zero-epwing-go/jacode.c

/*
 * Copyright (c) 1997-2006  Motoyuki Kasahara
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the project 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 THE PROJECT AND CONTRIBUTORS ``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 THE PROJECT OR CONTRIBUTORS 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 "build-pre.h"

/*
 * Convert a string from JIS X 0208 to EUC JP.
 */
void
eb_jisx0208_to_euc(char *out_string, const char *in_string)
{
    unsigned char *out_p = (unsigned char *)out_string;
    const unsigned char *in_p = (unsigned char *)in_string;

    while (*in_p != '\0')
    *out_p++ = ((*in_p++) | 0x80);

    *out_p = '\0';
}


/*
 * Convert a string from shift-JIS to EUC JP.
 * (Shift-JIS is used only in the `LANGUAGE' file.)
 */
void
eb_sjis_to_euc(char *out_string, const char *in_string)
{
    unsigned char *out_p = (unsigned char *)out_string;
    const unsigned char *in_p = (unsigned char *)in_string;
    unsigned char c1, c2;

    for (;;) {
    /*
     * Break at '\0'.
     */
    c1 = *in_p++;
    if (c1 == '\0')
        break;

    if (c1 <= 0x7f) {
        /*
         * JIS X 0201 Roman character.
         */
        *out_p++ = c1;
    } else if (0xa1 <= c1 && c1 <= 0xdf) {
        /*
         * JIS X 0201 Kana.
         */
        *out_p++ = ' ';
    } else {
        /*
         * JIS X 0208 character.
         */
        c2 = *in_p++;
        if (c2 == 0x00)
        break;

        if (c2 < 0x9f) {
        if (c1 < 0xdf)
            c1 = ((c1 - 0x30) << 1) - 1;
        else
            c1 = ((c1 - 0x70) << 1) - 1;

        if (c2 < 0x7f)
            c2 += 0x61;
        else
            c2 += 0x60;
        } else {
        if (c1 < 0xdf)
            c1 = (c1 - 0x30) << 1;
        else
            c1 = (c1 - 0x70) << 1;
        c2 += 0x02;
        }

        *out_p++ = c1;
        *out_p++ = c2;
    }
    }

    *out_p = '\0';
}