1 files changed, 522 insertions, 0 deletions

diff --git a/src/coord.c b/src/coord.c
new file mode 100644
index 0000000..8c978bc
--- /dev/null
+++ b/src/coord.c
@@ -0,0 +1,522 @@
+#include "coord.h"
+
+static Cube        antindex_eofb(uint64_t ind);
+static Cube        antindex_eofbepos(uint64_t ind);
+static Cube        antindex_epud(uint64_t ind);
+static Cube        antindex_coud(uint64_t ind);
+static Cube        antindex_corners(uint64_t ind);
+static Cube        antindex_cp(uint64_t ind);
+static Cube        antindex_cphtr(uint64_t);
+static Cube        antindex_cornershtr(uint64_t ind);
+static Cube        antindex_cornershtrfin(uint64_t ind);
+static Cube        antindex_drud(uint64_t ind);
+static Cube        antindex_drud_eofb(uint64_t ind);
+static Cube        antindex_htr_drud(uint64_t ind);
+static Cube        antindex_htrfin(uint64_t ind);
+
+static uint64_t    index_eofb(Cube cube);
+static uint64_t    index_eofbepos(Cube cube);
+static uint64_t    index_epud(Cube cube);
+static uint64_t    index_coud(Cube cube);
+static uint64_t    index_corners(Cube cube);
+static uint64_t    index_cp(Cube cube);
+static uint64_t    index_cphtr(Cube cube);
+static uint64_t    index_cornershtr(Cube cube);
+static uint64_t    index_cornershtrfin(Cube cube);
+static uint64_t    index_drud(Cube cube);
+static uint64_t    index_drud_eofb(Cube cube);
+static uint64_t    index_htr_drud(Cube cube);
+static uint64_t    index_htrfin(Cube cube);
+
+static void        init_cphtr_cosets();
+static void        init_cphtr_left_cosets_bfs(int i, int c);
+static void        init_cphtr_right_cosets_color(int i, int c);
+static void        init_cornershtrfin();
+
+
+/* All sorts of useful costants and tables  **********************************/
+
+static int              cphtr_left_cosets[FACTORIAL8];
+static int              cphtr_right_cosets[FACTORIAL8];
+static int              cphtr_right_rep[BINOM8ON4*6];
+static int              cornershtrfin_ind[FACTORIAL8];
+static int              cornershtrfin_ant[24*24/6];
+
+/* Coordinates and their implementation **************************************/
+
+Coordinate
+coord_eofb = {
+        .index  = index_eofb,
+        .cube   = antindex_eofb,
+        .max    = POW2TO11,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_eofbepos = {
+        .index  = index_eofbepos,
+        .cube   = antindex_eofbepos,
+        .max    = POW2TO11 * BINOM12ON4,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_coud = {
+        .index  = index_coud,
+        .cube   = antindex_coud,
+        .max    = POW3TO7,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_corners = {
+        .index  = index_corners,
+        .cube   = antindex_corners,
+        .max    = POW3TO7 * FACTORIAL8,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_cp = {
+        .index  = index_cp,
+        .cube   = antindex_cp,
+        .max    = FACTORIAL8,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_cphtr = {
+        .index  = index_cphtr,
+        .cube   = antindex_cphtr,
+        .max    = BINOM8ON4 * 6,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_cornershtr = {
+        .index  = index_cornershtr,
+        .cube   = antindex_cornershtr,
+        .max    = POW3TO7 * BINOM8ON4 * 6,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_cornershtrfin = {
+        .index  = index_cornershtrfin,
+        .cube   = antindex_cornershtrfin,
+        .max    = 24*24/6,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_epud = {
+        .index  = index_epud,
+        .cube   = antindex_epud,
+        .max    = FACTORIAL8,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_drud = {
+        .index  = index_drud,
+        .cube   = antindex_drud,
+        .max    = POW2TO11 * POW3TO7 * BINOM12ON4,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_htr_drud = {
+        .index  = index_htr_drud,
+        .cube   = antindex_htr_drud,
+        .max    = BINOM8ON4 * 6 * BINOM8ON4,
+        .ntrans = 1,
+};
+
+Coordinate
+coord_htrfin = {
+        .index  = index_htrfin,
+        .cube   = antindex_htrfin,
+        .max    = 24 * 24 * 24 *24 * 24 / 6, /* should be /12 but it's ok */
+        .ntrans = 1,
+};
+
+Coordinate
+coord_drud_eofb = {
+        .index  = index_drud_eofb,
+        .cube   = antindex_drud_eofb,
+        .max    = POW3TO7 * BINOM12ON4,
+        .ntrans = 1,
+};
+
+/* Functions *****************************************************************/
+
+static Cube
+antindex_eofb(uint64_t ind)
+{
+        return (Cube){ .eofb = ind, .eorl = ind, .eoud = ind };
+}
+
+static Cube
+antindex_eofbepos(uint64_t ind)
+{
+        Cube ret = {0};
+
+        ret.eofb = ind % POW2TO11;
+        ret.epose = (ind / POW2TO11) * 24;
+
+        return ret;
+}
+
+static Cube
+antindex_epud(uint64_t ind)
+{
+        static bool initialized = false;
+        static Cube epud_aux[FACTORIAL8];
+        int a[12];
+        uint64_t ui;
+        CubeArray arr;
+
+        if (!initialized) {
+                a[FR] = FR;
+                a[FL] = FL;
+                a[BL] = BL;
+                a[BR] = BR;
+                for (ui = 0; ui < FACTORIAL8; ui++) {
+                        index_to_perm(ui, 8, a);
+                        arr.ep = a;
+                        epud_aux[ui] = arrays_to_cube(&arr, pf_ep);
+                }
+
+                initialized = true;
+        }
+
+        return epud_aux[ind];
+}
+
+static Cube
+antindex_coud(uint64_t ind)
+{
+        return (Cube){ .coud = ind, .corl = ind, .cofb = ind };
+}
+
+static Cube
+antindex_corners(uint64_t ind)
+{
+        Cube c = {0};
+
+        c.coud = ind / FACTORIAL8;
+        c.cp   = ind % FACTORIAL8;
+
+        return c;
+}
+
+static Cube
+antindex_cp(uint64_t ind)
+{
+        Cube c = {0};
+
+        c.cp = ind;
+
+        return c;
+}
+
+static Cube
+antindex_cphtr(uint64_t ind)
+{
+        return (Cube) { .cp = cphtr_right_rep[ind] };
+}
+
+static Cube
+antindex_cornershtr(uint64_t ind)
+{
+        Cube c = antindex_cphtr(ind % (BINOM8ON4 * 6));
+
+        c.coud = ind / (BINOM8ON4 * 6);
+
+        return c;
+}
+
+static Cube
+antindex_cornershtrfin(uint64_t ind)
+{
+        return (Cube){ .cp = cornershtrfin_ant[ind] };
+}
+
+static Cube
+antindex_drud(uint64_t ind)
+{
+        uint64_t epos, eofb;
+        Cube c;
+
+        eofb = ind % POW2TO11;
+        epos = ind / (POW2TO11 * POW3TO7);
+        c = antindex_eofbepos(eofb + POW2TO11 * epos);
+
+        c.coud  = (ind / POW2TO11) % POW3TO7;
+
+        return c;
+}
+
+static Cube
+antindex_drud_eofb(uint64_t ind)
+{
+        return antindex_drud(ind * POW2TO11);
+}
+
+static Cube
+antindex_htr_drud(uint64_t ind)
+{
+        Cube ret;
+
+        ret       = antindex_cphtr(ind / BINOM8ON4);
+        ret.eposs = (ind % BINOM8ON4) * FACTORIAL4;
+
+        return ret;
+}
+
+static Cube
+antindex_htrfin(uint64_t ind)
+{
+        Cube ret;
+
+        ret = antindex_cornershtrfin(ind/(24*24*24));
+
+        ret.eposm = ind % 24;
+        ind /= 24;
+        ret.eposs = ind % 24;
+        ind /= 24;
+        ret.epose = ind % 24;
+
+        return ret;
+}
+
+static uint64_t
+index_eofb(Cube cube)
+{
+        return cube.eofb;
+}
+
+static uint64_t
+index_eofbepos(Cube cube)
+{
+        return (cube.epose / FACTORIAL4) * POW2TO11 + cube.eofb;
+}
+
+static uint64_t
+index_epud(Cube cube)
+{
+        uint64_t ret;
+        CubeArray *arr = new_cubearray(cube, pf_ep);
+
+        ret = perm_to_index(arr->ep, 8);
+        free_cubearray(arr, pf_ep);
+
+        return ret;
+}
+
+static uint64_t
+index_coud(Cube cube)
+{
+        return cube.coud;
+}
+
+static uint64_t
+index_corners(Cube cube)
+{
+        return cube.coud * FACTORIAL8 + cube.cp;
+}
+
+static uint64_t
+index_cp(Cube cube)
+{
+        return cube.cp;
+}
+
+static uint64_t
+index_cphtr(Cube cube)
+{
+        return cphtr_right_cosets[cube.cp];
+}
+
+static uint64_t
+index_cornershtr(Cube cube)
+{
+        return cube.coud * BINOM8ON4 * 6 + index_cphtr(cube);
+}
+
+static uint64_t
+index_cornershtrfin(Cube cube)
+{
+        return cornershtrfin_ind[cube.cp];
+}
+
+static uint64_t
+index_drud(Cube cube)
+{
+        uint64_t a, b, c;
+
+        a = cube.eofb;
+        b = cube.coud;
+        c = cube.epose / FACTORIAL4;
+
+        b *= POW2TO11;
+        c *= POW2TO11 * POW3TO7;
+
+        return a + b + c;
+}
+
+static uint64_t
+index_drud_eofb(Cube cube)
+{
+        return index_drud(cube) / POW2TO11;
+}
+
+static uint64_t
+index_htr_drud(Cube cube)
+{
+        return index_cphtr(cube) * BINOM8ON4 +
+               (cube.eposs / FACTORIAL4) % BINOM8ON4;
+}
+
+static uint64_t
+index_htrfin(Cube cube)
+{
+        uint64_t epe, eps, epm, cp, ep;
+
+        epe = cube.epose % 24;
+        eps = cube.eposs % 24;
+        epm = cube.eposm % 24;
+        ep = (epe * 24 + eps) *24 + epm;
+        cp = index_cornershtrfin(cube);
+
+        return cp * 24 * 24 * 24 + ep;
+}
+
+/* Init functions implementation *********************************************/
+
+/*
+ * There is certainly a better way to do this, but for now I just use
+ * a "graph coloring" algorithm to compute the left cosets, and I compose
+ * with every possible cp to get the right cosets (it is possible that I am
+ * mixing up left and right).
+ * 
+ * For doing it better "Mathematically", we need 3 things:
+ *   - Checking that cp separates the orbits (UFR,UBL,DFL,DBR) and the other
+ *     This is easy and it is done in the commented function cphtr_cp().
+ *   - Check that there is no ep/cp parity
+ *   - Check that we are not in the "3c" case; this is the part I don't
+ *     know how to do.
+ */
+static void
+init_cphtr_cosets()
+{
+        unsigned int i; 
+        int c = 0, d = 0;
+
+        for (i = 0; i < FACTORIAL8; i++) {
+                cphtr_left_cosets[i]  = -1;
+                cphtr_right_cosets[i] = -1;
+        }
+
+        /* First we compute left cosets with a bfs */
+        for (i = 0; i < FACTORIAL8; i++)
+                if (cphtr_left_cosets[i] == -1)
+                        init_cphtr_left_cosets_bfs(i, c++);
+
+        /* Then we compute right cosets using compose() */
+        for (i = 0; i < FACTORIAL8; i++)
+                if (cphtr_right_cosets[i] == -1)
+                        init_cphtr_right_cosets_color(i, d++);
+}
+
+static void
+init_cphtr_left_cosets_bfs(int i, int c)
+{
+        int j, jj, next[FACTORIAL8], next2[FACTORIAL8], n, n2;
+
+        Move k;
+
+        n = 1;
+        next[0] = i;
+        cphtr_left_cosets[i] = c;
+
+        while (n != 0) {
+                for (j = 0, n2 = 0; j < n; j++) {
+                        for (k = U2; k < B3; k++) {
+                                if (!moveset_htr(k))
+                                        continue;
+                                jj = apply_move(k, (Cube){ .cp = next[j] }).cp;
+
+                                if (cphtr_left_cosets[jj] == -1) {
+                                        cphtr_left_cosets[jj] = c;
+                                        next2[n2++] = jj;
+                                }
+                        }
+                }
+
+                for (j = 0; j < n2; j++)
+                        next[j] = next2[j];
+                n = n2;
+        }
+}
+
+static void
+init_cphtr_right_cosets_color(int i, int d)
+{
+        int cp;
+        unsigned int j;
+
+        cphtr_right_rep[d] = i;
+        for (j = 0; j < FACTORIAL8; j++) {
+                if (cphtr_left_cosets[j] == 0) {
+                        cp = compose((Cube){.cp = i}, (Cube){.cp = j}).cp;
+                        cphtr_right_cosets[cp] = d;
+                }
+        }
+}
+
+static void
+init_cornershtrfin()
+{
+        unsigned int i, j;
+        int n, c;
+        Move m;
+
+        for (i = 0; i < FACTORIAL8; i++)
+                cornershtrfin_ind[i] = -1;
+        cornershtrfin_ind[0] = 0;
+
+        /* 10-pass, I think 5 is enough, but just in case */
+        n = 1;
+        for (i = 0; i < 10; i++) {
+                for (j = 0; j < FACTORIAL8; j++) {
+                        if (cornershtrfin_ind[j] == -1)
+                                continue;
+                        for (m = U; m < NMOVES; m++) {
+                                if (moveset_htr(m)) {
+                                        c = apply_move(m, (Cube){.cp = j}).cp;
+                                        if (cornershtrfin_ind[c] == -1) {
+                                                cornershtrfin_ind[c] = n;
+                                                cornershtrfin_ant[n] = c;
+                                                n++;
+                                        }
+                                }
+                        }
+                }
+        }
+}
+
+void
+init_coord()
+{
+        static bool initialized = false;
+        if (initialized)
+                return;
+        initialized = true;
+
+        init_trans();
+
+        init_cphtr_cosets();
+        init_cornershtrfin();
+}
+