root/games/sail/dr_2.c
/*      $OpenBSD: dr_2.c,v 1.7 2016/01/08 20:26:33 mestre Exp $ */
/*      $NetBSD: dr_2.c,v 1.4 1995/04/24 12:25:12 cgd Exp $     */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * 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 <stdlib.h>
#include <string.h>

#include "driver.h"
#include "extern.h"
#include "player.h"

#define couldwin(f,t) (f->specs->crew2 > t->specs->crew2 * 1.5)

void
thinkofgrapples(void)
{
        struct ship *sp, *sq;
        char friendly;

        foreachship(sp) {
                if (sp->file->captain[0] || sp->file->dir == 0)
                        continue;
                foreachship(sq) {
                        friendly = sp->nationality == capship(sq)->nationality;
                        if (!friendly) {
                                if (sp->file->struck || sp->file->captured != 0)
                                        continue;
                                if (range(sp, sq) != 1)
                                        continue;
                                if (grappled2(sp, sq)) {
                                        if (is_toughmelee(sp, sq, 0, 0))
                                                ungrap(sp, sq);
                                        else
                                                grap(sp, sq);
                                } else if (couldwin(sp, sq)) {
                                        grap(sp, sq);
                                        sp->file->loadwith = L_GRAPE;
                                }
                        } else
                                ungrap(sp, sq);
                }
        }
}

void
checkup(void)
{
        struct ship *sp, *sq;
        char explode, sink;

        foreachship(sp) {
                if (sp->file->dir == 0)
                        continue;
                explode = sp->file->explode;
                sink = sp->file->sink;
                if (explode != 1 && sink != 1)
                        continue;
                if (die() < 5)
                        continue;
                Write(sink == 1 ? W_SINK : W_EXPLODE, sp, 2, 0, 0, 0);
                Write(W_DIR, sp, 0, 0, 0, 0);
                if (snagged(sp))
                        foreachship(sq)
                                cleansnag(sp, sq, 1);
                if (sink != 1) {
                        makemsg(sp, "exploding!");
                        foreachship(sq) {
                                if (sp != sq && sq->file->dir && range(sp, sq) < 4)
                                        table(RIGGING, L_EXPLODE, sp->specs->guns/13, sq, sp, 6);
                        }
                } else
                        makemsg(sp, "sinking!");
        }
}

void
prizecheck(void)
{
        struct ship *sp;

        foreachship(sp) {
                if (sp->file->captured == 0)
                        continue;
                if (sp->file->struck || sp->file->dir == 0)
                        continue;
                if (sp->specs->crew1 + sp->specs->crew2 + sp->specs->crew3 > sp->file->pcrew * 6) {
                        Writestr(W_SIGNAL, sp, "prize crew overthrown");
                        Write(W_POINTS, sp->file->captured, sp->file->captured->file->points - 2 * sp->specs->pts, 0, 0, 0);
                        Write(W_CAPTURED, sp, -1, 0, 0, 0);
                }
        }
}

int
str_end(const char *str)
{
        const char *p;

        for (p = str; *p; p++)
                ;
        return p == str ? 0 : p[-1];
}

void
closeon(struct ship *from, struct ship *to, char command[], size_t commandl,
    int ta, int ma, int af)
{
        int high;
        char temp[10];

        temp[0] = command[0] = '\0';
        high = -30000;
        try(command, commandl, temp, sizeof temp, ma, ta, af, ma, from->file->dir,
            from, to, &high, 0);
}

const int dtab[] = {0,1,1,2,3,4,4,5};   /* diagonal distances in x==y */

int
score(char movement[], size_t movementl, struct ship *ship, struct ship *to,
    int onlytemp)
{
        char drift;
        int row, col, dir, total, ran;
        struct File *fp = ship->file;

        if ((dir = fp->dir) == 0)
                return 0;
        row = fp->row;
        col = fp->col;
        drift = fp->drift;
        move_ship(movement, ship, &fp->dir, &fp->row, &fp->col, &drift);
        if (!*movement)
                (void) strlcpy(movement, "d", movementl);

        ran = range(ship, to);
        total = -50 * ran;
        if (ran < 4 && gunsbear(ship, to))
                total += 60;
        if ((ran = portside(ship, to, 1) - fp->dir) == 4 || ran == -4)
                total = -30000;

        if (!onlytemp) {
                fp->row = row;
                fp->col = col;
                fp->dir = dir;
        }
        return total;
}

void
move_ship(const char *p, struct ship *ship, unsigned char *dir, short *row,
    short *col, char *drift)
{
        int dist;
        char moved = 0;

        for (; *p; p++) {
                switch (*p) {
                case 'r':
                        if (++*dir == 9)
                                *dir = 1;
                        break;
                case 'l':
                        if (--*dir == 0)
                                *dir = 8;
                        break;
                case '1': case '2': case '3': case '4':
                case '5': case '6': case '7':
                        moved++;
                        if (*dir % 2 == 0)
                                dist = dtab[*p - '0'];
                        else
                                dist = *p - '0';
                        *row -= dr[*dir] * dist;
                        *col -= dc[*dir] * dist;
                        break;
                }
        }
        if (!moved) {
                if (windspeed != 0 && ++*drift > 2) {
                        if ((ship->specs->class >= 3 && !snagged(ship))
                            || (turn & 1) == 0) {
                                *row -= dr[winddir];
                                *col -= dc[winddir];
                        }
                }
        } else
                *drift = 0;
}

void
try(char command[], size_t commandl, char temp[], size_t templ, int ma, int ta,
    int af, int vma, int dir, struct ship *f, struct ship *t, int *high,
    int rakeme)
{
        int new, n;
        char st[4];
#define rakeyou (gunsbear(f, t) && !gunsbear(t, f))

        if ((n = str_end(temp)) < '1' || n > '9')
                for (n = 1; vma - n >= 0; n++) {
                        (void) snprintf(st, sizeof st, "%d", n);
                        (void) strlcat(temp, st, templ);
                        new = score(temp, templ, f, t, rakeme);
                        if (new > *high && (!rakeme || rakeyou)) {
                                *high = new;
                                (void) strlcpy(command, temp, commandl);
                        }
                        try(command, commandl, temp, templ, ma-n, ta, af, vma-n,
                                dir, f, t, high, rakeme);
                        rmend(temp);
                }
        if ((ma > 0 && ta > 0 && (n = str_end(temp)) != 'l' && n != 'r') || !strlen(temp)) {
                (void) strlcat(temp, "r", templ);
                new = score(temp, templ, f, t, rakeme);
                if (new > *high && (!rakeme || (gunsbear(f, t) && !gunsbear(t, f)))) {
                        *high = new;
                        (void) strlcpy(command, temp, commandl);
                }
                try(command, commandl, temp, templ, ma-1, ta-1, af, min(ma-1, maxmove(f, (dir == 8 ? 1 : dir+1), 0)), (dir == 8 ? 1 : dir+1),f,t,high,rakeme);
                rmend(temp);
        }
        if ((ma > 0 && ta > 0 && (n = str_end(temp)) != 'l' && n != 'r') || !strlen(temp)){
                (void) strlcat(temp, "l", templ);
                new = score(temp, templ, f, t, rakeme);
                if (new > *high && (!rakeme || (gunsbear(f, t) && !gunsbear(t, f)))){
                        *high = new;
                        (void) strlcpy(command, temp, commandl);
                }
                try(command, commandl, temp, templ, ma-1, ta-1, af, (min(ma-1,maxmove(f, (dir-1 ? dir-1 : 8), 0))), (dir-1 ? dir -1 : 8), f, t, high, rakeme);
                rmend(temp);
        }
}

void
rmend(char *str)
{
        char *p;

        for (p = str; *p; p++)
                ;
        if (p != str)
                *--p = 0;
}