public static IEnumerable <Actor> FindUnitsInCircle(this World world, int2 a, int r)
{
using (new PerfSample("FindUnitsInCircle"))
{
var min = a - new int2(r, r);
var max = a + new int2(r, r);
var actors = world.FindUnits(min, max);
var rect = new Rectangle(min.X, min.Y, max.X - min.X, max.Y - min.Y);
var inBox = actors.Where(x => x.ExtendedBounds.Value.IntersectsWith(rect));
return(inBox.Where(x => (x.CenterLocation - a).LengthSquared < r * r));
}
}