mame/src/lib/util/unicode.c
2009-10-12 08:45:25 +00:00

375 lines
9.5 KiB
C

/*********************************************************************
unicode.c
Unicode related functions
****************************************************************************
Copyright Aaron Giles
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in
the documentation and/or other materials provided with the
distribution.
* Neither the name 'MAME' nor the names of its contributors may be
used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY AARON GILES ''AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL AARON GILES BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
***************************************************************************/
#include "unicode.h"
/*-------------------------------------------------
uchar_isvalid - return true if a given
character is a legitimate unicode character
-------------------------------------------------*/
int uchar_isvalid(unicode_char uchar)
{
return (uchar < 0x110000) && !((uchar >= 0xd800) && (uchar <= 0xdfff));
}
/*-------------------------------------------------
uchar_from_utf8 - convert a UTF-8 sequence
into a unicode character
-------------------------------------------------*/
int uchar_from_utf8(unicode_char *uchar, const char *utf8char, size_t count)
{
unicode_char c, minchar;
int auxlen, i;
char auxchar;
/* validate parameters */
if (utf8char == NULL || count == 0)
return 0;
/* start with the first byte */
c = (unsigned char) *utf8char;
count--;
utf8char++;
/* based on that, determine how many additional bytes we need */
if (c < 0x80)
{
/* unicode char 0x00000000 - 0x0000007F */
c &= 0x7f;
auxlen = 0;
minchar = 0x00000000;
}
else if (c >= 0xc0 && c < 0xe0)
{
/* unicode char 0x00000080 - 0x000007FF */
c &= 0x1f;
auxlen = 1;
minchar = 0x00000080;
}
else if (c >= 0xe0 && c < 0xf0)
{
/* unicode char 0x00000800 - 0x0000FFFF */
c &= 0x0f;
auxlen = 2;
minchar = 0x00000800;
}
else if (c >= 0xf0 && c < 0xf8)
{
/* unicode char 0x00010000 - 0x001FFFFF */
c &= 0x07;
auxlen = 3;
minchar = 0x00010000;
}
else if (c >= 0xf8 && c < 0xfc)
{
/* unicode char 0x00200000 - 0x03FFFFFF */
c &= 0x03;
auxlen = 4;
minchar = 0x00200000;
}
else if (c >= 0xfc && c < 0xfe)
{
/* unicode char 0x04000000 - 0x7FFFFFFF */
c &= 0x01;
auxlen = 5;
minchar = 0x04000000;
}
else
{
/* invalid */
return -1;
}
/* exceeds the count? */
if (auxlen > count)
return -1;
/* we now know how long the char is, now compute it */
for (i = 0; i < auxlen; i++)
{
auxchar = utf8char[i];
/* all auxillary chars must be between 0x80-0xbf */
if ((auxchar & 0xc0) != 0x80)
return -1;
c = c << 6;
c |= auxchar & 0x3f;
}
/* make sure that this char is above the minimum */
if (c < minchar)
return -1;
*uchar = c;
return auxlen + 1;
}
/*-------------------------------------------------
uchar_from_utf16 - convert a UTF-16 sequence
into a unicode character
-------------------------------------------------*/
int uchar_from_utf16(unicode_char *uchar, const utf16_char *utf16char, size_t count)
{
int rc = -1;
/* validate parameters */
if (utf16char == NULL || count == 0)
return 0;
/* handle the two-byte case */
if (utf16char[0] >= 0xd800 && utf16char[0] <= 0xdbff)
{
if (count > 1 && utf16char[1] >= 0xdc00 && utf16char[1] <= 0xdfff)
{
*uchar = 0x10000 + ((utf16char[0] & 0x3ff) * 0x400) + (utf16char[1] & 0x3ff);
rc = 2;
}
}
/* handle the one-byte case */
else if (utf16char[0] < 0xdc00 || utf16char[0] > 0xdfff)
{
*uchar = utf16char[0];
rc = 1;
}
return rc;
}
/*-------------------------------------------------
uchar_from_utf16f - convert a UTF-16 sequence
into a unicode character from a flipped
byte order
-------------------------------------------------*/
int uchar_from_utf16f(unicode_char *uchar, const utf16_char *utf16char, size_t count)
{
utf16_char buf[2] = {0};
if (count > 0)
buf[0] = FLIPENDIAN_INT16(utf16char[0]);
if (count > 1)
buf[1] = FLIPENDIAN_INT16(utf16char[1]);
return uchar_from_utf16(uchar, buf, count);
}
/*-------------------------------------------------
utf8_from_uchar - convert a unicode character
into a UTF-8 sequence
-------------------------------------------------*/
int utf8_from_uchar(char *utf8string, size_t count, unicode_char uchar)
{
int rc = 0;
/* error on invalid characters */
if (!uchar_isvalid(uchar))
return -1;
/* based on the value, output the appropriate number of bytes */
if (uchar < 0x80)
{
/* unicode char 0x00000000 - 0x0000007F */
if (count < 1)
return -1;
utf8string[rc++] = (char) uchar;
}
else if (uchar < 0x800)
{
/* unicode char 0x00000080 - 0x000007FF */
if (count < 2)
return -1;
utf8string[rc++] = ((char) (uchar >> 6)) | 0xC0;
utf8string[rc++] = ((char) ((uchar >> 0) & 0x3F)) | 0x80;
}
else if (uchar < 0x10000)
{
/* unicode char 0x00000800 - 0x0000FFFF */
if (count < 3)
return -1;
utf8string[rc++] = ((char) (uchar >> 12)) | 0xE0;
utf8string[rc++] = ((char) ((uchar >> 6) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 0) & 0x3F)) | 0x80;
}
else if (uchar < 0x00200000)
{
/* unicode char 0x00010000 - 0x001FFFFF */
if (count < 4)
return -1;
utf8string[rc++] = ((char) (uchar >> 18)) | 0xF0;
utf8string[rc++] = ((char) ((uchar >> 12) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 6) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 0) & 0x3F)) | 0x80;
}
else if (uchar < 0x04000000)
{
/* unicode char 0x00200000 - 0x03FFFFFF */
if (count < 5)
return -1;
utf8string[rc++] = ((char) (uchar >> 24)) | 0xF8;
utf8string[rc++] = ((char) ((uchar >> 18) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 12) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 6) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 0) & 0x3F)) | 0x80;
}
else if (uchar < 0x80000000)
{
/* unicode char 0x04000000 - 0x7FFFFFFF */
if (count < 6)
return -1;
utf8string[rc++] = ((char) (uchar >> 30)) | 0xFC;
utf8string[rc++] = ((char) ((uchar >> 24) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 18) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 12) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 6) & 0x3F)) | 0x80;
utf8string[rc++] = ((char) ((uchar >> 0) & 0x3F)) | 0x80;
}
else
rc = -1;
return rc;
}
/*-------------------------------------------------
utf16_from_uchar - convert a unicode character
into a UTF-16 sequence
-------------------------------------------------*/
int utf16_from_uchar(utf16_char *utf16string, size_t count, unicode_char uchar)
{
int rc;
/* error on invalid characters */
if (!uchar_isvalid(uchar))
return -1;
/* single word case */
if (uchar < 0x10000)
{
if (count < 1)
return -1;
utf16string[0] = (utf16_char) uchar;
rc = 1;
}
/* double word case */
else if (uchar < 0x100000)
{
if (count < 2)
return -1;
utf16string[0] = ((uchar >> 10) & 0x03ff) | 0xd800;
utf16string[1] = ((uchar >> 0) & 0x03ff) | 0xdc00;
rc = 2;
}
else
return -1;
return rc;
}
/*-------------------------------------------------
utf16_from_uchar - convert a unicode character
into a UTF-16 sequence with flipped endianness
-------------------------------------------------*/
int utf16f_from_uchar(utf16_char *utf16string, size_t count, unicode_char uchar)
{
int rc;
utf16_char buf[2] = { 0, 0 };
rc = utf16_from_uchar(buf, count, uchar);
if (rc >= 1)
utf16string[0] = FLIPENDIAN_INT16(buf[0]);
if (rc >= 2)
utf16string[1] = FLIPENDIAN_INT16(buf[1]);
return rc;
}
/*-------------------------------------------------
utf8_previous_char - return a pointer to the
previous character in a string
-------------------------------------------------*/
const char *utf8_previous_char(const char *utf8string)
{
while ((*--utf8string & 0xc0) == 0x80)
;
return utf8string;
}
/*-------------------------------------------------
utf8_is_valid_string - return true if the
given string is a properly formed sequence of
UTF-8 characters
-------------------------------------------------*/
int utf8_is_valid_string(const char *utf8string)
{
int remaining_length = strlen(utf8string);
while (*utf8string != 0)
{
unicode_char uchar = 0;
int charlen;
/* extract the current character and verify it */
charlen = uchar_from_utf8(&uchar, utf8string, remaining_length);
if (charlen <= 0 || uchar == 0 || !uchar_isvalid(uchar))
return FALSE;
/* advance */
utf8string += charlen;
remaining_length -= charlen;
}
return TRUE;
}