ossimDemUtil Class Reference

#include <ossimDemUtil.h>

Static Public Member Functions
static bool	isUsgsDem (const ossimFilename &file)
	Does basic sanity checks to see if file is a dem. More...
static bool	isUsgsDem (std::shared_ptr< ossim::istream > str, const std::string &connectionString)
static bool	getRecord (ossim::istream &s, std::string &strbuf, long reclength=1024)
	Reads a single record from a DEM. More...
static bool	getRecord (ossim::istream &s, char *buf, long reclength=1024)
	Same as getRecord above. More...
static long	getLong (char *const strbuf, long const startpos, long const width)
static bool	getDouble (std::string const &strbuf, long const startpos, long const width, double &val)

Private Member Functions
	ossimDemUtil ()

Detailed Description

Definition at line 25 of file ossimDemUtil.h.

Constructor & Destructor Documentation

ossimDemUtil()

ossimDemUtil::ossimDemUtil ( )

private

Member Function Documentation

getDouble()

bool ossimDemUtil::getDouble ( std::string const &  strbuf, long const  startpos, long const  width, double &  val  )

static

Definition at line 185 of file ossimDemUtil.cpp.

Referenced by ossimDemHeader::open(), and operator>>().

{
   if ((startpos + width - 1) > (long)(strbuf.length()))
      return false;

   // Convert FORTRAN 'D' exponent indicator to 'E'.
   std::string tempbuf(strbuf.substr(startpos,width));
   for (unsigned int i = 0; i < tempbuf.length(); i++)
      if (tempbuf[i] == 'D')
         tempbuf[i] = 'E';

   val = atof(tempbuf.c_str());
   return true;
}

getLong()

long ossimDemUtil::getLong ( char *const  strbuf, long const  startpos, long const  width  )

static

Definition at line 203 of file ossimDemUtil.cpp.

Referenced by ossimDemHeader::open(), and operator>>().

{
   char temp[1024];
   std::strncpy(temp,strbuf+startpos,width);
   temp[width] = '\0';
   return atol(temp);
}

getRecord() [1/2]

bool ossimDemUtil::getRecord ( ossim::istream &  s, std::string &  strbuf, long  reclength = 1024  )

static

Reads a single record from a DEM.

Returns true if succesful. Returns false if EOF or error.

Definition at line 146 of file ossimDemUtil.cpp.

Referenced by ossimDemHeader::open(), and operator>>().

{
   char* buf = new char[reclength + 1];

   bool flag = ossimDemUtil::getRecord(s,buf,reclength);
   if (flag == true)
      strbuf = buf;

   delete [] buf;

   return flag;
}

getRecord() [2/2]

bool ossimDemUtil::getRecord ( ossim::istream &  s, char *  buf, long  reclength = 1024  )

static

Same as getRecord above.

buf should be at least reclength+1 in size.

Definition at line 159 of file ossimDemUtil.cpp.

{
   // buf is assumed to be at least reclength+1 in size.

   if (!s)
      return false;

   long curpos = 0;
   buf[curpos] = s.get();
   while ((buf[curpos] != EOF) && 
          (buf[curpos] != '\n') &&
          (curpos < reclength-1))
   {
      curpos++;
      buf[curpos] = s.get();
   }
   buf[curpos] = '\0';

   if (s.peek() == '\n')
      s.get();

   return true;

}

isUsgsDem() [1/2]

bool ossimDemUtil::isUsgsDem ( const ossimFilename &  file )

static

Does basic sanity checks to see if file is a dem.

1) Check extension for .dem

2) Look for file.omd (ossim meta data) file containing keyword "dem_type" with value of "usgs_dem".

3) Check 512 bytes and make sure there is no binary data.

Note

There is a keyword list template stored in the templates directory: "ossim/etc/templates/usgs_dem_template.kwl"

Parameters

file	The file to check.

Returns

true on success, false on error.

Definition at line 28 of file ossimDemUtil.cpp.

References ossimString::downcase(), ossimFilename::exists(), ossimFilename::ext(), ossimKeywordlist::find(), ossimErrorStatusInterface::getErrorStatus(), ossimErrorCodes::OSSIM_OK, and ossimFilename::setExtension().

Referenced by ossimDemInfo::open(), and ossimDemHeader::open().

{
   bool result = false;

   ossimString ext = file.ext();
   ext.downcase();
   if (ext == "dem")
   {
      result = true;
   }
   else
   {
      // Look for file.omd
      ossimFilename kwlFile = file;
      kwlFile.setExtension("omd");
      if (! kwlFile.exists() )
      {
         kwlFile.setExtension("OMD");
      }
      
      if ( kwlFile.exists() )
      {
         ossimKeywordlist kwl(kwlFile);
         if (kwl.getErrorStatus() == ossimErrorCodes::OSSIM_OK)
         {
            const char* lookup = kwl.find(DEM_TYPE_KW);
            if (lookup)
            {
               ossimString s = lookup;
               s.downcase();
               if (s == USGS_DEM_KW)
               {
                  result = true;
               }
            }
         }
      }
   }
   
   if ( result )
   {
      
      // Open up the file for reading.
      // std::shared_ptr<ossim::istream> is = ossim::StreamFactoryRegistry::instance()->
      //    createIstream(file, std::ios_base::in | std::ios_base::binary);
   }
      
   return result;
}

isUsgsDem() [2/2]

bool ossimDemUtil::isUsgsDem ( std::shared_ptr< ossim::istream >  str, const std::string &  connectionString  )

static

Definition at line 78 of file ossimDemUtil.cpp.

References ossimString::downcase(), ossimFilename::exists(), ossimFilename::ext(), ossimKeywordlist::find(), ossimErrorStatusInterface::getErrorStatus(), ossimErrorCodes::OSSIM_OK, and ossimFilename::setExtension().

{
   bool result = false;
   ossimFilename tempFile = connectionString;
   ossimString ext = tempFile.ext();
   ext.downcase();
   if (ext == "dem")
   {
      result = true;
   }
   else
   {
      // Look for file.omd
      ossimFilename kwlFile = tempFile;
      kwlFile.setExtension("omd");
      if (! kwlFile.exists() )
      {
         kwlFile.setExtension("OMD");
      }
      
      if ( kwlFile.exists() )
      {
         ossimKeywordlist kwl(kwlFile);
         if (kwl.getErrorStatus() == ossimErrorCodes::OSSIM_OK)
         {
            const char* lookup = kwl.find(DEM_TYPE_KW);
            if (lookup)
            {
               ossimString s = lookup;
               s.downcase();
               if (s == USGS_DEM_KW)
               {
                  result = true;
               }
            }
         }
      }
   }
   if(result&&str&&str->good())
   {
      //---
      // SPECIAL HACK (drb):
      // Check some bytes and make sure there is no binary data.
      // There are files out there with .dem extension that are binary
      // rasters.
      //---
      ossim_uint8* ubuf = new ossim_uint8[512];
      str->read((char*)ubuf, 512);
      for (int i = 0; i < 512; ++i)
      {
         if (ubuf[i] > 0x7f)
         {
            result = false;
            break;
         }
      }
      delete [] ubuf;
      ubuf = 0;
   }
   else
   {
      result = false;
   }

   return result;   
}

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The documentation for this class was generated from the following files:

• ossimDemUtil.h
• ossimDemUtil.cpp