Sweden-Number/libs/port/normalize.c

142 lines
4.2 KiB
C

/*
* Unicode normalization functions
*
* Copyright 2019 Huw Davies
*
* 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; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include "wine/unicode.h"
extern WCHAR wine_compose( const WCHAR *str ) DECLSPEC_HIDDEN;
extern unsigned int wine_decompose( int flags, WCHAR ch, WCHAR *dst, unsigned int dstlen ) DECLSPEC_HIDDEN;
extern const unsigned short combining_class_table[] DECLSPEC_HIDDEN;
static BYTE get_combining_class( WCHAR c )
{
return combining_class_table[combining_class_table[combining_class_table[c >> 8] + ((c >> 4) & 0xf)] + (c & 0xf)];
}
static BOOL is_starter( WCHAR c )
{
return !get_combining_class( c );
}
static BOOL reorderable_pair( WCHAR c1, WCHAR c2 )
{
BYTE ccc1, ccc2;
/* reorderable if ccc1 > ccc2 > 0 */
ccc1 = get_combining_class( c1 );
if (ccc1 < 2) return FALSE;
ccc2 = get_combining_class( c2 );
return ccc2 && (ccc1 > ccc2);
}
static void canonical_order_substring( WCHAR *str, unsigned int len )
{
unsigned int i;
BOOL swapped;
do
{
swapped = FALSE;
for (i = 0; i < len - 1; i++)
{
if (reorderable_pair( str[i], str[i + 1] ))
{
WCHAR tmp = str[i];
str[i] = str[i + 1];
str[i + 1] = tmp;
swapped = TRUE;
}
}
} while (swapped);
}
/****************************************************************************
* canonical_order_string
*
* Reorder the string into canonical order - D108/D109.
*
* Starters (chars with combining class == 0) don't move, so look for continuous
* substrings of non-starters and only reorder those.
*/
static void canonical_order_string( WCHAR *str, unsigned int len )
{
unsigned int i, next = 0;
for (i = 1; i <= len; i++)
{
if (i == len || is_starter( str[i] ))
{
if (i > next + 1) /* at least two successive non-starters */
canonical_order_substring( str + next, i - next );
next = i + 1;
}
}
}
unsigned int wine_decompose_string( int flags, const WCHAR *src, unsigned int src_len,
WCHAR *dst, unsigned int dst_len )
{
unsigned int src_pos, dst_pos = 0, decomp_len;
for (src_pos = 0; src_pos < src_len; src_pos++)
{
if (dst_pos == dst_len) return 0;
decomp_len = wine_decompose( flags, src[src_pos], dst + dst_pos, dst_len - dst_pos );
if (decomp_len == 0) return 0;
dst_pos += decomp_len;
}
if (flags & WINE_DECOMPOSE_REORDER) canonical_order_string( dst, dst_pos );
return dst_pos;
}
static BOOL is_blocked( WCHAR *starter, WCHAR *ptr )
{
if (ptr == starter + 1) return FALSE;
/* Because the string is already canonically ordered, the chars are blocked
only if the previous char's combining class is equal to the test char. */
if (get_combining_class( *(ptr - 1) ) == get_combining_class( *ptr )) return TRUE;
return FALSE;
}
unsigned int wine_compose_string( WCHAR *str, unsigned int len )
{
unsigned int i, last_starter = len;
WCHAR pair[2], comp;
for (i = 0; i < len; i++)
{
pair[1] = str[i];
if (last_starter == len || is_blocked( str + last_starter, str + i ) || !(comp = wine_compose( pair )))
{
if (is_starter( str[i] ))
{
last_starter = i;
pair[0] = str[i];
}
continue;
}
str[last_starter] = pair[0] = comp;
len--;
memmove( str + i, str + i + 1, (len - i) * sizeof(WCHAR) );
i = last_starter;
}
return len;
}