How do I Circle and object to destroy it

I have a sprite that leaves a trail behind it, and once its fully encircled it, i want to destroy the objects inside of it.

I've thought about trying to have the sprite collide with a copy of itself (its tail) to signify when the circle is complete, and that works sometimes, but not always. but i'm still stuck on how to determine what's inside of the circle in order to destroy them.

any suggestions?

You could try this:

R0J0hound - Thanks again R0j0 ! you're so smart!

I dont understand the math of what's going on (especially why the x/y is flipped for the prevX and prevY etc , but it works great !

thanks again!

If it's any consolation I don't understand how it works either. It was pulled from a stackoverflow solution where someone else came up with it. I probably should dissect it sometime to understand how it works. Anyways I'm glad it helps.

can you link the stackoverflow solution? or paste it in here? the link is dead.

Sounds like it's averaging the x, and y's and grabbing the closest to that point.

The capx's title "point in poly" are the keywords to find the stackoverflow page. But anyway I fixed the link.

You can use a sprite circle and destroy anything it overlaps.

Similar question was asked about trapping a lion and I designed this capx:

https://www.dropbox.com/s/yt9zhr4286swp ... .capx?dl=0

Might work for you and might not?