/*	SCCS Id: @(#)mkmap.c	3.1	92/07/15	*/
/* Copyright (c) J. C. Collet, M. Stephenson and D. Cohrs, 1992   */
/* NetHack may be freely redistributed.  See license for details. */

#include "hack.h"
#include "sp_lev.h"

#define	HEIGHT	(ROWNO - 1)
#define WIDTH	(COLNO - 2)

static void FDECL(init_map,(SCHAR_P));
static void FDECL(init_fill,(SCHAR_P,SCHAR_P));
static schar FDECL(get_map,(int,int,SCHAR_P));
static void FDECL(pass_one,(SCHAR_P,SCHAR_P));
static void FDECL(pass_two,(SCHAR_P,SCHAR_P));
static void FDECL(pass_three,(SCHAR_P,SCHAR_P));
static void NDECL(wallify_map);
static void FDECL(join_map,(SCHAR_P,SCHAR_P));
static void FDECL(finish_map,(SCHAR_P,SCHAR_P,XCHAR_P,XCHAR_P));
void FDECL(mkmap, (lev_init *));

char *new_locations;
int min_rx, max_rx, min_ry, max_ry; /* rectangle bounds for regions */
static int n_loc_filled;

static void
init_map(bg_typ)
	schar	bg_typ;
{
	register int i,j;

	for(i=1; i<COLNO; i++)
	    for(j=0; j<ROWNO; j++)
		levl[i][j].typ = bg_typ;
}

static void
init_fill(bg_typ, fg_typ)
	schar	bg_typ, fg_typ;
{
	register int i,j;
	long limit, count;

	limit = (WIDTH * HEIGHT * 2) / 5;
	count = 0;
	while(count < limit) {
	    i = rn1(WIDTH-1, 2);
	    j = rnd(HEIGHT-1);
	    if (levl[i][j].typ == bg_typ) {
		levl[i][j].typ = fg_typ;
		count++;
	    }
	}
}

static schar
get_map(col,row, bg_typ)
	int col,row;
	schar	bg_typ;
{
	if (col <= 0 || row < 0 || col > WIDTH || row >= HEIGHT)
		return bg_typ;
	return levl[col][row].typ;
}

static int dirs[16] = {
    -1, -1 /**/, -1, 0 /**/, -1, 1 /**/,
     0, -1 /**/,              0, 1 /**/,
     1, -1 /**/,  1, 0 /**/,  1, 1};

static void
pass_one(bg_typ, fg_typ)
	schar	bg_typ, fg_typ;
{
	register int i,j;
	short count, dr;

	for(i=2; i<=WIDTH; i++)
	    for(j=1; j<HEIGHT; j++) {
		for(count=0, dr=0; dr < 8; dr++)
		    if(get_map(i+dirs[dr*2], j+dirs[(dr*2)+1], bg_typ)
								== fg_typ)
			count++;

		switch(count) {
		  case 0 : /* death */
		  case 1 :
		  case 2:
			  levl[i][j].typ = bg_typ;
			  break;
		  case 5:
		  case 6:
		  case 7:
		  case 8:
			  levl[i][j].typ = fg_typ;
			  break;
		  default:
			  break;
		  }
	    }
}

#define new_loc(i,j)	*(new_locations+ ((j)*(WIDTH+1)) + (i))

static void
pass_two(bg_typ, fg_typ)
	schar	bg_typ, fg_typ;
{
	register int i,j;
	short count, dr;

	for(i=2; i<=WIDTH; i++)
	    for(j=1; j<HEIGHT; j++) {
		for(count=0, dr=0; dr < 8; dr++)
		    if(get_map(i+dirs[dr*2], j+dirs[(dr*2)+1], bg_typ)
								== fg_typ)
			count++;
		    if (count == 5)
			new_loc(i,j) = bg_typ;
		    else
			new_loc(i,j) = get_map(i,j, bg_typ);
	    }

	for(i=2; i<=WIDTH; i++)
	    for(j=1; j<HEIGHT; j++)
		levl[i][j].typ = new_loc(i,j);
}

static void
pass_three(bg_typ, fg_typ)
	schar	bg_typ, fg_typ;
{
	register int i,j;
	short count, dr;

	for(i=2; i<=WIDTH; i++)
	    for(j=1; j<HEIGHT; j++) {
		for(count=0, dr=0; dr < 8; dr++)
		    if(get_map(i+dirs[dr*2], j+dirs[(dr*2)+1], bg_typ)
								== fg_typ)
			count++;
		if (count < 3)
		    new_loc(i,j) = bg_typ;
		else
		    new_loc(i,j) = get_map(i,j, bg_typ);
	    }

	for(i=2; i<=WIDTH; i++)
	    for(j=1; j<HEIGHT; j++)
		levl[i][j].typ = new_loc(i,j);
}

/*
 * use a flooding algorithm to find all locations that should
 * have the same rm number as the current location.
 * if anyroom is TRUE, use IS_ROOM to check room membership instead of
 * exactly matching levl[sx][sy].typ and walls are included as well.
 */
void
flood_fill_rm(sx, sy, rmno, lit, anyroom)
    int sx;
    register int sy;
    register int rmno;
    boolean lit;
    boolean anyroom;
{
    register int i;
    int nx;
    schar fg_typ = levl[sx][sy].typ;

    /* back up to find leftmost uninitialized location */
    while(sx > 0
	  && (anyroom ? IS_ROOM(levl[sx][sy].typ) : levl[sx][sy].typ == fg_typ)
	  && levl[sx][sy].roomno != rmno)
	sx--;
    sx++; /* compensate for extra decrement */

    /* assume sx,sy is valid */
    if(sx < min_rx) min_rx = sx;
    if(sy < min_ry) min_ry = sy;

    for(i=sx; i<=WIDTH && levl[i][sy].typ == fg_typ; i++) {
	levl[i][sy].roomno = rmno;
	levl[i][sy].lit = lit;
	if(anyroom) {
	    /* add walls to room as well */
	    register int ii,jj;
	    for(ii= (i == sx ? i-1 : i); ii <= i+1; ii++)
		for(jj = sy-1; jj <= sy+1; jj++)
		    if(isok(ii,jj) &&
		       (IS_WALL(levl[ii][jj].typ) ||
			IS_DOOR(levl[ii][jj].typ))) {
			levl[ii][jj].edge = 1;
			if(lit) levl[ii][jj].lit = lit;
			if (levl[ii][jj].roomno != rmno)
			    levl[ii][jj].roomno = SHARED;
			else
			    levl[ii][jj].roomno = rmno;
		    }
	}
	n_loc_filled++;
    }
    nx = i;

    if(isok(sx,sy-1))
	for(i=sx; i<nx; i++)
	    if(levl[i][sy-1].typ == fg_typ) {
		if(levl[i][sy-1].roomno != rmno)
		    flood_fill_rm(i,sy-1,rmno,lit,anyroom);
	    } else {
		if((i>sx || isok(i-1,sy-1)) &&
		      levl[i-1][sy-1].typ == fg_typ) {
		    if(levl[i-1][sy-1].roomno != rmno)
			flood_fill_rm(i-1,sy-1,rmno,lit,anyroom);
		}
		if((i<nx-1 || isok(i+1,sy-1)) &&
		      levl[i+1][sy-1].typ == fg_typ) {
		    if(levl[i+1][sy-1].roomno != rmno)
			flood_fill_rm(i+1,sy-1,rmno,lit,anyroom);
		}
	    }
    if(isok(sx,sy+1))
	for(i=sx; i<nx; i++)
	    if(levl[i][sy+1].typ == fg_typ) {
		if(levl[i][sy+1].roomno != rmno)
		    flood_fill_rm(i,sy+1,rmno,lit,anyroom);
	    } else {
		if((i>sx || isok(i-1,sy+1)) &&
		      levl[i-1][sy+1].typ == fg_typ) {
		    if(levl[i-1][sy+1].roomno != rmno)
			flood_fill_rm(i-1,sy+1,rmno,lit,anyroom);
		}
		if((i<nx-1 || isok(i+1,sy+1)) &&
		      levl[i+1][sy+1].typ == fg_typ) {
		    if(levl[i+1][sy+1].roomno != rmno)
			flood_fill_rm(i+1,sy+1,rmno,lit,anyroom);
		}
	    }

    if(nx > max_rx) max_rx = nx - 1; /* nx is just past valid region */
    if(sy > max_ry) max_ry = sy;
}

/*
 *	If we have drawn a map without walls, this allows us to
 *	auto-magically wallify it.  Taken from lev_main.c.
 */
static void
wallify_map()
{

    int x, y, xx, yy;

    for(x = 1; x < COLNO; x++)
	for(y = 0; y < ROWNO; y++)
	    if(levl[x][y].typ == STONE) {
		for(yy = y - 1; yy <= y+1; yy++)
		    for(xx = x - 1; xx <= x+1; xx++)
			if(isok(xx,yy) && levl[xx][yy].typ == ROOM) {
			    if(yy != y)	levl[x][y].typ = HWALL;
			    else	levl[x][y].typ = VWALL;
			}
	    }
}

static void
join_map(bg_typ, fg_typ)
	schar	bg_typ, fg_typ;
{
    register struct mkroom *croom, *croom2;

    register int i, j;
    int sx, sy;
    coord sm, em;

    /* first, use flood filling to find all of the regions that need joining */
    for(i=2; i<=WIDTH; i++)
	for(j=1; j<HEIGHT; j++) {
	    if(levl[i][j].typ == fg_typ && levl[i][j].roomno == NO_ROOM) {
		min_rx = max_rx = i;
		min_ry = max_ry = j;
		n_loc_filled = 0;
		flood_fill_rm(i,j,nroom+ROOMOFFSET,FALSE,FALSE);
		if(n_loc_filled > 3) {
		    add_room(min_rx, min_ry, max_rx, max_ry,
			     FALSE, OROOM, TRUE);
		    rooms[nroom-1].irregular = TRUE;
		    if(nroom >= (MAXNROFROOMS*2))
			goto joinm;
		} else {
		    /*
		     * it's a tiny hole; erase it from the map to avoid
		     * having the player end up here with no way out.
		     */
		    for(sx = min_rx; sx<=max_rx; sx++)
			for(sy = min_ry; sy<=max_ry; sy++)
			    if(levl[sx][sy].roomno == nroom+ROOMOFFSET) {
				levl[sx][sy].typ = bg_typ;
				levl[sx][sy].roomno = NO_ROOM;
			    }
		}
	    }
	}

joinm:
    /*
     * Ok, now we can actually join the regions with fg_typ's.
     * The rooms are already sorted due to the previous loop,
     * so don't call sort_rooms(), which can screw up the roomno's
     * validity in the levl structure.
     */
    for(croom = &rooms[0], croom2 = croom + 1; croom2 < &rooms[nroom]; ) {
	/* pick random starting and end locations for "corridor" */
	if(!somexy(croom, &sm) || !somexy(croom2, &em)) {
	    /* ack! -- the level is going to be busted */
	    /* arbitrarily pick centers of both rooms and hope for the best */
	    impossible("No start/end room loc in join_map.");
	    sm.x = croom->lx + ((croom->hx - croom->lx) / 2);
	    sm.y = croom->ly + ((croom->hy - croom->ly) / 2);
	    em.x = croom2->lx + ((croom2->hx - croom2->lx) / 2);
	    em.y = croom2->ly + ((croom2->hy - croom2->ly) / 2);
	}

	(void) dig_corridor(sm, em, FALSE, fg_typ, bg_typ);

	/* choose next region to join */
	/* only increment croom if croom and croom2 are non-overlapping */
	if(croom2->lx > croom->hx ||
	   ((croom2->ly > croom->hy || croom2->hy < croom->ly) && rn2(3))) {
	    croom = croom2;
	}
	croom2++; /* always increment the next room */
    }
}

static void
finish_map(fg_typ, bg_typ, lit, walled)
        schar	fg_typ, bg_typ;
        boolean	lit, walled;
{
	int	i, j;

	if(walled) wallify_map();

	if(lit) {
	    for(i=1; i<COLNO; i++)
		for(j=0; j<ROWNO; j++)
		    if((!IS_ROCK(fg_typ) && levl[i][j].typ == fg_typ) ||
		       (!IS_ROCK(bg_typ) && levl[i][j].typ == bg_typ) ||
			(walled && IS_WALL(levl[i][j].typ)))
			levl[i][j].lit = TRUE;
	    for(i = 0; i < nroom; i++)
		rooms[i].rlit = 1;
	}
}

#define	N_P1_ITER	1	/* tune map generation via this value */
#define	N_P2_ITER	1	/* tune map generation via this value */
#define	N_P3_ITER	2	/* tune map smoothing via this value */

void
mkmap(init_lev)

	lev_init	*init_lev;
{
	schar	bg_typ = init_lev->bg,
		fg_typ = init_lev->fg;
	boolean smooth = init_lev->smoothed,
                join = init_lev->joined;
        xchar   lit = init_lev->lit,
                walled = init_lev->walled;
	int i;

	if(lit < 0)
	    lit = (rnd(1+abs(depth(&u.uz))) < 11 && rn2(77)) ? 1 : 0;

	new_locations = (char *)alloc((WIDTH+1) * HEIGHT);

	init_map(bg_typ);
	init_fill(bg_typ, fg_typ);

	for(i = 0; i < N_P1_ITER; i++)
	    pass_one(bg_typ, fg_typ);

	for(i = 0; i < N_P2_ITER; i++)
	pass_two(bg_typ, fg_typ);

	if(smooth)
	    for(i = 0; i < N_P3_ITER; i++)
		pass_three(bg_typ, fg_typ);

	if(join)
	    join_map(bg_typ, fg_typ);

	finish_map(fg_typ, bg_typ, (boolean)lit, (boolean)walled);
	/* a walled, joined level is cavernous, not mazelike -dlc */
	if (walled && join) {
	    level.flags.is_maze_lev = FALSE;
	    level.flags.is_cavernous_lev = TRUE;
	}
	free(new_locations);
}
