ylib/include/util/__3d/ConvertUTF.c

///*
// * Copyright 2001-2004 Unicode, Inc.
// * 
// * Disclaimer
// * 
// * This source code is provided as is by Unicode, Inc. No claims are
// * made as to fitness for any particular purpose. No warranties of any
// * kind are expressed or implied. The recipient agrees to determine
// * applicability of information provided. If this file has been
// * purchased on magnetic or optical media from Unicode, Inc., the
// * sole remedy for any claim will be exchange of defective media
// * within 90 days of receipt.
// * 
// * Limitations on Rights to Redistribute This Code
// * 
// * Unicode, Inc. hereby grants the right to freely use the information
// * supplied in this file in the creation of products supporting the
// * Unicode Standard, and to make copies of this file in any form
// * for internal or external distribution as long as this notice
// * remains attached.
// */
//
///* ---------------------------------------------------------------------
//
//    Conversions between UTF32, UTF-16, and UTF-8. Source code file.
//    Author: Mark E. Davis, 1994.
//    Rev History: Rick McGowan, fixes & updates May 2001.
//    Sept 2001: fixed const & error conditions per
//	mods suggested by S. Parent & A. Lillich.
//    June 2002: Tim Dodd added detection and handling of incomplete
//	source sequences, enhanced error detection, added casts
//	to eliminate compiler warnings.
//    July 2003: slight mods to back out aggressive FFFE detection.
//    Jan 2004: updated switches in from-UTF8 conversions.
//    Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions.
//
//    See the header file "ConvertUTF.h" for complete documentation.
//
//------------------------------------------------------------------------ */
//
//
//#include "simpleini/ConvertUTF.h"
//#ifdef CVTUTF_DEBUG
//#include <stdio.h>
//#endif
//
//static const int halfShift  = 10; /* used for shifting by 10 bits */
//
//static const UTF32 halfBase = 0x0010000UL;
//static const UTF32 halfMask = 0x3FFUL;
//
//#define UNI_SUR_HIGH_START  (UTF32)0xD800
//#define UNI_SUR_HIGH_END    (UTF32)0xDBFF
//#define UNI_SUR_LOW_START   (UTF32)0xDC00
//#define UNI_SUR_LOW_END     (UTF32)0xDFFF
//#define false	   0
//#define true	    1
//
///* --------------------------------------------------------------------- */
//
//ConversionResult ConvertUTF32toUTF16 (
//	const UTF32** sourceStart, const UTF32* sourceEnd, 
//	UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
//    ConversionResult result = conversionOK;
//    const UTF32* source = *sourceStart;
//    UTF16* target = *targetStart;
//    while (source < sourceEnd) {
//	UTF32 ch;
//	if (target >= targetEnd) {
//	    result = targetExhausted; break;
//	}
//	ch = *source++;
//	if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
//	    /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */
//	    if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
//		if (flags == strictConversion) {
//		    --source; /* return to the illegal value itself */
//		    result = sourceIllegal;
//		    break;
//		} else {
//		    *target++ = UNI_REPLACEMENT_CHAR;
//		}
//	    } else {
//		*target++ = (UTF16)ch; /* normal case */
//	    }
//	} else if (ch > UNI_MAX_LEGAL_UTF32) {
//	    if (flags == strictConversion) {
//		result = sourceIllegal;
//	    } else {
//		*target++ = UNI_REPLACEMENT_CHAR;
//	    }
//	} else {
//	    /* target is a character in range 0xFFFF - 0x10FFFF. */
//	    if (target + 1 >= targetEnd) {
//		--source; /* Back up source pointer! */
//		result = targetExhausted; break;
//	    }
//	    ch -= halfBase;
//	    *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
//	    *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
//	}
//    }
//    *sourceStart = source;
//    *targetStart = target;
//    return result;
//}
//
///* --------------------------------------------------------------------- */
//
//ConversionResult ConvertUTF16toUTF32 (
//	const UTF16** sourceStart, const UTF16* sourceEnd, 
//	UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
//    ConversionResult result = conversionOK;
//    const UTF16* source = *sourceStart;
//    UTF32* target = *targetStart;
//    UTF32 ch, ch2;
//    while (source < sourceEnd) {
//	const UTF16* oldSource = source; /*  In case we have to back up because of target overflow. */
//	ch = *source++;
//	/* If we have a surrogate pair, convert to UTF32 first. */
//	if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
//	    /* If the 16 bits following the high surrogate are in the source buffer... */
//	    if (source < sourceEnd) {
//		ch2 = *source;
//		/* If it's a low surrogate, convert to UTF32. */
//		if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
//		    ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
//			+ (ch2 - UNI_SUR_LOW_START) + halfBase;
//		    ++source;
//		} else if (flags == strictConversion) { /* it's an unpaired high surrogate */
//		    --source; /* return to the illegal value itself */
//		    result = sourceIllegal;
//		    break;
//		}
//	    } else { /* We don't have the 16 bits following the high surrogate. */
//		--source; /* return to the high surrogate */
//		result = sourceExhausted;
//		break;
//	    }
//	} else if (flags == strictConversion) {
//	    /* UTF-16 surrogate values are illegal in UTF-32 */
//	    if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
//		--source; /* return to the illegal value itself */
//		result = sourceIllegal;
//		break;
//	    }
//	}
//	if (target >= targetEnd) {
//	    source = oldSource; /* Back up source pointer! */
//	    result = targetExhausted; break;
//	}
//	*target++ = ch;
//    }
//    *sourceStart = source;
//    *targetStart = target;
//#ifdef CVTUTF_DEBUG
//if (result == sourceIllegal) {
//    fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2);
//    fflush(stderr);
//}
//#endif
//    return result;
//}
//
///* --------------------------------------------------------------------- */
//
///*
// * Index into the table below with the first byte of a UTF-8 sequence to
// * get the number of trailing bytes that are supposed to follow it.
// * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is
// * left as-is for anyone who may want to do such conversion, which was
// * allowed in earlier algorithms.
// */
//static const char trailingBytesForUTF8[256] = {
//    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
//    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
//    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
//    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
//    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
//    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
//    1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
//    2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5
//};
//
///*
// * Magic values subtracted from a buffer value during UTF8 conversion.
// * This table contains as many values as there might be trailing bytes
// * in a UTF-8 sequence.
// */
//static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, 
//		     0x03C82080UL, 0xFA082080UL, 0x82082080UL };
//
///*
// * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
// * into the first byte, depending on how many bytes follow.  There are
// * as many entries in this table as there are UTF-8 sequence types.
// * (I.e., one byte sequence, two byte... etc.). Remember that sequences
// * for *legal* UTF-8 will be 4 or fewer bytes total.
// */
//static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
//
///* --------------------------------------------------------------------- */
//
///* The interface converts a whole buffer to avoid function-call overhead.
// * Constants have been gathered. Loops & conditionals have been removed as
// * much as possible for efficiency, in favor of drop-through switches.
// * (See "Note A" at the bottom of the file for equivalent code.)
// * If your compiler supports it, the "isLegalUTF8" call can be turned
// * into an inline function.
// */
//
///* --------------------------------------------------------------------- */
//
//ConversionResult ConvertUTF16toUTF8 (
//	const UTF16** sourceStart, const UTF16* sourceEnd, 
//	UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
//    ConversionResult result = conversionOK;
//    const UTF16* source = *sourceStart;
//    UTF8* target = *targetStart;
//    while (source < sourceEnd) {
//	UTF32 ch;
//	unsigned short bytesToWrite = 0;
//	const UTF32 byteMask = 0xBF;
//	const UTF32 byteMark = 0x80; 
//	const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */
//	ch = *source++;
//	/* If we have a surrogate pair, convert to UTF32 first. */
//	if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
//	    /* If the 16 bits following the high surrogate are in the source buffer... */
//	    if (source < sourceEnd) {
//		UTF32 ch2 = *source;
//		/* If it's a low surrogate, convert to UTF32. */
//		if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
//		    ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
//			+ (ch2 - UNI_SUR_LOW_START) + halfBase;
//		    ++source;
//		} else if (flags == strictConversion) { /* it's an unpaired high surrogate */
//		    --source; /* return to the illegal value itself */
//		    result = sourceIllegal;
//		    break;
//		}
//	    } else { /* We don't have the 16 bits following the high surrogate. */
//		--source; /* return to the high surrogate */
//		result = sourceExhausted;
//		break;
//	    }
//	} else if (flags == strictConversion) {
//	    /* UTF-16 surrogate values are illegal in UTF-32 */
//	    if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
//		--source; /* return to the illegal value itself */
//		result = sourceIllegal;
//		break;
//	    }
//	}
//	/* Figure out how many bytes the result will require */
//	if (ch < (UTF32)0x80) {	     bytesToWrite = 1;
//	} else if (ch < (UTF32)0x800) {     bytesToWrite = 2;
//	} else if (ch < (UTF32)0x10000) {   bytesToWrite = 3;
//	} else if (ch < (UTF32)0x110000) {  bytesToWrite = 4;
//	} else {			    bytesToWrite = 3;
//					    ch = UNI_REPLACEMENT_CHAR;
//	}
//
//	target += bytesToWrite;
//	if (target > targetEnd) {
//	    source = oldSource; /* Back up source pointer! */
//	    target -= bytesToWrite; result = targetExhausted; break;
//	}
//	switch (bytesToWrite) { /* note: everything falls through. */
//	    case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
//	    case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
//	    case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
//	    case 1: *--target =  (UTF8)(ch | firstByteMark[bytesToWrite]);
//	}
//	target += bytesToWrite;
//    }
//    *sourceStart = source;
//    *targetStart = target;
//    return result;
//}
//
///* --------------------------------------------------------------------- */
//
///*
// * Utility routine to tell whether a sequence of bytes is legal UTF-8.
// * This must be called with the length pre-determined by the first byte.
// * If not calling this from ConvertUTF8to*, then the length can be set by:
// *  length = trailingBytesForUTF8[*source]+1;
// * and the sequence is illegal right away if there aren't that many bytes
// * available.
// * If presented with a length > 4, this returns false.  The Unicode
// * definition of UTF-8 goes up to 4-byte sequences.
// */
//
//static Boolean isLegalUTF8(const UTF8 *source, int length) {
//    UTF8 a;
//    const UTF8 *srcptr = source+length;
//    switch (length) {
//    default: return false;
//	/* Everything else falls through when "true"... */
//    case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
//    case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
//    case 2: if ((a = (*--srcptr)) > 0xBF) return false;
//
//	switch (*source) {
//	    /* no fall-through in this inner switch */
//	    case 0xE0: if (a < 0xA0) return false; break;
//	    case 0xED: if (a > 0x9F) return false; break;
//	    case 0xF0: if (a < 0x90) return false; break;
//	    case 0xF4: if (a > 0x8F) return false; break;
//	    default:   if (a < 0x80) return false;
//	}
//
//    case 1: if (*source >= 0x80 && *source < 0xC2) return false;
//    }
//    if (*source > 0xF4) return false;
//    return true;
//}
//
///* --------------------------------------------------------------------- */
//
///*
// * Exported function to return whether a UTF-8 sequence is legal or not.
// * This is not used here; it's just exported.
// */
//Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) {
//    int length = trailingBytesForUTF8[*source]+1;
//    if (source+length > sourceEnd) {
//	return false;
//    }
//    return isLegalUTF8(source, length);
//}
//
///* --------------------------------------------------------------------- */
//
//ConversionResult ConvertUTF8toUTF16 (
//	const UTF8** sourceStart, const UTF8* sourceEnd, 
//	UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
//    ConversionResult result = conversionOK;
//    const UTF8* source = *sourceStart;
//    UTF16* target = *targetStart;
//    while (source < sourceEnd) {
//	UTF32 ch = 0;
//	unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
//	if (source + extraBytesToRead >= sourceEnd) {
//	    result = sourceExhausted; break;
//	}
//	/* Do this check whether lenient or strict */
//	if (! isLegalUTF8(source, extraBytesToRead+1)) {
//	    result = sourceIllegal;
//	    break;
//	}
//	/*
//	 * The cases all fall through. See "Note A" below.
//	 */
//	switch (extraBytesToRead) {
//	    case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
//	    case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
//	    case 3: ch += *source++; ch <<= 6;
//	    case 2: ch += *source++; ch <<= 6;
//	    case 1: ch += *source++; ch <<= 6;
//	    case 0: ch += *source++;
//	}
//	ch -= offsetsFromUTF8[extraBytesToRead];
//
//	if (target >= targetEnd) {
//	    source -= (extraBytesToRead+1); /* Back up source pointer! */
//	    result = targetExhausted; break;
//	}
//	if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
//	    /* UTF-16 surrogate values are illegal in UTF-32 */
//	    if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
//		if (flags == strictConversion) {
//		    source -= (extraBytesToRead+1); /* return to the illegal value itself */
//		    result = sourceIllegal;
//		    break;
//		} else {
//		    *target++ = UNI_REPLACEMENT_CHAR;
//		}
//	    } else {
//		*target++ = (UTF16)ch; /* normal case */
//	    }
//	} else if (ch > UNI_MAX_UTF16) {
//	    if (flags == strictConversion) {
//		result = sourceIllegal;
//		source -= (extraBytesToRead+1); /* return to the start */
//		break; /* Bail out; shouldn't continue */
//	    } else {
//		*target++ = UNI_REPLACEMENT_CHAR;
//	    }
//	} else {
//	    /* target is a character in range 0xFFFF - 0x10FFFF. */
//	    if (target + 1 >= targetEnd) {
//		source -= (extraBytesToRead+1); /* Back up source pointer! */
//		result = targetExhausted; break;
//	    }
//	    ch -= halfBase;
//	    *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
//	    *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
//	}
//    }
//    *sourceStart = source;
//    *targetStart = target;
//    return result;
//}
//
///* --------------------------------------------------------------------- */
//
//ConversionResult ConvertUTF32toUTF8 (
//	const UTF32** sourceStart, const UTF32* sourceEnd, 
//	UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
//    ConversionResult result = conversionOK;
//    const UTF32* source = *sourceStart;
//    UTF8* target = *targetStart;
//    while (source < sourceEnd) {
//	UTF32 ch;
//	unsigned short bytesToWrite = 0;
//	const UTF32 byteMask = 0xBF;
//	const UTF32 byteMark = 0x80; 
//	ch = *source++;
//	if (flags == strictConversion ) {
//	    /* UTF-16 surrogate values are illegal in UTF-32 */
//	    if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
//		--source; /* return to the illegal value itself */
//		result = sourceIllegal;
//		break;
//	    }
//	}
//	/*
//	 * Figure out how many bytes the result will require. Turn any
//	 * illegally large UTF32 things (> Plane 17) into replacement chars.
//	 */
//	if (ch < (UTF32)0x80) {	     bytesToWrite = 1;
//	} else if (ch < (UTF32)0x800) {     bytesToWrite = 2;
//	} else if (ch < (UTF32)0x10000) {   bytesToWrite = 3;
//	} else if (ch <= UNI_MAX_LEGAL_UTF32) {  bytesToWrite = 4;
//	} else {			    bytesToWrite = 3;
//					    ch = UNI_REPLACEMENT_CHAR;
//					    result = sourceIllegal;
//	}
//	
//	target += bytesToWrite;
//	if (target > targetEnd) {
//	    --source; /* Back up source pointer! */
//	    target -= bytesToWrite; result = targetExhausted; break;
//	}
//	switch (bytesToWrite) { /* note: everything falls through. */
//	    case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
//	    case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
//	    case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
//	    case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]);
//	}
//	target += bytesToWrite;
//    }
//    *sourceStart = source;
//    *targetStart = target;
//    return result;
//}
//
///* --------------------------------------------------------------------- */
//
//ConversionResult ConvertUTF8toUTF32 (
//	const UTF8** sourceStart, const UTF8* sourceEnd, 
//	UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
//    ConversionResult result = conversionOK;
//    const UTF8* source = *sourceStart;
//    UTF32* target = *targetStart;
//    while (source < sourceEnd) {
//	UTF32 ch = 0;
//	unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
//	if (source + extraBytesToRead >= sourceEnd) {
//	    result = sourceExhausted; break;
//	}
//	/* Do this check whether lenient or strict */
//	if (! isLegalUTF8(source, extraBytesToRead+1)) {
//	    result = sourceIllegal;
//	    break;
//	}
//	/*
//	 * The cases all fall through. See "Note A" below.
//	 */
//	switch (extraBytesToRead) {
//	    case 5: ch += *source++; ch <<= 6;
//	    case 4: ch += *source++; ch <<= 6;
//	    case 3: ch += *source++; ch <<= 6;
//	    case 2: ch += *source++; ch <<= 6;
//	    case 1: ch += *source++; ch <<= 6;
//	    case 0: ch += *source++;
//	}
//	ch -= offsetsFromUTF8[extraBytesToRead];
//
//	if (target >= targetEnd) {
//	    source -= (extraBytesToRead+1); /* Back up the source pointer! */
//	    result = targetExhausted; break;
//	}
//	if (ch <= UNI_MAX_LEGAL_UTF32) {
//	    /*
//	     * UTF-16 surrogate values are illegal in UTF-32, and anything
//	     * over Plane 17 (> 0x10FFFF) is illegal.
//	     */
//	    if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
//		if (flags == strictConversion) {
//		    source -= (extraBytesToRead+1); /* return to the illegal value itself */
//		    result = sourceIllegal;
//		    break;
//		} else {
//		    *target++ = UNI_REPLACEMENT_CHAR;
//		}
//	    } else {
//		*target++ = ch;
//	    }
//	} else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */
//	    result = sourceIllegal;
//	    *target++ = UNI_REPLACEMENT_CHAR;
//	}
//    }
//    *sourceStart = source;
//    *targetStart = target;
//    return result;
//}
//
///* ---------------------------------------------------------------------
//
//    Note A.
//    The fall-through switches in UTF-8 reading code save a
//    temp variable, some decrements & conditionals.  The switches
//    are equivalent to the following loop:
//	{
//	    int tmpBytesToRead = extraBytesToRead+1;
//	    do {
//		ch += *source++;
//		--tmpBytesToRead;
//		if (tmpBytesToRead) ch <<= 6;
//	    } while (tmpBytesToRead > 0);
//	}
//    In UTF-8 writing code, the switches on "bytesToWrite" are
//    similarly unrolled loops.
//
//   --------------------------------------------------------------------- */