Move snake.

snake/game_object.py

@@ -1,3 +1,6 @@
 class GameObject:
     def draw(self, surface):
+        pass
+
+    def update(self):
         pass

snake/main.py

@@ -4,13 +4,18 @@ from input_manager import InputManager
 from snake import Snake
 from game_object import GameObject
 
-def draw(window: Window, game_objs: list[GameObject]) -> None:
+def draw_all(window: Window, game_objs: list[GameObject]) -> None:
     window.reset()
 
     for obj in game_objs:
         window.draw_object(obj)
 
 
+def update_all(game_objs: list[GameObject]) -> None:
+    for obj in game_objs:
+        obj.update()
+
+
 if __name__ == '__main__':
     window = Window(title='Snake', size=(800, 600), background_color=(0, 128, 0))
     input_manager = InputManager()
@@ -27,7 +32,8 @@ if __name__ == '__main__':
     while last_input != InputManager.QUIT:
         last_input = input_manager.process_input()
 
-        draw(window, game_objs)
+        draw_all(window, game_objs)
+        update_all(game_objs)
 
         clock.tick(framerate)
         pygame.display.flip()

snake/snake.py

@@ -12,4 +12,16 @@ class Snake(GameObject):
 
     def draw(self, surface: pygame.Surface) -> None:
         for segment in self.__segments:
-            segment.draw(surface)
+            segment.draw(surface)
+
+    def update(self) -> None:
+        head_pos = self.__segments[0].get_position()
+        head_radius = self.__segments[0].get_radius()
+        head_color = self.__segments[0].get_color()
+
+        new_head = SnakeSegment(center=(head_pos[0]-2*head_radius, head_pos[1]),
+                                radius=head_radius,
+                                color=head_color)
+        
+        self.__segments.insert(0, new_head)
+        self.__segments.pop()

snake/snake_segment.py

@@ -12,4 +12,13 @@ class SnakeSegment(GameObject):
         pygame.draw.circle(surface=surface, 
                            color=self.__color,
                            center=self.__center,
-                           radius=self.__radius)
+                           radius=self.__radius)
+        
+    def get_position(self) -> tuple:
+        return self.__center
+    
+    def get_radius(self) -> int|float:
+        return self.__radius
+    
+    def get_color(self) -> tuple:
+        return self.__color