/*
 * static char *rcsid_map_c =
 *   "$Id: square_spiral.c,v 1.2 2006/08/13 17:16:03 elmex dead $";
 */

/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 2001 Mark Wedel & Crossfire Development Team
    Copyright (C) 1992 Frank Tore Johansen

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    The authors can be reached via e-mail at crossfire-devel@real-time.com
*/


/* peterm@langmuir.eecs.berkeley.edu:  this function generates a random
snake-type layout.

input:  xsize, ysize;
output:  a char** array with # and . for closed and open respectively.

a char value of 0 represents a blank space:  a '#' is
a wall.

*/


#include <stdio.h>
#include <global.h>
#include <time.h>

#include <maze_gen.h>
#include <room_gen.h>
#include <random_map.h>
#include <sproto.h>
#include <rproto.h>


char **map_gen_onion(int xsize, int ysize, int option, int layers);


/* These are some helper functions which help with
   manipulating a centered onion and turning it into
   a square spiral */

/* this starts from within a centered onion layer (or between two layers),
   and looks up until it finds a wall, and then looks right until it
   finds a vertical wall, i.e., the corner.  It sets cx and cy to that.
   it also starts from cx and cy. */

void find_top_left_corner(char **maze,int *cx, int *cy) {

  (*cy)--;
  /* find the top wall. */
  while(maze[*cx][*cy]==0) (*cy)--;
  /* proceed right until a corner is detected */
  while(maze[*cx][*cy+1]==0) (*cx)++;
  
  /* cx and cy should now be the top-right corner of the onion layer */
}


char **make_square_spiral_layout(int xsize, int ysize,int options) {
  int i,j;
  int cx,cy;
  int tx,ty;

  /* generate and allocate a doorless, centered onion */
  char **maze = map_gen_onion(xsize,ysize,OPT_CENTERED | OPT_NO_DOORS,0);

  /* find the layout center.  */
  cx = 0; cy = 0;
  for(i=0;i<xsize;i++)
    for(j=0;j<ysize;j++) {
      if(maze[i][j]=='C' ) {
        cx = i; cy=j;
      }
    }
  tx = cx; ty = cy;
  while(1) {
    find_top_left_corner(maze,&tx,&ty);

    if(ty < 2 || tx < 2 || tx > xsize -2 || ty > ysize-2 ) break;
    make_wall(maze,tx,ty-1,1);  /* make a vertical wall with a door */

    maze[tx][ty-1]='#'; /* convert the door that make_wall puts here to a wall */
    maze[tx-1][ty]='D';/* make a doorway out of this layer */

    /* walk left until we find the top-left corner */
    while((tx>2) && maze[tx-1][ty]) tx--;

    make_wall(maze,tx-1,ty,0);     /* make a horizontal wall with a door */

    /* walk down until we find the bottom-left corner */
    while(((ty+1) < ysize) && maze[tx][ty+1] ) ty++;

    make_wall(maze,tx,ty+1,1);    /* make a vertical wall with a door */

    /* walk rightuntil we find the bottom-right corner */
    while(((tx + 1) < xsize) && maze[tx+1][ty]) tx++;
    
    make_wall(maze,tx+1,ty,0);   /* make a horizontal wall with a door */
    tx++;  /* set up for next layer. */
  }
      
  /* place the exits.  */

  if(RANDOM() %2) {
    maze[cx][cy]='>';
    maze[xsize-2][1]='<';
  }
  else {
    maze[cx][cy]='<';
    maze[xsize-2][1]='>';
  }
    
  return maze;
}