First steps

game/components.py

@@ -5,6 +5,7 @@ from __future__ import annotations
 from typing import Final, Self
 
 import attrs
+import math
 import tcod.ecs.callbacks
 from tcod.ecs import Entity
 
@@ -18,9 +19,19 @@ class Position:
 
     def __add__(self, direction: tuple[int, int]) -> Self:
         """Add a vector to this position."""
+        match direction:
+            case Position(x, y):
+                return self.__class__(self.x + x, self.y + y)
         x, y = direction
         return self.__class__(self.x + x, self.y + y)
-
+    def __sub__(self, direction: tuple[int, int]):
+        match direction:
+            case Position(x, y):
+                return self.__class__(self.x - x, self.y - y)
+        x, y = direction
+        return self.__class__(self.x - x, self.y - y)
+    def length(self):
+        return math.sqrt(self.x**2+self.y**2)
 
 @tcod.ecs.callbacks.register_component_changed(component=Position)
 def on_position_changed(entity: Entity, old: Position | None, new: Position | None) -> None: