xref: /src/games/sail/dr_2.c

/*	$NetBSD: dr_2.c,v 1.27 2019/02/03 10:48:46 mrg 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 <sys/cdefs.h>
#ifndef lint
#if 0
static char sccsid[] = "@(#)dr_2.c	8.1 (Berkeley) 5/31/93";
#else
__RCSID("$NetBSD: dr_2.c,v 1.27 2019/02/03 10:48:46 mrg Exp $");
#endif
#endif /* not lint */

#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "extern.h"
#include "driver.h"

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

static int str_end(const char *);
static int score(struct ship *, struct ship *, char *, size_t, int);
static void move_ship(struct ship *, const char *, unsigned char *,
		      short *, short *, int *);
static void try(struct ship *f, struct ship *t,
		char *command, size_t commandmax, char *temp, size_t tempmax,
		int ma, int ta, bool af, int vma, int dir, int *high,
		int rakeme);
static void rmend(char *);

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

void
thinkofgrapples(void)
{
	struct ship *sp, *sq;
	bool 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 (dieroll() < 5)
			continue;
		if (sink == 1) {
			send_sink(sp, 2);
		} else {
			send_explode(sp, 2);
		}
		send_dir(sp, 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(sp, sq, RIGGING, L_EXPLODE,
					      sp->specs->guns/13, 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) {
			send_signal(sp, "prize crew overthrown");
			send_points(sp->file->captured,
			      sp->file->captured->file->points
				- 2 * sp->specs->pts);
			send_captured(sp, -1);
		}
	}
}

static 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 commandmax,
	int ta, int ma, bool af)
{
	int high;
	char temp[10];

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

static int
score(struct ship *ship, struct ship *to, char *movement, size_t movementmax,
      int onlytemp)
{
	int 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(ship, movement, &fp->dir, &fp->row, &fp->col, &drift);
	if (!*movement)
		strlcpy(movement, "d", movementmax);

	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;
}

static void
move_ship(struct ship *ship, const char *p, unsigned char *dir,
	  short *row, short *col, int *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;
}

static void
try(struct ship *f, struct ship *t,
    char *command, size_t commandmax,
    char *temp, size_t tempmax,
    int ma, int ta, bool af, int vma, int dir, int *high, int rakeme)
{
	int new, n;
	char st[11];
#define rakeyou (gunsbear(f, t) && !gunsbear(t, f))

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

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

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