MBF21 - A_SeekTracer arguments

[ViolentBeetle]

Here's what specs for MBF21 tell me:

Quote

Args:

threshold (fixed): If angle to target is lower than this, missile will 'snap' directly to face the target

maxturnangle (fixed): Maximum angle a missile will turn towards the target if angle is above the threshold

So what exactly happens when the angle to target is between the two? I would assume it would also turn towards the target, but that would make threshold entirely meaningless.

[Doomy__Doom]

    dir = P_FaceMobj(actor, target, &delta);
    if (delta > thresh)
    {
        delta >>= 1;
        if (delta > turnMax)
        {
            delta = turnMax;
        }
    }
    if (dir)
    {                           // Turn clockwise
        actor->angle += delta;
    }
    else
    {                           // Turn counter clockwise
        actor->angle -= delta;
    }

"delta" is angle between actor and target, populated by P_FaceMobj. If delta is between thresh(hold) and turnMax, it is divided by 2 without remainder (delta >>= 1, a bitwise shift right), so it turns for half of the angle rather than the whole thing. If delta is less then thresh(hold), it turns to face target directly. And if it's too big, turnMax limits how much the turn can be.

 

Source is from dsda-doom p_mobj.c

[ViolentBeetle]

6 minutes ago, Doomy__Doom said:

    dir = P_FaceMobj(actor, target, &delta);
    if (delta > thresh)
    {
        delta >>= 1;
        if (delta > turnMax)
        {
            delta = turnMax;
        }
    }
    if (dir)
    {                           // Turn clockwise
        actor->angle += delta;
    }
    else
    {                           // Turn counter clockwise
        actor->angle -= delta;
    }

"delta" is angle between actor and target, populated by P_FaceMobj. If delta is between thresh(hold) and turnMax, it is divided by 2 without remainder (delta >>= 1, a bitwise shift right), so it turns for half of the angle rather than the whole thing. If delta is less then thresh(hold), it turns to face target directly. And if it's too big, turnMax limits how much the turn can be.

 

Source is from dsda-doom p_mobj.c

So it actually turn asymptotically, until it hits the threshold?

[Doomy__Doom]

Pretty much, it turns slowly until the angle is "small enough". If that small enough happens to be big, like say 30 degrees, you should get a very snappy projectile as a result.