Add unicode and NLS support

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