1 files changed, 219 insertions, 1 deletions

diff --git a/src/cube.c b/src/cube.c
index 24cca4d..1e2f5d7 100644
--- a/src/cube.c
+++ b/src/cube.c
@@ -1,6 +1,21 @@
 #include "cube.h"
 
-/* Public functions implementation *******************************************/
+/* Local functions ***********************************************************/
+
+static void             init_inverse();
+static bool             read_invtables_file();
+static bool             write_invtables_file();
+
+/* Tables ********************************************************************/
+
+static uint16_t         eo_invtable_e[POW2TO11][BINOM12ON4*FACTORIAL4];
+static uint16_t         eo_invtable_s[POW2TO11][BINOM12ON4*FACTORIAL4];
+static uint16_t         eo_invtable_m[POW2TO11][BINOM12ON4*FACTORIAL4];
+static uint16_t         co_invtable[POW3TO7][FACTORIAL8];
+static uint16_t         cp_invtable[FACTORIAL8];
+static uint16_t         cpos_invtable[FACTORIAL6];
+
+/* Functions implementation **************************************************/
 
 int
 array_ep_to_epos(int *ep, int *ss)
@@ -284,6 +299,7 @@ equal(Cube c1, Cube c2)
                c1.cpos  == c2.cpos;
 }
 
+/*
 Cube
 inverse_cube(Cube cube)
 {
@@ -319,6 +335,37 @@ inverse_cube(Cube cube)
 
         return ret;
 }
+*/
+
+Cube
+inverse_cube(Cube cube)
+{
+        CubeArray inv;
+        Cube ret;
+        int i, ep[12];
+
+        for (i = 0; i < 12; i++)
+                ep[i] = where_is_edge(cube, i);
+        inv = (CubeArray){.ep = ep};
+        ret = arrays_to_cube(&inv, pf_ep);
+
+        ret.eofb = ((int)eo_invtable_e[cube.eofb][cube.epose]) |
+                   ((int)eo_invtable_m[cube.eofb][cube.eposm]) |
+                   ((int)eo_invtable_s[cube.eofb][cube.eposs]);
+        ret.eorl = ((int)eo_invtable_e[cube.eorl][cube.epose]) |
+                   ((int)eo_invtable_m[cube.eorl][cube.eposm]) |
+                   ((int)eo_invtable_s[cube.eorl][cube.eposs]);
+        ret.eoud = ((int)eo_invtable_e[cube.eoud][cube.epose]) |
+                   ((int)eo_invtable_m[cube.eoud][cube.eposm]) |
+                   ((int)eo_invtable_s[cube.eoud][cube.eposs]);
+        ret.cp   = cp_invtable[cube.cp];
+        ret.cpos = cpos_invtable[cube.cpos];
+        ret.coud = co_invtable[cube.coud][cube.cp];
+        ret.corl = co_invtable[cube.corl][cube.cp];
+        ret.cofb = co_invtable[cube.cofb][cube.cp];
+
+        return ret;
+}
 
 bool
 is_admissible(Cube cube) {
@@ -684,3 +731,174 @@ where_is_edge(Cube c, Edge e)
         r2 = aux[2][c.eposm][e];
         return MAX(r0, MAX(r1, r2));
 }
+
+static bool
+read_invtables_file()
+{
+        init_env();
+
+        FILE *f;
+        char fname[strlen(tabledir)+20];
+        int b;
+        unsigned int ui, meeo, meco, mecp, mecpos;
+        bool r;
+
+        strcpy(fname, tabledir);
+        strcat(fname, "/invtables");
+
+        if ((f = fopen(fname, "rb")) == NULL)
+                return false;
+
+        b = sizeof(uint16_t);
+        r = true;
+        meeo = BINOM12ON4*FACTORIAL4;
+        meco = FACTORIAL8;
+        mecp = FACTORIAL8;
+        mecpos = FACTORIAL6;
+
+        for (ui = 0; ui < POW2TO11; ui++) {
+                r = r && fread(eo_invtable_e[ui], b, meeo, f) == meeo;
+                r = r && fread(eo_invtable_m[ui], b, meeo, f) == meeo;
+                r = r && fread(eo_invtable_s[ui], b, meeo, f) == meeo;
+        }
+
+        for (ui = 0; ui < POW3TO7; ui++) {
+                r = r && fread(co_invtable[ui], b, meco, f) == meco;
+        }
+
+        r = r && fread(cp_invtable,   b, mecp,   f) == mecp;
+        r = r && fread(cpos_invtable, b, mecpos, f) == mecpos;
+
+        fclose(f);
+        return r;
+}
+
+static bool
+write_invtables_file()
+{
+        init_env();
+
+        FILE *f;
+        char fname[strlen(tabledir)+20];
+        unsigned int ui, meeo, meco, mecp, mecpos;
+        int b;
+        bool r;
+
+        strcpy(fname, tabledir);
+        strcat(fname, "/invtables");
+
+        if ((f = fopen(fname, "wb")) == NULL)
+                return false;
+
+        b = sizeof(uint16_t);
+        r = true;
+        meeo = BINOM12ON4*FACTORIAL4;
+        meco = FACTORIAL8;
+        mecp = FACTORIAL8;
+        mecpos = FACTORIAL6;
+
+        for (ui = 0; ui < POW2TO11; ui++) {
+                r = r && fwrite(eo_invtable_e[ui], b, meeo, f) == meeo;
+                r = r && fwrite(eo_invtable_m[ui], b, meeo, f) == meeo;
+                r = r && fwrite(eo_invtable_s[ui], b, meeo, f) == meeo;
+        }
+
+        for (ui = 0; ui < POW3TO7; ui++) {
+                r = r && fwrite(co_invtable[ui], b, meco, f) == meco;
+        }
+
+        r = r && fwrite(cp_invtable,   b, mecp,   f) == mecp;
+        r = r && fwrite(cpos_invtable, b, mecpos, f) == mecpos;
+
+        fclose(f);
+        return r;
+}
+
+void
+init_inverse()
+{
+        static bool initialized = false;
+        if (initialized)
+                return;
+        initialized = true;
+
+        if (read_invtables_file())
+                return;
+
+        fprintf(stderr, "Cannot load invtables, generating it\n");
+
+        CubeArray *aux, *inv;
+        Cube c;
+        int i, j, eoaux[12], eoinv[12];
+        unsigned int ui, uj;
+
+        aux = new_cubearray((Cube){0}, pf_all);
+        inv = new_cubearray((Cube){0}, pf_all);
+
+        for (ui = 0; ui < POW2TO11; ui++) {
+                int_to_sum_zero_array(ui, 2, 12, eoaux);
+                for (uj = 0; uj < BINOM12ON4*FACTORIAL4; uj++) {
+                        for (j = 0; j < 12; j++)
+                                eoinv[j] = 0;
+                        c = (Cube){.epose = uj, .eposm = 0, .eposs = 0};
+                        eoinv[FR] = eoaux[where_is_edge(c, FR)];
+                        eoinv[FL] = eoaux[where_is_edge(c, FL)];
+                        eoinv[BL] = eoaux[where_is_edge(c, BL)];
+                        eoinv[BR] = eoaux[where_is_edge(c, BR)];
+                        eo_invtable_e[ui][uj] = digit_array_to_int(eoinv,11,2);
+ 
+                        for (j = 0; j < 12; j++)
+                                eoinv[j] = 0;
+                        c = (Cube){.epose = 0, .eposm = uj, .eposs = 0};
+                        eoinv[UF] = eoaux[where_is_edge(c, UF)];
+                        eoinv[UB] = eoaux[where_is_edge(c, UB)];
+                        eoinv[DF] = eoaux[where_is_edge(c, DF)];
+                        eoinv[DB] = eoaux[where_is_edge(c, DB)];
+                        eo_invtable_m[ui][uj] = digit_array_to_int(eoinv,11,2);
+ 
+                        for (j = 0; j < 12; j++)
+                                eoinv[j] = 0;
+                        c = (Cube){.epose = 0, .eposm = 0, .eposs = uj};
+                        eoinv[UL] = eoaux[where_is_edge(c, UL)];
+                        eoinv[UR] = eoaux[where_is_edge(c, UR)];
+                        eoinv[DL] = eoaux[where_is_edge(c, DL)];
+                        eoinv[DR] = eoaux[where_is_edge(c, DR)];
+                        eo_invtable_s[ui][uj] = digit_array_to_int(eoinv,11,2);
+                }
+        }
+
+        for (ui = 0; ui < FACTORIAL8; ui++) {
+                cube_to_arrays((Cube){.cp = ui}, aux, pf_cp);
+                for (i = 0; i < 8; i++)
+                        inv->cp[aux->cp[i]] = i;
+                cp_invtable[ui] = (uint16_t)arrays_to_cube(inv, pf_cp).cp;
+
+                for (uj = 0; uj < POW3TO7; uj++) {
+                        cube_to_arrays((Cube){.coud = uj}, aux, pf_coud);
+                        for (i = 0; i < 8; i++)
+                                inv->coud[aux->cp[i]] = (3-aux->coud[i])%3;
+                        co_invtable[uj][ui] =
+                            (uint16_t)arrays_to_cube(inv, pf_coud).coud;
+                }
+        }
+        
+        for (ui = 0; ui < FACTORIAL6; ui++) {
+                cube_to_arrays((Cube){.cpos = ui}, aux, pf_cpos);
+                for (i = 0; i < 6; i++)
+                        inv->cpos[aux->cpos[i]] = i;
+                cpos_invtable[ui] =
+                    (uint16_t)arrays_to_cube(inv, pf_cpos).cpos;
+        }
+
+        free_cubearray(aux, pf_all);
+        free_cubearray(inv, pf_all);
+
+        if (!write_invtables_file())
+                fprintf(stderr, "Error writing invtables\n");
+}
+
+void
+init_cube()
+{
+        init_inverse();
+}