//
// 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 "doomdef.h"
#include "doomstat.h"
#include "p_local.h"
#include "s_sound.h"

// Data.
#include "sounds.h"

// State.
#include "r_state.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;
}
