not loading already loaded chunks

src/game/world/mod.rs

@@ -57,9 +57,13 @@ impl World {
     *   Sends chunk position to the ChunkLoader
     */
     pub fn load_chunk(&mut self, pos: Vector3<i32>) {
+        if let Some(chunk) = self.chunks.get_mut(&pos) {
+            chunk.dirty = true;
+        } else {
             self.loader.load(pos);
             self.busy += 1;
         }
+    }
 
     /*
     *   Loads metadata