//
//  Copyright (C) 1999 by
//  id Software, Chi Hoang, Lee Killough, Jim Flynn, Rand Phares, Ty Halderman
//
//  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:
//      Map Objects, MObj, definition and handling.
//
//-----------------------------------------------------------------------------

#ifndef __P_MOBJ__
#define __P_MOBJ__

// Basics.
#include "tables.h"
#include "m_fixed.h"

// We need the thinker_t stuff.
#include "d_think.h"

// We need the WAD data structure for Map things,
// from the THINGS lump.
#include "doomdata.h"

// States are tied to finite states are
//  tied to animation frames.
// Needs precompiled tables/data structures.
#include "info.h"

//
// NOTES: mobj_t
//
// mobj_ts are used to tell the refresh where to draw an image,
// tell the world simulation when objects are contacted,
// and tell the sound driver how to position a sound.
//
// The refresh uses the next and prev links to follow
// lists of things in sectors as they are being drawn.
// The sprite, frame, and angle elements determine which patch_t
// is used to draw the sprite if it is visible.
// The sprite and frame values are allmost allways set
// from state_t structures.
// The statescr.exe utility generates the states.h and states.c
// files that contain the sprite/frame numbers from the
// statescr.txt source file.
// The xyz origin point represents a point at the bottom middle
// of the sprite (between the feet of a biped).
// This is the default origin position for patch_ts grabbed
// with lumpy.exe.
// A walking creature will have its z equal to the floor
// it is standing on.
//
// The sound code uses the x,y, and subsector fields
// to do stereo positioning of any sound effited by the mobj_t.
//
// The play simulation uses the blocklinks, x,y,z, radius, height
// to determine when mobj_ts are touching each other,
// touching lines in the map, or hit by trace lines (gunshots,
// lines of sight, etc).
// The mobj_t->flags element has various bit flags
// used by the simulation.
//
// Every mobj_t is linked into a single sector
// based on its origin coordinates.
// The subsector_t is found with R_PointInSubsector(x,y),
// and the sector_t can be found with subsector->sector.
// The sector links are only used by the rendering code,
// the play simulation does not care about them at all.
//
// Any mobj_t that needs to be acted upon by something else
// in the play world (block movement, be shot, etc) will also
// need to be linked into the blockmap.
// If the thing has the MF_NOBLOCK flag set, it will not use
// the block links. It can still interact with other things,
// but only as the instigator (missiles will run into other
// things, but nothing can run into a missile).
// Each block in the grid is 128*128 units, and knows about
// every line_t that it contains a piece of, and every
// interactable mobj_t that has its origin contained.  
//
// A valid mobj_t is a mobj_t that has the proper subsector_t
// filled in for its xy coordinates and is linked into the
// sector from which the subsector was made, or has the
// MF_NOSECTOR flag set (the subsector_t needs to be valid
// even if MF_NOSECTOR is set), and is linked into a blockmap
// block or has the MF_NOBLOCKMAP flag set.
// Links should only be modified by the P_[Un]SetThingPosition()
// functions.
// Do not change the MF_NO? flags while a thing is valid.
//
// Any questions?
//

//
// Misc. mobj flags
//
typedef enum
{
    // Call P_SpecialThing when touched.
    MF_SPECIAL          = 1,
    // Blocks.
    MF_SOLID            = 2,
    // Can be hit.
    MF_SHOOTABLE        = 4,
    // Don't use the sector links (invisible but touchable).
    MF_NOSECTOR         = 8,
    // Don't use the blocklinks (inert but displayable)
    MF_NOBLOCKMAP       = 16,                    

    // Not to be activated by sound, deaf monster.
    MF_AMBUSH           = 32,
    // Will try to attack right back.
    MF_JUSTHIT          = 64,
    // Will take at least one step before attacking.
    MF_JUSTATTACKED     = 128,
    // On level spawning (initial position),
    //  hang from ceiling instead of stand on floor.
    MF_SPAWNCEILING     = 256,
    // Don't apply gravity (every tic),
    //  that is, object will float, keeping current height
    //  or changing it actively.
    MF_NOGRAVITY        = 512,

    // Movement flags.
    // This allows jumps from high places.
    MF_DROPOFF          = 0x400,
    // For players, will pick up items.
    MF_PICKUP           = 0x800,
    // Player cheat. ???
    MF_NOCLIP           = 0x1000,
    // Player: keep info about sliding along walls.
    MF_SLIDE            = 0x2000,
    // Allow moves to any height, no gravity.
    // For active floaters, e.g. cacodemons, pain elementals.
    MF_FLOAT            = 0x4000,
    // Don't cross lines
    //   ??? or look at heights on teleport.
    MF_TELEPORT         = 0x8000,
    // Don't hit same species, explode on block.
    // Player missiles as well as fireballs of various kinds.
    MF_MISSILE          = 0x10000,      
    // Dropped by a demon, not level spawned.
    // E.g. ammo clips dropped by dying former humans.
    MF_DROPPED          = 0x20000,
    // Use fuzzy draw (shadow demons or spectres),
    //  temporary player invisibility powerup.
    MF_SHADOW           = 0x40000,
    // Flag: don't bleed when shot (use puff),
    //  barrels and shootable furniture shall not bleed.
    MF_NOBLOOD          = 0x80000,
    // Don't stop moving halfway off a step,
    //  that is, have dead bodies slide down all the way.
    MF_CORPSE           = 0x100000,
    // Floating to a height for a move, ???
    //  don't auto float to target's height.
    MF_INFLOAT          = 0x200000,

    // On kill, count this enemy object
    //  towards intermission kill total.
    // Happy gathering.
    MF_COUNTKILL        = 0x400000,
    
    // On picking up, count this item object
    //  towards intermission item total.
    MF_COUNTITEM        = 0x800000,

    // Special handling: skull in flight.
    // Neither a cacodemon nor a missile.
    MF_SKULLFLY         = 0x1000000,

    // Don't spawn this object
    //  in death match mode (e.g. key cards).
    MF_NOTDMATCH        = 0x2000000,

    // Player sprites in multiplayer modes are modified
    //  using an internal color lookup table for re-indexing.
    // If 0x4 0x8 or 0xc,
    //  use a translation table for player colormaps
    MF_TRANSLATION      = 0xc000000,
    // Hmm ???.
    MF_TRANSSHIFT       = 26,

    MF_TOUCHY = 0x10000000,        // killough 11/98: dies when solids touch it
    MF_BOUNCES = 0x20000000,       // killough 7/11/98: for beta BFG fireballs
    MF_FRIEND = 0x40000000,        // killough 7/18/98: friendly monsters

    // Translucent sprite?                                          // phares
    MF_TRANSLUCENT      = (int)0x80000000,                          // phares
} mobjflag_t;

typedef enum
{
    MF2_LOGRAV          = 0x00000001, // alternate gravity setting
    MF2_SHORTMRANGE     = 0x00000002, // has short missile range (archvile)
    MF2_DMGIGNORED      = 0x00000004, // other things ignore its attacks (archvile)
    MF2_NORADIUSDMG     = 0x00000008, // doesn't take damage from blast radius
    MF2_FORCERADIUSDMG  = 0x00000010, // does radius damage to everything, no exceptions
    MF2_HIGHERMPROB     = 0x00000020, // min prob. of miss. att. = 37.5% vs 22%
    MF2_RANGEHALF       = 0x00000040, // use half actual distance for missile attack probability
    MF2_NOTHRESHOLD     = 0x00000080, // has no target threshold
    MF2_LONGMELEE       = 0x00000100, // has long melee range (revenant)
    MF2_BOSS            = 0x00000200, // mobj is a major boss
    MF2_MAP07BOSS1      = 0x00000400, // is a MAP07 boss type 2 (667)
    MF2_MAP07BOSS2      = 0x00000800, // is a MAP07 boss type 2 (667)
    MF2_E1M8BOSS        = 0x00001000, // is an E1M8 boss
    MF2_E2M8BOSS        = 0x00002000, // is an E2M8 boss
    MF2_E3M8BOSS        = 0x00004000, // is an E3M8 boss
    MF2_E4M6BOSS        = 0x00008000, // is an E4M6 boss
    MF2_E4M8BOSS        = 0x00010000, // is an E4M8 boss
    MF2_RIP             = 0x00020000, // missile rips through solid
    MF2_FULLVOLSOUNDS   = 0x00040000, // full volume see / death sound
    MF2_COLOREDBLOOD    = 0x00080000, // [FG] colored blood and gibs
    MF2_FLIPPABLE       = 0x00100000, // [crispy] randomly flip corpse, blood and death animation sprites
} mobjflag2_t;

// killough 9/15/98: Same, but internal flags, not intended for .deh
// (some degree of opaqueness is good, to avoid compatibility woes)

enum {
  MIF_FALLING = 1,      // Object is falling
  MIF_ARMED = 2,        // Object is armed (for MF_TOUCHY objects)
  MIF_LINEDONE = 4,     // Object has activated W1 or S1 linedef via DEH frame
  // mbf21
  MIF_SCROLLING = 8,    // Object is affected by scroller / pusher / puller
  // cosmetic
  MIF_FLIP = 16,
};

// Map Object definition.
//
// killough 2/20/98:
//
// WARNING: Special steps must be taken in p_saveg.c if C pointers are added to
// this mobj_s struct, or else savegames will crash when loaded. See p_saveg.c.
// Do not add "struct mobj_s *fooptr" without adding code to p_saveg.c to
// convert the pointers to ordinals and back for savegames. This was the whole
// reason behind monsters going to sleep when loading savegames (the "target"
// pointer was simply nullified after loading, to prevent Doom from crashing),
// and the whole reason behind loadgames crashing on savegames of AV attacks.
// 

// killough 9/8/98: changed some fields to shorts,
// for better memory usage (if only for cache).

typedef struct mobj_s
{
    // List: thinker links.
    thinker_t           thinker;

    // Info for drawing: position.
    fixed_t             x;
    fixed_t             y;
    fixed_t             z;

    // More list: links in sector (if needed)
    struct mobj_s*      snext;
    struct mobj_s**     sprev; // killough 8/10/98: change to ptr-to-ptr

    //More drawing info: to determine current sprite.
    angle_t             angle;  // orientation
    spritenum_t         sprite; // used to find patch_t and flip value
    int                 frame;  // might be ORed with FF_FULLBRIGHT

    // Interaction info, by BLOCKMAP.
    // Links in blocks (if needed).
    struct mobj_s*      bnext;
    struct mobj_s**     bprev; // killough 8/11/98: change to ptr-to-ptr
    
    struct subsector_s* subsector;

    // The closest interval over all contacted Sectors.
    fixed_t             floorz;
    fixed_t             ceilingz;

    // killough 11/98: the lowest floor over all contacted Sectors.
    fixed_t             dropoffz;

    // For movement checking.
    fixed_t             radius;
    fixed_t             height; 

    // Momentums, used to update position.
    fixed_t             momx;
    fixed_t             momy;
    fixed_t             momz;

    // If == validcount, already checked.
    int                 validcount;

    mobjtype_t          type;
    mobjinfo_t*         info;   // &mobjinfo[mobj->type]
    
    int                 tics;   // state tic counter
    state_t*            state;
    int                 flags;
    int                 flags2; // mbf21
    int                 intflags;  // killough 9/15/98: internal flags
    int                 health;

    // Movement direction, movement generation (zig-zagging).
    short               movedir;        // 0-7
    short               movecount;      // when 0, select a new dir
    short               strafecount;    // killough 9/8/98: monster strafing

    // Thing being chased/attacked (or NULL),
    // also the originator for missiles.
    struct mobj_s*      target;

    // Reaction time: if non 0, don't attack yet.
    // Used by player to freeze a bit after teleporting.
    short               reactiontime;   

    // If >0, the current target will be chased no
    // matter what (even if shot by another object)
    short               threshold;

    // killough 9/9/98: How long a monster pursues a target.
    short               pursuecount;

    short               gear; // killough 11/98: used in torque simulation

    // Additional info record for player avatars only.
    // Only valid if type == MT_PLAYER
    struct player_s*    player;

    // Player number last looked for.
    short               lastlook;       

    // For nightmare respawn.
    mapthing_t          spawnpoint;     

    // Thing being chased/attacked for tracers.
    struct mobj_s*      tracer; 

    // new field: last known enemy -- killough 2/15/98
    struct mobj_s*      lastenemy;

    // Are we above a Thing? above_thing points to the Thing        // phares
    // if so, otherwise it's zero.                                  //   |
                                                                    //   V
    struct mobj_s* above_thing;

    // Are we below a Thing? below_thing points to the Thing
    // if so, otherwise it's zero.
                                                                    //   ^
    struct mobj_s* below_thing;                                     //   |
                                                                    // phares

    // killough 8/2/98: friction properties part of sectors,
    // not objects -- removed friction properties from here
    // Andrey Budko: restored friction properties here
    // Friction values for the sector the object is in
    int friction;                                           // phares 3/17/98
    int movefactor;

    // a linked list of sectors where this object appears
    struct msecnode_s* touching_sectorlist;                 // phares 3/14/98

    // SEE WARNING ABOVE ABOUT POINTER FIELDS!!!

    // [AM] If true, ok to interpolate this tic.
    int                 interp;

    // [AM] Previous position of mobj before think.
    //      Used to interpolate between positions.
    fixed_t		oldx;
    fixed_t		oldy;
    fixed_t		oldz;
    angle_t		oldangle;

    // [FG] colored blood and gibs
    int bloodcolor;
} mobj_t;

// External declarations (fomerly in p_local.h) -- killough 5/2/98

#define VIEWHEIGHT      (41*FRACUNIT)
#define PLAYERRADIUS    (16*FRACUNIT)

#define GRAVITY         FRACUNIT
#define MAXMOVE         (30*FRACUNIT)

#define ONFLOORZ        D_MININT
#define ONCEILINGZ      D_MAXINT

// Time interval for item respawning.
#define ITEMQUESIZE     128

#define FLOATSPEED      (FRACUNIT*4)
#define STOPSPEED       (FRACUNIT/16)

// killough 11/98:
// For torque simulation:

#define OVERDRIVE 6
#define MAXGEAR (OVERDRIVE+16)

// killough 11/98:
// Whether an object is "sentient" or not. Used for environmental influences.
#define sentient(mobj) ((mobj)->health > 0 && (mobj)->info->seestate)

extern mapthing_t itemrespawnque[];
extern int itemrespawntime[];
extern int iquehead;
extern int iquetail;

// [FG] colored blood and gibs
extern boolean colored_blood;

// The value `160` is used for the denominator because in Vanilla Doom
// the horizontal FOV is 90° and spans 320 px, so the height of the
// resulting triangle is 160.
// Heretic/Hexen used value `173` presumably because Raven assumed an
// equilateral triangle (i.e. 60°) for the vertical FOV which spans
// 200 px, so the height of that triangle would be 100*sqrt(3) = 173.
#define PLAYER_SLOPE(a)	((((a)->lookdir / MLOOKUNIT) << FRACBITS) / 160)
extern boolean direct_vertical_aiming, default_direct_vertical_aiming;
void P_UpdateDirectVerticalAiming(void);

mobj_t *P_SubstNullMobj(mobj_t *mobj);
void    P_RespawnSpecials(void);
mobj_t  *P_SpawnMobj(fixed_t x, fixed_t y, fixed_t z, mobjtype_t type);
void    P_RemoveMobj(mobj_t *th);
boolean P_SetMobjState(mobj_t *mobj, statenum_t state);
void    P_MobjThinker(mobj_t *mobj);
void    P_SpawnPuff(fixed_t x, fixed_t y, fixed_t z);
void    P_SpawnBlood(fixed_t x, fixed_t y, fixed_t z, int damage, mobj_t *bleeder);
mobj_t  *P_SpawnMissile(mobj_t *source, mobj_t *dest, mobjtype_t type);
mobj_t  *P_SpawnPlayerMissile(mobj_t *source, mobjtype_t type);
void    P_SpawnMapThing (mapthing_t*  mthing);
boolean P_CheckMissileSpawn(mobj_t*);  // killough 8/2/98
void    P_ExplodeMissile(mobj_t*);    // killough

boolean P_SeekerMissile(mobj_t *actor, mobj_t **seekTarget, angle_t thresh, angle_t turnMax, boolean seekcenter);
int     P_FaceMobj(mobj_t *source, mobj_t *target, angle_t *delta);
#endif

//----------------------------------------------------------------------------
//
// $Log: p_mobj.h,v $
// Revision 1.10  1998/05/03  23:45:09  killough
// beautification, fix headers, declarations
//
// Revision 1.9  1998/03/23  15:24:33  phares
// Changed pushers to linedef control
//
// Revision 1.8  1998/03/20  00:30:09  phares
// Changed friction to linedef control
//
// Revision 1.7  1998/03/09  18:27:13  phares
// Fixed bug in neighboring variable friction sectors
//
// Revision 1.6  1998/02/24  08:46:24  phares
// Pushers, recoil, new friction, and over/under work
//
// Revision 1.5  1998/02/20  21:56:34  phares
// Preliminarey sprite translucency
//
// Revision 1.4  1998/02/20  09:51:14  killough
// Add savegame warning
//
// Revision 1.3  1998/02/17  05:48:16  killough
// Add new last enemy field to prevent monster sleepiness
//
// Revision 1.2  1998/01/26  19:27:23  phares
// First rev with no ^Ms
//
// Revision 1.1.1.1  1998/01/19  14:03:08  rand
// Lee's Jan 19 sources
//
//
//----------------------------------------------------------------------------
