1 /* Arabic joining group of Unicode characters.
2 Copyright (C) 2011-2021 Free Software Foundation, Inc.
3 Written by Bruno Haible <bruno@clisp.org>, 2011.
4
5 This file is free software.
6 It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
7 You can redistribute it and/or modify it under either
8 - the terms of the GNU Lesser General Public License as published
9 by the Free Software Foundation; either version 3, or (at your
10 option) any later version, or
11 - the terms of the GNU General Public License as published by the
12 Free Software Foundation; either version 2, or (at your option)
13 any later version, or
14 - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".
15
16 This file is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Lesser General Public License and the GNU General Public License
20 for more details.
21
22 You should have received a copy of the GNU Lesser General Public
23 License and of the GNU General Public License along with this
24 program. If not, see <https://www.gnu.org/licenses/>. */
25
26 #include <config.h>
27
28 /* Specification. */
29 #include "unictype.h"
30
31 /* Define u_joining_group table. */
32 #include "joininggroup_of.h"
33
34 int
35 uc_joining_group (ucs4_t uc)
/* ![[previous]](../icons/n_left.png)
![[next]](../icons/n_right.png)
![[first]](../icons/n_first.png)
![[last]](../icons/n_last.png)
![[top]](../icons/top.png)
![[bottom]](../icons/bottom.png)
![[index]](../icons/index.png)
*/
36 {
37 unsigned int index1 = uc >> joining_group_header_0;
38 if (index1 < joining_group_header_1)
39 {
40 int lookup1 = u_joining_group.level1[index1];
41 if (lookup1 >= 0)
42 {
43 unsigned int index2 = (uc >> joining_group_header_2) & joining_group_header_3;
44 int lookup2 = u_joining_group.level2[lookup1 + index2];
45 if (lookup2 >= 0)
46 {
47 unsigned int index3 = ((uc & joining_group_header_4) + lookup2) * 7;
48 /* level3 contains 7-bit values, packed into 16-bit words. */
49 unsigned int lookup3 =
50 (((unsigned int) u_joining_group.level3[index3>>4]
51 | ((unsigned int) u_joining_group.level3[(index3>>4)+1] << 16))
52 >> (index3 % 16))
53 & 0x7f;
54
55 return lookup3;
56 }
57 }
58 }
59 return UC_JOINING_GROUP_NONE;
60 }