Merge commit 'edebc795d9df8936dd9311b06bdb06de0fe5d9cb'

.gitignore

@@ -87,3 +87,4 @@ cython_debug/
 .devcontainer/devcontainer.json
 
 output/
+artifacts/

README.md

@@ -58,7 +58,6 @@ If you prefer to set up the environment manually:
    export PYTHONPATH=$PWD
    ```
 
-
 ## Running the simulation
 
 To run the simulation, run the following command:

examples/5_take_a_picture.py

@@ -20,12 +20,16 @@ tello.streamoff()
 
 # Prepare directory to save
 script_dir = os.path.dirname(__file__)
-artifact_folder_path = os.path.join(script_dir, "../../artifacts/images")
+artifact_folder_path = os.path.join(os.path.dirname(script_dir), "artifacts", "images")
 os.makedirs(artifact_folder_path, exist_ok=True)
 
+print("[Example] Saving captured picture to:", artifact_folder_path)
+
 # Save the frame
 save_path = os.path.join(artifact_folder_path, "picture.png")
 cv2.imwrite(save_path, np.array(frame_read.frame))
 
+
+
 # Land
 tello.land()

tello_sim/command_server.py

@@ -1,7 +1,7 @@
 import os
 import socket
-from ursina import *
+import errno
-from cv2.typing import MatLike
+from ursina import * # type: ignore
 from time import time
 import cv2
 from ursina_adapter import UrsinaAdapter
@@ -17,10 +17,34 @@ class CommandServer:
         self.stream_active = False
         self.last_altitude = 0
         self._recording_folder = "output/recordings"
+        self.server_socket = None
         
         if not os.path.exists(self._recording_folder):
             os.makedirs(self._recording_folder)
 
+    def check_port_available(self, port: int = 9999) -> bool:
+        """
+        Check if the specified port is available.
+        Returns True if available, False if in use.
+        """
+        try:
+            test_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            test_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            test_socket.bind(('localhost', port))
+            test_socket.close()
+            return True
+        except OSError:
+            return False
+
+    def cleanup(self):
+        """Clean up resources and close the server socket."""
+        if self.server_socket:
+            try:
+                self.server_socket.close()
+                print("[Command Listener] Server socket closed.")
+            except Exception as e:
+                print(f"[Command Listener] Error closing socket: {e}")
+
     def streamon(self):
         """Start capturing screenshots and enable FPV video preview."""
         if not self.stream_active:
@@ -60,16 +84,35 @@ class CommandServer:
         """
         Listens for commands to send to the Simulator
         """
-        server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        server.bind(('localhost', 9999))  # Port number for communication
+        self.server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
-        server.listen(5)
-        print("[Command Listener] Listening on port 9999...")
         
-        while True:
+        try:
-            conn, _ = server.accept()
+            self.server_socket.bind(('localhost', 9999))  # Port number for communication
-            data = conn.recv(1024).decode()
+            self.server_socket.listen(5)
-            if data:
+            print("[Command Listener] Listening on port 9999...")
-                print(f"[Command Listener] Received command: {data}")
+        except OSError as e:
+            if e.errno == errno.EADDRINUSE:  # Address already in use
+                print("\n" + "="*70)
+                print("ERROR: Port 9999 is already in use!")
+                print("="*70)
+                print("\nAnother instance of the simulator may be running.")
+                print("\nTo fix this, run one of these commands in your terminal:")
+                print("  macOS/Linux: lsof -ti:9999 | xargs kill -9")
+                print("  Windows:     netstat -ano | findstr :9999")
+                print("               taskkill /PID <PID> /F")
+                print("\nOr simply restart your computer.")
+                print("="*70 + "\n")
+                raise
+            else:
+                raise
+
+        try:
+            while True:
+                conn, _ = self.server_socket.accept()
+                data = conn.recv(1024).decode()
+                if data:
+                    print(f"[Command Listener] Received command: {data}")
                 
                 if data == "connect":
                     self._ursina_adapter.connect()
@@ -202,13 +245,25 @@ class CommandServer:
                     conn.send(state.encode())
 
                 elif data == "get_latest_frame":
-                    # Save the frame to disk first
+                    # Send frame data directly over TCP instead of using filesystem
-                    frame_path = os.path.join(self._recording_folder, "latest_frame.png")
                     if self._ursina_adapter.latest_frame is not None:
-                        cv2.imwrite(frame_path, self._ursina_adapter.latest_frame)
+                        # Encode frame as PNG in memory
-                        conn.send(frame_path.encode())  
+                        success, buffer = cv2.imencode('.png', self._ursina_adapter.latest_frame)
+                        if success:
+                            # Send frame size first (4 bytes)
+                            frame_data = buffer.tobytes()
+                            frame_size = len(frame_data)
+                            conn.send(frame_size.to_bytes(4, byteorder='big'))
+                            # Then send the actual frame data
+                            conn.send(frame_data)
+                            print(f"[Frame Transfer] Sent {frame_size} bytes over TCP")
+                        else:
+                            # Send 0 size to indicate no frame
+                            conn.send((0).to_bytes(4, byteorder='big'))
                     else:
-                        conn.send(b"N/A")
+                        # Send 0 size to indicate no frame available
+                        conn.send((0).to_bytes(4, byteorder='big'))
+                        
                 elif data == "capture_frame":
                     self._ursina_adapter.capture_frame()
                 elif data.startswith("set_speed"):
@@ -221,4 +276,11 @@ class CommandServer:
                 elif data == "end":
                     self.end()
 
-            conn.close()
+                conn.close()
+        except KeyboardInterrupt:
+            print("\n[Command Listener] Shutting down...")
+            self.cleanup()
+        except Exception as e:
+            print(f"[Command Listener] Error: {e}")
+            self.cleanup()
+            raise

tello_sim/tello_drone_sim.py

@@ -1,21 +1,63 @@
 from command_server import CommandServer
 from ursina_adapter import UrsinaAdapter
 import threading
+import atexit
+import signal
+import sys
 
 class TelloDroneSim:
     def __init__(self):
         self._ursina_adapter = UrsinaAdapter()
         self._server = CommandServer(self._ursina_adapter)
         
+        # Register cleanup handlers
+        atexit.register(self.cleanup)
+        signal.signal(signal.SIGINT, self._signal_handler)
+        signal.signal(signal.SIGTERM, self._signal_handler)
+
+    def _signal_handler(self, signum, frame):
+        """Handle termination signals gracefully."""
+        print("\n[Tello Sim] Received shutdown signal, cleaning up...")
+        self.cleanup()
+        sys.exit(0)
+
+    def cleanup(self):
+        """Clean up resources."""
+        if hasattr(self, '_server'):
+            self._server.cleanup()
+
     @property
     def state(self):
         return self._ursina_adapter
 
     def start(self):
+        # Check if port is available before starting
+        if not self._server.check_port_available(9999):
+            print("\n" + "="*70)
+            print("ERROR: Cannot start simulator - Port 9999 is already in use!")
+            print("="*70)
+            print("\nAnother instance of the simulator may be running.")
+            print("\nTo fix this, run one of these commands in your terminal:")
+            print("  macOS/Linux: lsof -ti:9999 | xargs kill -9")
+            print("  Windows:     netstat -ano | findstr :9999")
+            print("               taskkill /PID <PID> /F")
+            print("\nOr simply restart your computer.")
+            print("="*70 + "\n")
+            sys.exit(1)
+        
         server_thread = threading.Thread(target=self._server.listen)
         server_thread.daemon = True
         server_thread.start()
-        self._ursina_adapter.run()
+        
+        try:
+            self._ursina_adapter.run()
+        except KeyboardInterrupt:
+            print("\n[Tello Sim] Interrupted, cleaning up...")
+            self.cleanup()
+        except Exception as e:
+            print(f"[Tello Sim] Error: {e}")
+            self.cleanup()
+            raise
 
     def update(self) -> None:
         self._ursina_adapter.tick()

tello_sim/tello_sim_client.py

@@ -69,12 +69,53 @@ class TelloSimClient:
             print(f"[Error] Unable to connect to the simulation at {self.host}:{self.port}")
     
     def get_frame_read(self) -> BackgroundFrameRead:
-        frame_path = self._request_data('get_latest_frame')
+        """Get the latest frame directly from the simulator over TCP."""
-        if frame_path != "N/A" and os.path.exists(frame_path):
+        try:
-            image = cv2.imread(frame_path)
+            with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
-            if image is not None:
+                s.connect((self.host, self.port))
-                return BackgroundFrameRead(frame=cv2.cvtColor(image, cv2.COLOR_BGR2RGB))
+                s.send(b'get_latest_frame')
-        return BackgroundFrameRead(frame=np.zeros([360, 640, 3], dtype=np.uint8))
+                
+                # Receive frame size (4 bytes)
+                size_data = s.recv(4)
+                if len(size_data) != 4:
+                    print("[Error] Failed to receive frame size")
+                    return BackgroundFrameRead(frame=np.zeros([360, 640, 3], dtype=np.uint8))
+                
+                frame_size = int.from_bytes(size_data, byteorder='big')
+                
+                # If size is 0, no frame available
+                if frame_size == 0:
+                    print("[Debug] No frame available from simulator")
+                    return BackgroundFrameRead(frame=np.zeros([360, 640, 3], dtype=np.uint8))
+                
+                # Receive the frame data
+                frame_data = b''
+                bytes_received = 0
+                while bytes_received < frame_size:
+                    chunk = s.recv(min(4096, frame_size - bytes_received))
+                    if not chunk:
+                        break
+                    frame_data += chunk
+                    bytes_received += len(chunk)
+                
+                # Decode the frame from PNG bytes
+                if len(frame_data) == frame_size:
+                    nparr = np.frombuffer(frame_data, np.uint8)
+                    image = cv2.imdecode(nparr, cv2.IMREAD_COLOR)
+                    if image is not None:
+                        # Return frame in BGR format (OpenCV's native format)
+                        # Users should convert to RGB if needed for display
+                        return BackgroundFrameRead(frame=image)
+                
+                print("[Error] Failed to decode frame data")
+                return BackgroundFrameRead(frame=np.zeros([360, 640, 3], dtype=np.uint8))
+                
+        except ConnectionRefusedError:
+            print(f"[Error] Unable to connect to the simulation at {self.host}:{self.port}")
+            return BackgroundFrameRead(frame=np.zeros([360, 640, 3], dtype=np.uint8))
+        except Exception as e:
+            print(f"[Error] Failed to get frame: {e}")
+            return BackgroundFrameRead(frame=np.zeros([360, 640, 3], dtype=np.uint8))
     
     def _request_data(self, command):
         try:

tello_sim/ursina_adapter.py

@@ -828,7 +828,7 @@ class UrsinaAdapter():
 
           
     def capture_frame(self):
-        """Capture and save the latest FPV frame from update()"""
+        """Capture the latest FPV frame. Optionally save to disk if save_frames_to_disk is True."""
         if not self.stream_active:
             print("[Capture] Stream not active. Cannot capture frame.")
             return  
@@ -837,11 +837,9 @@ class UrsinaAdapter():
             print("[Capture] No latest frame available.")
             return
 
-        frame_path = os.path.join(self.recording_folder, f"frame_{self.frame_count}.png")
+        # Always increment frame count for tracking
-        cv2.imwrite(frame_path, self.latest_frame)
-        self.saved_frames.append(frame_path)
         self.frame_count += 1
-        print(f"[Capture] Screenshot {self.frame_count} saved: {frame_path}")
+        print(f"[Capture] Frame {self.frame_count} captured (memory only)")
         
     def set_speed(self, x: int):
         """Set drone speed by adjusting acceleration force.
@@ -899,7 +897,7 @@ class UrsinaAdapter():
         
         if self.bezier_mode:
             t_now = time()
-            elapsed = t_now - self.bezier_start_time
+            elapsed = t_now - self.bezier_start_time # type: ignore
             t = min(1.0, elapsed / self.bezier_duration)
 
             # Bézier point