double ossimDtedHandler::getHeightAboveMSL(const ossimGpt& gpt)
{
if(m_fileStr.is_open())
{
return getHeightAboveMSL(gpt, true);
}
else if(m_memoryMap.size())
{
return getHeightAboveMSL(gpt, false);
}
return ossim::nan();
}
double ossimTiledElevationDatabase::getHeightAboveEllipsoid(const ossimGpt& gpt)
{
double h = getHeightAboveMSL(gpt);
if(h != ossim::nan())
{
h += getOffsetFromEllipsoid(gpt);
}
return h;
}
double ossimImageElevationDatabase::getHeightAboveEllipsoid(const ossimGpt& gpt)
{
double h = getHeightAboveMSL(gpt);
if(!ossim::isnan(h))
{
h += getOffsetFromEllipsoid(gpt);
}
return h;
}
void ossimElevManager::getCellsForBounds( const ossim_float64& minLat,
const ossim_float64& minLon,
const ossim_float64& maxLat,
const ossim_float64& maxLon,
std::vector<std::string>& cells,
ossim_uint32 maxNumberOfCells )
{
//TODO: Presently incrementing by 0.1 deg. If an elev cell
// is smaller than this, it may be missed. Need to generalize to support arbitrary cell sizes.
//TODO: This method relies on the caching of open cells. If the bounds are too large too permit
// all cells to remain open, this method will incorrectly return a subset of all cells providing
// coverage.
// Ping the collection of databases for elevation values at regular intervals inside the bounds.
// This will autoload the best cells:
cells.clear();
const ossim_float64 DELTA_DEG = 0.1; // degree
ossimGpt gpt;
for (gpt.lat=minLat; gpt.lat<=maxLat; gpt.lat+=DELTA_DEG)
{
for (gpt.lon=minLon; gpt.lon<=maxLon; gpt.lon+=DELTA_DEG)
{
getHeightAboveMSL(gpt);
}
}
// Convert filename list to string list (why are they different)?
ossim_uint32 limitCells = maxNumberOfCells>0?maxNumberOfCells:static_cast<ossim_uint32>(9999999999);
std::vector<ossimFilename> open_cells;
getOpenCellList(open_cells);
std::vector<ossimFilename>::iterator iter = open_cells.begin();
while ((iter != open_cells.end()) && (cells.size() < limitCells))
{
cells.push_back(iter->string());
++iter;
}
}