diff --git a/trap/renderer.py b/trap/renderer.py
index d48d693..7165c9e 100644
--- a/trap/renderer.py
+++ b/trap/renderer.py
@@ -78,19 +78,31 @@ class DrawnTrack:
         self.track_id = track_id
         self.renderer = renderer
         self.drawn_positions = []
-        self.drawn_predictions = []
-        self.predictions: deque[DrawnPrediction] = deque(maxlen=20) # TODO; make configurable
+        # self.drawn_predictions = []
+        self.predictions: deque[DrawnPrediction] = deque(maxlen=2) # TODO; make configurable
         self.shapes: list[pyglet.shapes.Line] = []
 
         self.set_track(track, H)
         self.set_prediction(track)
+    
+    def __del__(self):
+        self.destroy()
+
+    def destroy(self):
+        # TODO)) not working yet 
+        logger.warning(f'del track  {self}')
+        for s in self.shapes:
+            s.delete()
+        
+        for p in self.predictions:
+            p.destroy()
 
     def set_track(self, track: Track, H):
         self.update_at = time.time()
 
         self.track = track
         self.H = H
-        self.coords = [d.get_foot_coords() for d in track.history]
+        self.coords = [d.get_foot_coords() for d in track.history[-30:]] # maximum of 30 past positions (prevent collapse of FPS on loitering object)
 
         # perhaps only do in constructor:
         self.inv_H = np.linalg.pinv(self.H)
@@ -98,6 +110,7 @@ class DrawnTrack:
     def set_prediction(self, track: Track):
         # TODO: turn into add_prediction
         pred_coords = []
+    
         if not track.predictions:
             return
         
@@ -248,6 +261,11 @@ class DrawnPrediction:
                 line.opacity = 5
                 prediction_shapes.append(line)
             self.pred_shapes.append(prediction_shapes)
+    
+    def destroy(self):
+        for pred in self.pred_shapes:
+            for shape in pred:
+                shape.delete()
 
 
     def update_opacities(self, dt: float):
@@ -547,6 +565,7 @@ class Renderer:
             # TODO make delay configurable
             if self.drawn_tracks[track_id].update_at < time.time() - 5:
                 # TODO fade out
+                self.drawn_tracks[track_id].destroy()
                 del self.drawn_tracks[track_id]
     
     def update_predictions(self):
@@ -592,6 +611,7 @@ class Renderer:
         self.window.clear()
 
         self.batch_bg.draw()
+
         
         for track in self.drawn_tracks.values():
             for shape in track.shapes: