Added loaded flag to FGTileEntry so that the main thread knows when the

tile has been loaded.  Since this flag can be set by another thread I've
declared it "volatile bool".

Also cleaned up delete vs delete[] usage.  Gcc is happy with delete[],
which is the correct usage.

src/Scenery/tileentry.cxx

@@ -58,7 +58,8 @@ FGTileEntry::FGTileEntry ( const SGBucket& b )
       center( Point3D( 0.0 ) ),
       tile_bucket( b ),
       terra_transform( new ssgTransform ),
-      terra_range( new ssgRangeSelector )
+      terra_range( new ssgRangeSelector ),
+      loaded(false)
 {
     nodes.clear();
 
@@ -114,20 +115,12 @@ void FGTileEntry::free_tile() {
 	    << " texture coordinate arrays" );
 
     for ( i = 0; i < (int)vec3_ptrs.size(); ++i ) {
-#if defined(macintosh) || defined(_MSC_VER)
 	delete [] vec3_ptrs[i];  //that's the correct version
-#else
-	delete vec3_ptrs[i];
-#endif
     }
     vec3_ptrs.clear();
 
     for ( i = 0; i < (int)vec2_ptrs.size(); ++i ) {
-#if defined(macintosh) || defined(_MSC_VER)
 	delete [] vec2_ptrs[i];  //that's the correct version
-#else
-	delete vec2_ptrs[i];
-#endif
     }
     vec2_ptrs.clear();
 
@@ -182,6 +175,8 @@ void FGTileEntry::free_tile() {
 // Update the ssg transform node for this tile so it can be
 // properly drawn relative to our (0,0,0) point
 void FGTileEntry::prep_ssg_node( const Point3D& p, float vis) {
+    if ( !loaded ) return;
+
     SetOffset( p );
 
 // #define USE_UP_AND_COMING_PLIB_FEATURE
@@ -329,7 +324,7 @@ FGTileEntry::obj_load( const std::string& path,
 
 
 void
-FGTileEntry::load( SGPath& tile_path, bool is_base )
+FGTileEntry::load( const SGPath& base, bool is_base )
 {
     // a cheesy hack (to be fixed later)
     extern ssgBranch *terrain;
@@ -337,6 +332,7 @@ FGTileEntry::load( SGPath& tile_path, bool is_base )
 
     string index_str = tile_bucket.gen_index_str();
 
+    SGPath tile_path = base;
     // Generate name of file to load.
     tile_path.append( tile_bucket.gen_base_path() );
     SGPath basename = tile_path;
@@ -417,4 +413,6 @@ FGTileEntry::load( SGPath& tile_path, bool is_base )
 	ground->addKid( lights_transform );
     }
     /* end of ground light section */
+
+    loaded = true;
 }

src/Scenery/tileentry.hxx

@@ -117,6 +117,12 @@ private:
     // want based on lighting conditions.
     ssgSelector *lights_brightness;
 
+    /**
+     * Indicates this tile has been loaded from a file.
+     * Note that this may be set asynchronously by another thread.
+     */
+    volatile bool loaded;
+
     ssgBranch* obj_load( const std::string& path,
 			 ssgVertexArray* lights, bool is_base );
 
@@ -153,7 +159,7 @@ public:
      * @param is_base is this a base terrain object for which we should generate
      *        random ground light points
      */
-    void load( SGPath& base, bool is_base );
+    void load( const SGPath& base, bool is_base );
 };