Refactoring lab

games/snake/observation.py

@@ -0,0 +1,18 @@
+import numpy as np
+from retro.views.headless import HeadlessView
+from retro_gamer.observation import egocentric_board, encode_board, encode_state
+
+CHARACTER_SET = ["@", "*", ">", "<", "^", "v"]
+RADIUS = 8
+
+
+def egocentric_observation(game):
+    """17×17 window centered on the snake's head, plus apple_dx and apple_dy."""
+    view = HeadlessView()
+    view.on_game_start(game)
+    view.render(game)
+    head = game.get_agent_by_name("Snake head")
+    cropped = egocentric_board(view.board_characters, head.position, RADIUS)
+    board_vec = encode_board(cropped, CHARACTER_SET).flatten()
+    extras = encode_state(game.state, ["apple_dx", "apple_dy"])
+    return np.concatenate([board_vec, extras])