stg: Add flag to load only specific parts of the stg files.

The flags are meant to be used for fgelev and for an ai
module that will probably only need ground elevation queries
in those reagions where the aircraft simulated there will roll
that is on airports.

diff --git a/simgear/scene/tgdb/ReaderWriterSTG.cxx b/simgear/scene/tgdb/ReaderWriterSTG.cxx
index 8e5913d800aadeb2a6399a409b99ab8ded606c18..0f800791ea3300addf327030923d067628fde965 100644 (file)
--- a/simgear/scene/tgdb/ReaderWriterSTG.cxx
+++ b/simgear/scene/tgdb/ReaderWriterSTG.cxx
@@ -49,6 +49,24 @@
 
 using namespace simgear;
 
+/// Ok, this is a hack - we do not exactly know if it's an airport or not.
+/// This feature might also vanish again later. This is currently to
+/// support testing an external ai component that just loads the the airports
+/// and supports ground queries on only these areas.
+static bool isAirportBtg(const std::string& name)
+{
+    if (name.size() < 8)
+        return false;
+    if (name.substr(4, 8) != ".btg")
+        return false;
+    for (unsigned i = 0; i < 4; ++i) {
+        if (name[i] < 'A' || 'Z' < name[i])
+            continue;
+        return true;
+    }
+    return false;
+}
+
 static SGBucket bucketIndexFromFileName(const std::string& fileName)
 {
   // Extract the bucket from the filename
@@ -194,7 +212,12 @@ ReaderWriterSTG::readStgFile(const std::string& absoluteFileName,
     sharedOptions->getDatabasePathList().push_back(path.str());
     std::string fg_root = options->getPluginStringData("SimGear::FG_ROOT");
     sharedOptions->getDatabasePathList().push_back(fg_root);
-    
+
+    // do only load airport btg files.
+    bool onlyAirports = options->getPluginStringData("SimGear::FG_ONLY_AIRPORTS") == "ON";
+    // do only load terrain btg files
+    bool onlyTerrain = options->getPluginStringData("SimGear::FG_ONLY_TERRAIN") == "ON";
+
     simgear::AirportSignBuilder signBuilder(staticOptions->getMaterialLib(), bucket.get_center());
   
     bool has_base = false;
@@ -221,23 +244,28 @@ ReaderWriterSTG::readStgFile(const std::string& absoluteFileName,
             SG_LOG( SG_TERRAIN, SG_BULK, "    " << token << " " << name );
             
             has_base = true;
-            node = osgDB::readRefNodeFile(path.str(),
-                                          staticOptions.get());
+
+            if (!onlyAirports || isAirportBtg(name)) {
+                node = osgDB::readRefNodeFile(path.str(),
+                                              staticOptions.get());
                 
-            if (!node.valid()) {
-                SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
-                        << ": Failed to load OBJECT_BASE '"
-                        << name << "'" );
+                if (!node.valid()) {
+                    SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
+                            << ": Failed to load OBJECT_BASE '"
+                            << name << "'" );
+                }
             }
             
         } else if ( token == "OBJECT" ) {
-            node = osgDB::readRefNodeFile(path.str(),
-                                          staticOptions.get());
+            if (!onlyAirports || isAirportBtg(name)) {
+                node = osgDB::readRefNodeFile(path.str(),
+                                              staticOptions.get());
                 
-            if (!node.valid()) {
-                SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
-                        << ": Failed to load OBJECT '"
-                        << name << "'" );
+                if (!node.valid()) {
+                    SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
+                            << ": Failed to load OBJECT '"
+                            << name << "'" );
+                }
             }
             
         } else {
@@ -246,46 +274,50 @@ ReaderWriterSTG::readStgFile(const std::string& absoluteFileName,
             
             // Always OK to load
             if ( token == "OBJECT_STATIC" ) {
-                osg::ref_ptr<SGReaderWriterOptions> opt;
-                opt = new SGReaderWriterOptions(*staticOptions);
-                osg::ProxyNode* proxyNode = new osg::ProxyNode;
-                proxyNode->setLoadingExternalReferenceMode(osg::ProxyNode::DEFER_LOADING_TO_DATABASE_PAGER);
-                /// Hmm, the findDataFile should happen downstream
-                std::string absName = osgDB::findDataFile(name, opt.get());
-                proxyNode->setFileName(0, absName);
-                if (SGPath(absName).lower_extension() == "ac")
-                {
-                    proxyNode->setNodeMask( ~simgear::MODELLIGHT_BIT );
-                    opt->setInstantiateEffects(true);
-                }
-                else
-                    opt->setInstantiateEffects(false);
-                proxyNode->setDatabaseOptions(opt.get());
-                node = proxyNode;
-                
-                if (!node.valid()) {
-                    SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
-                            << ": Failed to load OBJECT_STATIC '"
-                            << name << "'" );
+                if (!onlyTerrain) {
+                    osg::ref_ptr<SGReaderWriterOptions> opt;
+                    opt = new SGReaderWriterOptions(*staticOptions);
+                    osg::ProxyNode* proxyNode = new osg::ProxyNode;
+                    proxyNode->setLoadingExternalReferenceMode(osg::ProxyNode::DEFER_LOADING_TO_DATABASE_PAGER);
+                    /// Hmm, the findDataFile should happen downstream
+                    std::string absName = osgDB::findDataFile(name, opt.get());
+                    proxyNode->setFileName(0, absName);
+                    if (SGPath(absName).lower_extension() == "ac")
+                    {
+                        proxyNode->setNodeMask( ~simgear::MODELLIGHT_BIT );
+                        opt->setInstantiateEffects(true);
+                    }
+                    else
+                        opt->setInstantiateEffects(false);
+                    proxyNode->setDatabaseOptions(opt.get());
+                    node = proxyNode;
+                    
+                    if (!node.valid()) {
+                        SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
+                                << ": Failed to load OBJECT_STATIC '"
+                                << name << "'" );
+                    }
                 }
                 
             } else if ( token == "OBJECT_SHARED" ) {
-                osg::ref_ptr<SGReaderWriterOptions> opt;
-                opt = new SGReaderWriterOptions(*sharedOptions);
-                /// Hmm, the findDataFile should happen in the downstream readers
-                std::string absName = osgDB::findDataFile(name, opt.get());
-                if (SGPath(absName).lower_extension() == "ac")
-                    opt->setInstantiateEffects(true);
-                else
-                    opt->setInstantiateEffects(false);
-                node = osgDB::readRefNodeFile(absName, opt.get());
-                if (SGPath(absName).lower_extension() == "ac")
-                    node->setNodeMask( ~simgear::MODELLIGHT_BIT );
-                
-                if (!node.valid()) {
-                    SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
-                            << ": Failed to load OBJECT_SHARED '"
-                            << name << "'" );
+                if (!onlyTerrain) {
+                    osg::ref_ptr<SGReaderWriterOptions> opt;
+                    opt = new SGReaderWriterOptions(*sharedOptions);
+                    /// Hmm, the findDataFile should happen in the downstream readers
+                    std::string absName = osgDB::findDataFile(name, opt.get());
+                    if (SGPath(absName).lower_extension() == "ac")
+                        opt->setInstantiateEffects(true);
+                    else
+                        opt->setInstantiateEffects(false);
+                    node = osgDB::readRefNodeFile(absName, opt.get());
+                    if (SGPath(absName).lower_extension() == "ac")
+                        node->setNodeMask( ~simgear::MODELLIGHT_BIT );
+                    
+                    if (!node.valid()) {
+                        SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
+                                << ": Failed to load OBJECT_SHARED '"
+                                << name << "'" );
+                    }
                 }
                 
             } else if ( token == "OBJECT_SIGN" ) {
@@ -294,7 +326,8 @@ ReaderWriterSTG::readStgFile(const std::string& absoluteFileName,
                 if ( hasOptionalValue(in) ){
                     in >> size;
                 }
-                signBuilder.addSign(SGGeod::fromDegM(lon, lat, elev), hdg, name, size);
+                if (!onlyTerrain)
+                    signBuilder.addSign(SGGeod::fromDegM(lon, lat, elev), hdg, name, size);
             } else {
                 SG_LOG( SG_TERRAIN, SG_ALERT, absoluteFileName
                         << ": Unknown token '" << token << "'" );