI_SENTINEL, indicating
* start or end of string. */
/* 0-61 == 0-9,a-z,A-Z are the the only valid levels before resolving
* implicits. after that the level @ may be appear too. */
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
'u', 'v', 'w', 'x', 'y', 'z', 'A', 'B', 'C', 'D',
'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N',
'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z',
/* TBD - insert another 125-64 levels */
'@', /* 62 == only must appear after resolving
* implicits. */
'!', /* 63 == FRIBIDI_LEVEL_INVALID, internal error,
* this level shouldn't be seen. */
'*', '*', '*', '*', '*' /* >= 64 == overflows, this levels and higher
* levels show a real bug!. */
};
#define fribidi_char_from_level(level) char_from_level_array[(level) + 1]
static void
print_types_re (
const FriBidiRun *pp
)
{
fribidi_assert (pp);
MSG (" Run types : ");
for_run_list (pp, pp)
{
MSG6 ("%d:%d(%s)[%d,%d] ",
pp->pos, pp->len, fribidi_get_bidi_type_name (pp->type), pp->level, pp->isolate_level);
}
MSG ("\n");
}
static void
print_resolved_levels (
const FriBidiRun *pp
)
{
fribidi_assert (pp);
MSG (" Res. levels: ");
for_run_list (pp, pp)
{
register FriBidiStrIndex i;
for (i = RL_LEN (pp); i; i--)
MSG2 ("%c", fribidi_char_from_level (RL_LEVEL (pp)));
}
MSG ("\n");
}
static void
print_resolved_types (
const FriBidiRun *pp
)
{
fribidi_assert (pp);
MSG (" Res. types : ");
for_run_list (pp, pp)
{
FriBidiStrIndex i;
for (i = RL_LEN (pp); i; i--)
MSG2 ("%s ", fribidi_get_bidi_type_name (pp->type));
}
MSG ("\n");
}
static void
print_bidi_string (
/* input */
const FriBidiCharType *bidi_types,
const FriBidiStrIndex len
)
{
register FriBidiStrIndex i;
fribidi_assert (bidi_types);
MSG (" Org. types : ");
for (i = 0; i < len; i++)
MSG2 ("%s ", fribidi_get_bidi_type_name (bidi_types[i]));
MSG ("\n");
}
static void print_pairing_nodes(FriBidiPairingNode *nodes)
{
MSG ("Pairs: ");
while (nodes)
{
MSG3 ("(%d, %d) ", nodes->open->pos, nodes->close->pos);
nodes = nodes->next;
}
MSG ("\n");
}
#endif /* DEBUG */
/*=========================================================================
* define macros for push and pop the status in to / out of the stack
*-------------------------------------------------------------------------*/
/* There are a few little points in pushing into and popping from the status
stack:
1. when the embedding level is not valid (more than
FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL=125), you must reject it, and not to push
into the stack, but when you see a PDF, you must find the matching code,
and if it was pushed in the stack, pop it, it means you must pop if and
only if you have pushed the matching code, the over_pushed var counts the
number of rejected codes so far.
2. there's a more confusing point too, when the embedding level is exactly
FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL-1=124, an LRO, LRE, or LRI is rejected
because the new level would be FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL+1=126, that
is invalid; but an RLO, RLE, or RLI is accepted because the new level is
FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL=125, that is valid, so the rejected codes
may be not continuous in the logical order, in fact there are at most two
continuous intervals of codes, with an RLO, RLE, or RLI between them. To
support this case, the first_interval var counts the number of rejected
codes in the first interval, when it is 0, means that there is only one
interval.
*/
/* a. If this new level would be valid, then this embedding code is valid.
Remember (push) the current embedding level and override status.
Reset current level to this new level, and reset the override status to
new_override.
b. If the new level would not be valid, then this code is invalid. Don't
change the current level or override status.
*/
#define PUSH_STATUS \
FRIBIDI_BEGIN_STMT \
if LIKELY(over_pushed == 0 \
&& isolate_overflow == 0 \
&& new_level <= FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL) \
{ \
if UNLIKELY(level == FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL - 1) \
first_interval = over_pushed; \
status_stack[stack_size].level = level; \
status_stack[stack_size].isolate_level = isolate_level; \
status_stack[stack_size].isolate = isolate; \
status_stack[stack_size].override = override; \
stack_size++; \
level = new_level; \
override = new_override; \
} else if LIKELY(isolate_overflow == 0) \
over_pushed++; \
FRIBIDI_END_STMT
/* If there was a valid matching code, restore (pop) the last remembered
(pushed) embedding level and directional override.
*/
#define POP_STATUS \
FRIBIDI_BEGIN_STMT \
if (stack_size) \
{ \
if UNLIKELY(over_pushed > first_interval) \
over_pushed--; \
else \
{ \
if LIKELY(over_pushed == first_interval) \
first_interval = 0; \
stack_size--; \
level = status_stack[stack_size].level; \
override = status_stack[stack_size].override; \
isolate = status_stack[stack_size].isolate; \
isolate_level = status_stack[stack_size].isolate_level; \
} \
} \
FRIBIDI_END_STMT
/* Return the type of previous run or the SOR, if already at the start of
a level run. */
#define PREV_TYPE_OR_SOR(pp) \
( \
RL_LEVEL(pp->prev) == RL_LEVEL(pp) ? \
RL_TYPE(pp->prev) : \
FRIBIDI_LEVEL_TO_DIR(MAX(RL_LEVEL(pp->prev), RL_LEVEL(pp))) \
)
/* Return the type of next run or the EOR, if already at the end of
a level run. */
#define NEXT_TYPE_OR_EOR(pp) \
( \
RL_LEVEL(pp->next) == RL_LEVEL(pp) ? \
RL_TYPE(pp->next) : \
FRIBIDI_LEVEL_TO_DIR(MAX(RL_LEVEL(pp->next), RL_LEVEL(pp))) \
)
/* Return the embedding direction of a link. */
#define FRIBIDI_EMBEDDING_DIRECTION(link) \
FRIBIDI_LEVEL_TO_DIR(RL_LEVEL(link))
FRIBIDI_ENTRY FriBidiParType
fribidi_get_par_direction (
/* input */
const FriBidiCharType *bidi_types,
const FriBidiStrIndex len
)
{
register FriBidiStrIndex i;
fribidi_assert (bidi_types);
for (i = 0; i < len; i++)
if (FRIBIDI_IS_LETTER (bidi_types[i]))
return FRIBIDI_IS_RTL (bidi_types[i]) ? FRIBIDI_PAR_RTL :
FRIBIDI_PAR_LTR;
return FRIBIDI_PAR_ON;
}
/* Push a new entry to the pairing linked list */
static FriBidiPairingNode * pairing_nodes_push(FriBidiPairingNode *nodes,
FriBidiRun *open,
FriBidiRun *close)
{
FriBidiPairingNode *node = fribidi_malloc(sizeof(FriBidiPairingNode));
node->open = open;
node->close = close;
node->next = nodes;
nodes = node;
return nodes;
}
/* Sort by merge sort */
static void pairing_nodes_front_back_split(FriBidiPairingNode *source,
/* output */
FriBidiPairingNode **front,
FriBidiPairingNode **back)
{
FriBidiPairingNode *pfast, *pslow;
if (!source || !source->next)
{
*front = source;
*back = NULL;
}
else
{
pslow = source;
pfast = source->next;
while (pfast)
{
pfast= pfast->next;
if (pfast)
{
pfast = pfast->next;
pslow = pslow->next;
}
}
*front = source;
*back = pslow->next;
pslow->next = NULL;
}
}
static FriBidiPairingNode *
pairing_nodes_sorted_merge(FriBidiPairingNode *nodes1,
FriBidiPairingNode *nodes2)
{
FriBidiPairingNode *res = NULL;
if (!nodes1)
return nodes2;
if (!nodes2)
return nodes1;
if (nodes1->open->pos < nodes2->open->pos)
{
res = nodes1;
res->next = pairing_nodes_sorted_merge(nodes1->next, nodes2);
}
else
{
res = nodes2;
res->next = pairing_nodes_sorted_merge(nodes1, nodes2->next);
}
return res;
}
static void sort_pairing_nodes(FriBidiPairingNode **nodes)
{
FriBidiPairingNode *front, *back;
/* 0 or 1 node case */
if (!*nodes || !(*nodes)->next)
return;
pairing_nodes_front_back_split(*nodes, &front, &back);
sort_pairing_nodes(&front);
sort_pairing_nodes(&back);
*nodes = pairing_nodes_sorted_merge(front, back);
}
static void free_pairing_nodes(FriBidiPairingNode *nodes)
{
while (nodes)
{
FriBidiPairingNode *p = nodes;
nodes = nodes->next;
fribidi_free(p);
}
}
FRIBIDI_ENTRY FriBidiLevel
fribidi_get_par_embedding_levels_ex (
/* input */
const FriBidiCharType *bidi_types,
const FriBidiBracketType *bracket_types,
const FriBidiStrIndex len,
/* input and output */
FriBidiParType *pbase_dir,
/* output */
FriBidiLevel *embedding_levels
)
{
FriBidiLevel base_level_per_iso_level[FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL];
FriBidiLevel base_level, max_level = 0;
FriBidiParType base_dir;
FriBidiRun *main_run_list = NULL, *explicits_list = NULL, *pp;
fribidi_boolean status = false;
int max_iso_level = 0;
if UNLIKELY
(!len)
{
status = true;
goto out;
}
DBG ("in fribidi_get_par_embedding_levels");
fribidi_assert (bidi_types);
fribidi_assert (pbase_dir);
fribidi_assert (embedding_levels);
/* Determinate character types */
{
/* Get run-length encoded character types */
main_run_list = run_list_encode_bidi_types (bidi_types, bracket_types, len);
if UNLIKELY
(!main_run_list) goto out;
}
/* Find base level */
/* If no strong base_dir was found, resort to the weak direction
that was passed on input. */
base_level = FRIBIDI_DIR_TO_LEVEL (*pbase_dir);
if (!FRIBIDI_IS_STRONG (*pbase_dir))
/* P2. P3. Search for first strong character and use its direction as
base direction */
{
int valid_isolate_count = 0;
for_run_list (pp, main_run_list)
{
if (RL_TYPE(pp) == FRIBIDI_TYPE_PDI)
{
/* Ignore if there is no matching isolate */
if (valid_isolate_count>0)
valid_isolate_count--;
}
else if (FRIBIDI_IS_ISOLATE(RL_TYPE(pp)))
valid_isolate_count++;
else if (valid_isolate_count==0 && FRIBIDI_IS_LETTER (RL_TYPE (pp)))
{
base_level = FRIBIDI_DIR_TO_LEVEL (RL_TYPE (pp));
*pbase_dir = FRIBIDI_LEVEL_TO_DIR (base_level);
break;
}
}
}
base_dir = FRIBIDI_LEVEL_TO_DIR (base_level);
DBG2 (" base level : %c", fribidi_char_from_level (base_level));
DBG2 (" base dir : %s", fribidi_get_bidi_type_name (base_dir));
base_level_per_iso_level[0] = base_level;
# if DEBUG
if UNLIKELY
(fribidi_debug_status ())
{
print_types_re (main_run_list);
}
# endif /* DEBUG */
/* Explicit Levels and Directions */
DBG ("explicit levels and directions");
{
FriBidiLevel level, new_level = 0;
int isolate_level = 0;
FriBidiCharType override, new_override;
FriBidiStrIndex i;
int stack_size, over_pushed, first_interval;
int valid_isolate_count = 0;
int isolate_overflow = 0;
int isolate = 0; /* The isolate status flag */
struct
{
FriBidiCharType override; /* only LTR, RTL and ON are valid */
FriBidiLevel level;
int isolate;
int isolate_level;
} status_stack[FRIBIDI_BIDI_MAX_RESOLVED_LEVELS];
FriBidiRun temp_link;
FriBidiRun *run_per_isolate_level[FRIBIDI_BIDI_MAX_RESOLVED_LEVELS];
memset(run_per_isolate_level, 0, sizeof(run_per_isolate_level[0])
* FRIBIDI_BIDI_MAX_RESOLVED_LEVELS);
/* explicits_list is a list like main_run_list, that holds the explicit
codes that are removed from main_run_list, to reinsert them later by
calling the shadow_run_list.
*/
explicits_list = new_run_list ();
if UNLIKELY
(!explicits_list) goto out;
/* X1. Begin by setting the current embedding level to the paragraph
embedding level. Set the directional override status to neutral,
and directional isolate status to false.
Process each character iteratively, applying rules X2 through X8.
Only embedding levels from 0 to 123 are valid in this phase. */
level = base_level;
override = FRIBIDI_TYPE_ON;
/* stack */
stack_size = 0;
over_pushed = 0;
first_interval = 0;
valid_isolate_count = 0;
isolate_overflow = 0;
for_run_list (pp, main_run_list)
{
FriBidiCharType this_type = RL_TYPE (pp);
RL_ISOLATE_LEVEL (pp) = isolate_level;
if (FRIBIDI_IS_EXPLICIT_OR_BN (this_type))
{
if (FRIBIDI_IS_STRONG (this_type))
{ /* LRE, RLE, LRO, RLO */
/* 1. Explicit Embeddings */
/* X2. With each RLE, compute the least greater odd
embedding level. */
/* X3. With each LRE, compute the least greater even
embedding level. */
/* 2. Explicit Overrides */
/* X4. With each RLO, compute the least greater odd
embedding level. */
/* X5. With each LRO, compute the least greater even
embedding level. */
new_override = FRIBIDI_EXPLICIT_TO_OVERRIDE_DIR (this_type);
for (i = RL_LEN (pp); i; i--)
{
new_level =
((level + FRIBIDI_DIR_TO_LEVEL (this_type) + 2) & ~1) -
FRIBIDI_DIR_TO_LEVEL (this_type);
isolate = 0;
PUSH_STATUS;
}
}
else if (this_type == FRIBIDI_TYPE_PDF)
{
/* 3. Terminating Embeddings and overrides */
/* X7. With each PDF, determine the matching embedding or
override code. */
for (i = RL_LEN (pp); i; i--)
{
if (stack_size && status_stack[stack_size-1].isolate != 0)
break;
POP_STATUS;
}
}
/* X9. Remove all RLE, LRE, RLO, LRO, PDF, and BN codes. */
/* Remove element and add it to explicits_list */
RL_LEVEL (pp) = FRIBIDI_SENTINEL;
temp_link.next = pp->next;
move_node_before (pp, explicits_list);
pp = &temp_link;
}
else if (this_type == FRIBIDI_TYPE_PDI)
/* X6a. pop the direction of the stack */
{
for (i = RL_LEN (pp); i; i--)
{
if (isolate_overflow > 0)
{
isolate_overflow--;
RL_LEVEL (pp) = level;
}
else if (valid_isolate_count > 0)
{
/* Pop away all LRE,RLE,LRO, RLO levels
from the stack, as these are implicitly
terminated by the PDI */
while (stack_size && !status_stack[stack_size-1].isolate)
POP_STATUS;
over_pushed = 0; /* The PDI resets the overpushed! */
POP_STATUS;
isolate_level-- ;
valid_isolate_count--;
RL_LEVEL (pp) = level;
RL_ISOLATE_LEVEL (pp) = isolate_level;
}
else
{
/* Ignore isolated PDI's by turning them into ON's */
RL_TYPE (pp) = FRIBIDI_TYPE_ON;
RL_LEVEL (pp) = level;
}
}
}
else if (FRIBIDI_IS_ISOLATE(this_type))
{
/* TBD support RL_LEN > 1 */
new_override = FRIBIDI_TYPE_ON;
isolate = 1;
if (this_type == FRIBIDI_TYPE_LRI)
new_level = level + 2 - (level%2);
else if (this_type == FRIBIDI_TYPE_RLI)
new_level = level + 1 + (level%2);
else if (this_type == FRIBIDI_TYPE_FSI)
{
/* Search for a local strong character until we
meet the corresponding PDI or the end of the
paragraph */
FriBidiRun *fsi_pp;
int isolate_count = 0;
int fsi_base_level = 0;
for_run_list (fsi_pp, pp)
{
if (RL_TYPE(fsi_pp) == FRIBIDI_TYPE_PDI)
{
isolate_count--;
if (valid_isolate_count < 0)
break;
}
else if (FRIBIDI_IS_ISOLATE(RL_TYPE(fsi_pp)))
isolate_count++;
else if (isolate_count==0 && FRIBIDI_IS_LETTER (RL_TYPE (fsi_pp)))
{
fsi_base_level = FRIBIDI_DIR_TO_LEVEL (RL_TYPE (fsi_pp));
break;
}
}
/* Same behavior like RLI and LRI above */
if (FRIBIDI_LEVEL_IS_RTL (fsi_base_level))
new_level = level + 1 + (level%2);
else
new_level = level + 2 - (level%2);
}
RL_LEVEL (pp) = level;
RL_ISOLATE_LEVEL (pp) = isolate_level;
if (isolate_level < FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL-1)
isolate_level++;
base_level_per_iso_level[isolate_level] = new_level;
if (!FRIBIDI_IS_NEUTRAL (override))
RL_TYPE (pp) = override;
if (new_level <= FRIBIDI_BIDI_MAX_EXPLICIT_LEVEL)
{
valid_isolate_count++;
PUSH_STATUS;
level = new_level;
}
else
isolate_overflow += 1;
}
else if (this_type == FRIBIDI_TYPE_BS)
{
/* X8. All explicit directional embeddings and overrides are
completely terminated at the end of each paragraph. Paragraph
separators are not included in the embedding. */
break;
}
else
{
/* X6. For all types besides RLE, LRE, RLO, LRO, and PDF:
a. Set the level of the current character to the current
embedding level.
b. Whenever the directional override status is not neutral,
reset the current character type to the directional override
status. */
RL_LEVEL (pp) = level;
if (!FRIBIDI_IS_NEUTRAL (override))
RL_TYPE (pp) = override;
}
}
/* Build the isolate_level connections */
for_run_list (pp, main_run_list)
{
int isolate_level = RL_ISOLATE_LEVEL (pp);
if (run_per_isolate_level[isolate_level])
{
run_per_isolate_level[isolate_level]->next_isolate = pp;
pp->prev_isolate = run_per_isolate_level[isolate_level];
}
run_per_isolate_level[isolate_level] = pp;
}
/* Implementing X8. It has no effect on a single paragraph! */
level = base_level;
override = FRIBIDI_TYPE_ON;
stack_size = 0;
over_pushed = 0;
}
/* X10. The remaining rules are applied to each run of characters at the
same level. For each run, determine the start-of-level-run (sor) and
end-of-level-run (eor) type, either L or R. This depends on the
higher of the two levels on either side of the boundary (at the start
or end of the paragraph, the level of the 'other' run is the base
embedding level). If the higher level is odd, the type is R, otherwise
it is L. */
/* Resolving Implicit Levels can be done out of X10 loop, so only change
of Resolving Weak Types and Resolving Neutral Types is needed. */
compact_list (main_run_list);
# if DEBUG
if UNLIKELY
(fribidi_debug_status ())
{
print_types_re (main_run_list);
print_bidi_string (bidi_types, len);
print_resolved_levels (main_run_list);
print_resolved_types (main_run_list);
}
# endif /* DEBUG */
/* 4. Resolving weak types. Also calculate the maximum isolate level */
max_iso_level = 0;
DBG ("resolving weak types");
{
int last_strong_stack[FRIBIDI_BIDI_MAX_RESOLVED_LEVELS];
FriBidiCharType prev_type_orig;
fribidi_boolean w4;
last_strong_stack[0] = base_dir;
for_run_list (pp, main_run_list)
{
register FriBidiCharType prev_type, this_type, next_type;
FriBidiRun *ppp_prev, *ppp_next;
int iso_level;
ppp_prev = get_adjacent_run(pp, false, false);
ppp_next = get_adjacent_run(pp, true, false);
this_type = RL_TYPE (pp);
iso_level = RL_ISOLATE_LEVEL(pp);
if (iso_level > max_iso_level)
max_iso_level = iso_level;
if (RL_LEVEL(ppp_prev) == RL_LEVEL(pp))
prev_type = RL_TYPE(ppp_prev);
else
prev_type = FRIBIDI_LEVEL_TO_DIR(MAX(RL_LEVEL(ppp_prev), RL_LEVEL(pp)));
if (RL_LEVEL(ppp_next) == RL_LEVEL(pp))
next_type = RL_TYPE(ppp_next);
else
next_type = FRIBIDI_LEVEL_TO_DIR(MAX(RL_LEVEL(ppp_next), RL_LEVEL(pp)));
if (FRIBIDI_IS_STRONG (prev_type))
last_strong_stack[iso_level] = prev_type;
/* W1. NSM
Examine each non-spacing mark (NSM) in the level run, and change the
type of the NSM to the type of the previous character. If the NSM
is at the start of the level run, it will get the type of sor. */
/* Implementation note: it is important that if the previous character
is not sor, then we should merge this run with the previous,
because of rules like W5, that we assume all of a sequence of
adjacent ETs are in one FriBidiRun. */
if (this_type == FRIBIDI_TYPE_NSM)
{
/* New rule in Unicode 6.3 */
if (FRIBIDI_IS_ISOLATE (RL_TYPE (pp->prev)))
RL_TYPE(pp) = FRIBIDI_TYPE_ON;
if (RL_LEVEL (ppp_prev) == RL_LEVEL (pp))
{
if (ppp_prev == pp->prev)
pp = merge_with_prev (pp);
}
else
RL_TYPE (pp) = prev_type;
if (prev_type == next_type && RL_LEVEL (pp) == RL_LEVEL (pp->next))
{
if (ppp_next == pp->next)
pp = merge_with_prev (pp->next);
}
continue; /* As we know the next condition cannot be true. */
}
/* W2: European numbers. */
if (this_type == FRIBIDI_TYPE_EN && last_strong_stack[iso_level] == FRIBIDI_TYPE_AL)
{
RL_TYPE (pp) = FRIBIDI_TYPE_AN;
/* Resolving dependency of loops for rules W1 and W2, so we
can merge them in one loop. */
if (next_type == FRIBIDI_TYPE_NSM)
RL_TYPE (ppp_next) = FRIBIDI_TYPE_AN;
}
}
last_strong_stack[0] = base_dir;
/* Resolving dependency of loops for rules W4 and W5, W5 may
want to prevent W4 to take effect in the next turn, do this
through "w4". */
w4 = true;
/* Resolving dependency of loops for rules W4 and W5 with W7,
W7 may change an EN to L but it sets the prev_type_orig if needed,
so W4 and W5 in next turn can still do their works. */
prev_type_orig = FRIBIDI_TYPE_ON;
/* Each isolate level has its own memory of the last strong character */
for_run_list (pp, main_run_list)
{
register FriBidiCharType prev_type, this_type, next_type;
int iso_level;
FriBidiRun *ppp_prev, *ppp_next;
this_type = RL_TYPE (pp);
iso_level = RL_ISOLATE_LEVEL(pp);
ppp_prev = get_adjacent_run(pp, false, false);
ppp_next = get_adjacent_run(pp, true, false);
if (RL_LEVEL(ppp_prev) == RL_LEVEL(pp))
prev_type = RL_TYPE(ppp_prev);
else
prev_type = FRIBIDI_LEVEL_TO_DIR(MAX(RL_LEVEL(ppp_prev), RL_LEVEL(pp)));
if (RL_LEVEL(ppp_next) == RL_LEVEL(pp))
next_type = RL_TYPE(ppp_next);
else
next_type = FRIBIDI_LEVEL_TO_DIR(MAX(RL_LEVEL(ppp_next), RL_LEVEL(pp)));
if (FRIBIDI_IS_STRONG (prev_type))
last_strong_stack[iso_level] = prev_type;
/* W2 ??? */
/* W3: Change ALs to R. */
if (this_type == FRIBIDI_TYPE_AL)
{
RL_TYPE (pp) = FRIBIDI_TYPE_RTL;
w4 = true;
prev_type_orig = FRIBIDI_TYPE_ON;
continue;
}
/* W4. A single european separator changes to a european number.
A single common separator between two numbers of the same type
changes to that type. */
if (w4
&& RL_LEN (pp) == 1 && FRIBIDI_IS_ES_OR_CS (this_type)
&& FRIBIDI_IS_NUMBER (prev_type_orig)
&& prev_type_orig == next_type
&& (prev_type_orig == FRIBIDI_TYPE_EN
|| this_type == FRIBIDI_TYPE_CS))
{
RL_TYPE (pp) = prev_type;
this_type = RL_TYPE (pp);
}
w4 = true;
/* W5. A sequence of European terminators adjacent to European
numbers changes to All European numbers. */
if (this_type == FRIBIDI_TYPE_ET
&& (prev_type_orig == FRIBIDI_TYPE_EN
|| next_type == FRIBIDI_TYPE_EN))
{
RL_TYPE (pp) = FRIBIDI_TYPE_EN;
w4 = false;
this_type = RL_TYPE (pp);
}
/* W6. Otherwise change separators and terminators to other neutral. */
if (FRIBIDI_IS_NUMBER_SEPARATOR_OR_TERMINATOR (this_type))
RL_TYPE (pp) = FRIBIDI_TYPE_ON;
/* W7. Change european numbers to L. */
if (this_type == FRIBIDI_TYPE_EN && last_strong_stack[iso_level] == FRIBIDI_TYPE_LTR)
{
RL_TYPE (pp) = FRIBIDI_TYPE_LTR;
prev_type_orig = (RL_LEVEL (pp) == RL_LEVEL (pp->next) ?
FRIBIDI_TYPE_EN : FRIBIDI_TYPE_ON);
}
else
prev_type_orig = PREV_TYPE_OR_SOR (pp->next);
}
}
compact_neutrals (main_run_list);