读取SDTS(Spatial Data Transfer Standard )DEM数据显示三维分层设色地图

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更多发布于：2007-11-06 00:19

SDTS(Spatial Data Transfer Standard ) DEM
读取也是颇费力的一件事情,首先这个体系并不是一个单一的数据文件,而是由一系列的相同后缀(.ddf)构成文件的组合.其中,*CATD.DDF是首要
文件,相当于一个索引,告知其他文件的功能.剩下的文件中,*LDEF.DDF可以获得格网的长宽数值。*IREF.DDF文件可以得到XY轴的分辨率。
*CELL.DDF是真正带有数据的文件。可以提取高程数值。另外还涉及到读取8211文件的问题,所以说,是件比较费力的事情. 
 下面提供程序框架和结果图供大家参考。 
 bool ImportDEMDataSDTS::LoadSingleFile(LPCSTR lpszPathName) 
{ 
string temp(lpszPathName); 
long totalSteps = FillSDTSDEM(temp); //加载进文件并返回可能需要的时间总长度
 long stepsLeft=1; 
while (stepsLeft > 0) 
{ 
 stepsLeft = FillSDTSDEM(temp); 
}
 int x=0,y=0; 
long lindex = 0;
 for(y=0;y<m_Height;y++) 
{ 
 for (x=0;x<m_Width;x++) 
 { 
 lindex = y*m_Width + x; 
 m_ppt3dPoint[lindex][0] = x*m_xRes; //m_xRes 
 m_ppt3dPoint[lindex][1] = y*m_yRes; //m_yRes 
 if( m_grid[lindex] > -500 ;; m_grid[lindex] < 20000) //防止出现异常数据 
 { 
 m_grid[lindex] = m_grid[lindex] - 17000; 
 m_ppt3dPoint[lindex][2] = m_grid[lindex]; 
 if(m_dminElevation>m_grid[lindex]) m_dminElevation = m_grid[lindex]; //如果出现更小的数值 
 if(m_dmaxElevation<m_grid[lindex]) m_dmaxElevation = m_grid[lindex]; //如果出现更大的数值 
 } 
 else 
 { 
 m_ppt3dPoint[lindex][2] = 0; 
 } 
 } 
} 
m_p3dDEMGrid->SetSurfacePoint( m_ppt3dPoint ); 
m_p3dDEMGrid->SetRows(m_Height); 
m_p3dDEMGrid->SetColumns(m_Width); 
//m_p3dDEMGrid->SetXMax(dXMin + width*dXCellSize); 
//m_p3dDEMGrid->SetYMax(dYMin + height*dYCellSize); 
m_p3dDEMGrid->SetZMin( m_dminElevation ); 
m_p3dDEMGrid->SetZMax( m_dmaxElevation ); 
m_p3dDEMGrid->SetPointTotal( m_index );
 if( m_bDisplayLegendAndDistributeColor) ImportDEMData::DisplayLegendAndDistributeColor(); //显示图例和分层设色
 return true; 
}
long ImportDEMDataSDTS::FillSDTSDEM(const string; filename) //主入口 
{ 
if (m_bLoadingFileFirstTime) 
{ 
 m_filePrefix = filename.substr(0,filename.length() - string("CATD.DDF").length()); 
 m_filePath = m_filePrefix.substr(0,(m_filePrefix.length() -
((filename.length() - filename.find_last_of("\\")) -
string("CATD.DDF").length()))+1);
 m_converters["X"] = ;bi32_converter; 
 m_converters["Y"] = ;bi32_converter; 
 m_converters["ELEVATION"] = ;bi16_converter; // This should be changed...
 loadCATD(); 
 loadLDEF(); 
 //loadDDOM(); 
 loadIREF(); 
 //loadDDSH(); 
 //loadDQLC(); 
 //loadDQPA(); 
 //loadDQHL();
 m_ppt3dPoint = new POINT3d[m_Height*m_Width]; //_grid = new long[_width * _height]; 
 m_grid = new long[m_Height*m_Width]; 
 //// XXX need to change this: 
 //_missingData = -32766; 
} 
 return LoadCELL(true); //读取数据文件 
}
void ImportDEMDataSDTS::loadCATD() //起头的文件 
{ 
sb_CatalogDir* _catd;
 // get module names 
string _nameCATD = m_filePrefix + "CATD.DDF"; 
ifstream ddf(_nameCATD.c_str(), ios::binary); 
sio_8211Reader reader(ddf, ;m_converters); 
for( sio_8211ForwardIterator i( reader );! i.done();++i ) 
{ 
 i.get( m_record ); 
 _catd = new sb_CatalogDir( m_record ); 
 m_modules[_catd->getName()] = m_filePath + _catd->getFile(); 
 delete _catd; 
} 
}
void ImportDEMDataSDTS::loadLDEF() 
{ 
// Get important layer info //得到层信息 
//string _nameLDEF = m_modules["LDEF"]; 
string _nameLDEF = m_filePrefix + "LDEF.DDF"; 
ifstream ddf(_nameLDEF.c_str(), ios::binary); 
sio_8211Reader reader(ddf, ;m_converters); 
for ( sio_8211ForwardIterator i( reader ); ! i.done(); ++i ) 
{ 
 
 i.get ( m_record ); 
 for ( m_field_itr = m_record.begin();m_field_itr != m_record.end(); m_field_itr++ ) 
 { 
 
 for ( m_subfield_itr = m_field_itr->begin();m_subfield_itr != m_field_itr->end();m_subfield_itr++ ) 
 { 
 
 if (m_subfield_itr->getMnemonic() == "CMNM") 
 { 
 m_subfield_itr->getA( m_cellModuleName ); 
 } 
 else if (m_subfield_itr->getMnemonic() == "LLBL") 
 { 
 
 m_subfield_itr->getA( m_label ); 
 } 
 else if (m_subfield_itr->getMnemonic() == "NROW") 
 { 
 m_subfield_itr->getI( m_Height ); 
 } 
 else if (m_subfield_itr->getMnemonic() == "NCOL") 
 { 
 m_subfield_itr->getI( m_Width ); 
 } 
 } 
 } 
} //结束第一重循环 
}
void ImportDEMDataSDTS::loadIREF() 
{ 
sb_IntSpatialRef* _iref;
 // Get x and y resolution //XY轴分辨率 
//string _nameIREF = _modules["IREF"]; 
string _nameIREF = m_filePrefix + "IREF.DDF"; 
ifstream ddf(_nameIREF.c_str(), ios::binary); 
sio_8211Reader reader(ddf, ;m_converters); 
for( sio_8211ForwardIterator i( reader );! i.done();++i ) 
{ 
 i.get( m_record ); 
 _iref = new sb_IntSpatialRef( m_record ); 
 m_xRes = _iref->getXCompHorizRes(); 
 m_yRes = _iref->getYCompHorizRes(); 
 delete _iref; 
} 
}
long ImportDEMDataSDTS::LoadCELL(bool incrementalRead) //此函数本身处在循环中 
{ 
if (m_bLoadingFileFirstTime) 
{ 
 //string _nameCELL = m_modules["CEL0"]; 
 string _nameCELL = m_filePrefix + "CEL0.DDF"; 
 m_ddf.open(_nameCELL.c_str(),ios::binary); 
 
 m_reader = new sio_8211Reader(m_ddf, ;m_converters); 
 m_curRecord = new sio_8211ForwardIterator( *m_reader ); 
 m_bLoadingFileFirstTime = false; 
}
 while (! m_curRecord->done() ) 
{ 
 readNextRecord(); 
 if (incrementalRead) 
 return m_Height - m_curHeight; // 所剩下的 
} 
m_ddf.close(); 
return 0; //返回0将使得函数调处fill所处的循环 
}
void ImportDEMDataSDTS::readNextRecord() 
{ 
long *temp = 0; 
m_curRecord->get ( m_record ); 
for ( m_field_itr = m_record.begin();m_field_itr != m_record.end();m_field_itr++ ) 
{ 
 for ( m_subfield_itr = m_field_itr->begin();m_subfield_itr != m_field_itr->end();m_subfield_itr++ ) 
 { 
 if (m_subfield_itr->getMnemonic() == m_label) 
 { 
 //m_ppt3dPoint[m_index][0] = (m_index - m_curHeight*m_Width)*m_xRes; 
 //m_ppt3dPoint[m_index][1] = m_curHeight*m_yRes; 
 m_subfield_itr->getBI16(m_grid[m_index]); //m_subfield_itr->getBI16(_grid[_gridLocation]); //_grid赋值 
 
 m_index++; 
 } 
 } 
} 
++(*m_curRecord); //一直加，直到m_curRecord->done() 
m_curHeight++; 
}

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