AngleDir8() and weapons

[Colossal]

The AngleDir8() function is commonly used to set weapon->Dir, but it is inconsistent with unscripted eweapons when it comes to which directions Link can be facing in order to block them when the weapon's angle is close to a multiple of 90 degrees. A more consistent function would be something like this (-180 <= angle <= 180):

int AngleDir8W(float angle) {
   if(angle == 0) return DIR_RIGHT;
   else if(angle == 90) return DIR_DOWN;
   else if(angle == -90) return DIR_UP;
   else if(angle == 180 || angle == -180) return DIR_LEFT;
   else if(angle < -90) return DIR_LEFTUP;
   else if(angle < 0) return DIR_RIGHTUP;
   else if(angle < 90) return DIR_RIGHTDOWN;
   else return DIR_LEFTDOWN;
}

int RadianAngleDir8W(float angle) {
   return AngleDir8W(angle*57.2958);
}

I think it would make a good addition to std.zh, though other functions that use AngleDir8() with weapon->Dir would need to be updated to fix the inconsistency.

EDIT: Maybe this could be improved. I'll do some testing with radian values.

EDIT 2: There are going to be roundoff errors when using radians, so I think there should be some tolerance for that with the non-diagonal directions. I'm not sure how much though.

[cbailey78]

I think this thread belongs in the scripting section.

[Colossal]

Yeah, I guess you're right about that. I must have been tired when I posted that here.

Anyway, another std.zh question: what's up with SpinDir()? It doesn't do what it claims at all, or anything seemingly useful right now, for that matter.

//Converts directions to go round in a circle rather than U, D, L, R
int SpinDir(int dir) {
    if(dir == DIR_DOWN || dir == DIR_RIGHT)
        return dir;
    else if(dir == DIR_LEFT)
        return DIR_UP;
    else if(dir == DIR_UP)
        return DIR_LEFT;
    return -1;
}

[Gleeok]

I don't know either. Why does it start from left = 0?

[Imzogelmo]

I noticed this function when I was making my Spark script. I really needed a way to easily get the next direction clockwise or counterclockwise, and the functions using it should not have to care which direction it was, so I wrote my "Turn" function for that purpose. Of course, that was all just to help me learn, so I didn't intend it to be used by anyone else, but it does seem like such a function should be possible without converting into angles.

[Colossal]

This is what I came up with when I tackled that issue:

// Constants to use as arguments for spin
const int SPIN_CCW = 10b;
const int SPIN_CW = 11b;

int SpinDir(int dir, int spin) {
   return dir ^ spin ^ (dir >> 1);
}

I've been having way too much fun with bitwise operators lately.

[Imzogelmo]

That's much more concise and perfect for my application. Do you mind if I use it?

[Colossal]

Go ahead. I don't mind at all.