/**
    Pull toward a point, The further away, the stronger the pull.
**/
vector steerlib_arrive(vector point,float maximal_distance)
{
    float distance;
    vector direction;

    distance = bound(0.001,vlen(self.origin - point),maximal_distance);
    direction = normalize(point - self.origin);
    return  direction * (distance / maximal_distance);
}

/**
    Pull toward a point increasing the pull the closer we get
**/
vector steerlib_attract(vector point, float maximal_distance)
{
    float distance;
    vector direction;

    distance = bound(0.001,vlen(self.origin - point),maximal_distance);
    direction = normalize(point - self.origin);

    return  direction * (1-(distance / maximal_distance));
}

/**
    Move away from a point.
**/
vector steerlib_repell(vector point,float maximal_distance)
{
    float distance;
    vector direction;

    distance = bound(0.001,vlen(self.origin - point),maximal_distance);
    direction = normalize(self.origin - point);

    return  direction * (1-(distance / maximal_distance));
}

/**
    Keep at ideal_distance away from point
**/
vector steerlib_standoff(vector point,float ideal_distance)
{
    float distance;
    vector direction;

    distance = vlen(self.origin - point);


    if(distance < ideal_distance)
    {
        direction = normalize(self.origin - point);
        return direction * (distance / ideal_distance);
    }

    direction = normalize(point - self.origin);
    return direction * (ideal_distance / distance);

}

/**
    A random heading in a forward halfcicrle
**/
vector steerlib_waner(float range,float tresh,vector oldpoint)
{
    vector wander_point;
    wander_point = v_forward - oldpoint;

    if (vlen(wander_point) > tresh)
        return oldpoint;

    range = bound(0,range,1);

    wander_point = self.origin + v_forward * 128;
    wander_point = wander_point + randomvec() * (range * 128) - randomvec() * (range * 128);

    return normalize(wander_point - self.origin);
}

/**
    Dodge a point-
**/
vector steerlib_dodge(vector point,vector dodge_dir,float min_distance)
{
    float distance;

    distance = max(vlen(self.origin - point),min_distance);

    return dodge_dir * (min_distance/distance);
}

/**
    flocking by .flock_id
    Group will move towards the unified direction while keeping close to eachother.
**/
.float flock_id;
vector steerlib_flock(float radius, float standoff,float separation_force,float flock_force)
{
    entity flock_member;
    vector push,pull;
    float ccount;

    flock_member = findradius(self.origin,radius);
    while(flock_member)
    {
        if(flock_member != self)
        if(flock_member.flock_id == self.flock_id)
        {
            ++ccount;
            push = push + (steerlib_repell(flock_member.origin,standoff) * separation_force);
            pull = pull + (steerlib_arrive(flock_member.origin + flock_member.velocity,radius) * flock_force);
        }
        flock_member = flock_member.chain;
    }
    return push + (pull* (1 / ccount));
}

/**
    All members want to be in the center, and keep away from eachother.
    The furtehr form the center the more they want to be there.
**/
vector steerlib_swarm(float radius, float standoff,float separation_force,float swarm_force)
{
    entity swarm_member;
    vector force,center;
    float ccount;

    swarm_member = findradius(self.origin,radius);

    while(swarm_member)
    {
        if(swarm_member.flock_id == self.flock_id)
        {
            ++ccount;
            center = center + swarm_member.origin;
            force = force + (steerlib_repell(swarm_member.origin,standoff) * separation_force);
        }
        swarm_member = swarm_member.chain;
    }

    center = center * (1 / ccount);
    force = force + (steerlib_arrive(center,radius) * swarm_force);

    return force;
}

/**
    Steer towards the direction least obstructed.
    Run four tracelines in a forward funnel, bias each diretion negative if something is found there.
**/
vector steerlib_traceavoid(float pitch,float length)
{
    vector vup_left,vup_right,vdown_left,vdown_right;
    float fup_left,fup_right,fdown_left,fdown_right;
    vector v_left,v_down;
    //vector point;

    /*
    traceline(self.origin,self.origin + v_forward * length,MOVE_NOMONSTERS,self);
    if(trace_fraction == 1)
        return '0 0 0';
    */

    v_left = v_right * -1;
    v_down = v_up * -1;

    vup_left = (v_forward + (v_left * pitch + v_up * pitch)) * length;
    traceline(self.origin, self.origin +  vup_left,MOVE_NOMONSTERS,self);
    //vup_left = trace_endpos;
    fup_left = trace_fraction;

    //te_lightning1(world,self.origin, trace_endpos);

    vup_right = (v_forward + (v_right * pitch + v_up * pitch)) * length;
    traceline(self.origin,self.origin + vup_right ,MOVE_NOMONSTERS,self);
    //vup_right = trace_endpos;
    fup_right = trace_fraction;

    //te_lightning1(world,self.origin, trace_endpos);

    vdown_left = (v_forward + (v_left * pitch + v_down * pitch)) * length;
    traceline(self.origin,self.origin + vdown_left,MOVE_NOMONSTERS,self);
    //vdown_left = trace_endpos;
    fdown_left = trace_fraction;

    //te_lightning1(world,self.origin, trace_endpos);

    vdown_right = (v_forward + (v_right * pitch + v_down * pitch)) * length;
    traceline(self.origin,self.origin + vdown_right,MOVE_NOMONSTERS,self);
    //vdown_right = trace_endpos;
    fdown_right = trace_fraction;

    //te_lightning1(world,self.origin, trace_endpos);

    //(v_for * f_for) +

    //point = self.origin + (vup_left * fup_left) + (vup_right * fup_right) +
    //        (vdown_left * fdown_left) + (vdown_right * fdown_right);

    vector upwish,downwish,leftwish,rightwish;
    upwish    = v_up    * (fup_left   + fup_right);
    downwish  = v_down  * (fdown_left + fdown_right);
    leftwish  = v_left  * (fup_left   + fdown_left);
    rightwish = v_right * (fup_right  + fdown_right);

    return (upwish+leftwish+downwish+rightwish) * 0.25;

    //point = point * 0.2; // /5

   // return normalize(point - self.origin) * (1- (fup_left+fup_right+fdown_left+fdown_right) * 0.25);
}



//////////////////////////////////////////////
//     Testting                             //
// Everything below this point is a mess :D //
//////////////////////////////////////////////
#define TLIBS_TETSLIBS
#ifdef TLIBS_TETSLIBS
void flocker_die()
{
	sound (self, CHAN_PROJECTILE, "weapons/rocket_impact.wav", VOL_BASE, ATTN_NORM);

	pointparticles(particleeffectnum("rocket_explode"), self.origin, '0 0 0', 1);

    self.owner.cnt += 1;
    self.owner = world;

    self.nextthink = time;
    self.think = SUB_Remove;
}


void flocker_think()
{
    vector dodgemove,swarmmove;
    vector reprellmove,wandermove,newmove;

    self.angles_x = self.angles_x * -1;
    makevectors(self.angles);
    self.angles_x = self.angles_x * -1;

    dodgemove   = steerlib_traceavoid(0.35,1000);
    swarmmove   = steerlib_swarm(1000,100,150,400);
    reprellmove = steerlib_repell(self.owner.enemy.origin+self.enemy.velocity,1000) * 700;

    if(vlen(dodgemove) == 0)
    {
        self.pos1 = steerlib_waner(0.5,0.1,self.pos1);
        wandermove  = self.pos1 * 50;
    }
    else
        self.pos1 = normalize(self.velocity);

    dodgemove = dodgemove * 700;

    newmove = swarmmove + reprellmove + wandermove + dodgemove;
    self.velocity = movelib_inertmove_byspeed(newmove,900,0.4,0.8);
    //self.velocity  = movelib_inertmove(dodgemove,0.65);

    self.velocity = movelib_drag(0.02,0.6);

    self.angles = vectoangles(self.velocity);

    if(self.health <= 0)
        flocker_die();
    else
        self.nextthink = time + 0.1;
}


void spawn_flocker()
{
    entity flocker;

    flocker = spawn ();

    setorigin(flocker, self.origin + '0 0 32');
    setmodel (flocker, "models/turrets/rocket.md3");
    setsize (flocker, '-3 -3 -3', '3 3 3');

    flocker.flock_id   = self.flock_id;
    flocker.classname  = "flocker";
    flocker.owner      = self;
    flocker.think      = flocker_think;
    flocker.nextthink  = time + random() * 5;
    flocker.solid      = SOLID_BBOX;
    flocker.movetype   = MOVETYPE_BOUNCEMISSILE;
    flocker.effects    = EF_LOWPRECISION;
    flocker.velocity   = randomvec() * 300;
    flocker.angles     = vectoangles(flocker.velocity);
    flocker.health     = 10;
    flocker.pos1      = normalize(flocker.velocity + randomvec() * 0.1);

    self.cnt = self.cnt -1;

}

void flockerspawn_think()
{


    if(self.cnt > 0)
        spawn_flocker();

    self.nextthink = time + self.delay;

}

void flocker_hunter_think()
{
    vector dodgemove,attractmove,newmove;
    entity e,ee;
    float d,bd;

    self.angles_x = self.angles_x * -1;
    makevectors(self.angles);
    self.angles_x = self.angles_x * -1;

    if(self.enemy)
    if(vlen(self.enemy.origin - self.origin) < 64)
    {
        ee = self.enemy;
        ee.health = -1;
        self.enemy = world;

    }

    if(!self.enemy)
    {
        e = findchainfloat(flock_id,self.flock_id);
        while(e)
        {
            d = vlen(self.origin - e.origin);

            if(e != self.owner)
            if(e != ee)
            if(d > bd)
            {
                self.enemy = e;
                bd = d;
            }
            e = e.chain;
        }
    }

    if(self.enemy)
        attractmove = steerlib_attract(self.enemy.origin,5000) * 1100;
    else
        attractmove = normalize(self.velocity) * 200;

    dodgemove = steerlib_traceavoid(0.35,1500) * 1700;

    newmove = dodgemove + attractmove;
    self.velocity = movelib_inertmove_byspeed(newmove,850,0.5,0.9);
    self.velocity = movelib_drag(0.01,0.5);


    self.angles = vectoangles(self.velocity);
    self.nextthink = time + 0.1;
}


float globflockcnt;
void spawnfunc_flockerspawn()
{
    precache_model ( "models/turrets/rocket.md3");
    precache_model("models/turrets/c512.md3");
    ++globflockcnt;

    if(!self.cnt)      self.cnt = 20;
    if(!self.delay)    self.delay = 0.25;
    if(!self.flock_id) self.flock_id = globflockcnt;

    self.think     = flockerspawn_think;
    self.nextthink = time + 0.25;

    self.enemy = spawn();

    setmodel(self.enemy, "models/turrets/rocket.md3");
    setorigin(self.enemy,self.origin + '0 0 768' + (randomvec() * 128));

    self.enemy.classname = "FLock Hunter";
    self.enemy.scale     = 3;
    self.enemy.effects   = EF_LOWPRECISION;
    self.enemy.movetype  = MOVETYPE_BOUNCEMISSILE;
    self.enemy.solid     = SOLID_BBOX;
    self.enemy.think     = flocker_hunter_think;
    self.enemy.nextthink = time + 10;
    self.enemy.flock_id  = self.flock_id;
    self.enemy.owner     = self;
}
#endif