VARP(nosway, 0, 0, 1);
VARP(swayspeeddiv, 1, 105, 1000);
VARP(swaymovediv, 1, 200, 1000);
VARP(swayupspeeddiv, 1, 105, 1000);
VARP(swayupmovediv, 1, 200, 1000);

struct weaponmove
{
    static vec swaydir;
    static int swaymillis, lastsway;

    float k_rot, kick;
    vec pos;
    int anim, basetime;

    weaponmove() : k_rot(0), kick(0), anim(0), basetime(0) { pos.x = pos.y = pos.z = 0.0f; }

    void calcmove(vec aimdir, int lastaction, playerent *p)
    {
        kick = k_rot = 0.0f;
        pos = p->o;

        if(!nosway)
        {
            float k = pow(0.7f, (lastmillis-lastsway)/10.0f);
            swaydir.mul(k);
            vec dv(p->vel);
            dv.mul((1-k)/max(p->vel.magnitude(), p->maxspeed));
            dv.x *= 1.5f;
            dv.y *= 1.5f;
            dv.z *= 0.4f;
            swaydir.add(dv);
            pos.add(swaydir);
        }

        if(p->onfloor || p->onladder || p->inwater) swaymillis += lastmillis-lastsway;
        lastsway = lastmillis;

        if(p->weaponchanging)
        {
            anim = ANIM_GUN_RELOAD;
            basetime = p->weaponchanging;
            float progress = clamp((lastmillis - p->weaponchanging)/(float)weapon::weaponchangetime, 0.0f, 1.0f);
            k_rot = -90*sinf(progress*PI);
        }
        else if(p->weaponsel->reloading)
        {
            anim = ANIM_GUN_RELOAD;
            basetime = p->weaponsel->reloading;
            float reloadtime = (float)p->weaponsel->info.reloadtime,
                  progress = clamp((lastmillis - p->weaponsel->reloading)/reloadtime, 0.0f, clamp(1.0f - (p->lastaction + p->weaponsel->gunwait - lastmillis)/reloadtime, 0.5f, 1.0f));
            k_rot = -90*sinf(progress*PI);
        }
        else
        {
            anim = ANIM_GUN_IDLE;
            basetime = lastaction;

            int timediff = lastmillis-lastaction,
                animtime = min(p->weaponsel->gunwait, (int)p->weaponsel->info.attackdelay);
            vec sway = aimdir;
            float progress = 0.0f;
            float k_back = 0.0f;

            if(p->weaponsel==p->lastattackweapon)
            {
                progress = max(0.0f, min(1.0f, timediff/(float)animtime));
                // f(x) = -sin(x-1.5)^3
                kick = -sinf(pow((1.5f*progress)-1.5f,3));
                if(p->crouching) kick *= 0.75f;
                if(p->lastaction) anim = p->weaponsel->modelanim();
            }

            if(p->weaponsel->info.mdl_kick_rot || p->weaponsel->info.mdl_kick_back)
            {
                k_rot = p->weaponsel->info.mdl_kick_rot*kick;
                k_back = p->weaponsel->info.mdl_kick_back*kick/10;
            }

            if(nosway) sway.x = sway.y = sway.z = 0;
            else
            {
                float swayspeed = sinf((float)swaymillis/swayspeeddiv)/(swaymovediv/10.0f);
                float swayupspeed = cosf((float)swaymillis/swayupspeeddiv)/(swayupmovediv/10.0f);

                float plspeed = min(1.0f, sqrtf(p->vel.x*p->vel.x + p->vel.y*p->vel.y));

                swayspeed *= plspeed/2;
                swayupspeed *= plspeed/2;

                swap(sway.x, sway.y);
                sway.y = -sway.y;

                swayupspeed = fabs(swayupspeed); // sway a semicirle only
                sway.z = 1.0f;

                sway.x *= swayspeed;
                sway.y *= swayspeed;
                sway.z *= swayupspeed;

                if(p->crouching) sway.mul(0.75f);
            }

            pos.x -= aimdir.x*k_back+sway.x;
            pos.y -= aimdir.y*k_back+sway.y;
            pos.z -= aimdir.z*k_back+sway.z;
        }
    }
};

vec weaponmove::swaydir(0, 0, 0);
int weaponmove::lastsway = 0, weaponmove::swaymillis = 0;

void preload_hudguns()
{
    loopi(NUMGUNS)
    {
        defformatstring(path)("weapons/%s", guns[i].modelname);
        loadmodel(path);
    }
}