question of performance

Can someone advice me the best way performance wise to do this:

i want to make an effective performance wise way to register when a unit has moved to a new wc3 terrain section (128x128 polygon).

Im planning to create 8 rects around the unit and move them as the unit progress toward the rects. So ill always have 8 rects around each unit in the map. But if tere are too many units then this will cause bad performance (8 loop each unit).

Or i can do a heavy init, to create rects of 128x128 all over. But then dunno if this is slow since tere are too many rects to register event for.

3rd alternative is wat i wouldnt wanna do, but who knows maybe u guys know its faster. It is to repeatedly check the units positions...
Some may suggest to use this method but only when unit recieve move order. But i want this to work with SetUnitX/SetUnitY too so ye... this wont work.

EDIT: ive figured a great way to do it with method 3. But id still wanna hear people out

Make 2 'checkerboarded' regions

(Only requires ~10 handles -.-)

And store current one : reset when set x/y

may need 3 4 depending on how wc diagonal movement works

(
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232323
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wat do u mean

Im planning to use unit leave region...

rect = square

region = lot of squares

so you do this:

a = region 1
b = region 2

ababababab
bababababa

and so on;

do register enter region for both regions
when event fires get square based on x/y pos ?

Clever.

I think if the diagonal motion case is screwball you'll need four colors. One possible tile:

Four is the minimum since all the blocks of a 2x2 tile are in contact with each other.

Ive been thinking and this doesnt solve my problem... cus i dont only wanna detect the displacement of 128x128 square. I want a cube 128x128x128...
So i need to detect when a unit's flying height changes.

Then do the check when you update their movement if you have that loop running anyways.

Why are you interested in discretized Z position?

z ruins it. You'll have to stick with method 3.