fix clockwise_twist

skewb_solver.py

@@ -161,36 +161,43 @@ def test_rotation_permutations(p: CornerRotPermutation):
 MID_DIR_INCREMENT: dict[MidRotState, MidRotState] = {"Y": "O", "R": "Y", "O": "R"}
 
 
-def clockwise_twist(s: Skewb, twist: Axis) -> Skewb:
+def clockwise_twist(s: Skewb, axis: Axis) -> Skewb:
-    rot_before, rot_after = {"G": (0, 0), "O": (3, 1), "B": (2, 2), "R": (1, 3)}[twist]
+    """Applies a clockwise twist to the axis.
+
+    Coordinate frame is define as follows:
+    - axis goes through the `top` of a solved cube of a given color
+    - the axis-top is on top and faces away from the observer twisting it,
+    - clockwise is twisting the bottom when looking up from diagonally-below the skewb
+    """
+    rot_before, rot_after = {"G": (0, 0), "O": (3, 1), "B": (2, 2), "R": (1, 3)}[axis]
     for _ in range(rot_before):
         s = rotate_everything_about_W(s)
     s = Skewb(
         top=(
             s.top[0],
             s.top[1],
-            Corner((c := s.bot[3]).col, BOT_LEFT_TO_TOP[c.rot]),
+            Corner((c := s.bot[0]).col, BOT_LEFT_TO_TOP[c.rot]),
             s.top[3],
         ),
         bot=(
-            s.bot[0],
+            Corner((c := s.bot[2]).col, BOT_RIGHT_TO_BOT_LEFT[c.rot]),
+            s.bot[1],
             Corner((c := s.top[2]).col, TOP_TO_BOT_RIGHT[c.rot]),
-            Corner((c := s.bot[2]).col, ROTATE_CORNER_CLOCKWISE[c.rot]),
+            Corner((c := s.bot[3]).col, ROTATE_CORNER_CLOCKWISE[c.rot]),
-            Corner((c := s.bot[1]).col, BOT_RIGHT_TO_BOT_LEFT[c.rot]),
         ),
         mids=(
             s.mids[0],
+            s.mids[1],
             Middle(
-                (m := s.mids[2]).col,
+                (m := s.mids[3]).col,
                 "Y" if m.col == "Y" else MID_DIR_INCREMENT[m.rot],
             ),
             Middle(
                 (m := s.mids[4]).col,
                 "Y" if m.col == "Y" else MID_DIR_INCREMENT[m.rot],
             ),
-            s.mids[3],
             Middle(
-                (m := s.mids[1]).col,
+                (m := s.mids[2]).col,
                 "Y" if m.col == "Y" else ("O" if m.rot == "Y" else "R"),
             ),
         ),
@@ -200,6 +207,22 @@ def clockwise_twist(s: Skewb, twist: Axis) -> Skewb:
     return s
 
 
+@pytest.mark.parametrize(
+    "axis, want",
+    [
+        (
+            "O",
+            Skewb(
+                top=(G0, O0, B0, O2), bot=(G1, R2, B0, R2), mids=(YY, OY, BY, GR, RR)
+            ),
+        )
+    ],
+)
+def test_clockwise_twist_from_solved(axis: Axis, want: Skewb):
+    want.assert_valid()
+    assert clockwise_twist(solved_skewb, axis) == want
+
+
 def anticlockwise_twist(s: Skewb, twist: Axis) -> Skewb:
     return clockwise_twist(clockwise_twist(s, twist), twist)