Texture Atlas Maker

#include "PreCompile.h"
#include "XParser.h"

void XParser::Open(const string& fileName)
{
	FILE* pFile;
	pFile = fopen(fileName.c_str(), "rb");
	if (pFile == NULL)
		throw RacException("cannot open ", fileName);
	Open(pFile);
}

void XParser::Open(FILE* pFile)
{
	m_currLine = 0;
	fseek(pFile, 0, 2 /* SEEK_END */);
	m_fileSize = (int)ftell(pFile);
	m_currPos = 0;
	m_mapAttrib.clear();
	if (m_fileSize == 0) return;
	fseek(pFile, 0, 0 /* SEEK_SET */);
	m_buffer.Init(m_fileSize);
	int bytesRead = (int)fread(m_buffer.GetCache(), m_fileSize, 1, pFile);	// read length and type
	fclose(pFile);
	if (bytesRead != 1)
		throw RacException("error reading file");
	m_currChar = m_buffer.Get(m_currPos);
	m_mapElement.clear();
}

void XParser::ReadNextElement()
{
	if (m_fileSize == 0) return;
	m_mapAttrib.clear();
	EatWhiteSpace();
	if (EndFileReached() || m_currChar != '<')
		throw RacException("fucked up xml element after ", m_elementName);
	CheckComment();
	m_currPos++;
	m_currChar = m_buffer.Get(m_currPos);
	if (m_currChar == '/')
	{
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
		GetNextWord(m_elementName);
		fmap<string, int>::iterator iter;
		iter = m_mapElement.find(m_elementName);
		if (iter == m_mapElement.end())
		{
			throw RacException("end tag without any opening tag:", m_elementName);
		}
		else
		{
			iter->second--;
			if (iter->second < 0)
				throw RacException("end tag without any start:", m_elementName);
		}
		if (m_currChar != '>' || EndFileReached())
			throw RacException("fucked up end tag:", m_elementName);
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
		m_elementName.clear();
		return;
	}
	GetNextWord(m_elementName);
	if (EndFileReached() || m_elementName.empty())
		throw RacException("fucked up xml element");
	fmap<string, int>::iterator iter;
	iter = m_mapElement.find(m_elementName);
	if (iter == m_mapElement.end())
	{
		m_mapElement[m_elementName] = 1;
	}
	else
	{
		iter->second++;
	}
	string attribName, attribValue;
	while(m_currChar != '>')
	{
		GetNextWord(attribName);
		if (m_currChar != '=' || attribName.empty() || EndFileReached())
			throw RacException("fucked up attribute in ", m_elementName);
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
		GetNextValue(attribValue);
		if (EndFileReached())
			throw RacException("missing end to element ", m_elementName);
		m_mapAttrib[attribName] = attribValue;
		if (m_currChar == '/')
		{
			iter = m_mapElement.find(m_elementName);

			if (iter == m_mapElement.end())
			{
				throw RacException("end tag without any opening tag:", m_elementName);
			}
			else
			{
				iter->second--;
			}
			m_currPos++;
			m_currChar = m_buffer.Get(m_currPos);
		}
	}
	m_currPos++;
	m_currChar = m_buffer.Get(m_currPos);
}

// gets the next word delimited by whitespace
// if the word has format "keyx=valuex" then it will return the key and value
// seperated, otherwise value will be empty string
// returns false if there is a file read error
void XParser::GetNextWord(string& token) 
{
	int startPos = m_currPos;
	while (m_currChar != '\n' && m_currChar != '\r' && m_currChar != ' ' && 
		m_currChar != '\t' && m_currChar != '>' && m_currChar != '=' && 
		m_currPos < m_fileSize && m_currChar != '\"' && m_currChar != '/')
	{
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
		if (m_currChar == '\n') m_currLine++; 
	}	// end while
	if (m_currPos == m_fileSize)
		token.assign(m_buffer.GetPtr(startPos), m_currPos-startPos);
	else
		token.assign(m_buffer.GetPtr(startPos), m_currPos-startPos);
	EatWhiteSpace(); 
}	//	getNextStr

void XParser::GetNextValue(string& token) 
{
	EatWhiteSpace();
	if (EndFileReached())
		throw RacException("fucked up attribute value in ", m_elementName);
	int startPos;
	if (m_currChar == '\"' )
	{
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
		startPos = m_currPos;
		while (m_currChar != '\"' && m_currPos < m_fileSize)
		{
			m_currPos++;
			m_currChar = m_buffer.Get(m_currPos);
		}	// end while
		if (m_currPos == m_fileSize)
			throw RacException("fucked up attribute value in ", m_elementName);
		token.assign(m_buffer.GetPtr(startPos), m_currPos-startPos);
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
	}
	else	// value is not enclosed in quotes
	{
		startPos = m_currPos;
		while (m_currChar != '\n' && m_currChar != '\r' && m_currChar != ' ' && 
			m_currChar != '\t' && m_currChar != '>' && m_currChar != '=' && 
			m_currPos < m_fileSize && m_currChar != '\"' && m_currChar != '/')
		{
			m_currPos++;
			m_currChar = m_buffer.Get(m_currPos);
		}	// end while
		token.assign(m_buffer.GetPtr(startPos), m_currPos-startPos);
	}
	EatWhiteSpace(); 
}	

void XParser::EatWhiteSpace() 
{
	// leading whitespace is ignored
	while ((m_currChar == '\n' || m_currChar == '\r' || m_currChar == ' ' 
		|| m_currChar == '\t') && !EndFileReached())
	{
		m_currPos++;
		m_currChar = m_buffer.Get(m_currPos);
		if (m_currChar == '\n') m_currLine++; 
	} 
}

void XParser::CheckComment() 
{
	if (m_buffer.Get(m_currPos+1) != '!' 
		|| m_buffer.Get(m_currPos+2) != '-' || m_buffer.Get(m_currPos+3) != '-')
		return;
	m_currPos += 4;
	// leading whitespace is ignored
	while (m_buffer.Get(m_currPos) != '-' || m_buffer.Get(m_currPos+1) != '-'
		|| m_buffer.Get(m_currPos+2) != '>')
	{
		m_currPos++;
		if (EndFileReached())
			throw RacException("file ended in middle of comment ");
	} 
	m_currPos += 3;
	m_currChar = m_buffer.Get(m_currPos);
	EatWhiteSpace();
	if (m_currChar != '<')
		throw RacException("fucked up xml element");
}


const string& XParser::GetValue(const char* szKey) const
{
	//string key(szKey);
	//to_lower(key);
	fmap<string, string>::const_iterator iter;
	iter = m_mapAttrib.find(szKey);
	if (iter == m_mapAttrib.end())
	{
		string strErr = "missing key ";
		strErr += szKey;
		strErr += " in ";
		strErr += m_elementName;
		throw RacException(strErr);
	}
	return iter->second;
}


bool XParser::GetOptionalValue(const char* szKey, string& value) const
{
	//string key(szKey);
	//to_lower(key);
	fmap<string, string>::const_iterator iter;
	iter = m_mapAttrib.find(szKey);
	if (iter == m_mapAttrib.end())
	{
		return false;
	}
	value = iter->second;
	return true;
}

int XParser::GetOptionalInt(const char* szKey, int defaultValue) const
{
	//string key(szKey);
	//to_lower(key);
	fmap<string, string>::const_iterator iter;
	iter = m_mapAttrib.find(szKey);
	if (iter == m_mapAttrib.end())
	{
		return defaultValue;
	}
	return atoi(iter->second.c_str());
}