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Diffstat (limited to 'unicode.h')
| -rw-r--r-- | unicode.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/unicode.h b/unicode.h new file mode 100644 index 0000000..9e70895 --- /dev/null +++ b/unicode.h @@ -0,0 +1,215 @@ +/* + * VBSF - unix to DOS time conversion + * Copyright (C) 2022 Javier S. Pedro + * + * unicode.h: Unicode conversion routines + * Copyright (C) 2011-2022 Eduardo Casino + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + + * This program 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 General License for more details. + * + * You should have received a copy of the GNU General License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#ifndef UNICODE_H +#define UNICODE_H + +#include <stdint.h> +#include "sftsr.h" + + +#ifdef __IN_SFTSR__ +#define TSRDATAPTR PTSRDATA +#else +#define TSRDATAPTR LPTSRDATA +#endif + +static inline uint8_t lookup_codepage( TSRDATAPTR data, uint16_t cp ) +{ + uint8_t i; + + for ( i = 0; i < 128 && data->unicode_table[i] != cp; ++i ); + + return ( i < 128 ? (uint8_t) i + 128 : '\0' ); +} + +// dst and src CAN'T BE THE SAME !!!! +// Returns resulting length or -1 if buffer overflow +// +static uint16_t local_to_utf8_n( TSRDATAPTR data, uint8_t *dst, const char far *src, uint16_t buflen, uint16_t count ) +{ + uint16_t len = 0; // Resulting length + uint16_t cp; // Unicode Code Point + + while ( *src && count ) + { + // UTF-8 bytes: 0xxxxxxx + // Binary CP: 0xxxxxxx + // CP range: U+0000 to U+007F (Direct ASCII translation) + // + if ( ! (*src & 0x80) ) + { + if ( buflen > len ) + { + *dst++ = *src; + ++len; + goto cont; + } + else + { + return -1; + } + } + + cp = data->unicode_table[*src - 128]; + + // UTF-8 bytes: 110yyyyy 10xxxxxx + // Binary CP: 00000yyy yyxxxxxx + // CP range: U+0080 to U+07FF + // + if ( ! (cp & 0xF000) ) + { + if ( buflen > len + 1 ) + { + *dst++ = (uint8_t)( cp >> 6 ) | 0xC0; + *dst++ = (uint8_t)( cp & 0x3f ) | 0x80; + len += 2; + } + else + { + return -1; + } + } + + // UTF-8 bytes: 1110zzzz 10yyyyyy 10xxxxxx + // Binary CP: zzzzyyyy yyxxxxxx + // CP range: U+0800 to U+FFFF + // + else + { + if ( buflen > len +2 ) + { + *dst++ = (uint8_t)( cp >> 12 ) | 0xE0; + *dst++ = (uint8_t)( (cp >> 6) & 0x3F ) | 0x80; + *dst++ = (uint8_t)( cp & 0x3F ) | 0x80; + len += 3; + } + else + { + return -1; + } + } +cont: + ++src, --count; + }; + + // Terminate string + // + *dst = '\0'; + + return len; + +} + +static inline uint16_t local_to_utf8( TSRDATAPTR data, uint8_t *dst, const char far *src, uint16_t buflen ) +{ + return local_to_utf8_n( data, dst, src, buflen, buflen ); +} + +// Returns true on success, false if any unsupported char is found +// +static bool utf8_to_local( TSRDATAPTR data, char *dst, char *src, uint16_t *len ) +{ + bool ret = true; // Return code + uint16_t cp; // Unicode Code point + uint16_t l = 0; + + while ( *src ) + { + // UTF-8 bytes: 0xxxxxxx + // Binary CP: 0xxxxxxx + // CP range: U+0000 to U+007F (Direct ASCII translation) + // + if ( ! (*src & 0x80) ) + { + *dst = *src; + ++src; + goto cont; + } + + // UTF-8 bytes: 110yyyyy 10xxxxxx + // Binary CP: 00000yyy yyxxxxxx + // CP range: U+0080 to U+07FF + // + if ( ! (*src & 0x20) ) + { + cp = ( (uint16_t)(*src & 0x1F) << 6 ) | *(src+1) & 0x3F; + *dst = lookup_codepage( data, cp ); + if ( *dst == '\0' ) + { + *dst = '_'; + ret = false; + } + src += 2; + goto cont; + } + + // UTF-8 bytes: 1110zzzz 10yyyyyy 10xxxxxx + // Binary CP: zzzzyyyy yyxxxxxx + // CP range: U+0800 to U+FFFF + // + if ( ! (*src & 0x10) ) + { + cp = ( (uint16_t)(*src & 0xF) << 12 ) | ( (uint16_t)(*(src+1) & 0x3F) << 6 ) | *(src+2) & 0x3F; + *dst = lookup_codepage( data, cp ); + if ( *dst == '\0' ) + { + *dst = '_'; + ret = false; + } + src += 3; + goto cont; + } + + // UTF-8 bytes: 11110www 10zzzzzz 10yyyyyy 10xxxxxx + // Binary CP: 000wwwzz zzzzyyyy yyxxxxxx + // CP range: U+010000 to U+10FFFF + // + if ( ! (*src & 0x08) ) + { + *dst = '_'; // Currently unsupported + ret = false; + src += 4; + goto cont; + } + + // Should not reach here + // + *dst = '_'; + ret = false; + ++src; +cont: + ++dst, ++l; + + }; + + // Terminate string + // + *dst = '\0'; + + if (len) *len = l; + + return ret; + +} + +#endif |