tojisjms.c

C标准库源代码

/***
*tojisjms.c:  Converts JIS to JMS code, and JMS to JIS code.
*
*       Copyright (c) 1988-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       Convert JIS code into Microsoft Kanji code, and vice versa.
*
*******************************************************************************/

#ifdef _MBCS

#include <cruntime.h>
#include <mbdata.h>
#include <mbstring.h>
#include <mbctype.h>


/***
*unsigned int _mbcjistojms(c) - Converts JIS code to Microsoft Kanji Code.
*
*Purpose:
*       Convert JIS code to Microsoft Kanji code.
*
*Entry:
*       unsigned int c - JIS code to be converted. First byte is the upper
*                          8 bits, and second is the lower 8 bits.
*
*Exit:
*       Returns related Microsoft Kanji Code. First byte is the upper 8 bits
*       and second byte is the lower 8 bits.
*
*Exceptions:
*       If c is out of range, _mbcjistojms returns zero.
*
*******************************************************************************/

unsigned int __cdecl _mbcjistojms(
    unsigned int c
    )
{
        unsigned int h, l;

    if (__mbcodepage != _KANJI_CP)
        return (c);

    h = (c >> 8) & 0xff;
    l = c & 0xff;
    if (h < 0x21 || h > 0x7e || l < 0x21 || l > 0x7e)
        return 0;
    if (h & 0x01) {    /* first byte is odd */
        if (l <= 0x5f)
            l += 0x1f;
        else
            l += 0x20;
    }
    else
        l += 0x7e;

    h = ((h - 0x21) >> 1) + 0x81;
    if (h > 0x9f)
        h += 0x40;
    return (h << 8) | l;
}


/***
*unsigned int _mbcjmstojis(c) - Converts Microsoft Kanji code into JIS code.
*
*Purpose:
*       To convert Microsoft Kanji code into JIS code.
*
*Entry:
*       unsigned int c - Microsoft Kanji code to be converted. First byte is
*                          the upper 8 bits, and the second is the lower 8 bits.
*
*Exit:
*       Returns related JIS Code. First byte is the upper 8 bits and the second
*       byte is the lower 8 bits. If c is out of range, return zero.
*
*Exceptions:
*
*******************************************************************************/

unsigned int __cdecl _mbcjmstojis(
    unsigned int c
    )
{
        unsigned int    h, l;

    if (__mbcodepage != _KANJI_CP)
        return (c);

    h = (c >> 8) & 0xff;
    l = c & 0xff;

    /* make sure input is valid shift-JIS */
    if ((!(_ISLEADBYTE(h))) || (!(_ISTRAILBYTE(l))))
        return 0;

    h -= (h >= 0xa0) ? 0xc1 : 0x81;
    if(l >= 0x9f) {
        c = (h << 9) + 0x2200;
        c |= l - 0x7e;
    } else {
        c = (h << 9) + 0x2100;
        c |= l - ((l <= 0x7e) ? 0x1f : 0x20);
    }

    /* not all shift-JIS maps to JIS, so make sure output is valid */
    if ( (c>0x7E7E) || (c<0x2121) || ((c&0xFF)>0x7E) || ((c&0xFF)<0x21) )
        return 0;

    return c;
}

#endif  /* _MBCS */