p_enemy.c

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//
// A_Chase
// Actor has a melee attack,
// so it tries to close as fast as possible
//
void A_Chase (mobj_t*	actor)
{
    int		delta;

    if (actor->reactiontime)
	actor->reactiontime--;
				

    // modify target threshold
    if  (actor->threshold)
    {
	if (!actor->target
	    || actor->target->health <= 0)
	{
	    actor->threshold = 0;
	}
	else
	    actor->threshold--;
    }
    
    // turn towards movement direction if not there yet
    if (actor->movedir < 8)
    {
	actor->angle &= (7<<29);
	delta = actor->angle - (actor->movedir << 29);
	
	if (delta > 0)
	    actor->angle -= ANG90/2;
	else if (delta < 0)
	    actor->angle += ANG90/2;
    }

    if (!actor->target
	|| !(actor->target->flags&MF_SHOOTABLE))
    {
	// look for a new target
	if (P_LookForPlayers(actor,true))
	    return; 	// got a new target
	
	P_SetMobjState (actor, actor->info->spawnstate);
	return;
    }
    
    // do not attack twice in a row
    if (actor->flags & MF_JUSTATTACKED)
    {
	actor->flags &= ~MF_JUSTATTACKED;
	if (gameskill != sk_nightmare && !fastparm)
	    P_NewChaseDir (actor);
	return;
    }
    
    // check for melee attack
    if (actor->info->meleestate
	&& P_CheckMeleeRange (actor))
    {
	if (actor->info->attacksound)
	    S_StartSound (actor, actor->info->attacksound);

	P_SetMobjState (actor, actor->info->meleestate);
	return;
    }
    
    // check for missile attack
    if (actor->info->missilestate)
    {
	if (gameskill < sk_nightmare
	    && !fastparm && actor->movecount)
	{
	    goto nomissile;
	}
	
	if (!P_CheckMissileRange (actor))
	    goto nomissile;
	
	P_SetMobjState (actor, actor->info->missilestate);
	actor->flags |= MF_JUSTATTACKED;
	return;
    }

    // ?
  nomissile:
    // possibly choose another target
    if (netgame
	&& !actor->threshold
	&& !P_CheckSight (actor, actor->target) )
    {
	if (P_LookForPlayers(actor,true))
	    return;	// got a new target
    }
    
    // chase towards player
    if (--actor->movecount<0
	|| !P_Move (actor))
    {
	P_NewChaseDir (actor);
    }
    
    // make active sound
    if (actor->info->activesound
	&& P_Random () < 3)
    {
	S_StartSound (actor, actor->info->activesound);
    }
}


//
// A_FaceTarget
//
void A_FaceTarget (mobj_t* actor)
{	
    if (!actor->target)
	return;
    
    actor->flags &= ~MF_AMBUSH;
	
    actor->angle = R_PointToAngle2 (actor->x,
				    actor->y,
				    actor->target->x,
				    actor->target->y);
    
    if (actor->target->flags & MF_SHADOW)
	actor->angle += (P_Random()-P_Random())<<21;
}


//
// A_PosAttack
//
void A_PosAttack (mobj_t* actor)
{
    int		angle;
    int		damage;
    int		slope;
	
    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
    angle = actor->angle;
    slope = P_AimLineAttack (actor, angle, MISSILERANGE);

    S_StartSound (actor, sfx_pistol);
    angle += (P_Random()-P_Random())<<20;
    damage = ((P_Random()%5)+1)*3;
    P_LineAttack (actor, angle, MISSILERANGE, slope, damage);
}

void A_SPosAttack (mobj_t* actor)
{
    int		i;
    int		angle;
    int		bangle;
    int		damage;
    int		slope;
	
    if (!actor->target)
	return;

    S_StartSound (actor, sfx_shotgn);
    A_FaceTarget (actor);
    bangle = actor->angle;
    slope = P_AimLineAttack (actor, bangle, MISSILERANGE);

    for (i=0 ; i<3 ; i++)
    {
	angle = bangle + ((P_Random()-P_Random())<<20);
	damage = ((P_Random()%5)+1)*3;
	P_LineAttack (actor, angle, MISSILERANGE, slope, damage);
    }
}

void A_CPosAttack (mobj_t* actor)
{
    int		angle;
    int		bangle;
    int		damage;
    int		slope;
	
    if (!actor->target)
	return;

    S_StartSound (actor, sfx_shotgn);
    A_FaceTarget (actor);
    bangle = actor->angle;
    slope = P_AimLineAttack (actor, bangle, MISSILERANGE);

    angle = bangle + ((P_Random()-P_Random())<<20);
    damage = ((P_Random()%5)+1)*3;
    P_LineAttack (actor, angle, MISSILERANGE, slope, damage);
}

void A_CPosRefire (mobj_t* actor)
{	
    // keep firing unless target got out of sight
    A_FaceTarget (actor);

    if (P_Random () < 40)
	return;

    if (!actor->target
	|| actor->target->health <= 0
	|| !P_CheckSight (actor, actor->target) )
    {
	P_SetMobjState (actor, actor->info->seestate);
    }
}


void A_SpidRefire (mobj_t* actor)
{	
    // keep firing unless target got out of sight
    A_FaceTarget (actor);

    if (P_Random () < 10)
	return;

    if (!actor->target
	|| actor->target->health <= 0
	|| !P_CheckSight (actor, actor->target) )
    {
	P_SetMobjState (actor, actor->info->seestate);
    }
}

void A_BspiAttack (mobj_t *actor)
{	
    if (!actor->target)
	return;
		
    A_FaceTarget (actor);

    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_ARACHPLAZ);
}


//
// A_TroopAttack
//
void A_TroopAttack (mobj_t* actor)
{
    int		damage;
	
    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
    if (P_CheckMeleeRange (actor))
    {
	S_StartSound (actor, sfx_claw);
	damage = (P_Random()%8+1)*3;
	P_DamageMobj (actor->target, actor, actor, damage);
	return;
    }

    
    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_TROOPSHOT);
}


void A_SargAttack (mobj_t* actor)
{
    int		damage;

    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
    if (P_CheckMeleeRange (actor))
    {
	damage = ((P_Random()%10)+1)*4;
	P_DamageMobj (actor->target, actor, actor, damage);
    }
}

void A_HeadAttack (mobj_t* actor)
{
    int		damage;
	
    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
    if (P_CheckMeleeRange (actor))
    {
	damage = (P_Random()%6+1)*10;
	P_DamageMobj (actor->target, actor, actor, damage);
	return;
    }
    
    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_HEADSHOT);
}

void A_CyberAttack (mobj_t* actor)
{	
    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
    P_SpawnMissile (actor, actor->target, MT_ROCKET);
}


void A_BruisAttack (mobj_t* actor)
{
    int		damage;
	
    if (!actor->target)
	return;
		
    if (P_CheckMeleeRange (actor))
    {
	S_StartSound (actor, sfx_claw);
	damage = (P_Random()%8+1)*10;
	P_DamageMobj (actor->target, actor, actor, damage);
	return;
    }
    
    // launch a missile
    P_SpawnMissile (actor, actor->target, MT_BRUISERSHOT);
}


//
// A_SkelMissile
//
void A_SkelMissile (mobj_t* actor)
{	
    mobj_t*	mo;
	
    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
    actor->z += 16*FRACUNIT;	// so missile spawns higher
    mo = P_SpawnMissile (actor, actor->target, MT_TRACER);
    actor->z -= 16*FRACUNIT;	// back to normal

    mo->x += mo->momx;
    mo->y += mo->momy;
    mo->tracer = actor->target;
}

int	TRACEANGLE = 0xc000000;

void A_Tracer (mobj_t* actor)
{
    angle_t	exact;
    fixed_t	dist;
    fixed_t	slope;
    mobj_t*	dest;
    mobj_t*	th;
		
    if (gametic & 3)
	return;
    
    // spawn a puff of smoke behind the rocket		
    P_SpawnPuff (actor->x, actor->y, actor->z);
	
    th = P_SpawnMobj (actor->x-actor->momx,
		      actor->y-actor->momy,
		      actor->z, MT_SMOKE);
    
    th->momz = FRACUNIT;
    th->tics -= P_Random()&3;
    if (th->tics < 1)
	th->tics = 1;
    
    // adjust direction
    dest = actor->tracer;
	
    if (!dest || dest->health <= 0)
	return;
    
    // change angle	
    exact = R_PointToAngle2 (actor->x,
			     actor->y,
			     dest->x,
			     dest->y);

    if (exact != actor->angle)
    {
	if (exact - actor->angle > 0x80000000)
	{
	    actor->angle -= TRACEANGLE;
	    if (exact - actor->angle < 0x80000000)
		actor->angle = exact;
	}
	else
	{
	    actor->angle += TRACEANGLE;
	    if (exact - actor->angle > 0x80000000)
		actor->angle = exact;
	}
    }
	
    exact = actor->angle>>ANGLETOFINESHIFT;
    actor->momx = FixedMul (actor->info->speed, finecosine[exact]);
    actor->momy = FixedMul (actor->info->speed, finesine[exact]);
    
    // change slope
    dist = P_AproxDistance (dest->x - actor->x,
			    dest->y - actor->y);
    
    dist = dist / actor->info->speed;

    if (dist < 1)
	dist = 1;
    slope = (dest->z+40*FRACUNIT - actor->z) / dist;

    if (slope < actor->momz)
	actor->momz -= FRACUNIT/8;
    else
	actor->momz += FRACUNIT/8;
}


void A_SkelWhoosh (mobj_t*	actor)
{
    if (!actor->target)
	return;
    A_FaceTarget (actor);
    S_StartSound (actor,sfx_skeswg);
}

void A_SkelFist (mobj_t*	actor)
{
    int		damage;

    if (!actor->target)
	return;
		
    A_FaceTarget (actor);
	
    if (P_CheckMeleeRange (actor))
    {
	damage = ((P_Random()%10)+1)*6;
	S_StartSound (actor, sfx_skepch);
	P_DamageMobj (actor->target, actor, actor, damage);
    }
}



//
// PIT_VileCheck
// Detect a corpse that could be raised.
//
mobj_t*		corpsehit;
mobj_t*		vileobj;
fixed_t		viletryx;
fixed_t		viletryy;

boolean PIT_VileCheck (mobj_t*	thing)
{
    int		maxdist;
    boolean	check;
	
    if (!(thing->flags & MF_CORPSE) )
	return true;	// not a monster
    
    if (thing->tics != -1)
	return true;	// not lying still yet
    
    if (thing->info->raisestate == S_NULL)
	return true;	// monster doesn't have a raise state
    
    maxdist = thing->info->radius + mobjinfo[MT_VILE].radius;
	
    if ( abs(thing->x - viletryx) > maxdist
	 || abs(thing->y - viletryy) > maxdist )
	return true;		// not actually touching
		
    corpsehit = thing;
    corpsehit->momx = corpsehit->momy = 0;
    corpsehit->height <<= 2;
    check = P_CheckPosition (corpsehit, corpsehit->x, corpsehit->y);
    corpsehit->height >>= 2;

    if (!check)
	return true;		// doesn't fit here
		
    return false;		// got one, so stop checking
}



//
// A_VileChase
// Check for ressurecting a body
//
void A_VileChase (mobj_t* actor)
{
    int			xl;
    int			xh;
    int			yl;
    int			yh;
    
    int			bx;
    int			by;

    mobjinfo_t*		info;
    mobj_t*		temp;
	
    if (actor->movedir != DI_NODIR)
    {
	// check for corpses to raise
	viletryx =
	    actor->x + actor->info->speed*xspeed[actor->movedir];
	viletryy =
	    actor->y + actor->info->speed*yspeed[actor->movedir];

	xl = (viletryx - bmaporgx - MAXRADIUS*2)>>MAPBLOCKSHIFT;
	xh = (viletryx - bmaporgx + MAXRADIUS*2)>>MAPBLOCKSHIFT;
	yl = (viletryy - bmaporgy - MAXRADIUS*2)>>MAPBLOCKSHIFT;
	yh = (viletryy - bmaporgy + MAXRADIUS*2)>>MAPBLOCKSHIFT;
	
	vileobj = actor;
	for (bx=xl ; bx<=xh ; bx++)
	{
	    for (by=yl ; by<=yh ; by++)
	    {
		// Call PIT_VileCheck to check
		// whether object is a corpse
		// that canbe raised.
		if (!P_BlockThingsIterator(bx,by,PIT_VileCheck))
		{
		    // got one!
		    temp = actor->target;
		    actor->target = corpsehit;
		    A_FaceTarget (actor);
		    actor->target = temp;
					
		    P_SetMobjState (actor, S_VILE_HEAL1);
		    S_StartSound (corpsehit, sfx_slop);
		    info = corpsehit->info;
		    
		    P_SetMobjState (corpsehit,info->raisestate);
		    corpsehit->height <<= 2;
		    corpsehit->flags = info->flags;
		    corpsehit->health = info->spawnhealth;
		    corpsehit->target = NULL;

		    return;
		}
	    }
	}
    }

    // Return to normal attack.
    A_Chase (actor);
}


//
// A_VileStart
//
void A_VileStart (mobj_t* actor)
{
    S_StartSound (actor, sfx_vilatk);
}


//
// A_Fire
// Keep fire in front of player unless out of sight
//
void A_Fire (mobj_t* actor);

void A_StartFire (mobj_t* actor)
{
    S_StartSound(actor,sfx_flamst);
    A_Fire(actor);
}

void A_FireCrackle (mobj_t* actor)
{
    S_StartSound(actor,sfx_flame);
    A_Fire(actor);
}

void A_Fire (mobj_t* actor)
{
    mobj_t*	dest;
    unsigned	an;
		
    dest = actor->tracer;
    if (!dest)
	return;
		
    // don't move it if the vile lost sight
    if (!P_CheckSight (actor->target, dest) )
	return;

    an = dest->angle >> ANGLETOFINESHIFT;

    P_UnsetThingPosition (actor);
    actor->x = dest->x + FixedMul (24*FRACUNIT, finecosine[an]);
    actor->y = dest->y + FixedMul (24*FRACUNIT, finesine[an]);
    actor->z = dest->z;
    P_SetThingPosition (actor);
}



//
// A_VileTarget
// Spawn the hellfire
//
void A_VileTarget (mobj_t*	actor)
{
    mobj_t*	fog;
	
    if (!actor->target)
	return;

    A_FaceTarget (actor);

    fog = P_SpawnMobj (actor->target->x,
		       actor->target->x,
		       actor->target->z, MT_FIRE);
    
    actor->tracer = fog;
    fog->target = actor;
    fog->tracer = actor->target;
    A_Fire (fog);
}




//
// A_VileAttack
//
void A_VileAttack (mobj_t* actor)
{	
    mobj_t*	fire;
    int		an;
	
    if (!actor->target)
	return;
    
    A_FaceTarget (actor);

    if (!P_CheckSight (actor, actor->target) )
	return;

    S_StartSound (actor, sfx_barexp);
    P_DamageMobj (actor->target, actor, actor, 20);
    actor->target->momz = 1000*FRACUNIT/actor->target->info->mass;
	
    an = actor->angle >> ANGLETOFINESHIFT;

    fire = actor->tracer;

    if (!fire)
	return;
		
    // move the fire between the vile and the player
    fire->x = actor->target->x - FixedMul (24*FRACUNIT, finecosine[an]);
    fire->y = actor->target->y - FixedMul (24*FRACUNIT, finesine[an]);	
    P_RadiusAttack (fire, actor, 70 );