[Nero_3D]

you go in game and just go to two corners of your area

Wrong
A _____ _____
| | | |
| | | |
|_____| |_____|
B A B

Right
_____ A A _____
| | | |
| | | |
|_____| |_____|
B B

than save the position of the point from A and B and sort the x, y
X , Y
If we get for example for point A - 234.5, 987.6
and for example for point B - 123.4, 1798.3
we just need to sort it in the right oder (minx, maxx, miny, maxy)
so we get - 123.4, 234.5, 987.6, 1798.3

That should be understandable