1 files changed, 291 insertions, 0 deletions

diff --git a/src/core/cube.h b/src/core/cube.h
new file mode 100644
index 0000000..fe36f90
--- /dev/null
+++ b/src/core/cube.h
@@ -0,0 +1,291 @@
+#define _move(M, c) compose(c, _move_cube_ ## M)
+#define _premove(M, c) compose(_move_cube_ ## M, c)
+
+_static cube_t cubefromarray(uint8_t [static 8], uint8_t [static 12]);
+_static cube_t solvedcube(void);
+_static bool isconsistent(cube_t);
+_static bool issolvable(cube_t);
+_static bool issolved(cube_t);
+_static bool iserror(cube_t);
+_static cube_t applymoves(cube_t, const char *);
+_static cube_t applytrans(cube_t, const char *);
+_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);
+
+_static cube_t
+cubefromarray(uint8_t c[static 8], uint8_t e[static 12])
+{
+        return static_cube(
+            c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7],
+            e[0], e[1], e[2], e[3], e[4], e[5], e[6], e[7],
+            e[8], e[9], e[10], e[11]);
+}
+
+_static cube_t
+solvedcube(void)
+{
+        return solved;
+}
+
+_static bool
+isconsistent(cube_t cube)
+{
+        uint8_t i, p, e, piece, corner[8], edge[12];
+        bool found[12];
+
+        pieces(&cube, corner, edge);
+
+        for (i = 0; i < 12; i++)
+                found[i] = false;
+        for (i = 0; i < 12; i++) {
+                piece = edge[i];
+                p = piece & _pbits;
+                e = piece & _eobit;
+                if (p >= 12)
+                        goto inconsistent_ep;
+                if (e != 0 && e != _eobit)
+                        goto inconsistent_eo;
+                found[p] = true;
+        }
+        for (i = 0; i < 12; i++)
+                if (!found[i])
+                        goto inconsistent_ep;
+
+        for (i = 0; i < 8; i++)
+                found[i] = false;
+        for (i = 0; i < 8; i++) {
+                piece = corner[i];
+                p = piece & _pbits;
+                e = piece & _cobits;
+                if (p >= 8)
+                        goto inconsistent_cp;
+                if (e != 0 && e != _ctwist_cw && e != _ctwist_ccw)
+                        goto inconsistent_co;
+                found[p] = true;
+        }
+        for (i = 0; i < 8; i++)
+                if (!found[i])
+                        goto inconsistent_co;
+
+        return true;
+
+inconsistent_ep:
+        LOG("Inconsistent EP\n");
+        return false;
+inconsistent_cp:
+        LOG("Inconsistent CP\n");
+        return false;
+inconsistent_eo:
+        LOG("Inconsistent EO\n");
+        return false;
+inconsistent_co:
+        LOG("Inconsistent CO\n");
+        return false;
+}
+
+_static bool
+issolvable(cube_t cube)
+{
+        uint8_t i, eo, co, piece, edge[12], corner[8], ep[12], cp[8];
+
+        DBG_ASSERT(isconsistent(cube), false,
+            "issolvable: cube is inconsistent\n");
+
+        pieces(&cube, corner, edge);
+        for (i = 0; i < 12; i++)
+                ep[i] = edge[i] & _pbits;
+        for (i = 0; i < 8; i++)
+                cp[i] = corner[i] & _pbits;
+
+        if (permsign(ep, 12) != permsign(cp, 8))
+                goto issolvable_parity;
+
+        eo = 0;
+        for (i = 0; i < 12; i++) {
+                piece = edge[i];
+                eo += (piece & _eobit) >> _eoshift;
+        }
+        if (eo % 2 != 0)
+                goto issolvable_eo;
+
+        co = 0;
+        for (i = 0; i < 8; i++) {
+                piece = corner[i];
+                co += (piece & _cobits) >> _coshift;
+        }
+        if (co % 3 != 0)
+                goto issolvable_co;
+
+        return true;
+
+issolvable_parity:
+        LOG("EP and CP parities are different\n");
+        return false;
+issolvable_eo:
+        LOG("Odd number of flipped edges\n");
+        return false;
+issolvable_co:
+        LOG("Sum of corner orientation is not multiple of 3\n");
+        return false;
+}
+
+bool
+issolved(cube_t cube)
+{
+        return equal(cube, solved);
+}
+
+bool
+iserror(cube_t cube)
+{
+        return equal(cube, zero);
+}
+
+_static cube_t
+applymoves(cube_t cube, const char *buf)
+{
+        uint8_t r, m;
+        const char *b;
+
+        DBG_ASSERT(isconsistent(cube), zero,
+            "move error: inconsistent cube\n");
+
+        for (b = buf; *b != '\0'; b++) {
+                while (*b == ' ' || *b == '\t' || *b == '\n')
+                        b++;
+                if (*b == '\0')
+                        goto applymoves_finish;
+                if ((r = readmove(*b)) == _error)
+                        goto applymoves_error;
+                if ((m = readmodifier(*(b+1))) != 0)
+                        b++;
+                cube = move(cube, r + m);
+        }
+
+applymoves_finish:
+        return cube;
+
+applymoves_error:
+        LOG("applymoves error\n");
+        return zero;
+}
+
+_static cube_t
+frommoves(const char *buf)
+{
+        return applymoves(solved, buf);
+}
+
+_static void
+getcube_fix(int64_t *ep, int64_t *eo, int64_t *cp, int64_t *co)
+{
+        uint8_t e[12], c[8], coarr[8];
+
+        *ep = (*ep % _12f + _12f) % _12f;
+        *eo = (*eo % _2p11 + _2p11) % _2p11;
+        *cp = (*cp % _8f + _8f) % _8f;
+        *co = (*cp % _3p7 + _3p7) % _3p7;
+
+        indextoperm(*ep, 12, e);
+        indextoperm(*cp, 8, c);
+        if (permsign(e, 12) != permsign(c, 8)) {
+                _swap(c[0], c[1]);
+                *cp = permtoindex(c, 8);
+
+                sumzerotodigits(*co, 8, 3, coarr);
+                _swap(coarr[0], coarr[1]);
+                *co = digitstosumzero(coarr, 8, 3);
+        }
+}
+
+_static cube_t
+getcube(int64_t ep, int64_t eo, int64_t cp, int64_t co)
+{
+        uint8_t i, earr[12], carr[8], eoarr[12], coarr[8];
+
+        sumzerotodigits(eo, 12, 2, eoarr);
+        DBG_ASSERT(eoarr[0] != _error, zero, "Error making EO");
+        indextoperm(ep, 12, earr);
+        DBG_ASSERT(earr[0] != _error, zero, "Error making EP");
+        for (i = 0; i < 12; i++)
+                earr[i] |= eoarr[i] << _eoshift;
+
+        sumzerotodigits(co, 8, 3, coarr);
+        DBG_ASSERT(coarr[0] != _error, zero, "Error making CO");
+        indextoperm(cp, 8, carr);
+        DBG_ASSERT(carr[0] != _error, zero, "Error making CP");
+        for (i = 0; i < 8; i++)
+                carr[i] |= coarr[i] << _coshift;
+
+        return cubefromarray(carr, earr);
+}
+
+_static cube_t
+applytrans(cube_t cube, const char *buf)
+{
+        uint8_t t;
+
+        DBG_ASSERT(isconsistent(cube), zero,
+            "transformation error: inconsistent cube\n");
+
+        t = readtrans(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.
+*/