p_mobj.c

doom游戏

// Emacs style mode select   -*- C++ -*- 
//-----------------------------------------------------------------------------
//
// $Id:$
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This source is available for distribution and/or modification
// only under the terms of the DOOM Source Code License as
// published by id Software. All rights reserved.
//
// The source is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// FITNESS FOR A PARTICULAR PURPOSE. See the DOOM Source Code License
// for more details.
//
// $Log:$
//
// DESCRIPTION:
//	Moving object handling. Spawn functions.
//
//-----------------------------------------------------------------------------

static const char
rcsid[] = "$Id: p_mobj.c,v 1.5 1997/02/03 22:45:12 b1 Exp $";

#include "i_system.h"
#include "z_zone.h"
#include "m_random.h"

#include "doomdef.h"
#include "p_local.h"
#include "sounds.h"

#include "st_stuff.h"
#include "hu_stuff.h"

#include "s_sound.h"

#include "doomstat.h"


void G_PlayerReborn (int player);
void P_SpawnMapThing (mapthing_t*	mthing);


//
// P_SetMobjState
// Returns true if the mobj is still present.
//
int test;

boolean
P_SetMobjState
( mobj_t*	mobj,
  statenum_t	state )
{
    state_t*	st;

    do
    {
	if (state == S_NULL)
	{
	    mobj->state = (state_t *) S_NULL;
	    P_RemoveMobj (mobj);
	    return false;
	}

	st = &states[state];
	mobj->state = st;
	mobj->tics = st->tics;
	mobj->sprite = st->sprite;
	mobj->frame = st->frame;

	// Modified handling.
	// Call action functions when the state is set
	if (st->action.acp1)		
	    st->action.acp1(mobj);	
	
	state = st->nextstate;
    } while (!mobj->tics);
				
    return true;
}


//
// P_ExplodeMissile  
//
void P_ExplodeMissile (mobj_t* mo)
{
    mo->momx = mo->momy = mo->momz = 0;

    P_SetMobjState (mo, mobjinfo[mo->type].deathstate);

    mo->tics -= P_Random()&3;

    if (mo->tics < 1)
	mo->tics = 1;

    mo->flags &= ~MF_MISSILE;

    if (mo->info->deathsound)
	S_StartSound (mo, mo->info->deathsound);
}


//
// P_XYMovement  
//
#define STOPSPEED		0x1000
#define FRICTION		0xe800

void P_XYMovement (mobj_t* mo) 
{ 	
    fixed_t 	ptryx;
    fixed_t	ptryy;
    player_t*	player;
    fixed_t	xmove;
    fixed_t	ymove;
			
    if (!mo->momx && !mo->momy)
    {
	if (mo->flags & MF_SKULLFLY)
	{
	    // the skull slammed into something
	    mo->flags &= ~MF_SKULLFLY;
	    mo->momx = mo->momy = mo->momz = 0;

	    P_SetMobjState (mo, mo->info->spawnstate);
	}
	return;
    }
	
    player = mo->player;
		
    if (mo->momx > MAXMOVE)
	mo->momx = MAXMOVE;
    else if (mo->momx < -MAXMOVE)
	mo->momx = -MAXMOVE;

    if (mo->momy > MAXMOVE)
	mo->momy = MAXMOVE;
    else if (mo->momy < -MAXMOVE)
	mo->momy = -MAXMOVE;
		
    xmove = mo->momx;
    ymove = mo->momy;
	
    do
    {
	if (xmove > MAXMOVE/2 || ymove > MAXMOVE/2)
	{
	    ptryx = mo->x + xmove/2;
	    ptryy = mo->y + ymove/2;
	    xmove >>= 1;
	    ymove >>= 1;
	}
	else
	{
	    ptryx = mo->x + xmove;
	    ptryy = mo->y + ymove;
	    xmove = ymove = 0;
	}
		
	if (!P_TryMove (mo, ptryx, ptryy))
	{
	    // blocked move
	    if (mo->player)
	    {	// try to slide along it
		P_SlideMove (mo);
	    }
	    else if (mo->flags & MF_MISSILE)
	    {
		// explode a missile
		if (ceilingline &&
		    ceilingline->backsector &&
		    ceilingline->backsector->ceilingpic == skyflatnum)
		{
		    // Hack to prevent missiles exploding
		    // against the sky.
		    // Does not handle sky floors.
		    P_RemoveMobj (mo);
		    return;
		}
		P_ExplodeMissile (mo);
	    }
	    else
		mo->momx = mo->momy = 0;
	}
    } while (xmove || ymove);
    
    // slow down
    if (player && player->cheats & CF_NOMOMENTUM)
    {
	// debug option for no sliding at all
	mo->momx = mo->momy = 0;
	return;
    }

    if (mo->flags & (MF_MISSILE | MF_SKULLFLY) )
	return; 	// no friction for missiles ever
		
    if (mo->z > mo->floorz)
	return;		// no friction when airborne

    if (mo->flags & MF_CORPSE)
    {
	// do not stop sliding
	//  if halfway off a step with some momentum
	if (mo->momx > FRACUNIT/4
	    || mo->momx < -FRACUNIT/4
	    || mo->momy > FRACUNIT/4
	    || mo->momy < -FRACUNIT/4)
	{
	    if (mo->floorz != mo->subsector->sector->floorheight)
		return;
	}
    }

    if (mo->momx > -STOPSPEED
	&& mo->momx < STOPSPEED
	&& mo->momy > -STOPSPEED
	&& mo->momy < STOPSPEED
	&& (!player
	    || (player->cmd.forwardmove== 0
		&& player->cmd.sidemove == 0 ) ) )
    {
	// if in a walking frame, stop moving
	if ( player&&(unsigned)((player->mo->state - states)- S_PLAY_RUN1) < 4)
	    P_SetMobjState (player->mo, S_PLAY);
	
	mo->momx = 0;
	mo->momy = 0;
    }
    else
    {
	mo->momx = FixedMul (mo->momx, FRICTION);
	mo->momy = FixedMul (mo->momy, FRICTION);
    }
}

//
// P_ZMovement
//
void P_ZMovement (mobj_t* mo)
{
    fixed_t	dist;
    fixed_t	delta;
    
    // check for smooth step up
    if (mo->player && mo->z < mo->floorz)
    {
	mo->player->viewheight -= mo->floorz-mo->z;

	mo->player->deltaviewheight
	    = (VIEWHEIGHT - mo->player->viewheight)>>3;
    }
    
    // adjust height
    mo->z += mo->momz;
	
    if ( mo->flags & MF_FLOAT
	 && mo->target)
    {
	// float down towards target if too close
	if ( !(mo->flags & MF_SKULLFLY)
	     && !(mo->flags & MF_INFLOAT) )
	{
	    dist = P_AproxDistance (mo->x - mo->target->x,
				    mo->y - mo->target->y);
	    
	    delta =(mo->target->z + (mo->height>>1)) - mo->z;

	    if (delta<0 && dist < -(delta*3) )
		mo->z -= FLOATSPEED;
	    else if (delta>0 && dist < (delta*3) )
		mo->z += FLOATSPEED;			
	}
	
    }
    
    // clip movement
    if (mo->z <= mo->floorz)
    {
	// hit the floor

	// Note (id):
	//  somebody left this after the setting momz to 0,
	//  kinda useless there.
	if (mo->flags & MF_SKULLFLY)
	{
	    // the skull slammed into something
	    mo->momz = -mo->momz;
	}
	
	if (mo->momz < 0)
	{
	    if (mo->player
		&& mo->momz < -GRAVITY*8)	
	    {
		// Squat down.
		// Decrease viewheight for a moment
		// after hitting the ground (hard),
		// and utter appropriate sound.
		mo->player->deltaviewheight = mo->momz>>3;
		S_StartSound (mo, sfx_oof);
	    }
	    mo->momz = 0;
	}
	mo->z = mo->floorz;

	if ( (mo->flags & MF_MISSILE)
	     && !(mo->flags & MF_NOCLIP) )
	{
	    P_ExplodeMissile (mo);
	    return;
	}
    }
    else if (! (mo->flags & MF_NOGRAVITY) )
    {
	if (mo->momz == 0)
	    mo->momz = -GRAVITY*2;
	else
	    mo->momz -= GRAVITY;
    }
	
    if (mo->z + mo->height > mo->ceilingz)
    {
	// hit the ceiling
	if (mo->momz > 0)
	    mo->momz = 0;
	{
	    mo->z = mo->ceilingz - mo->height;
	}

	if (mo->flags & MF_SKULLFLY)
	{	// the skull slammed into something
	    mo->momz = -mo->momz;
	}
	
	if ( (mo->flags & MF_MISSILE)
	     && !(mo->flags & MF_NOCLIP) )
	{
	    P_ExplodeMissile (mo);
	    return;
	}
    }
} 



//
// P_NightmareRespawn
//
void
P_NightmareRespawn (mobj_t* mobj)
{
    fixed_t		x;
    fixed_t		y;
    fixed_t		z; 
    subsector_t*	ss; 
    mobj_t*		mo;
    mapthing_t*		mthing;
		
    x = mobj->spawnpoint.x << FRACBITS; 
    y = mobj->spawnpoint.y << FRACBITS; 

    // somthing is occupying it's position?
    if (!P_CheckPosition (mobj, x, y) ) 
	return;	// no respwan

    // spawn a teleport fog at old spot
    // because of removal of the body?
    mo = P_SpawnMobj (mobj->x,
		      mobj->y,
		      mobj->subsector->sector->floorheight , MT_TFOG); 
    // initiate teleport sound
    S_StartSound (mo, sfx_telept);

    // spawn a teleport fog at the new spot
    ss = R_PointInSubsector (x,y); 

    mo = P_SpawnMobj (x, y, ss->sector->floorheight , MT_TFOG); 

    S_StartSound (mo, sfx_telept);

    // spawn the new monster
    mthing = &mobj->spawnpoint;
	
    // spawn it
    if (mobj->info->flags & MF_SPAWNCEILING)
	z = ONCEILINGZ;
    else
	z = ONFLOORZ;

    // inherit attributes from deceased one
    mo = P_SpawnMobj (x,y,z, mobj->type);
    mo->spawnpoint = mobj->spawnpoint;	
    mo->angle = ANG45 * (mthing->angle/45);

    if (mthing->options & MTF_AMBUSH)
	mo->flags |= MF_AMBUSH;

    mo->reactiontime = 18;
	
    // remove the old monster,
    P_RemoveMobj (mobj);
}


//
// P_MobjThinker
//
void P_MobjThinker (mobj_t* mobj)
{
    // momentum movement
    if (mobj->momx
	|| mobj->momy
	|| (mobj->flags&MF_SKULLFLY) )
    {
	P_XYMovement (mobj);

	// FIXME: decent NOP/NULL/Nil function pointer please.
	if (mobj->thinker.function.acv == (actionf_v) (-1))
	    return;		// mobj was removed
    }
    if ( (mobj->z != mobj->floorz)
	 || mobj->momz )
    {
	P_ZMovement (mobj);
	
	// FIXME: decent NOP/NULL/Nil function pointer please.
	if (mobj->thinker.function.acv == (actionf_v) (-1))
	    return;		// mobj was removed
    }

    
    // cycle through states,
    // calling action functions at transitions
    if (mobj->tics != -1)
    {
	mobj->tics--;
		
	// you can cycle through multiple states in a tic
	if (!mobj->tics)
	    if (!P_SetMobjState (mobj, mobj->state->nextstate) )
		return;		// freed itself
    }
    else
    {
	// check for nightmare respawn
	if (! (mobj->flags & MF_COUNTKILL) )
	    return;

	if (!respawnmonsters)
	    return;

	mobj->movecount++;

	if (mobj->movecount < 12*35)
	    return;

	if ( leveltime&31 )
	    return;

	if (P_Random () > 4)
	    return;

	P_NightmareRespawn (mobj);
    }

}


//
// P_SpawnMobj
//
mobj_t*
P_SpawnMobj
( fixed_t	x,
  fixed_t	y,
  fixed_t	z,
  mobjtype_t	type )
{
    mobj_t*	mobj;
    state_t*	st;
    mobjinfo_t*	info;
	
    mobj = Z_Malloc (sizeof(*mobj), PU_LEVEL, NULL);
    memset (mobj, 0, sizeof (*mobj));
    info = &mobjinfo[type];
	
    mobj->type = type;
    mobj->info = info;