/*
    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@schmorp.de>
*/


/* 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, RMOPT_CENTERED | RMOPT_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;
}