feat: add rollback button

src/car.py

@@ -8,7 +8,8 @@ from src.remote_controller import RemoteController
 from src.utils import get_segments_intersection, segments_intersect
 from src.vec import Vec
 
-sign = lambda x: 0 if x == 0 else (-1 if x < 0 else 1)
+
+def sign(x): return 0 if x == 0 else (-1 if x < 0 else 1)
 
 
 class Car:
@@ -27,6 +28,8 @@ class Car:
     RAYS_MAX_DIST = 100
 
     def __init__(self, pos: Vec, direction: Vec) -> None:
+        self.initial_pos: Vec = pos.copy()
+        self.initial_dir: Vec = direction.copy()
         self.pos: Vec = pos
         self.direction: Vec = direction
         self.speed: float = 0
@@ -77,7 +80,8 @@ class Car:
         if show_raycasts:
             pos: Vec = camera.world2screen(self.pos)
             for p in self.rays_end:
-                pygame.draw.line(surf, (255, 0, 0), pos, camera.world2screen(p), 2)
+                pygame.draw.line(surf, (255, 0, 0), pos,
+                                 camera.world2screen(p), 2)
 
         pts: list[Vec] = self.get_corners()
         pts = [camera.world2screen(p) for p in pts]
@@ -127,14 +131,17 @@ class Car:
                             n *= -1
                             dist = -dist
                         self.speed = 0
-                        self.pos = self.pos + n * (self.COLLISION_MARGIN - dist)
+                        self.pos = self.pos + n * \
+                            (self.COLLISION_MARGIN - dist)
                         return
 
     def cast_rays(self, polygons: list[list[Vec]]):
         for i in range(self.N_RAYS):
-            angle: float = radians((i / (self.N_RAYS - 1) - 0.5) * self.RAYS_FOV)
+            angle: float = radians(
+                (i / (self.N_RAYS - 1) - 0.5) * self.RAYS_FOV)
             p: Optional[Vec] = self.cast_ray(angle, polygons)
-            self.rays[i] = self.RAYS_MAX_DIST if p is None else (p - self.pos).mag()
+            self.rays[i] = self.RAYS_MAX_DIST if p is None else (
+                p - self.pos).mag()
             self.rays_end[i] = self.pos if p is None else p
 
     def cast_ray(self, angle: float, polygons: list[list[Vec]]) -> Optional[Vec]:
@@ -161,3 +168,8 @@ class Car:
                     dist = d
                     closest = p
         return closest
+
+    def reset(self):
+        self.pos = self.initial_pos.copy()
+        self.direction = self.initial_dir.copy()
+        self.speed = 0

src/command.py

@@ -5,10 +5,14 @@ from enum import IntEnum
 import struct
 from typing import Type
 
+from src.snapshot import Snapshot
+
 
 class CommandType(IntEnum):
     CAR_CONTROL = 0
     RECORDING = 1
+    APPLY_SNAPSHOT = 2
+    RESET = 3
 
 
 class CarControl(IntEnum):
@@ -30,8 +34,8 @@ class Command(abc.ABC):
             )
         Command.REGISTRY[cls.TYPE] = cls
 
-    @abc.abstractmethod
-    def get_payload(self) -> bytes: ...
+    def get_payload(self) -> bytes:
+        return b""
 
     def pack(self) -> bytes:
         payload: bytes = self.get_payload()
@@ -43,8 +47,8 @@ class Command(abc.ABC):
         return Command.REGISTRY[type].from_payload(data[1:])
 
     @classmethod
-    @abc.abstractmethod
-    def from_payload(cls, payload: bytes) -> Command: ...
+    def from_payload(cls, payload: bytes) -> Command:
+        return cls()
 
 
 class ControlCommand(Command):
@@ -82,3 +86,24 @@ class RecordingCommand(Command):
     def from_payload(cls, payload: bytes) -> Command:
         state: bool = struct.unpack(">B", payload)[0]
         return RecordingCommand(state)
+
+
+class ApplySnapshotCommand(Command):
+    TYPE = CommandType.APPLY_SNAPSHOT
+    __match_args__ = ("snapshot",)
+
+    def __init__(self, snapshot: Snapshot) -> None:
+        super().__init__()
+        self.snapshot: Snapshot = snapshot
+
+    def get_payload(self) -> bytes:
+        return self.snapshot.pack()
+
+    @classmethod
+    def from_payload(cls, payload: bytes) -> Command:
+        snapshot: Snapshot = Snapshot.unpack(payload)
+        return ApplySnapshotCommand(snapshot)
+
+
+class ResetCommand(Command):
+    TYPE = CommandType.RESET

src/recorder.py

@@ -9,7 +9,7 @@ from PyQt6.QtCore import QObject, QThread, QTimer, pyqtSignal, pyqtSlot
 from PyQt6.QtGui import QKeyEvent
 from PyQt6.QtWidgets import QMainWindow
 
-from src.command import CarControl, Command, ControlCommand, RecordingCommand
+from src.command import ApplySnapshotCommand, CarControl, Command, ControlCommand, RecordingCommand, ResetCommand
 from src.record_file import RecordFile
 from src.recorder_ui import Ui_Recorder
 from src.snapshot import Snapshot
@@ -203,7 +203,19 @@ class RecorderWindow(Ui_Recorder, QMainWindow):
         self.send_command(RecordingCommand(self.recording))
 
     def rollback(self):
-        pass
+        rollback_by: int = self.forgetSnapshotNumber.value()
+        rollback_by = max(0, min(rollback_by, len(self.snapshots) - 1))
+
+        self.snapshots = self.snapshots[:-rollback_by]
+        self.nbrSnapshotSaved.setText(str(len(self.snapshots)))
+
+        if len(self.snapshots) == 0:
+            self.send_command(ResetCommand())
+        else:
+            self.send_command(ApplySnapshotCommand(self.snapshots[-1]))
+
+        if self.recording:
+            self.toggle_record()
 
     def toggle_autopilot(self):
         self.autopiloting = not self.autopiloting

src/remote_controller.py

@@ -6,7 +6,7 @@ import struct
 import threading
 from typing import TYPE_CHECKING, Optional
 
-from src.command import CarControl, Command, ControlCommand, RecordingCommand
+from src.command import ApplySnapshotCommand, CarControl, Command, ControlCommand, RecordingCommand, ResetCommand
 from src.snapshot import Snapshot
 from src.utils import RepeatTimer
 
@@ -119,6 +119,10 @@ class RemoteController:
                 self.set_control(control, active)
             case RecordingCommand(state):
                 self.recording = state
+            case ApplySnapshotCommand(snapshot):
+                snapshot.apply(self.car)
+            case ResetCommand():
+                self.car.reset()
 
     def set_control(self, control: CarControl, active: bool):
         setattr(self.car, self.CONTROL_ATTRIBUTES[control], active)

src/snapshot.py

@@ -94,3 +94,8 @@ class Snapshot:
             raycast_distances=car.rays.copy(),
             image=None
         )
+
+    def apply(self, car: Car):
+        car.pos = self.position.copy()
+        car.direction = self.direction.copy()
+        car.speed = 0