/*      $NetBSD: expl.c,v 1.9 2021/05/02 12:50:45 rillig Exp $  */
/*
 * Copyright (c) 1983-2003, 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:
 *
 * + Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * + 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.
 * + Neither the name of the University of California, San Francisco 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 COPYRIGHT HOLDERS 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 COPYRIGHT
 * OWNER 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
__RCSID("$NetBSD: expl.c,v 1.9 2021/05/02 12:50:45 rillig Exp $");
#endif /* not lint */

#include <stdlib.h>
#include "hunt.h"


static EXPL *Expl[EXPLEN];              /* explosion lists */
static EXPL *Last_expl;                 /* last explosion on Expl[0] */

static void remove_wall(int, int);


/*
 * showexpl:
 *      Show the explosions as they currently are
 */
void
showexpl(int y, int x, char type)
{
        PLAYER *pp;
        EXPL *ep;

        if (y < 0 || y >= HEIGHT)
                return;
        if (x < 0 || x >= WIDTH)
                return;
        ep = malloc(sizeof(*ep));
        ep->e_y = y;
        ep->e_x = x;
        ep->e_char = type;
        ep->e_next = NULL;
        if (Last_expl == NULL)
                Expl[0] = ep;
        else
                Last_expl->e_next = ep;
        Last_expl = ep;
        for (pp = Player; pp < End_player; pp++) {
                if (pp->p_maze[y][x] == type)
                        continue;
                pp->p_maze[y][x] = type;
                cgoto(pp, y, x);
                outch(pp, type);
        }
#ifdef MONITOR
        for (pp = Monitor; pp < End_monitor; pp++) {
                if (pp->p_maze[y][x] == type)
                        continue;
                pp->p_maze[y][x] = type;
                cgoto(pp, y, x);
                outch(pp, type);
        }
#endif
        switch (Maze[y][x]) {
          case WALL1:
          case WALL2:
          case WALL3:
#ifdef RANDOM
          case DOOR:
#endif
#ifdef REFLECT
          case WALL4:
          case WALL5:
#endif
                if (y >= UBOUND && y < DBOUND && x >= LBOUND && x < RBOUND)
                        remove_wall(y, x);
                break;
        }
}

/*
 * rollexpl:
 *      Roll the explosions over, so the next one in the list is at the
 *      top
 */
void
rollexpl(void)
{
        EXPL *ep;
        PLAYER *pp;
        int y, x;
        char c;
        EXPL *nextep;

        for (ep = Expl[EXPLEN - 1]; ep != NULL; ep = nextep) {
                nextep = ep->e_next;
                y = ep->e_y;
                x = ep->e_x;
                if (y < UBOUND || y >= DBOUND || x < LBOUND || x >= RBOUND)
                        c = Maze[y][x];
                else
                        c = SPACE;
                for (pp = Player; pp < End_player; pp++)
                        if (pp->p_maze[y][x] == ep->e_char) {
                                pp->p_maze[y][x] = c;
                                cgoto(pp, y, x);
                                outch(pp, c);
                        }
#ifdef MONITOR
                for (pp = Monitor; pp < End_monitor; pp++)
                        check(pp, y, x);
#endif
                free(ep);
        }
        for (x = EXPLEN - 1; x > 0; x--)
                Expl[x] = Expl[x - 1];
        Last_expl = Expl[0] = NULL;
}

/* There's about 700 walls in the initial maze.  So we pick a number
 * that keeps the maze relatively full. */
#define MAXREMOVE       40

static REGEN removed[MAXREMOVE];
static REGEN *rem_index = removed;

/*
 * remove_wall - add a location where the wall was blown away.
 *               if there is no space left over, put the a wall at
 *               the location currently pointed at.
 */
static void
remove_wall(int y, int x)
{
        REGEN *r;
#if defined(MONITOR) || defined(FLY)
        PLAYER *pp;
#endif
#ifdef FLY
        char save_char = 0;
#endif

        r = rem_index;
        while (r->r_y != 0) {
#ifdef FLY
                switch (Maze[r->r_y][r->r_x]) {
                  case SPACE:
                  case LEFTS:
                  case RIGHT:
                  case ABOVE:
                  case BELOW:
                  case FLYER:
                        save_char = Maze[r->r_y][r->r_x];
                        goto found;
                }
#else
                if (Maze[r->r_y][r->r_x] == SPACE)
                        break;
#endif
                if (++r >= &removed[MAXREMOVE])
                        r = removed;
        }

found:
        if (r->r_y != 0) {
                /* Slot being used, put back this wall */
#ifdef FLY
                if (save_char == SPACE)
                        Maze[r->r_y][r->r_x] = Orig_maze[r->r_y][r->r_x];
                else {
                        pp = play_at(r->r_y, r->r_x);
                        if (pp->p_flying >= 0)
                                pp->p_flying += rand_num(10);
                        else {
                                pp->p_flying = rand_num(20);
                                pp->p_flyx = 2 * rand_num(6) - 5;
                                pp->p_flyy = 2 * rand_num(6) - 5;
                        }
                        pp->p_over = Orig_maze[r->r_y][r->r_x];
                        pp->p_face = FLYER;
                        Maze[r->r_y][r->r_x] = FLYER;
                        showexpl(r->r_y, r->r_x, FLYER);
                }
#else
                Maze[r->r_y][r->r_x] = Orig_maze[r->r_y][r->r_x];
#endif
#ifdef RANDOM
                if (rand_num(100) == 0)
                        Maze[r->r_y][r->r_x] = DOOR;
#endif
#ifdef REFLECT
                if (rand_num(100) == 0)         /* one percent of the time */
                        Maze[r->r_y][r->r_x] = WALL4;
#endif
#ifdef MONITOR
                for (pp = Monitor; pp < End_monitor; pp++)
                        check(pp, r->r_y, r->r_x);
#endif
        }

        r->r_y = y;
        r->r_x = x;
        if (++r >= &removed[MAXREMOVE])
                rem_index = removed;
        else
                rem_index = r;

        Maze[y][x] = SPACE;
#ifdef MONITOR
        for (pp = Monitor; pp < End_monitor; pp++)
                check(pp, y, x);
#endif
}

/*
 * clearwalls:
 *      Clear out the walls array
 */
void
clearwalls(void)
{
        REGEN *rp;

        for (rp = removed; rp < &removed[MAXREMOVE]; rp++)
                rp->r_y = 0;
        rem_index = removed;
}