//*************************************************************************************************
//! Returns a projection corresponding to the group (e.g., "EPSG") and PCS code provided,
//! or NULL if no entry found.
//*************************************************************************************************
ossimProjection* ossimEpsgProjectionDatabase::findProjection(ossim_uint32 epsg_code) const
{
ossimMapProjection* proj = 0;
// Quick check for bogus EPSG:
if ((epsg_code == 0) || (epsg_code == 32767))
return 0;
// Check for Google projection:
else if (epsg_code == 900913)
{
const ossimDatum* datum = ossimDatumFactory::instance()->create(ossimString("6055"));
ossimMercatorProjection* merc_proj = new ossimMercatorProjection();
ossimGpt origin(0.0,0.0,0.0, datum);
merc_proj->setFalseEasting(0.0);
merc_proj->setFalseNorthing(0.0);
merc_proj->setOrigin(origin); // Also sets the projections datum to the origin's datum
merc_proj->update();
merc_proj->setPcsCode(900913);
proj = merc_proj;
}
else
{
// Search database for entry:
std::multimap<ossim_uint32, ossimRefPtr<ProjDbRecord> >::iterator db_iter =
m_projDatabase.find(epsg_code);
if (db_iter != m_projDatabase.end())
{
// See if a projection has already been created for this entry:
ProjDbRecord* db_record = db_iter->second.get();
if (db_record->proj.valid())
proj = (ossimMapProjection*) db_record->proj->dup();
else
{
// Try decoding the EPSG code before accessing DB:
proj = createProjFromUtmCode(epsg_code);
if (proj)
{
db_record->proj = proj;
db_record->datumValid = true;
}
else if (db_iter->second->csvFormat == FORMAT_A)
proj = createProjFromFormatARecord(db_record);
else if (db_iter->second->csvFormat == FORMAT_B)
proj = createProjFromFormatBRecord(db_record);
if (proj)
{
// To save allocated memory, get rid of the original CSV entry since a real
// projection is now represented in the database:
db_record->csvRecord.clear();
db_record->csvFormat = NOT_ASSIGNED;
}
}
}
}
return proj;
}
//*************************************************************************************************
//! Populates the database with contents of DB files as specified in ossim_preferences.
//*************************************************************************************************
void ossimEpsgProjectionDatabase::initialize()
{
// Fetch filenames of all projection DB files specified in ossim_preferences:
ossimString regEx = ossimString("^epsg_database_file[0-9]+");
std::vector<ossimString> keys =
ossimPreferences::instance()->preferencesKWL().getSubstringKeyList(regEx);
std::vector<ossimString>::const_iterator i = keys.begin();
// Create only once outside the loop:
ossimFilename db_name;
ossimString group_id;
ossimString format_id;
ossimString line;
DbEntry file_record;
// Loop over each file and read contents into memory:
while ( i != keys.end() )
{
db_name = ossimPreferences::instance()->preferencesKWL().find( (*i).c_str() );
++i;
if (!db_name.isReadable())
continue;
// Open the DB file:
std::ifstream db_stream (db_name.chars());
bool good_file = false;
if (db_stream.good())
{
// Format specification implied in file's magic number:
std::getline(db_stream, format_id);
format_id.trim();
if ((format_id == EPSG_DB_FORMAT_A) ||
(format_id == STATE_PLANE_FORMAT_B) ||
(format_id == SPCS_EPSG_MAP_FORMAT_C) ||
(format_id == WKT_PCS_FORMAT_D))
good_file = true;
}
if (!good_file)
{
ossimNotify(ossimNotifyLevel_WARN)<<"ossimEpsgProjectionDatabase::initialize() -- "
"Encountered bad database file <"<<db_name<<">. Skipping this file."<<endl;
db_stream.close();
continue;
}
// The file is good. Skip over the column descriptor line:
std::getline(db_stream, line);
file_record.clear();
// Loop to read all data records:
while (!db_stream.eof())
{
std::getline(db_stream, line);
file_record = line.explode(","); // ONLY CSV FILES CONSIDERED HERE
if (file_record.size())
{
ossimRefPtr<ossimMapProjection> proj;
ProjRecord proj_record;
// Check if primary EPSG database format A:
if (format_id == EPSG_DB_FORMAT_A)
{
proj = createProjFromFormatARecord(file_record, proj_record.datumValid);
proj_record.code = file_record[A_CODE].toUInt32();
proj_record.name = file_record[A_NAME];
}
// Check if State Plane (subset of EPSG but handled differently until projection
// geotrans-EPSG disconnect is resolved.
else if (format_id == STATE_PLANE_FORMAT_B)
{
proj = createProjFromFormatBRecord(file_record);
proj_record.code = file_record[B_CODE].toUInt32();
proj_record.name = file_record[B_NAME];
proj_record.datumValid = true;
}
// This format is for Ming-special State Plane Coordinate System coded format.
// This format is simply a mapping from SPCS spec name (OSSIM-specific) to EPSG code.
// Note that no proj is instantiated and no KWL is populated. Only name and EPSG mapped
// code is saved.
else if (format_id == SPCS_EPSG_MAP_FORMAT_C)
{
proj_record.code = file_record[C_CODE].toUInt32();
proj_record.name = file_record[C_NAME];
m_projDatabase.push_back(proj_record);
}
// This format is for alternate projection naming scheme database CSV file format.
// WKT_PCS coding is an alternate naming scheme that maps to EPSG.
// Note that no proj is instantiated and no KWL is populated. Only name and EPSG mapped
// code is saved.
else if (format_id == WKT_PCS_FORMAT_D)
{
proj_record.code = file_record[D_CODE].toUInt32();
proj_record.name = file_record[D_NAME];
m_projDatabase.push_back(proj_record);
}
if (proj.valid() && proj_record.datumValid)
{
// Serialize the projection to a KWL and stick it in the in-memory database:
proj->saveState(proj_record.kwl);
m_projDatabase.push_back(proj_record);
}
}
}
db_stream.close();
} // end of while loop over all DB files
}
