Add support for specifying a ";" delimited list of scenery locations to

search when loading scenery tiles.  (I am not set on using ";" as the
delimiter because it is a command separator in unix, but ":" is a critical
part of the windows file naming scheme (c:\foo\bar) so that is even worse.)

Example:

--fg-scenery=/stage/fgfs04/curt/Scenery-0.9.1/Scenery;/stage/helio1/curt/Scenery
-0.7.9

src/Scenery/FGTileLoader.cxx

@@ -92,12 +92,14 @@ FGTileLoader::add( FGTileEntry* tile )
     static bool beenhere = false;
     if (!beenhere)
     {
+        SGPath tmp;
 	if ( !globals->get_fg_scenery().empty() ) {
-	    tile_path.set( globals->get_fg_scenery() );
+	    tmp.set( globals->get_fg_scenery() );
 	} else {
-	    tile_path.set( globals->get_fg_root() );
+	    tmp.set( globals->get_fg_root() );
 	    tile_path.append( "Scenery" );
 	}
+        tile_path = tmp.str();
 	beenhere = true;
     }
 

src/Scenery/FGTileLoader.hxx

@@ -111,7 +111,7 @@ private:
     /**
      * Base name of directory containing tile data file.
      */
-    SGPath tile_path;
+    string tile_path;
 
 #ifdef ENABLE_THREADS
     /**

src/Scenery/tileentry.cxx

@@ -557,17 +557,6 @@ bool FGTileEntry::obj_load( const string& path,
             center = c;
             bounding_radius = br;
         }
-    } else {
-        // default to an ocean tile
-        if ( sgGenTile( path, tile_bucket, &c, &br,
-                        globals->get_matlib(), geometry ) )
-        {
-            center = c;
-            bounding_radius = br;
-        } else {
-            SG_LOG( SG_TERRAIN, SG_ALERT,
-                    "Warning: failed to generate ocean tile!" );
-        }
     }
 
     return (geometry != NULL);
@@ -575,14 +564,27 @@ bool FGTileEntry::obj_load( const string& path,
 
 
 void
-FGTileEntry::load( const SGPath& base, bool is_base )
+FGTileEntry::load( const string &base_path, bool is_base )
 {
-    SG_LOG( SG_TERRAIN, SG_INFO, "load() base = " << base.str() );
+    SG_LOG( SG_TERRAIN, SG_INFO, "load() base search path = "
+            << base_path );
+
+    bool found_tile_base = false;
+
+    string_list search = sgPathSplit( base_path );
+
+    // obj_load() will generate ground lighting for us ...
+    ssgVertexArray *light_pts = new ssgVertexArray( 100 );
+
+    ssgBranch* new_tile = new ssgBranch;
+
+    unsigned int i = 0;
+    while ( i < search.size() && !found_tile_base ) {
 
         // Generate names for later use
         string index_str = tile_bucket.gen_index_str();
 
-    SGPath tile_path = base;
+        SGPath tile_path = search[i];
         tile_path.append( tile_bucket.gen_base_path() );
 
         SGPath basename = tile_path;
@@ -593,11 +595,6 @@ FGTileEntry::load( const SGPath& base, bool is_base )
 
 #define FG_MAX_LIGHTS 1000
 
-    // obj_load() will generate ground lighting for us ...
-    ssgVertexArray *light_pts = new ssgVertexArray( 100 );
-
-    ssgBranch* new_tile = new ssgBranch;
-
         // Check for master .stg (scene terra gear) file
         SGPath stg_name = basename;
         stg_name.concat( ".stg" );
@@ -615,6 +612,8 @@ FGTileEntry::load( const SGPath& base, bool is_base )
                     SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
                             << " name = " << name );
 
+                    found_tile_base = true;
+
                     SGPath custom_path = tile_path;
                     custom_path.append( name );
 
@@ -676,8 +675,9 @@ FGTileEntry::load( const SGPath& base, bool is_base )
                     // object loading is deferred to main render thread,
                     // but lets figure out the paths right now.
                     SGPath custom_path;
-                if ( token == "OBJECT_STATIC" )
+                    if ( token == "OBJECT_STATIC" ) {
                         custom_path= tile_path;
+                    }
                     custom_path.append( name );
 
                     sgCoord obj_pos;
@@ -694,7 +694,8 @@ FGTileEntry::load( const SGPath& base, bool is_base )
 
                     // push an entry onto the model load queue
                     FGDeferredModel *dm
-                    = new FGDeferredModel( custom_path.str(), tile_path.str(),
+                        = new FGDeferredModel( custom_path.str(),
+                                               tile_path.str(),
                                                this, obj_trans );
                     FGTileMgr::model_ready( dm );
                 } else if ( token == "OBJECT_TAXI_SIGN" ) {
@@ -773,14 +774,20 @@ FGTileEntry::load( const SGPath& base, bool is_base )
                     in >> ::skipws;
                 }
             }
-    } else {
-        // no .stg file, generate an ocean tile on the fly for this
-        // area
+        }
+
+        i++;
+    }
+
+    if ( !found_tile_base ) {
+        // no tile base found, generate an ocean tile on the fly for
+        // this area
         ssgBranch *geometry = new ssgBranch;
         Point3D c;
         double br;
-        if ( sgGenTile( basename.str(), tile_bucket, &c, &br,
-                        globals->get_matlib(), geometry ) ) {
+        if ( sgGenTile( search[0], tile_bucket, &c, &br,
+                        globals->get_matlib(), geometry ) )
+        {
             center = c;
             bounding_radius = br;
             new_tile -> addKid( geometry );

src/Scenery/tileentry.hxx

@@ -212,7 +212,7 @@ public:
      * @param base name of directory containing tile data file.
      * @param is_base is this a base terrain object for which we should generate
      *        random ground light points */
-    void load( const SGPath& base, bool is_base );
+    void load( const string &base_path, bool is_base );
 
     /**
      * Return true if the tile entry is loaded, otherwise return false