1 files changed, 33 insertions, 21 deletions

diff --git a/src/core/moves.h b/src/core/moves.h
index e3a9bc1..7d4972e 100644
--- a/src/core/moves.h
+++ b/src/core/moves.h
@@ -2,8 +2,8 @@
 #define PREMOVE(M, c) compose(MOVE_CUBE_ ## M, c)
 
 STATIC_INLINE bool allowednextmove(uint8_t *, uint8_t);
+STATIC_INLINE uint32_t allowednextmove_mask(uint8_t *, uint8_t);
 
-STATIC_INLINE uint8_t inverse_trans(uint8_t);
 STATIC_INLINE uint8_t movebase(uint8_t);
 STATIC_INLINE uint8_t moveaxis(uint8_t);
 STATIC_INLINE uint32_t disable_moves(uint32_t, uint8_t);
@@ -38,26 +38,38 @@ STATIC cube_t applymoves(cube_t, const char *);
 STATIC bool
 allowednextmove(uint8_t *moves, uint8_t n)
 {
-        uint8_t base[3], axis[3];
+        return n == 0 ? true :
+            allowednextmove_mask(moves, n-1) & (1 << moves[n-1]);
+}
+
+STATIC uint32_t
+allowednextmove_mask(uint8_t *moves, uint8_t n)
+{
+        uint32_t result;
+        uint8_t base1, base2, axis1, axis2;
+
+        result = MM_ALLMOVES;
 
-        if (n < 2)
-                return true;
+        if (n == 0)
+                return result;
 
-        base[0] = movebase(moves[n-1]);
-        axis[0] = moveaxis(moves[n-1]);
-        base[1] = movebase(moves[n-2]);
-        axis[1] = moveaxis(moves[n-2]);
+        base1 = movebase(moves[n-1]);
+        axis1 = moveaxis(moves[n-1]);
+        result = disable_moves(result, base1 * 3);
 
-        if (base[0] == base[1] || (axis[0] == axis[1] && base[0] < base[1]))
-                return false;
+        if (base1 % 2)
+                result = disable_moves(result, (base1 - 1) * 3);
 
-        if (n == 2)
-                return true;
+        if (n == 1)
+        return result;
 
-        base[2] = movebase(moves[n-3]);
-        axis[2] = moveaxis(moves[n-3]);
+        base2 = movebase(moves[n-2]);
+        axis2 = moveaxis(moves[n-2]);
 
-        return axis[1] != axis[2] || base[0] != base[2];
+        if(axis1 == axis2)
+                result = disable_moves(result, base2 * 3);
+
+        return result;
 }
 
 STATIC_INLINE uint32_t 
@@ -67,12 +79,6 @@ disable_moves(uint32_t current_result, uint8_t base_index)
 }
 
 STATIC_INLINE uint8_t
-inverse_trans(uint8_t t)
-{
-        return inverse_trans_table[t];
-}
-
-STATIC_INLINE uint8_t
 movebase(uint8_t move)
 {
         return move / 3;
@@ -84,6 +90,12 @@ moveaxis(uint8_t move)
         return move / 6;
 }
 
+STATIC_INLINE uint8_t
+moveopposite(uint8_t move)
+{
+        return movebase(move) == 2 * moveaxis(move) ? move + 3 : move - 3;
+}
+
 STATIC cube_t
 move(cube_t c, uint8_t m)
 {