teraterm/teraterm/charset.cpp

/*
 * (C) 2023- TeraTerm Project
 * All rights reserved.
 *
 * 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. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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 "teraterm.h"
#include "tttypes.h"
#include <stdio.h>
#include <string.h>
#if !defined(_CRTDBG_MAP_ALLOC)
#define _CRTDBG_MAP_ALLOC
#endif
#include <stdlib.h>
#include <crtdbg.h>
#include <assert.h>

#include "ttwinman.h"
#include "codeconv.h"
#include "unicode.h"
#include "language.h"   // for JIS2SJIS()
#include "ttcstd.h"
#include "vtterm.h"

#include "charset.h"

// UTF-8���s�����l�����������\����������
#define REPLACEMENT_CHARACTER   0xfffd          // REPLACEMENT CHARACTER
//#define REPLACEMENT_CHARACTER 0x2e2e          // Reversed Question Mark (VT382)

typedef struct CharSetDataTag {
        /* GL, GR code group */
        int Glr[2];
        /* G0, G1, G2, G3 code group */
        int Gn[4];
        /* GL for single shift 2/3 */
        int GLtmp;
        /* single shift 2/3 flag */
        BOOL SSflag;
        //
        char32_t replacement_char;
        // UTF-8 work
        BYTE buf[4];
        int count;
        BOOL Fallbacked;

        // MBCS
        BOOL KanjiIn;                           // TRUE = MBCS��1byte�������M��������
        WORD Kanji;

        // EUC
        BOOL EUCkanaIn;
        BOOL EUCsupIn;
        int  EUCcount;

        /* JIS -> SJIS conversion flag */
        BOOL ConvJIS;
        BYTE DebugFlag;

        // Operations
        CharSetOp Op;
        void *ClientData;
} CharSetData;

static BOOL IsC0(char32_t b)
{
        return (b <= US);
}

static BOOL IsC1(char32_t b)
{
        return ((b>=0x80) && (b<=0x9F));
}

/**
 *      ISO2022�p���[�N������������
 */
static void CharSetInit2(CharSetData *w)
{
        if (ts.Language==IdJapanese) {
                w->Gn[0] = IdASCII;
                w->Gn[1] = IdKatakana;
                w->Gn[2] = IdKatakana;
                w->Gn[3] = IdKanji;
                w->Glr[0] = 0;
                if ((ts.KanjiCode==IdJIS) && (ts.JIS7Katakana==0))
                        w->Glr[1] = 2;  // 8-bit katakana
                else
                        w->Glr[1] = 3;
        }
        else {
                w->Gn[0] = IdASCII;
                w->Gn[1] = IdSpecial;
                w->Gn[2] = IdASCII;
                w->Gn[3] = IdASCII;
                w->Glr[0] = 0;
                w->Glr[1] = 0;
        }
}

/**
 *      �������A���[�N������������
 */
CharSetData *CharSetInit(const CharSetOp *op, void *client_data)
{
        CharSetData *w = (CharSetData *)calloc(sizeof(*w), 1);
        if (w == NULL) {
                return NULL;
        }

        w->Op = *op;
        w->ClientData = client_data;

        CharSetInit2(w);
        w->GLtmp = 0;
        w->SSflag = FALSE;

        w->DebugFlag = DEBUG_FLAG_NONE;

        w->replacement_char = REPLACEMENT_CHARACTER;
        w->SSflag = FALSE;

        w->KanjiIn = FALSE;
        w->EUCkanaIn = FALSE;
        w->EUCsupIn = FALSE;
        w->ConvJIS = FALSE;
        w->Fallbacked = FALSE;

        return w;
}

void CharSetFinish(CharSetData *w)
{
        assert(w != NULL);
        free(w);
}

/**
 *      1byte���`�F�b�N
 */
static BOOL CheckFirstByte(BYTE b, int lang, int kanji_code)
{
        switch (lang) {
                case IdKorean:
                        return __ismbblead(b, 949);
                case IdChinese:
                        if (kanji_code == IdCnGB2312) {
                                return __ismbblead(b, 936);
                        }
                        else if (ts.KanjiCode == IdCnBig5) {
                                return __ismbblead(b, 950);
                        }
                        break;
                default:
                        assert(FALSE);
                        break;
        }
        assert(FALSE);
        return FALSE;
}

/**
 *      Double-byte Character Sets
 *      SJIS��1byte��?
 *
 *      ��1�o�C�g0x81...0x9F or 0xE0...0xEF
 *      ��1�o�C�g0x81...0x9F or 0xE0...0xFC
 */
static BOOL ismbbleadSJIS(BYTE b)
{
        if (((0x80<b) && (b<0xa0)) || ((0xdf<b) && (b<0xfd))) {
                return TRUE;
        }
        return FALSE;
}

/**
 *      ts.Language == IdJapanese ��
 *      1byte���`�F�b�N
 */
static BOOL CheckKanji(CharSetData *w, BYTE b)
{
        BOOL Check;

        if (ts.Language!=IdJapanese)
                return FALSE;

        w->ConvJIS = FALSE;

        if (ts.KanjiCode==IdSJIS ||
           (ts.FallbackToCP932 && ts.KanjiCode==IdUTF8)) {
                if (((0x80<b) && (b<0xa0)) || ((0xdf<b) && (b<0xfd))) {
                        w->Fallbacked = TRUE;
                        return TRUE; // SJIS kanji
                }
                if ((0xa1<=b) && (b<=0xdf)) {
                        return FALSE; // SJIS katakana
                }
        }

        if ((b>=0x21) && (b<=0x7e)) {
                Check = (w->Gn[w->Glr[0]] == IdKanji);
                w->ConvJIS = Check;
        }
        else if ((b>=0xA1) && (b<=0xFE)) {
                Check = (w->Gn[w->Glr[1]] == IdKanji);
                if (ts.KanjiCode==IdEUC) {
                        Check = TRUE;
                }
                else if (ts.KanjiCode==IdJIS && ((ts.TermFlag & TF_FIXEDJIS)!=0) && (ts.JIS7Katakana==0)) {
                        Check = FALSE; // 8-bit katakana
                }
                w->ConvJIS = Check;
        }
        else {
                Check = FALSE;
        }

        return Check;
}

static BOOL ParseFirstJP(CharSetData *w, BYTE b)
// returns TRUE if b is processed
//  (actually allways returns TRUE)
{
        if (w->KanjiIn) {
                if (((! w->ConvJIS) && (0x3F<b) && (b<0xFD)) ||
                        (w->ConvJIS && ( ((0x20<b) && (b<0x7f)) ||
                                                  ((0xa0<b) && (b<0xff)) )) )
                {
                        unsigned long u32;
                        w->Kanji = w->Kanji + b;
                        if (w->ConvJIS) {
                                // JIS -> Shift_JIS(CP932)
                                w->Kanji = JIS2SJIS((WORD)(w->Kanji & 0x7f7f));
                        }
                        u32 = CP932ToUTF32(w->Kanji);
                        w->Op.PutU32(u32, w->ClientData);
                        w->KanjiIn = FALSE;
                        return TRUE;
                }
                else if ((ts.TermFlag & TF_CTRLINKANJI)==0) {
                        w->KanjiIn = FALSE;
                }
        }

        if (w->SSflag) {
                if (w->Gn[w->GLtmp] == IdKanji) {
                        w->Kanji = b << 8;
                        w->KanjiIn = TRUE;
                        w->SSflag = FALSE;
                        return TRUE;
                }
                else if (w->Gn[w->GLtmp] == IdKatakana) {
                        b = b | 0x80;
                }

                w->Op.PutU32(b, w->ClientData);
                w->SSflag = FALSE;
                return TRUE;
        }

        if ((!w->EUCsupIn) && (!w->EUCkanaIn) && (!w->KanjiIn) && CheckKanji(w, b)) {
                w->Kanji = b << 8;
                w->KanjiIn = TRUE;
                return TRUE;
        }

        if (b<=US) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0x20) {
                w->Op.PutU32(b, w->ClientData);
        }
        else if ((b>=0x21) && (b<=0x7E)) {
                if (w->EUCsupIn) {
                        w->EUCcount--;
                        w->EUCsupIn = (w->EUCcount==0);
                        return TRUE;
                }

                if ((w->Gn[w->Glr[0]] == IdKatakana) || w->EUCkanaIn) {
                        b = b | 0x80;
                        w->EUCkanaIn = FALSE;
                        {
                                // b��sjis�����p�J�^�J�i
                                unsigned long u32 = CP932ToUTF32(b);
                                w->Op.PutU32(u32, w->ClientData);
                        }
                        return TRUE;
                }
                w->Op.PutU32(b, w->ClientData);
        }
        else if (b==0x7f) {
                return TRUE;
        }
        else if ((b>=0x80) && (b<=0x8D)) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0x8E) { // SS2
                switch (ts.KanjiCode) {
                case IdEUC:
                        if (ts.ISO2022Flag & ISO2022_SS2) {
                                w->EUCkanaIn = TRUE;
                        }
                        break;
                case IdUTF8:
                        w->Op.PutU32(w->replacement_char, w->ClientData);
                        break;
                default:
                        w->Op.ParseControl(b, w->ClientData);
                }
        }
        else if (b==0x8F) { // SS3
                switch (ts.KanjiCode) {
                case IdEUC:
                        if (ts.ISO2022Flag & ISO2022_SS3) {
                                w->EUCcount = 2;
                                w->EUCsupIn = TRUE;
                        }
                        break;
                case IdUTF8:
                        w->Op.PutU32(w->replacement_char, w->ClientData);
                        break;
                default:
                        w->Op.ParseControl(b, w->ClientData);
                }
        }
        else if ((b>=0x90) && (b<=0x9F)) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0xA0) {
                w->Op.PutU32(0x20, w->ClientData);
        }
        else if ((b>=0xA1) && (b<=0xFE)) {
                if (w->EUCsupIn) {
                        w->EUCcount--;
                        w->EUCsupIn = (w->EUCcount==0);
                        return TRUE;
                }

                if ((w->Gn[w->Glr[1]] != IdASCII) ||
                    ((ts.KanjiCode==IdEUC) && w->EUCkanaIn) ||
                    (ts.KanjiCode==IdSJIS) ||
                    ((ts.KanjiCode==IdJIS) &&
                         (ts.JIS7Katakana==0) &&
                         ((ts.TermFlag & TF_FIXEDJIS)!=0))) {
                        // b��sjis�����p�J�^�J�i
                        unsigned long u32 = CP932ToUTF32(b);
                        w->Op.PutU32(u32, w->ClientData);
                } else {
                        if (w->Gn[w->Glr[1]] == IdASCII) {
                                b = b & 0x7f;
                        }
                        w->Op.PutU32(b, w->ClientData);
                }
                w->EUCkanaIn = FALSE;
        }
        else {
                w->Op.PutU32(b, w->ClientData);
        }

        return TRUE;
}

static BOOL ParseFirstKR(CharSetData *w, BYTE b)
// returns TRUE if b is processed
//  (actually allways returns TRUE)
{
        if (w->KanjiIn) {
                if (((0x41<=b) && (b<=0x5A)) ||
                        ((0x61<=b) && (b<=0x7A)) ||
                        ((0x81<=b) && (b<=0xFE)))
                {
                        unsigned long u32 = 0;
                        if (ts.KanjiCode == IdKoreanCP949) {
                                // CP949
                                w->Kanji = w->Kanji + b;
                                u32 = MBCP_UTF32(w->Kanji, 949);
                        }
                        else {
                                assert(FALSE);
                        }
                        w->Op.PutU32(u32, w->ClientData);
                        w->KanjiIn = FALSE;
                        return TRUE;
                }
                else if ((ts.TermFlag & TF_CTRLINKANJI)==0) {
                        w->KanjiIn = FALSE;
                }
        }

        if ((!w->KanjiIn) && CheckFirstByte(b, ts.Language, ts.KanjiCode)) {
                w->Kanji = b << 8;
                w->KanjiIn = TRUE;
                return TRUE;
        }

        if (b<=US) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0x20) {
                w->Op.PutU32(b, w->ClientData);
        }
        else if ((b>=0x21) && (b<=0x7E)) {
//              if (Gn[Glr[0]] == IdKatakana) {
//                      b = b | 0x80;
//              }
                w->Op.PutU32(b, w->ClientData);
        }
        else if (b==0x7f) {
                return TRUE;
        }
        else if ((0x80<=b) && (b<=0x9F)) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0xA0) {
                w->Op.PutU32(0x20, w->ClientData);
        }
        else if ((b>=0xA1) && (b<=0xFE)) {
                if (w->Gn[w->Glr[1]] == IdASCII) {
                        b = b & 0x7f;
                }
                w->Op.PutU32(b, w->ClientData);
        }
        else {
                w->Op.PutU32(b, w->ClientData);
        }

        return TRUE;
}

static BOOL ParseFirstCn(CharSetData *w, BYTE b)
// returns TRUE if b is processed
//  (actually allways returns TRUE)
{
        if (w->KanjiIn) {
                // TODO
                if (((0x40<=b) && (b<=0x7e)) ||
                    ((0xa1<=b) && (b<=0xFE)))
                {
                        unsigned long u32 = 0;
                        w->Kanji = w->Kanji + b;
                        if (ts.KanjiCode == IdCnGB2312) {
                                // CP936 GB2312
                                u32 = MBCP_UTF32(w->Kanji, 936);
                        }
                        else if (ts.KanjiCode == IdCnBig5) {
                                // CP950 Big5
                                u32 = MBCP_UTF32(w->Kanji, 950);
                        }
                        else {
                                assert(FALSE);
                        }
                        w->Op.PutU32(u32, w->ClientData);
                        w->KanjiIn = FALSE;
                        return TRUE;
                }
                else if ((ts.TermFlag & TF_CTRLINKANJI)==0) {
                        w->KanjiIn = FALSE;
                }
        }

        if ((!w->KanjiIn) && CheckFirstByte(b, ts.Language, ts.KanjiCode)) {
                w->Kanji = b << 8;
                w->KanjiIn = TRUE;
                return TRUE;
        }

        if (b<=US) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0x20) {
                w->Op.PutU32(b, w->ClientData);
        }
        else if ((b>=0x21) && (b<=0x7E)) {
//              if (Gn[Glr[0]] == IdKatakana) {
//                      b = b | 0x80;
//              }
                w->Op.PutU32(b, w->ClientData);
        }
        else if (b==0x7f) {
                return TRUE;
        }
        else if ((0x80<=b) && (b<=0x9F)) {
                w->Op.ParseControl(b, w->ClientData);
        }
        else if (b==0xA0) {
                w->Op.PutU32(0x20, w->ClientData);
        }
        else if ((b>=0xA1) && (b<=0xFE)) {
                if (w->Gn[w->Glr[1]] == IdASCII) {
                        b = b & 0x7f;
                }
                w->Op.PutU32(b, w->ClientData);
        }
        else {
                w->Op.PutU32(b, w->ClientData);
        }

        return TRUE;
}

static void ParseASCII(CharSetData *w, BYTE b)
{
        if (w->SSflag) {
                w->Op.PutU32(b, w->ClientData);
                w->SSflag = FALSE;
                return;
        }

        if (b<=US) {
                w->Op.ParseControl(b, w->ClientData);
        } else if ((b>=0x20) && (b<=0x7E)) {
                w->Op.PutU32(b, w->ClientData);
        } else if ((b==0x8E) || (b==0x8F)) {
                w->Op.PutU32(w->replacement_char, w->ClientData);
        } else if ((b>=0x80) && (b<=0x9F)) {
                w->Op.ParseControl(b, w->ClientData);
        } else if (b>=0xA0) {
                w->Op.PutU32(b, w->ClientData);
        }
}

/**
 *      REPLACEMENT_CHARACTER ���\��
 *      UTF-8 �f�R�[�h�����g�p
 */
static void PutReplacementChr(CharSetData *w, const BYTE *ptr, size_t len, BOOL fallback)
{
        const char32_t replacement_char = w->replacement_char;
        int i;
        for (i = 0; i < len; i++) {
                BYTE c = *ptr++;
                assert(!IsC0(c));
                if (fallback) {
                        // fallback ISO8859-1
                        w->Op.PutU32(c, w->ClientData);
                }
                else {
                        // fallback������
                        if (c < 0x80) {
                                // �s����UTF-8��������������0x80�������������A
                                // 1������UTF-8�������������������\������
                                w->Op.PutU32(c, w->ClientData);
                        }
                        else {
                                w->Op.PutU32(replacement_char, w->ClientData);
                        }
                }
        }
}

/**
 * UTF-8�����M�f�[�^����������
 *
 * returns TRUE if b is processed
 */
static BOOL ParseFirstUTF8(CharSetData *w, BYTE b)
{
        char32_t code;

        if (w->Fallbacked) {
                BOOL r = ParseFirstJP(w, b);
                w->Fallbacked = FALSE;
                return r;
        }

        // UTF-8�G���R�[�h
        //      The Unicode Standard Chapter 3
        //      Table 3-7. Well-Formed UTF-8 Byte Sequences
        // | Code Points        | 1st Byte | 2nd Byte | 3rd Byte | 4th Byte |
        // | U+0000..U+007F     | 00..7F   |          |          |          |
        // | U+0080..U+07FF     | C2..DF   | 80..BF   |          |          |
        // | U+0800..U+0FFF     | E0       | A0..BF   | 80..BF   |          |
        // | U+1000..U+CFFF     | E1..EC   | 80..BF   | 80..BF   |          |
        // | U+D000..U+D7FF     | ED       | 80..9F   | 80..BF   |          |
        // | U+E000..U+FFFF     | EE..EF   | 80..BF   | 80..BF   |          |
        // | U+10000..U+3FFFF   | F0       | 90..BF   | 80..BF   | 80..BF   |
        // | U+40000..U+FFFFF   | F1..F3   | 80..BF   | 80..BF   | 80..BF   |
        // | U+100000..U+10FFFF | F4       | 80..8F   | 80..BF   | 80..BF   |
        //      - 1byte��
        //              - 0x00 - 0x7f           ok
        //              - 0x80 - 0xc1           ng
        //              - 0xc2 - 0xf4           ok
        //              - 0xf5 - 0xff           ng
        //      - 2byte�����~
        //              - 0x00 - 0x7f           ng
        //              - 0x80 - 0xbf           ok
        //              - 0xc0 - 0xff           ng
        //  - 2byte�����O
        //              - 1byte == 0xe0 ������ 0xa0 - 0xbf����ok
        //              - 1byte == 0xed ������ 0x80 - 0x9f����ok
        //              - 1byte == 0xf0 ������ 0x90 - 0xbf����ok
        //              - 1byte == 0xf4 ������ 0x90 - 0x8f����ok
recheck:
        // 1byte(7bit)
        if (w->count == 0) {
                if (IsC0(b)) {
                        // U+0000 .. U+001f
                        // C0��������, C0 Coontrols
                        w->Op.ParseControl(b, w->ClientData);
                        return TRUE;
                }
                else if (b <= 0x7f) {
                        // 0x7f����, �������A���������o��
                        w->Op.PutU32(b, w->ClientData);
                        return TRUE;
                }
                else if (0xc2 <= b && b <= 0xf4) {
                        // 1byte������
                        w->buf[w->count++] = b;
                        return TRUE;
                }

                // 0x80 - 0xc1, 0xf5 - 0xff
                // UTF-8��1byte���o���������R�[�h������
                if (ts.FallbackToCP932) {
                        // fallback��������
                        if ((ts.Language == IdJapanese) && ismbbleadSJIS(b)) {
                                // ���{�������� && Shift_JIS 1byte��
                                // Shift_JIS �� fallback
                                w->Fallbacked = TRUE;
                                w->ConvJIS = FALSE;
                                w->Kanji = b << 8;
                                w->KanjiIn = TRUE;
                                return TRUE;
                        }
                }
                // fallback������, �s������������
                w->buf[0] = b;
                PutReplacementChr(w, w->buf, 1, FALSE);
                return TRUE;
        }

        // 2byte���~����?
        if((b & 0xc0) != 0x80) {        // == (b <= 0x7f || 0xc0 <= b)
                // �s��������, (����2bit�� 0b10xx_xxxx ��������)
                PutReplacementChr(w, w->buf, w->count, ts.FallbackToCP932);
                w->count = 0;
                goto recheck;
        }

        // 2byte�����~����
        w->buf[w->count++] = b;

        // 2byte(11bit)
        if (w->count == 2) {
                if ((w->buf[0] & 0xe0) == 0xc0) {       // == (0xc2 <= w->buf[0] && w->buf[0] <= 0xdf)
                        // 5bit + 6bit
                        code = ((w->buf[0] & 0x1f) << 6) | (b & 0x3f);
                        if (IsC1(code)) {
                                // U+0080 .. u+009f
                                // C1��������, C1 Controls
                                w->Op.ParseControl((BYTE)code, w->ClientData);
                        }
                        else {
                                w->Op.PutU32(code, w->ClientData);
                        }
                        w->count = 0;
                        return TRUE;
                }
                return TRUE;
        }

        // 3byte(16bit)
        if (w->count == 3) {
                if ((w->buf[0] & 0xf0) == 0xe0) {
                        if ((w->buf[0] == 0xe0 && (w->buf[1] < 0xa0 || 0xbf < w->buf[1])) ||
                                (w->buf[0] == 0xed && (                 0x9f < w->buf[1]))) {
                                // �s���� UTF-8
                                PutReplacementChr(w, w->buf, 2, ts.FallbackToCP932);
                                w->count = 0;
                                goto recheck;
                        }
                        // 4bit + 6bit + 6bit
                        code = ((w->buf[0] & 0xf) << 12);
                        code |= ((w->buf[1] & 0x3f) << 6);
                        code |= ((w->buf[2] & 0x3f));
                        w->Op.PutU32(code, w->ClientData);
                        w->count = 0;
                        return TRUE;
                }
                return TRUE;
        }

        // 4byte(21bit)
        assert(w->count == 4);
        assert((w->buf[0] & 0xf8) == 0xf0);
        if ((w->buf[0] == 0xf0 && (w->buf[1] < 0x90 || 0x9f < w->buf[1])) ||
                (w->buf[0] == 0xf4 && (w->buf[1] < 0x80 || 0x8f < w->buf[1]))) {
                // �s���� UTF-8
                PutReplacementChr(w, w->buf, 3, ts.FallbackToCP932);
                w->count = 0;
                goto recheck;
        }
        // 3bit + 6bit + 6bit + 6bit
        code = ((w->buf[0] & 0x07) << 18);
        code |= ((w->buf[1] & 0x3f) << 12);
        code |= ((w->buf[2] & 0x3f) << 6);
        code |= (w->buf[3] & 0x3f);
        w->Op.PutU32(code, w->ClientData);
        w->count = 0;
        return TRUE;
}

static BOOL ParseFirstRus(CharSetData *w, BYTE b)
// returns if b is processed
{
        if (IsC0(b)) {
                w->Op.ParseControl(b, w->ClientData);
                return TRUE;
        }
        // CP1251������
        BYTE c = RussConv(ts.KanjiCode, IdWindows, b);
        // CP1251->Unicode
        unsigned long u32 = MBCP_UTF32(c, 1251);
        w->Op.PutU32(u32, w->ClientData);
        return TRUE;
}

static BOOL ParseEnglish(CharSetData *w, BYTE b)
{
        unsigned short u16 = 0;
        int part = KanjiCodeToISO8859Part(ts.KanjiCode);
        int r = UnicodeFromISO8859(part, b, &u16);
        if (r == 0) {
                return FALSE;
        }
        if (u16 < 0x100) {
                ParseASCII(w, (BYTE)u16);
        }
        else {
                w->Op.PutU32(u16, w->ClientData);
        }
        return TRUE;
}

static void PutDebugChar(CharSetData *w, BYTE b)
{
        int i;
        BOOL svInsertMode, svAutoWrapMode;
        TCharAttr svCharAttr;
        TCharAttr char_attr;

        svInsertMode = TermGetInsertMode();
        TermSetInsertMode(FALSE);
        svAutoWrapMode = TermGetAutoWrapMode();
        TermSetAutoWrapMode(TRUE);

        TermGetAttr(&svCharAttr);
        char_attr = svCharAttr;
        char_attr.Attr = AttrDefault;
        TermSetAttr(&char_attr);

        if (w->DebugFlag==DEBUG_FLAG_HEXD) {
                char buff[3];
                _snprintf(buff, 3, "%02X", (unsigned int) b);

                for (i=0; i<2; i++)
                        w->Op.PutU32(buff[i], w->ClientData);
                w->Op.PutU32(' ', w->ClientData);
        }
        else if (w->DebugFlag==DEBUG_FLAG_NORM) {

                if ((b & 0x80) == 0x80) {
                        //UpdateStr();
                        char_attr.Attr = AttrReverse;
                        TermSetAttr(&char_attr);
                        b = b & 0x7f;
                }

                if (b<=US) {
                        w->Op.PutU32('^', w->ClientData);
                        w->Op.PutU32((char)(b + 0x40), w->ClientData);
                }
                else if (b==DEL) {
                        w->Op.PutU32('<', w->ClientData);
                        w->Op.PutU32('D', w->ClientData);
                        w->Op.PutU32('E', w->ClientData);
                        w->Op.PutU32('L', w->ClientData);
                        w->Op.PutU32('>', w->ClientData);
                }
                else
                        w->Op.PutU32(b, w->ClientData);
        }

        TermSetAttr(&char_attr);
        TermSetInsertMode(svInsertMode);
        TermSetAutoWrapMode(svAutoWrapMode);
}

void ParseFirst(CharSetData *w, BYTE b)
{
        WORD language = ts.Language;
        if (w->DebugFlag != DEBUG_FLAG_NONE) {
                language = IdDebug;
        }

        switch (language) {
        default:
                assert(FALSE);
                language = IdUtf8;
                // FALLTHROUGH
        case IdUtf8:
                ParseFirstUTF8(w, b);
                return;

        case IdJapanese:
                switch (ts.KanjiCode) {
                case IdUTF8:
                        if (ParseFirstUTF8(w, b)) {
                                return;
                        }
                        break;
                default:
                        if (ParseFirstJP(w, b))  {
                                return;
                        }
                }
                break;

        case IdKorean:
                switch (ts.KanjiCode) {
                case IdUTF8:
                        if (ParseFirstUTF8(w, b)) {
                                return;
                        }
                        break;
                default:
                        if (ParseFirstKR(w, b))  {
                                return;
                        }
                }
                break;

        case IdRussian:
                if (ParseFirstRus(w, b)) {
                        return;
                }
                break;

        case IdChinese:
                switch (ts.KanjiCode) {
                case IdUTF8:
                        if (ParseFirstUTF8(w, b)) {
                                return;
                        }
                        break;
                default:
                        if (ParseFirstCn(w, b)) {
                                return;
                        }
                }
                break;
        case IdEnglish: {
                if (ParseEnglish(w, b)) {
                        return;
                }
                break;
        }
        case IdDebug: {
                PutDebugChar(w, b);
                return;
        }
        }

        if (w->SSflag) {
                w->Op.PutU32(b, w->ClientData);
                w->SSflag = FALSE;
                return;
        }

        if (b<=US)
                w->Op.ParseControl(b, w->ClientData);
        else if ((b>=0x20) && (b<=0x7E))
                w->Op.PutU32(b, w->ClientData);
        else if ((b>=0x80) && (b<=0x9F))
                w->Op.ParseControl(b, w->ClientData);
        else if (b>=0xA0)
                w->Op.PutU32(b, w->ClientData);
}

/**
 *      �w��(Designate)
 *
 *      @param  Gn                      0/1/2/3 = G0/G1/G2/G3
 *      @param  codeset         IdASCII    0
 *                                              IdKatakana 1
 *                                              IdKanji    2
 *                                              IdSpecial  3
 */
void CharSet2022Designate(CharSetData *w, int gn, int cs)
{
        w->Gn[gn] = cs;
}

/**
 *      �����o��(Invoke)
 *      @param  shift
 */
void CharSet2022Invoke(CharSetData *w, CharSet2022Shift shift)
{
        switch (shift) {
        case CHARSET_LS0:
                // Locking Shift 0 (G0->GL)
                w->Glr[0] = 0;
                break;
        case CHARSET_LS1:
                // Locking Shift 1 (G1->GL)
                w->Glr[0] = 1;
                break;
        case CHARSET_LS2:
                // Locking Shift 2 (G2->GL)
                w->Glr[0] = 2;
                break;
        case CHARSET_LS3:
                // Locking Shift 3 (G3->GL)
                w->Glr[0] = 3;
                break;
        case CHARSET_LS1R:
                // Locking Shift 1 (G1->GR)
                w->Glr[1] = 1;
                break;
        case CHARSET_LS2R:
                // Locking Shift 2 (G2->GR)
                w->Glr[1] = 2;
                break;
        case CHARSET_LS3R:
                // Locking Shift 3 (G3->GR)
                w->Glr[1] = 3;
                break;
        case CHARSET_SS2:
                // Single Shift 2
                w->GLtmp = 2;
                w->SSflag = TRUE;
                break;
        case CHARSET_SS3:
                // Single Shift 3
                w->GLtmp = 3;
                w->SSflag = TRUE;
                break;
        default:
                assert(FALSE);
                break;
        }
}

/**
 *      DEC�����t�H���g(Tera Special font)
 *      0140(0x60) ... 0176(0x7f) ���r�����A�T�C������������
 *      (0xe0) ...     (0xff) ��?
 *      <ESC>(0 �������������G�X�P�[�v�V�[�P���X�����`
 *      about/emulations.html
 *
 *      @param  b               �R�[�h
 *      @retval TRUE    IdSpecial
 *      @retval FALSE   IdSpecial��������
 */
BOOL CharSetIsSpecial(CharSetData *w, BYTE b)
{
        BOOL SpecialNew = FALSE;

        if ((b>0x5F) && (b<0x80)) {
                if (w->SSflag)
                        SpecialNew = (w->Gn[w->GLtmp]==IdSpecial);
                else
                        SpecialNew = (w->Gn[w->Glr[0]]==IdSpecial);
        }
        else if (b>0xDF) {
                if (w->SSflag)
                        SpecialNew = (w->Gn[w->GLtmp]==IdSpecial);
                else
                        SpecialNew = (w->Gn[w->Glr[1]]==IdSpecial);
        }

        return SpecialNew;
}

static void CharSetSaveStateLow(CharSetState *state, const CharSetData *w)
{
        int i;
        state->infos[0] = w->Glr[0];
        state->infos[1] = w->Glr[1];
        for (i=0 ; i<=3; i++) {
                state->infos[2 + i] = w->Gn[i];
        }
}

/**
 *      ��������������
 */
void CharSetSaveState(CharSetData *w, CharSetState *state)
{
        CharSetSaveStateLow(state, w);
}

/**
 *      ���������A����
 */
void CharSetLoadState(CharSetData *w, const CharSetState *state)
{
        int i;
        w->Glr[0] = state->infos[0];
        w->Glr[1] = state->infos[1];
        for (i=0 ; i<=3; i++) {
                w->Gn[i] = state->infos[2 + i];
        }
}

/**
 *      �t�H�[���o�b�N���I��
 *              ���M�f�[�^UTF-8�����AShift_JIS�o����(fallback����)�����f����
 *
 */
void CharSetFallbackFinish(CharSetData *w)
{
        w->Fallbacked = FALSE;
}

/**
 *      �f�o�O�o�����������[�h�����X����
 */
void CharSetSetNextDebugMode(CharSetData *w)
{
        // ts.DebugModes ���� tttypes.h �� DBGF_* �� OR ����������
        do {
                w->DebugFlag = (w->DebugFlag + 1) % DEBUG_FLAG_MAXD;
        } while (w->DebugFlag != DEBUG_FLAG_NONE && !((ts.DebugModes >> (w->DebugFlag - 1)) & 1));
}

BYTE CharSetGetDebugMode(CharSetData *w)
{
        return w->DebugFlag;
}

void CharSetSetDebugMode(CharSetData *w, BYTE mode)
{
        w->DebugFlag = mode % DEBUG_FLAG_MAXD;
}