Method Utf8ToUtf16

astyle/src/astyle_main.cpp:2114–2198

Adapted from SciTE Utf8_16.cxx. Copyright (C) 2002 Scott Kirkwood. Modified for Artistic Style by Jim Pattee. Convert a utf-8 file to utf-16.

//
// Convert a utf-8 file to utf-16.
size_t ASConsole::Utf8ToUtf16(char* utf8In, size_t inLen, FileEncoding encoding, char* utf16Out) const
{
	typedef unsigned short utf16;	// 16 bits
	typedef unsigned char  ubyte;	// 8 bits
	enum { SURROGATE_LEAD_FIRST = 0xD800 };
	enum { SURROGATE_LEAD_LAST = 0xDBFF };
	enum { SURROGATE_TRAIL_FIRST = 0xDC00 };
	enum { SURROGATE_TRAIL_LAST = 0xDFFF };
	enum { SURROGATE_FIRST_VALUE = 0x10000 };
	enum eState { eStart, eSecondOf4Bytes, ePenultimate, eFinal };

	int nCur = 0;
	ubyte* pRead = reinterpret_cast<ubyte*>(utf8In);
	utf16* pCur = reinterpret_cast<utf16*>(utf16Out);
	const ubyte* pEnd = pRead + inLen;
	const utf16* pCurStart = pCur;
	eState eState = eStart;

	// the BOM will automatically be converted to utf-16
	while (pRead < pEnd)
	{
		switch (eState)
		{
		case eStart:
			if ((0xF0 & *pRead) == 0xF0)
			{
				nCur = (0x7 & *pRead) << 18;
				eState = eSecondOf4Bytes;
			}
			else if ((0xE0 & *pRead) == 0xE0)
			{
				nCur = (~0xE0 & *pRead) << 12;
				eState = ePenultimate;
			}
			else if ((0xC0 & *pRead) == 0xC0)
			{
				nCur = (~0xC0 & *pRead) << 6;
				eState = eFinal;
			}
			else
			{
				nCur = *pRead;
				eState = eStart;
			}
			break;
		case eSecondOf4Bytes:
			nCur |= (0x3F & *pRead) << 12;
			eState = ePenultimate;
			break;
		case ePenultimate:
			nCur |= (0x3F & *pRead) << 6;
			eState = eFinal;
			break;
		case eFinal:
			nCur |= (0x3F & *pRead);
			eState = eStart;
			break;
		default: