2 files changed, 166 insertions, 47 deletions

diff --git a/src/core/cube.h b/src/core/cube.h
index fe36f90..4b28103 100644
--- a/src/core/cube.h
+++ b/src/core/cube.h
@@ -13,11 +13,13 @@ _static cube_t frommoves(const char *);
 _static void getcube_fix(int64_t *, int64_t *, int64_t *, int64_t *);
 _static cube_t getcube(int64_t, int64_t, int64_t, int64_t);
 
-_static cube_t move(cube_t, uint8_t);
 _static cube_t transform_edges(cube_t, uint8_t);
 _static cube_t transform_corners(cube_t, uint8_t);
 _static cube_t transform(cube_t, uint8_t);
 
+/* declared in moves.h */
+_static cube_t move(cube_t, uint8_t);
+
 _static cube_t
 cubefromarray(uint8_t c[static 8], uint8_t e[static 12])
 {
@@ -239,52 +241,6 @@ applytrans(cube_t cube, const char *buf)
         return transform(cube, t);
 }
 
-_static cube_t
-move(cube_t c, uint8_t m)
-{
-        switch (m) {
-        case _move_U:
-                return _move(U, c);
-        case _move_U2:
-                return _move(U2, c);
-        case _move_U3:
-                return _move(U3, c);
-        case _move_D:
-                return _move(D, c);
-        case _move_D2:
-                return _move(D2, c);
-        case _move_D3:
-                return _move(D3, c);
-        case _move_R:
-                return _move(R, c);
-        case _move_R2:
-                return _move(R2, c);
-        case _move_R3:
-                return _move(R3, c);
-        case _move_L:
-                return _move(L, c);
-        case _move_L2:
-                return _move(L2, c);
-        case _move_L3:
-                return _move(L3, c);
-        case _move_F:
-                return _move(F, c);
-        case _move_F2:
-                return _move(F2, c);
-        case _move_F3:
-                return _move(F3, c);
-        case _move_B:
-                return _move(B, c);
-        case _move_B2:
-                return _move(B2, c);
-        case _move_B3:
-                return _move(B3, c);
-        default:
-                LOG("move error, unknown move\n");
-                return zero;
-        }
-}
-
 /*
 TODO transform is now relegated to a separated file because it is too long.
 It would be nice to make it shorter without loosing performance.
diff --git a/src/core/moves.h b/src/core/moves.h
index 7da6405..8f9c8f5 100644
--- a/src/core/moves.h
+++ b/src/core/moves.h
@@ -1,7 +1,23 @@
+/* probably these can be placed in constants file */
+#define NORMAL 0x00
+#define INVERSE 0x01
+#define INVERSEBRANCH 0x03
+#define NORMALBRANCH 0x02
+#define ALLMOVES 0x3FFFF
+#define NOHALFTURNS 0x2DB6D
+
 _static_inline bool allowednextmove(uint8_t *, uint8_t);
+_static uint32_t allowednextmoveH48(uint8_t *, uint8_t, uint32_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);
+
+_static cube_t move(cube_t, uint8_t);
+_static cube_t premove(cube_t, uint8_t);
+_static uint8_t inverse_move(uint8_t);
+_static uint8_t* invertpremoves(uint8_t *, uint8_t);
 
 _static bool
 allowednextmove(uint8_t *moves, uint8_t n)
@@ -28,6 +44,40 @@ allowednextmove(uint8_t *moves, uint8_t n)
         return axis[1] != axis[2] || base[0] != base[2];
 }
 
+_static_inline uint32_t 
+disable_moves(uint32_t current_result, uint8_t base_index)
+{
+        return current_result & ~(7 << base_index);
+}
+
+_static uint32_t
+allowednextmoveH48(uint8_t *moves, uint8_t n, uint32_t h48branch)
+{
+        uint32_t result = ALLMOVES;
+        if (h48branch & NORMALBRANCH)
+                result &= NOHALFTURNS;
+        if (n < 1)
+                return result;
+
+        uint8_t base1 = movebase(moves[n-1]);
+        uint8_t axis1 = moveaxis(moves[n-1]);
+
+        result = disable_moves(result, base1 * 3);
+        if (base1 % 2)
+                result = disable_moves(result, (base1 - 1) * 3);
+
+        if (n == 1)
+                return result;
+        
+        uint8_t base2 = movebase(moves[n-2]);
+        uint8_t axis2 = moveaxis(moves[n-2]);
+
+        if(axis1 == axis2)
+                result = disable_moves(result, base2 * 3);
+
+        return result;
+}
+
 _static_inline uint8_t
 inverse_trans(uint8_t t)
 {
@@ -45,3 +95,116 @@ moveaxis(uint8_t move)
 {
         return move / 6;
 }
+
+_static cube_t
+move(cube_t c, uint8_t m)
+{
+        switch (m) {
+        case _move_U:
+                return _move(U, c);
+        case _move_U2:
+                return _move(U2, c);
+        case _move_U3:
+                return _move(U3, c);
+        case _move_D:
+                return _move(D, c);
+        case _move_D2:
+                return _move(D2, c);
+        case _move_D3:
+                return _move(D3, c);
+        case _move_R:
+                return _move(R, c);
+        case _move_R2:
+                return _move(R2, c);
+        case _move_R3:
+                return _move(R3, c);
+        case _move_L:
+                return _move(L, c);
+        case _move_L2:
+                return _move(L2, c);
+        case _move_L3:
+                return _move(L3, c);
+        case _move_F:
+                return _move(F, c);
+        case _move_F2:
+                return _move(F2, c);
+        case _move_F3:
+                return _move(F3, c);
+        case _move_B:
+                return _move(B, c);
+        case _move_B2:
+                return _move(B2, c);
+        case _move_B3:
+                return _move(B3, c);
+        default:
+                LOG("move error, unknown move\n");
+                return zero;
+        }
+}
+
+_static cube_t
+premove(cube_t c, uint8_t m)
+{
+        switch (m) {
+        case _move_U:
+                return _premove(U3, c);
+        case _move_U2:
+                return _premove(U2, c);
+        case _move_U3:
+                return _premove(U, c);
+        case _move_D:
+                return _premove(D3, c);
+        case _move_D2:
+                return _premove(D2, c);
+        case _move_D3:
+                return _premove(D, c);
+        case _move_R:
+                return _premove(R3, c);
+        case _move_R2:
+                return _premove(R2, c);
+        case _move_R3:
+                return _premove(R, c);
+        case _move_L:
+                return _premove(L3, c);
+        case _move_L2:
+                return _premove(L2, c);
+        case _move_L3:
+                return _premove(L, c);
+        case _move_F:
+                return _premove(F3, c);
+        case _move_F2:
+                return _premove(F2, c);
+        case _move_F3:
+                return _premove(F, c);
+        case _move_B:
+                return _premove(B3, c);
+        case _move_B2:
+                return _premove(B2, c);
+        case _move_B3:
+                return _premove(B, c);
+        default:
+                LOG("move error, unknown move\n");
+                return zero;
+        }
+}
+
+_static uint8_t
+inverse_move(uint8_t m)
+{
+        return m - 2 * (m % 3) + 2;     
+}
+
+_static uint8_t*
+invertpremoves(uint8_t *moves, uint8_t nmoves)
+{
+        uint8_t i;
+        uint8_t *ret = malloc(nmoves * sizeof(uint8_t));
+
+        for (i = 0; i < nmoves; i++)
+                ret[i] = inverse_move(moves[i]);
+
+        // invert elements in the array
+        for (i = 0; i < nmoves / 2; i++)
+                _swap(ret[i], ret[nmoves - i - 1]);
+        return ret;
+}