Disclaimer: I don't know much about ActionScript, but this is what I'd think the difference is:
point1.subtract(point2)
probably creates some vector object that represents the vector from point2
to point1
. Obviously, the distance between the points is the length of that vector.
I could imagine that the first line would be less efficient than the second line, because in the first line a temporary vector object is created, which is only needed because you need the length of the vector. In the second line, no temporary object needs to be made - the distance between the points is probably calculated from the coordinates of the points directly.
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