Negative fixed values

[Nifflas]

I'm having an unexpected problem, it turns out MMF2 can assign negative fixed values to objects. Thing is, I need a null value that I can use as "no object is selected", I used to let -1 represent this, but now I realize that doesn't work. Sure, it's extremely unlikely that the value -1 will be assigned to an object, but I always try to go for the scientifically correcy solution. Is there any fixed value an object can not have?

There's no need to suggest a workaround btw, I know about them all. I just strive to to have the smallest possible solution to every problem.

[Looki]

It seems to me that 0 should work.

Based on a function in the extension SDK, a fixed value is:
(Creation ID << 16)+Object Number

I guess that you have reached such a high number of objects that the last bit of the number turned 1 which results in a negative value.

I've just done some tests and the first fixed value seems to be 65536, and it will always increase - at one point, you'll get negative values.

So I guess 0 works. The fixed value increases with each object, there's just this one point where it will start all over again (at 65536?), but with a minus.

[DavidN]

Given that function, I think you're safe with -1, as that equally can't be a fixed value assigned to an object (for active ones, at least).

[Looki]

Oops, typo there. It's not *, it's +.

[Dynasoft]

As Looki says, the fixed value uses the high 16 bits for the creation id (IIRC it is the frame number) and the low 16 bits for the object number (which is its index in MMF's fixed-length object list).
The frame number can in theory be any value, but the object number is always between 0 and the "number of objects" setting in the frame properties (which is capped at 20000). Using a value with the low 16 bits (the object number) set to between that and 65535 (max of a 16 bit number) should be guaranteed invalid.

-1 fits this, as it would be interpreted as 65535,65535.

0 is unsafe, if unlikely to be hit.

[Looki]

Oh, I wasn't aware that both of the components can be zero. Your method seems to make more sense

[Nifflas]

Awesome, thanks for checking it out!

[Dynasoft]

Also, it's worth remembering that the fixed value of a destroyed object will be reused eventually. It may take a long time to be reused, but it will be.

[Nifflas]

Thanks for the info! That won't be a problem though.