/*      $OpenBSD: bdinit.c,v 1.8 2016/01/08 21:38:33 mestre Exp $       */
/*
 * Copyright (c) 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Ralph Campbell.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <string.h>

#include "gomoku.h"

void
bdinit(struct spotstr *bp)
{
        int i, j, r;
        struct spotstr *sp;
        struct combostr *cbp;

        movenum = 1;

        /* mark the borders as such */
        sp = bp;
        for (i = BSZ2; --i >= 0; sp++) {
                sp->s_occ = BORDER;             /* top border */
                sp->s_flg = BFLAGALL;
        }

        /* fill entire board with EMPTY spots */
        memset(frames, 0, sizeof(frames));
        cbp = frames;
        for (j = 0; ++j < BSZ1; sp++) {                 /* for each row */
                for (i = 0; ++i < BSZ1; sp++) {         /* for each column */
                        sp->s_occ = EMPTY;
                        sp->s_flg = 0;
                        sp->s_wval = 0;
                        if (j < 5) {
                                /* directions 1, 2, 3 are blocked */
                                sp->s_flg |= (BFLAG << 1) | (BFLAG << 2) |
                                        (BFLAG << 3);
                                sp->s_fval[BLACK][1].s = MAXCOMBO;
                                sp->s_fval[BLACK][2].s = MAXCOMBO;
                                sp->s_fval[BLACK][3].s = MAXCOMBO;
                                sp->s_fval[WHITE][1].s = MAXCOMBO;
                                sp->s_fval[WHITE][2].s = MAXCOMBO;
                                sp->s_fval[WHITE][3].s = MAXCOMBO;
                        } else if (j == 5) {
                                /* five spaces, blocked on one side */
                                sp->s_fval[BLACK][1].s = 0x500;
                                sp->s_fval[BLACK][2].s = 0x500;
                                sp->s_fval[BLACK][3].s = 0x500;
                                sp->s_fval[WHITE][1].s = 0x500;
                                sp->s_fval[WHITE][2].s = 0x500;
                                sp->s_fval[WHITE][3].s = 0x500;
                        } else {
                                /* six spaces, not blocked */
                                sp->s_fval[BLACK][1].s = 0x401;
                                sp->s_fval[BLACK][2].s = 0x401;
                                sp->s_fval[BLACK][3].s = 0x401;
                                sp->s_fval[WHITE][1].s = 0x401;
                                sp->s_fval[WHITE][2].s = 0x401;
                                sp->s_fval[WHITE][3].s = 0x401;
                        }
                        if (i > (BSZ - 4)) {
                                /* directions 0, 1 are blocked */
                                sp->s_flg |= BFLAG | (BFLAG << 1);
                                sp->s_fval[BLACK][0].s = MAXCOMBO;
                                sp->s_fval[BLACK][1].s = MAXCOMBO;
                                sp->s_fval[WHITE][0].s = MAXCOMBO;
                                sp->s_fval[WHITE][1].s = MAXCOMBO;
                        } else if (i == (BSZ - 4)) {
                                sp->s_fval[BLACK][0].s = 0x500;
                                sp->s_fval[WHITE][0].s = 0x500;
                                /* if direction 1 is not blocked */
                                if (!(sp->s_flg & (BFLAG << 1))) {
                                        sp->s_fval[BLACK][1].s = 0x500;
                                        sp->s_fval[WHITE][1].s = 0x500;
                                }
                        } else {
                                sp->s_fval[BLACK][0].s = 0x401;
                                sp->s_fval[WHITE][0].s = 0x401;
                                if (i < 5) {
                                        /* direction 3 is blocked */
                                        sp->s_flg |= (BFLAG << 3);
                                        sp->s_fval[BLACK][3].s = MAXCOMBO;
                                        sp->s_fval[WHITE][3].s = MAXCOMBO;
                                } else if (i == 5 &&
                                    !(sp->s_flg & (BFLAG << 3))) {
                                        sp->s_fval[BLACK][3].s = 0x500;
                                        sp->s_fval[WHITE][3].s = 0x500;
                                }
                        }
                        /*
                         * Allocate a frame structure for non blocked frames.
                         */
                        for (r = 4; --r >= 0; ) {
                                if (sp->s_flg & (BFLAG << r))
                                        continue;
                                cbp->c_combo.s = sp->s_fval[BLACK][r].s;
                                cbp->c_vertex = sp - board;
                                cbp->c_nframes = 1;
                                cbp->c_dir = r;
                                sp->s_frame[r] = cbp;
                                cbp++;
                        }
                }
                sp->s_occ = BORDER;             /* left & right border */
                sp->s_flg = BFLAGALL;
        }

        /* mark the borders as such */
        for (i = BSZ1; --i >= 0; sp++) {
                sp->s_occ = BORDER;             /* bottom border */
                sp->s_flg = BFLAGALL;
        }

        sortframes[BLACK] = (struct combostr *)0;
        sortframes[WHITE] = (struct combostr *)0;
        init_overlap();
}

/*
 * Initialize the overlap array.
 * Each entry in the array is a bit mask with eight bits corresponding
 * to whether frame B overlaps frame A (as indexed by overlap[A * FAREA + B]).
 * The eight bits coorespond to whether A and B are open ended (length 6) or
 * closed (length 5).
 *      0       A closed and B closed
 *      1       A closed and B open
 *      2       A open and B closed
 *      3       A open and B open
 *      4       A closed and B closed and overlaps in more than one spot
 *      5       A closed and B open and overlaps in more than one spot
 *      6       A open and B closed and overlaps in more than one spot
 *      7       A open and B open and overlaps in more than one spot
 * As pieces are played, it can make frames not overlap if there are no
 * common open spaces shared between the two frames.
 */
void
init_overlap(void)
{
        struct spotstr *sp1, *sp2;
        struct combostr *cbp;
        int i, f, r, n, d1, d2;
        int mask, bmask, vertex, s;
        u_char *str;
        short *ip;

        memset(overlap, 0, sizeof(overlap));
        memset(intersect, 0, sizeof(intersect));
        str = &overlap[FAREA * FAREA];
        ip = &intersect[FAREA * FAREA];
        for (cbp = frames + FAREA; --cbp >= frames; ) {         /* each frame */
            str -= FAREA;
            ip -= FAREA;
            sp1 = &board[vertex = cbp->c_vertex];
            d1 = dd[r = cbp->c_dir];
            /*
             * s = 5 if closed, 6 if open.
             * At this point black & white are the same.
             */
            s = 5 + sp1->s_fval[BLACK][r].c.b;
            /* for each spot in frame A */
            for (i = 0; i < s; i++, sp1 += d1, vertex += d1) {
                /* the sixth spot in frame A only overlaps if it is open */
                mask = (i == 5) ? 0xC : 0xF;
                /* for each direction */
                for (r = 4; --r >= 0; ) {
                    bmask = BFLAG << r;
                    sp2 = sp1;
                    d2 = dd[r];
                    /* for each frame that intersects at spot sp1 */
                    for (f = 0; f < 6; f++, sp2 -= d2) {
                        if (sp2->s_occ == BORDER)
                            break;
                        if (sp2->s_flg & bmask)
                            continue;
                        n = sp2->s_frame[r] - frames;
                        ip[n] = vertex;
                        str[n] |= (f == 5) ? mask & 0xA : mask;
                        if (r == cbp->c_dir) {
                            /* compute the multiple spot overlap values */
                            switch (i) {
                            case 0:     /* sp1 is the first spot in A */
                                if (f == 4)
                                    str[n] |= 0xA0;
                                else if (f != 5)
                                    str[n] |= 0xF0;
                                break;
                            case 1:     /* sp1 is the second spot in A */
                                if (f == 5)
                                    str[n] |= 0xA0;
                                else
                                    str[n] |= 0xF0;
                                break;
                            case 4:     /* sp1 is the penultimate spot in A */
                                if (f == 0)
                                    str[n] |= 0xC0;
                                else
                                    str[n] |= 0xF0;
                                break;
                            case 5:     /* sp1 is the last spot in A */
                                if (f == 1)
                                    str[n] |= 0xC0;
                                else if (f != 0)
                                    str[n] |= 0xF0;
                                break;
                            default:
                                str[n] |= 0xF0;
                            }
                        }
                    }
                }
            }
        }
}