Files
OpenSceneGraph/src/osgText/EncodedText.cpp

259 lines
8.3 KiB
C++

//C++ header - Open Scene Graph - Copyright (C) 1998-2002 Robert Osfield
//Distributed under the terms of the GNU Library General Public License (LGPL)
//as published by the Free Software Foundation.
/* --------------------------------------------------------------------------
*
* openscenegraph textLib / FTGL wrapper (http://homepages.paradise.net.nz/henryj/code/)
*
* --------------------------------------------------------------------------
*
* prog: max rheiner;mrn@paus.ch
* date: 4/25/2001 (m/d/y)
*
* --------------------------------------------------------------------------
*
* --------------------------------------------------------------------------
*/
#include <osgText/EncodedText>
#include <osg/Notify>
using namespace osgText;
EncodedText::EncodedText()
{
_encoding = ENCODING_ASCII;
_overrideEncoding = ENCODING_SIGNATURE;
}
int EncodedText::getNextCharacter(const unsigned char*& charString) const
{
// For more info on unicode encodings see:
// http://www-106.ibm.com/developerworks/unicode/library/u-encode.html
switch(_encoding)
{
case ENCODING_ASCII:
{
return *charString++;
}
case ENCODING_UTF8:
{
int char0 = *charString++;
if (char0 < 0x80) // 1-byte character
{
return char0;
}
int char1 = *charString++;
if (char0<0xe0) // 2-byte character
{
return ((char0&0x1f)<<6) | (char1&0x3f);
}
int char2 = *charString++;
if (char0<0xf0) // 3-byte character
{
return ((char0&0xf)<<12) | ((char1&0x3f)<<6) | (char2&0x3f);
}
int char3 = *charString++;
if (char0<0xf8) // 4-byte character
{
return ((char0&0x7)<<18) | ((char1&0x3f)<<12) | ((char2&0x3f)<<6) | (char3&0x3f);
}
break;
}
case ENCODING_UTF16_BE:
{
int char0 = *charString++;
int char1 = *charString++;
if ((char0<=0xD7) || (char0>=0xE0)) // simple character
{
return (char0<<8) | char1;
}
else if ((char0>=0xD8)&&(char0<=0xDB)) //using planes (this should get called very rarely)
{
int char2 = *charString++;
int char3 = *charString++;
int highSurrogate = (char0<<8) | char1;
int lowSurrogate = (char2<<8) | char3;
if ((char2>=0xDC)&&(char2<=0xDF)) //only for the valid range of low surrogate
{
// This covers the range of all 17 unicode planes
return ((highSurrogate-0xD800)*0x400) + (lowSurrogate-0xD800) + 0x10000;
}
}
break;
}
case ENCODING_UTF16_LE:
{
int char1 = *charString++;
int char0 = *charString++;
if ((char0<=0xD7) || (char0>=0xE0)) // simple character
{
return (char0<<8) | char1;
}
else if ((char0>=0xD8)&&(char0<=0xDB)) //using planes (this should get called very rarely)
{
int char3 = *charString++;
int char2 = *charString++;
int highSurrogate = (char0<<8) | char1;
int lowSurrogate = (char2<<8) | char3;
if ((char2>=0xDC)&&(char2<=0xDF)) //only for the valid range of low surrogate
{
// This covers the range of all 17 unicode planes
return ((highSurrogate-0xD800)*0x400) + (lowSurrogate-0xD800) + 0x10000;
}
}
break;
}
case ENCODING_UTF32_BE:
{
int character = ((((int)charString[0])<<24) | (((int)charString[1])<<16) |
(((int)charString[2])<<8) | charString[3]);
charString+=4;
if (character<0x110000)
{
// Character is constrained to the range set by the unicode standard
return character;
}
break;
}
case ENCODING_UTF32_LE:
{
int character = ((((int)charString[3])<<24) | (((int)charString[2])<<16) |
(((int)charString[1])<<8) | charString[0]);
charString+=4;
if (character<0x110000)
{
// Character is constrained to the range set by the unicode standard
return character;
}
break;
}
default:
{
// Should not reach this point unless the encoding is unhandled
// ENCODING_UTF16, ENCODING_UTF32 and ENCODING_SIGNATURE should never enter this method
osg::notify(osg::FATAL)<<"Error: Invalid string encoding"<<std::endl;
break;
}
}
return 0;
}
EncodedText::Encoding EncodedText::findEncoding(const unsigned char*& charString) const
{
switch (charString[0])
{
case 0xEF: // 8-bit encoding
{
// 8-bit signature = EF BB BF
if ((charString[1]==0xBB) && (charString[2]==0xBF))
{
charString+=3;
return ENCODING_UTF8;
}
break;
}
case 0xFE: // big-endian 16-bit
{
// 16-bit signature = FE FF
if (charString[1]==0xFF)
{
charString+=2;
return ENCODING_UTF16_BE;
}
break;
}
case 0xFF: // little-endian
{
// 16-bit signature = FF FE
// 32-bit signature = FF FE 00 00
if (charString[1]==0xFE)
{
// NOTE: There is an a potential problem as a 16-bit empty string
// is identical to a 32-bit start signature
if ((charString[2]==0) && (charString[3]==0) && (_overrideEncoding != ENCODING_UTF16)) //32-bit
{
charString+=4;
return ENCODING_UTF32_LE;
}
else //16-bit
{
charString+=2;
return ENCODING_UTF16_LE;
}
}
break;
}
case 0x00: // 32-bit big-endian
{
// 32-bit signature = 00 00 FE FF
if ((charString[1]==0x00) && (charString[2]==0xFE) && (charString[3]==0xFF))
{
charString+=4;
return ENCODING_UTF32_BE;
}
break;
}
}
return ENCODING_ASCII;
}
void EncodedText::setText(const unsigned char* text, int length)
{
_unicodeText.clear();
if (text != NULL)
{
const unsigned char* textStart = text;
if ((_overrideEncoding == ENCODING_SIGNATURE) ||
(_overrideEncoding == ENCODING_UTF16) ||
(_overrideEncoding == ENCODING_UTF32))
_encoding = findEncoding(text);
int character = getNextCharacter(text);
int charCount = (int)(text-textStart);
while ((character) && (length<0 || (charCount <= length)))
{
_unicodeText.push_back(character);
character = getNextCharacter(text);
charCount = (int)(text-textStart);
}
}
}
void EncodedText::setOverrideEncoding(EncodedText::Encoding encoding)
{
if (_overrideEncoding != encoding)
{
_overrideEncoding = encoding;
_encoding = encoding;
//NB As the original text is not cached we cannot confirm any ENCODING_SIGNATURE until text is set again
}
}
std::string EncodedText::convertWideString(const wchar_t* text)
{
std::string utf8string;
const wchar_t* pChars = text;
int currentChar = *pChars;
while (currentChar)
{
if (currentChar < 0x80)
utf8string+=(char)currentChar;
else if (currentChar < 0x800)
{
utf8string+=(char)(0xc0 | (currentChar>>6));
utf8string+=(char)(0x80 | currentChar & 0x3f);
}
else
{
utf8string+=(char)(0xe0 | (currentChar>>12));
utf8string+=(char)(0x80 | (currentChar>>6) & 0x3f);
utf8string+=(char)(0x80 | currentChar & 0x3f);
}
currentChar = *(++pChars);
}
return utf8string;
}