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p_enemy.c
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//
// Copyright (C) 1993-1996 Id Software, Inc.
// Copyright (C) 2023 Frenkel Smeijers
//
// 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.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
//
// P_enemy.c
#include "doomdef.h"
#include "p_local.h"
#include "soundst.h"
void A_Fall (mobj_t *actor);
/*
===============================================================================
ENEMY THINKING
enemies are allways spawned with targetplayer = -1, threshold = 0
Most monsters are spawned unaware of all players, but some can be made preaware
===============================================================================
*/
//
// Called by P_NoiseAlert.
// Recursively traverse adjacent sectors,
// sound blocking lines cut off traversal.
//
static mobj_t *soundtarget;
static void P_RecursiveSound (sector_t *sec, int32_t soundblocks)
{
int32_t i;
line_t *check;
sector_t *other;
// wake up all monsters in this sector
if (sec->validcount == validcount && sec->soundtraversed <= soundblocks+1)
return; // already flooded
sec->validcount = validcount;
sec->soundtraversed = soundblocks+1;
sec->soundtarget = soundtarget;
for (i=0 ;i<sec->linecount ; i++)
{
check = sec->lines[i];
if(! (check->flags&ML_TWOSIDED) )
continue;
P_LineOpening (check);
if(openrange <= 0)
continue; // closed door
if( sides[ check->sidenum[0] ].sector == sec )
other = sides[ check->sidenum[1] ].sector;
else
other = sides[ check->sidenum[0] ].sector;
if (check->flags & ML_SOUNDBLOCK)
{
if(!soundblocks)
P_RecursiveSound (other, 1);
}
else
P_RecursiveSound (other, soundblocks);
}
}
/*
================
=
= P_NoiseAlert
=
= If a monster yells at a player, it will alert other monsters to the
= player.
=
================
*/
void P_NoiseAlert(mobj_t *target, mobj_t *emmiter)
{
soundtarget = target;
validcount++;
P_RecursiveSound (emmiter->subsector->sector, 0);
}
/*
================
=
= P_CheckMeleeRange
=
================
*/
static boolean P_CheckMeleeRange(mobj_t *actor)
{
mobj_t *pl;
fixed_t dist;
if (!actor->target)
return false;
pl = actor->target;
dist = P_AproxDistance (pl->x-actor->x, pl->y-actor->y);
if (dist >= MELEERANGE-20*FRACUNIT+pl->info->radius)
return false;
if (! P_CheckSight (actor, actor->target) )
return false;
return true;
}
/*
================
=
= P_CheckMissileRange
=
================
*/
static boolean P_CheckMissileRange(mobj_t *actor)
{
fixed_t dist;
if (! P_CheckSight (actor, actor->target) )
return false;
if(actor->flags&MF_JUSTHIT)
{ // the target just hit the enemy, so fight back!
actor->flags &= ~MF_JUSTHIT;
return true;
}
if (actor->reactiontime)
return false; // don't attack yet
dist = P_AproxDistance ( actor->x-actor->target->x, actor->y-actor->target->y) - 64*FRACUNIT;
if(!actor->info->meleestate)
dist -= 128*FRACUNIT; // no melee attack, so fire more
dist >>= 16;
if (actor->type == MT_VILE)
{
if (dist > 14*64)
return false; // too far away
}
if (actor->type == MT_UNDEAD)
{
if (dist < 196)
return false; // close for fist attack
dist >>= 1;
}
if (actor->type == MT_CYBORG || actor->type == MT_SPIDER || actor->type == MT_SKULL)
dist >>= 1;
if (dist > 200)
dist = 200;
if (actor->type == MT_CYBORG && dist > 160)
dist = 160;
if (P_Random() < dist)
return false;
return true;
}
/*
================
=
= P_Move
=
= Move in the current direction
= returns false if the move is blocked
================
*/
static const fixed_t xspeed[8] = {FRACUNIT,47000,0,-47000,-FRACUNIT,-47000,0,47000};
static const fixed_t yspeed[8] = {0,47000,FRACUNIT,47000,0,-47000,-FRACUNIT,-47000};
#define MAXSPECIALCROSS 8
extern line_t *spechit[MAXSPECIALCROSS];
extern int32_t numspechit;
static boolean P_Move(mobj_t *actor)
{
fixed_t tryx, tryy;
line_t *ld;
boolean try, good;
if (actor->movedir == DI_NODIR)
return false;
if ((uint32_t)actor->movedir >= 8)
I_Error ("Weird actor->movedir!");
tryx = actor->x+actor->info->speed*xspeed[actor->movedir];
tryy = actor->y+actor->info->speed*yspeed[actor->movedir];
try = P_TryMove (actor, tryx, tryy);
if (!try)
{ // open any specials
if (actor->flags&MF_FLOAT && floatok)
{ // must adjust height
if (actor->z < tmfloorz)
actor->z += FLOATSPEED;
else
actor->z -= FLOATSPEED;
actor->flags |= MF_INFLOAT;
return true;
}
if(!numspechit)
return false;
actor->movedir = DI_NODIR;
good = false;
while (numspechit--)
{
ld = spechit[numspechit];
// if the special isn't a door that can be opened, return false
if (P_UseSpecialLine (actor, ld,0))
good = true;
}
return good;
}
else
{
actor->flags &= ~MF_INFLOAT;
}
if (! (actor->flags & MF_FLOAT) )
actor->z = actor->floorz;
return true;
}
/*
==================================
=
= TryWalk
=
= Attempts to move actoron in its current (ob->moveangle) direction.
=
= If blocked by either a wall or an actor returns FALSE
= If move is either clear or blocked only by a door, returns TRUE and sets
= If a door is in the way, an OpenDoor call is made to start it opening.
=
==================================
*/
static boolean P_TryWalk(mobj_t *actor)
{
if (!P_Move (actor))
{
return false;
}
actor->movecount = P_Random()&15;
return true;
}
/*
================
=
= P_NewChaseDir
=
================
*/
static const dirtype_t opposite[] =
{DI_WEST, DI_SOUTHWEST, DI_SOUTH, DI_SOUTHEAST, DI_EAST, DI_NORTHEAST,
DI_NORTH, DI_NORTHWEST, DI_NODIR};
static const dirtype_t diags[] = {DI_NORTHWEST,DI_NORTHEAST,DI_SOUTHWEST,DI_SOUTHEAST};
static void P_NewChaseDir (mobj_t *actor)
{
fixed_t deltax,deltay;
dirtype_t d[3];
dirtype_t tdir, olddir, turnaround;
if (!actor->target)
I_Error ("P_NewChaseDir: called with no target");
olddir = actor->movedir;
turnaround=opposite[olddir];
deltax = actor->target->x - actor->x;
deltay = actor->target->y - actor->y;
if (deltax>10*FRACUNIT)
d[1]= DI_EAST;
else if (deltax<-10*FRACUNIT)
d[1]= DI_WEST;
else
d[1]=DI_NODIR;
if (deltay<-10*FRACUNIT)
d[2]= DI_SOUTH;
else if (deltay>10*FRACUNIT)
d[2]= DI_NORTH;
else
d[2]=DI_NODIR;
// try direct route
if (d[1] != DI_NODIR && d[2] != DI_NODIR)
{
actor->movedir = diags[((deltay<0)<<1)+(deltax>0)];
if (actor->movedir != turnaround && P_TryWalk(actor))
return;
}
// try other directions
if (P_Random() > 200 || abs(deltay)>abs(deltax))
{
tdir=d[1];
d[1]=d[2];
d[2]=tdir;
}
if (d[1]==turnaround)
d[1]=DI_NODIR;
if (d[2]==turnaround)
d[2]=DI_NODIR;
if (d[1]!=DI_NODIR)
{
actor->movedir = d[1];
if (P_TryWalk(actor))
return; /*either moved forward or attacked*/
}
if (d[2]!=DI_NODIR)
{
actor->movedir =d[2];
if (P_TryWalk(actor))
return;
}
/* there is no direct path to the player, so pick another direction */
if (olddir!=DI_NODIR)
{
actor->movedir =olddir;
if (P_TryWalk(actor))
return;
}
if (P_Random()&1) /*randomly determine direction of search*/
{
for (tdir=DI_EAST ; tdir<=DI_SOUTHEAST ; tdir++)
{
if (tdir!=turnaround)
{
actor->movedir =tdir;
if ( P_TryWalk(actor) )
return;
}
}
}
else
{
for (tdir=DI_SOUTHEAST ; tdir != (DI_EAST-1);tdir--)
{
if (tdir!=turnaround)
{
actor->movedir =tdir;
if ( P_TryWalk(actor) )
return;
}
}
}
if (turnaround != DI_NODIR)
{
actor->movedir =turnaround;
if ( P_TryWalk(actor) )
return;
}
actor->movedir = DI_NODIR; // can't move
}
/*
================
=
= P_LookForPlayers
=
= If allaround is false, only look 180 degrees in front
= returns true if a player is targeted
================
*/
static boolean P_LookForPlayers(mobj_t *actor, boolean allaround)
{
int32_t c;
int32_t stop;
player_t *player;
angle_t an;
fixed_t dist;
c = 0;
stop = (actor->lastlook-1)&3;
for( ; ; actor->lastlook = (actor->lastlook+1)&3 )
{
if (!playeringame[actor->lastlook])
continue;
if (c++ == 2 || actor->lastlook == stop)
return false; // done looking
player = &players[actor->lastlook];
if (player->health <= 0)
continue; // dead
if (!P_CheckSight (actor, player->mo))
continue; // out of sight
if (!allaround)
{
an = R_PointToAngle2 (actor->x, actor->y,
player->mo->x, player->mo->y) - actor->angle;
if (an > ANG90 && an < ANG270)
{
dist = P_AproxDistance (player->mo->x - actor->x,
player->mo->y - actor->y);
// if real close, react anyway
if (dist > MELEERANGE)
continue; // behind back
}
}
actor->target = player->mo;
return true;
}
}
/*
==============
=
= A_KeenDie
=
= DOOM II special, map 32
= Uses special tag 666
=
==============
*/
void A_KeenDie (mobj_t *mo)
{
thinker_t *th;
mobj_t *mo2;
line_t junk;
A_Fall (mo);
// scan the remaining thinkers
// to see if all Keens are dead
for (th = thinkercap.next ; th != &thinkercap ; th=th->next)
{
if (th->function != P_MobjThinker)
continue;
mo2 = (mobj_t *)th;
if (mo2 != mo && mo2->type == mo->type && mo2->health > 0)
{
// other Keen not dead
return;
}
}
junk.tag = 666;
EV_DoDoor(&junk,open);
}
/*
===============================================================================
ACTION ROUTINES
===============================================================================
*/
/*
==============
=
= A_Look
=
= Stay in state until a player is sighted
=
==============
*/
void A_Look (mobj_t *actor)
{
mobj_t *targ;
actor->threshold = 0; // any shot will wake up
targ = actor->subsector->sector->soundtarget;
if (targ && (targ->flags & MF_SHOOTABLE) )
{
actor->target = targ;
if ( actor->flags & MF_AMBUSH )
{
if (P_CheckSight (actor, actor->target))
goto seeyou;
}
else
goto seeyou;
}
if (!P_LookForPlayers (actor, false) )
return;
// go into chase state
seeyou:
if (actor->info->seesound)
{
int32_t sound;
switch (actor->info->seesound)
{
case sfx_posit1:
case sfx_posit2:
case sfx_posit3:
sound = sfx_posit1+P_Random()%3;
break;
case sfx_bgsit1:
case sfx_bgsit2:
sound = sfx_bgsit1+P_Random()%2;
break;
default:
sound = actor->info->seesound;
break;
}
if (actor->type == MT_SPIDER || actor->type == MT_CYBORG)
{ // full volume
S_StartSound (NULL, sound);
}
else
{
S_StartSound (actor, sound);
}
}
P_SetMobjState (actor, actor->info->seestate);
}
/*
==============
=
= A_Chase
=
= Actor has a melee attack, so it tries to close as fast as possible
=
==============
*/
void A_Chase (mobj_t *actor)
{
int32_t 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;
}
//
// don't 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)
{
int32_t angle, damage, 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)
{
int32_t i;
int32_t angle, bangle, damage, 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)
{
int32_t angle, bangle, damage, 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)
{
int32_t 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)
{
int32_t 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)
{
int32_t 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)
{
int32_t 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;
}
static int32_t 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;