1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
|
/* FriBidi
* fribidi-joining.h - Arabic joining algorithm
*
* Authors:
* Behdad Esfahbod, 2004
*
* Copyright (C) 2004 Sharif FarsiWeb, Inc
* Copyright (C) 2004 Behdad Esfahbod
*
* 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-joining.h>
#include "bidi-types.h"
#include "joining-types.h"
#if DEBUG+0
/*======================================================================
* For debugging, define some functions for printing joining types and
* properties.
*----------------------------------------------------------------------*/
static void
print_joining_types (
/* input */
const FriBidiLevel *embedding_levels,
const FriBidiStrIndex len,
const FriBidiJoiningType *jtypes
)
{
register FriBidiStrIndex i;
fribidi_assert (jtypes);
MSG (" Join. types: ");
for (i = 0; i < len; i++)
MSG2 ("%c", fribidi_char_from_joining_type (jtypes[i],
!FRIBIDI_LEVEL_IS_RTL
(embedding_levels[i])));
MSG ("\n");
}
#endif /* DEBUG */
#define FRIBIDI_CONSISTENT_LEVEL(i) \
(FRIBIDI_IS_EXPLICIT_OR_BN (bidi_types[(i)]) \
? FRIBIDI_SENTINEL \
: embedding_levels[(i)])
#define FRIBIDI_LEVELS_MATCH(i, j) \
((i) == (j) || (i) == FRIBIDI_SENTINEL || (j) == FRIBIDI_SENTINEL)
FRIBIDI_ENTRY void
fribidi_join_arabic (
/* input */
const FriBidiCharType *bidi_types,
const FriBidiStrIndex len,
const FriBidiLevel *embedding_levels,
/* input and output */
FriBidiArabicProp *ar_props
)
{
if UNLIKELY
(len == 0) return;
DBG ("in fribidi_join_arabic");
fribidi_assert (bidi_types);
fribidi_assert (embedding_levels);
fribidi_assert (ar_props);
# if DEBUG
if UNLIKELY
(fribidi_debug_status ())
{
print_joining_types (embedding_levels, len, ar_props);
}
# endif /* DEBUG */
/* The joining algorithm turned out very very dirty :(. That's what happens
* when you follow the standard which has never been implemented closely
* before.
*/
/* 8.2 Arabic - Cursive Joining */
DBG ("Arabic cursive joining");
{
/* The following do not need to be initialized as long as joins is
* initialized to false. We just do to turn off compiler warnings. */
register FriBidiStrIndex saved = 0;
register FriBidiLevel saved_level = FRIBIDI_SENTINEL;
register fribidi_boolean saved_shapes = false;
register FriBidiArabicProp saved_joins_following_mask = 0;
register fribidi_boolean joins = false;
register FriBidiStrIndex i;
for (i = 0; i < len; i++)
if (!FRIBIDI_IS_JOINING_TYPE_G (ar_props[i]))
{
register fribidi_boolean disjoin = false;
register fribidi_boolean shapes = FRIBIDI_ARAB_SHAPES (ar_props[i]);
register FriBidiLevel level = FRIBIDI_CONSISTENT_LEVEL (i);
if (joins && !FRIBIDI_LEVELS_MATCH (saved_level, level))
{
disjoin = true;
joins = false;
}
if (!FRIBIDI_IS_JOIN_SKIPPED (ar_props[i]))
{
register const FriBidiArabicProp joins_preceding_mask =
FRIBIDI_JOINS_PRECEDING_MASK (level);
if (!joins)
{
if (shapes)
FRIBIDI_UNSET_BITS (ar_props[i], joins_preceding_mask);
}
else if (!FRIBIDI_TEST_BITS (ar_props[i], joins_preceding_mask))
{
disjoin = true;
}
else
{
register FriBidiStrIndex j;
/* This is a FriBidi extension: we set joining properties
* for skipped characters in between, so we can put NSMs on tatweel
* later if we want. Useful on console for example.
*/
for (j = saved + 1; j < i; j++)
FRIBIDI_SET_BITS (ar_props[j], joins_preceding_mask | saved_joins_following_mask);
}
}
if (disjoin && saved_shapes)
FRIBIDI_UNSET_BITS (ar_props[saved], saved_joins_following_mask);
if (!FRIBIDI_IS_JOIN_SKIPPED (ar_props[i]))
{
saved = i;
saved_level = level;
saved_shapes = shapes;
saved_joins_following_mask =
FRIBIDI_JOINS_FOLLOWING_MASK (level);
joins =
FRIBIDI_TEST_BITS (ar_props[i], saved_joins_following_mask);
}
}
if ((joins) && saved_shapes)
FRIBIDI_UNSET_BITS (ar_props[saved], saved_joins_following_mask);
}
# if DEBUG
if UNLIKELY
(fribidi_debug_status ())
{
print_joining_types (embedding_levels, len, ar_props);
}
# endif /* DEBUG */
DBG ("leaving fribidi_join_arabic");
}
/* Editor directions:
* vim:textwidth=78:tabstop=8:shiftwidth=2:autoindent:cindent
*/
|
