1 files changed, 224 insertions, 0 deletions

diff --git a/src/cube_portable.h b/src/cube_portable.h
new file mode 100644
index 0000000..281faa0
--- /dev/null
+++ b/src/cube_portable.h
@@ -0,0 +1,224 @@
+typedef cube_t cube_fast_t;
+
+_static_inline cube_fast_t fastcube(
+    uint8_t, uint8_t, uint8_t, uint8_t, uint8_t,
+    uint8_t, uint8_t, uint8_t, uint8_t, uint8_t,
+    uint8_t, uint8_t, uint8_t, uint8_t, uint8_t,
+    uint8_t, uint8_t, uint8_t, uint8_t, uint8_t
+);
+_static cube_fast_t cubetofast(cube_t);
+_static cube_t fasttocube(cube_fast_t);
+_static_inline bool equal_fast(cube_fast_t, cube_fast_t);
+_static_inline bool issolved_fast(cube_fast_t);
+_static_inline cube_fast_t invertco_fast(cube_fast_t);
+_static_inline cube_fast_t compose_fast(cube_fast_t, cube_fast_t);
+
+_static_inline int64_t coord_fast_co(cube_fast_t);
+_static_inline int64_t coord_fast_csep(cube_fast_t);
+_static_inline int64_t coord_fast_cocsep(cube_fast_t);
+_static_inline int64_t coord_fast_eo(cube_fast_t);
+_static_inline int64_t coord_fast_esep(cube_fast_t);
+
+_static_inline cube_fast_t
+fastcube(
+        uint8_t c_ufr,
+        uint8_t c_ubl,
+        uint8_t c_dfl,
+        uint8_t c_dbr,
+        uint8_t c_ufl,
+        uint8_t c_ubr,
+        uint8_t c_dfr,
+        uint8_t c_dbl,
+
+        uint8_t e_uf,
+        uint8_t e_ub,
+        uint8_t e_db,
+        uint8_t e_df,
+        uint8_t e_ur,
+        uint8_t e_ul,
+        uint8_t e_dl,
+        uint8_t e_dr,
+        uint8_t e_fr,
+        uint8_t e_fl,
+        uint8_t e_bl,
+        uint8_t e_br
+)
+{
+        cube_fast_t cube = {
+                .corner = {
+                        c_ufr, c_ubl, c_dfl, c_dbr, c_ufl, c_ubr, c_dfr, c_dbl
+                },
+                .edge = {
+                        e_uf, e_ub, e_db, e_df, e_ur, e_ul,
+                        e_dl, e_dr, e_fr, e_fl, e_bl, e_br
+                }
+        };
+
+        return cube;
+}
+
+_static cube_fast_t
+cubetofast(cube_t cube)
+{
+        cube_fast_t fast;
+        memcpy(&fast, &cube, sizeof(cube_fast_t));
+        return fast;
+}
+
+_static cube_t
+fasttocube(cube_fast_t fast)
+{
+        cube_t cube;
+        memcpy(&cube, &fast, sizeof(cube_fast_t));
+        return cube;
+}
+
+_static_inline bool
+equal_fast(cube_fast_t c1, cube_fast_t c2)
+{
+        uint8_t i;
+        bool ret;
+
+        ret = true;
+        for (i = 0; i < 8; i++)
+                ret = ret && c1.corner[i] == c2.corner[i];
+        for (i = 0; i < 12; i++)
+                ret = ret && c1.edge[i] == c2.edge[i];
+
+        return ret;
+}
+
+_static_inline bool
+issolved_fast(cube_fast_t cube)
+{
+        return equal_fast(cube, solved_fast);
+}
+
+_static_inline cube_fast_t
+invertco_fast(cube_fast_t c)
+{
+        uint8_t i, piece, orien;
+        cube_fast_t ret;
+
+        ret = c;
+        for (i = 0; i < 8; i++) {
+                piece = c.corner[i];
+                orien = ((piece << 1) | (piece >> 1)) & _cobits2;
+                ret.corner[i] = (piece & _pbits) | orien;
+        }
+
+        return ret;
+}
+
+_static_inline cube_fast_t
+compose_fast(cube_fast_t c1, cube_fast_t c2)
+{
+        cube_fast_t ret;
+        uint8_t i, piece1, piece2, p, orien, aux, auy;
+
+        ret = zero_fast;
+
+        for (i = 0; i < 12; i++) {
+                piece2 = c2.edge[i];
+                p = piece2 & _pbits;
+                piece1 = c1.edge[p];
+                orien = (piece2 ^ piece1) & _eobit;
+                ret.edge[i] = (piece1 & _pbits) | orien;
+        }
+
+        for (i = 0; i < 8; i++) {
+                piece2 = c2.corner[i];
+                p = piece2 & _pbits;
+                piece1 = c1.corner[p];
+                aux = (piece2 & _cobits) + (piece1 & _cobits);
+                auy = (aux + _ctwist_cw) >> 2U;
+                orien = (aux + auy) & _cobits2;
+                ret.corner[i] = (piece1 & _pbits) | orien;
+        }
+
+        return ret;
+}
+
+_static_inline int64_t
+coord_fast_co(cube_fast_t c)
+{
+        int i, p;
+        int64_t ret;
+
+        for (ret = 0, i = 0, p = 1; i < 7; i++, p *= 3)
+                ret += p * (c.corner[i] >> _coshift);
+
+        return ret;
+}
+
+/*
+For corner separation, we consider the axis (a.k.a. tetrad) each
+corner belongs to as 0 or 1 and we translate this sequence into binary.
+Ignoring the last bit, we have a value up to 2^7, but not all values are
+possible. Encoding this as a number from 0 to C(8,4) would save about 40%
+of space, but we are not going to use this coordinate in large tables.
+*/
+_static_inline int64_t
+coord_fast_csep(cube_fast_t c)
+{
+        int i, p;
+        int64_t ret;
+
+        for (ret = 0, i = 0, p = 1; i < 7; i++, p *= 2)
+                ret += p * ((c.corner[i] & _csepbit) >> 2U);
+
+        return ret;
+}
+
+_static_inline int64_t
+coord_fast_cocsep(cube_fast_t c)
+{
+        return (coord_fast_co(c) << 7) + coord_fast_csep(c);
+}
+
+_static_inline int64_t
+coord_fast_eo(cube_fast_t c)
+{
+        int i, p;
+        int64_t ret;
+
+        for (ret = 0, i = 1, p = 1; i < 12; i++, p *= 2)
+                ret += p * (c.edge[i] >> _eoshift);
+
+        return ret;
+}
+
+/*
+We encode the edge separation as a number from 0 to C(12,4)*C(8,4).
+It can be seen as the composition of two "subset index" coordinates.
+*/
+_static_inline int64_t
+coord_fast_esep(cube_fast_t c)
+{
+        int64_t i, j, k, l, ret1, ret2, bit1, bit2, is1;
+
+        for (i = 0, j = 0, k = 4, l = 4, ret1 = 0, ret2 = 0; i < 12; i++) {
+                /* Simple version:
+                if (c.edge[i] & _esepbit2) {
+                        ret1 += binomial[11-i][k--];
+                } else {
+                        if (c.edge[i] & _esepbit1)
+                                ret2 += binomial[7-j][l--];
+                        j++;
+                }
+                */
+
+                bit1 = (c.edge[i] & _esepbit1) >> 2U;
+                bit2 = (c.edge[i] & _esepbit2) >> 3U;
+                is1 = (1 - bit2) * bit1;
+
+                ret1 += bit2 * binomial[11-i][k];
+                k -= bit2;
+
+                ret2 += is1 * binomial[7-j][l];
+                l -= is1;
+                j += (1-bit2);
+        }
+
+        return ret1 * 70 + ret2;
+}