//
// Copyright(C) 1993-1996 Id Software, Inc.
// Copyright(C) 2005-2014 Simon Howard
//
// 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.
//
// DESCRIPTION:
//	Teleportation.
//

#include "d_mode.h"
#include "d_player.h"
#include "d_think.h"
#include "doomstat.h"
#include "info.h"
#include "m_fixed.h"
#include "p_local.h"
#include "p_mobj.h"
#include "r_defs.h"
// State.
#include "r_state.h"
#include "s_sound.h"
// Data.
#include "sounds.h"
#include "tables.h"

//
// TELEPORTATION
//
int EV_Teleport(line_t *line, int side, mobj_t *thing) {
  int i;
  int tag;
  mobj_t *m;
  mobj_t *fog;
  unsigned an;
  thinker_t *thinker;
  sector_t *sector;
  fixed_t oldx;
  fixed_t oldy;
  fixed_t oldz;

  // don't teleport missiles
  if (thing->flags & MF_MISSILE)
    return 0;

  // Don't teleport if hit back of line,
  //  so you can get out of teleporter.
  if (side == 1)
    return 0;

  tag = line->tag;
  for (i = 0; i < numsectors; i++) {
    if (sectors[i].tag == tag) {
      thinker = thinkercap.next;
      for (thinker = thinkercap.next; thinker != &thinkercap;
           thinker = thinker->next) {
        // not a mobj
        if (thinker->function.acp1 != (actionf_p1)P_MobjThinker)
          continue;

        m = (mobj_t *)thinker;

        // not a teleportman
        if (m->type != MT_TELEPORTMAN)
          continue;

        sector = m->subsector->sector;
        // wrong sector
        if (sector - sectors != i)
          continue;

        oldx = thing->x;
        oldy = thing->y;
        oldz = thing->z;

        if (!P_TeleportMove(thing, m->x, m->y))
          return 0;

        // The first Final Doom executable does not set thing->z
        // when teleporting. This quirk is unique to this
        // particular version; the later version included in
        // some versions of the Id Anthology fixed this.

        if (gameversion != exe_final)
          thing->z = thing->floorz;

        if (thing->player)
          thing->player->viewz = thing->z + thing->player->viewheight;

        // spawn teleport fog at source and destination
        fog = P_SpawnMobj(oldx, oldy, oldz, MT_TFOG);
        S_StartSound(fog, sfx_telept);
        an = m->angle >> ANGLETOFINESHIFT;
        fog = P_SpawnMobj(m->x + 20 * finecosine[an], m->y + 20 * finesine[an],
                          thing->z, MT_TFOG);

        // emit sound, where?
        S_StartSound(fog, sfx_telept);

        // don't move for a bit
        if (thing->player)
          thing->reactiontime = 18;

        thing->angle = m->angle;
        thing->momx = thing->momy = thing->momz = 0;
        return 1;
      }
    }
  }
  return 0;
}