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Diffstat (limited to 'Source/modules/asura-base/Misc/UTF8.cpp')
| -rw-r--r-- | Source/modules/asura-base/Misc/UTF8.cpp | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/Source/modules/asura-base/Misc/UTF8.cpp b/Source/modules/asura-base/Misc/UTF8.cpp new file mode 100644 index 0000000..8cfb3ab --- /dev/null +++ b/Source/modules/asura-base/Misc/UTF8.cpp @@ -0,0 +1,395 @@ +#include "UTF8.h" + +namespace_begin(AsuraEngine) + +typedef unsigned long UTF32; /* at least 32 bits */ +typedef unsigned short UTF16; /* at least 16 bits */ +typedef unsigned char UTF8; /* typically 8 bits */ +typedef unsigned char Boolean; /* 0 or 1 */ + +typedef enum { + strictConversion = 0, + lenientConversion +} ConversionFlags; + +typedef enum { + conversionOK, /* conversion successful */ + sourceExhausted, /* partial character in source, but hit end */ + targetExhausted, /* insuff. room in target for conversion */ + sourceIllegal /* source sequence is illegal/malformed */ +} ConversionResult; + +/* Some fundamental constants */ +#define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD +#define UNI_MAX_BMP (UTF32)0x0000FFFF +#define UNI_MAX_UTF16 (UTF32)0x0010FFFF +#define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF +#define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF + +ConversionResult ConvertUTF8toUTF16( + const UTF8** sourceStart, const UTF8* sourceEnd, + UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags); + + +/* +* 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 "UTF8.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 + + +/* --------------------------------------------------------------------- */ + +/* +* 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 sequencs +* for *legal* UTF-8 will be 4 or fewer bytes total. +*/ +static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC }; + + +/* --------------------------------------------------------------------- */ + +/* +* 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; +} + + +/* --------------------------------------------------------------------- */ + +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]; + + //DebugAssertIf(target >= targetEnd); + + 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; +} + +/* --------------------------------------------------------------------- + +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. + +--------------------------------------------------------------------- */ + +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 && source < sourceEnd) { + UTF32 ch2 = *source; + 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 if ((flags == strictConversion) && (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)0x200000) { + bytesToWrite = 4; + } + else { + bytesToWrite = 2; + 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 = (ch | byteMark) & byteMask; ch >>= 6; + case 3: *--target = (ch | byteMark) & byteMask; ch >>= 6; + case 2: *--target = (ch | byteMark) & byteMask; ch >>= 6; + case 1: *--target = ch | firstByteMark[bytesToWrite]; + } + target += bytesToWrite; + } + *sourceStart = source; + *targetStart = target; + return result; +} + + +bool ConvertUTF8toUTF16(const char* source, int srcLength, uint16* output, int& outlength) +{ + uint16* newoutput = output; + const UTF8* src = (UTF8*)source; + if (ConvertUTF8toUTF16(&src, src + srcLength, &newoutput, newoutput + srcLength, lenientConversion) != sourceIllegal) + { + outlength = newoutput - output; + return true; + } + else + { + outlength = 0; + return false; + } +} + +bool ConvertUTF8toUTF16(const std::string& source, dynamic_array<uint16>& utf16) +{ + utf16.resize_uninitialized(source.size()); + int length = 0; + bool success = ConvertUTF8toUTF16(source.data(), (int)source.size(), utf16.begin(), length); + utf16.resize_uninitialized(length); + return success; +} + +bool ConvertUTF16toUTF8(const uint16* source, int srcLength, char* output, int& outlength) +{ + UTF8* newoutput = (UTF8*)output; + const UTF16* src = (UTF16*)source; + if (ConvertUTF16toUTF8(&src, src + srcLength, &newoutput, newoutput + (srcLength * 4), lenientConversion) != sourceIllegal) + { + outlength = newoutput - (UTF8*)output; + return true; + } + else + { + outlength = 0; + return false; + } +} + + +bool ConvertUTF16toUTF8(const dynamic_array<UnicodeChar>& source, std::string& utf8) +{ + utf8.resize(source.size() * 4); + int length = 0; + bool success = ConvertUTF16toUTF8(source.data(), (int)source.size(), &utf8[0], length); + utf8.resize(length); + return success; +} + +bool ConvertUTF16toUTF8(const uint16 utf16character, std::string& utf8) +{ + int len; + char character[5]; + if (!ConvertUTF16toUTF8(&utf16character, 1, character, len)) + return false; + character[len] = 0; + utf8 = std::string(character); + return true; +} + + +namespace_end
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