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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:44:05 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 19:44:05 +0000 |
commit | d318611dd6f23fcfedd50e9b9e24620b102ba96a (patch) | |
tree | 8b9eef82ca40fdd5a8deeabf07572074c236095d /lib/uniwidth/width.c | |
parent | Initial commit. (diff) | |
download | groff-upstream/1.23.0.tar.xz groff-upstream/1.23.0.zip |
Adding upstream version 1.23.0.upstream/1.23.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/uniwidth/width.c')
-rw-r--r-- | lib/uniwidth/width.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/lib/uniwidth/width.c b/lib/uniwidth/width.c new file mode 100644 index 0000000..c9d4d1d --- /dev/null +++ b/lib/uniwidth/width.c @@ -0,0 +1,95 @@ +/* Determine display width of Unicode character. + Copyright (C) 2001-2002, 2006-2023 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2002. + + This file 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 file 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 program. If not, see <https://www.gnu.org/licenses/>. */ + +#include <config.h> + +/* Specification. */ +#include "uniwidth.h" + +#include "cjk.h" + +/* The non-spacing attribute table consists of: + * Non-spacing characters; generated from PropList.txt or + "grep '^[^;]*;[^;]*;[^;]*;[^;]*;NSM;' UnicodeData.txt" + * Format control characters; generated from + "grep '^[^;]*;[^;]*;Cf;' UnicodeData.txt" + * Zero width characters; generated from + "grep '^[^;]*;ZERO WIDTH ' UnicodeData.txt" + * Hangul Jamo characters that have conjoining behaviour: + - jungseong = syllable-middle vowels + - jongseong = syllable-final consonants + Rationale: + 1) These characters act like combining characters. They have no + equivalent in legacy character sets. Therefore the EastAsianWidth.txt + file does not really matter for them; UAX #11 East Asian Width + <https://www.unicode.org/reports/tr11/> makes it clear that it focus + is on compatibility with traditional Japanese layout. + By contrast, the same glyphs without conjoining behaviour are available + in the U+3130..U+318F block, and these characters are mapped to legacy + character sets, and traditional Japanese layout matters for them. + 2) glibc does the same thing, see + <https://sourceware.org/bugzilla/show_bug.cgi?id=21750> + <https://sourceware.org/bugzilla/show_bug.cgi?id=26120> + */ +#include "uniwidth/width0.h" + +#include "uniwidth/width2.h" +#include "unictype/bitmap.h" + +#define SIZEOF(a) (sizeof(a) / sizeof(a[0])) + + +/* Determine number of column positions required for UC. */ +int +uc_width (ucs4_t uc, const char *encoding) +{ + /* Test for non-spacing or control character. */ + if ((uc >> 9) < SIZEOF (nonspacing_table_ind)) + { + int ind = nonspacing_table_ind[uc >> 9]; + if (ind >= 0) + if ((nonspacing_table_data[64*ind + ((uc >> 3) & 63)] >> (uc & 7)) & 1) + { + if (uc > 0 && uc < 0xa0) + return -1; + else + return 0; + } + } + else if ((uc >> 9) == (0xe0000 >> 9)) + { + if (uc >= 0xe0100) + { + if (uc <= 0xe01ef) + return 0; + } + else + { + if (uc >= 0xe0020 ? uc <= 0xe007f : uc == 0xe0001) + return 0; + } + } + /* Test for double-width character. */ + if (bitmap_lookup (&u_width2, uc)) + return 2; + /* In ancient CJK encodings, Cyrillic and most other characters are + double-width as well. */ + if (uc >= 0x00A1 && uc < 0xFF61 && uc != 0x20A9 + && is_cjk_encoding (encoding)) + return 2; + return 1; +} |