CenterX and CenterY problem On ABPhysicsEngine

[asmag]

Hi!

I have a problem to pass parameters to method buildParticle ( below ):

Sub buildParticle(TypeP As Int,centerX As Double, centerY As Double, Width As Double, Height As Double, Radius As Double, Collidable As Boolean,seeCollisionAsHit As Boolean, rotation As Double, elasticity As Double, friction As Double, mass As Double, isFixed As Boolean, Name As String) As ABParticle
Dim p As ABParticle
p.Initialize(TypeP,centerX,centerY,Width,Height,Radius,Collidable, seeCollisionAsHit, rotation,Name)
p.elasticity = elasticity
p.friction = friction
p.isFixed = isFixed
p.mass = mass
Return p
End Sub

My screen resolution is : 480x854, scale:1.5 (240dpi)

I didn't undertand the centerX and centerY parameters to show exactly way I see on the abstract layout.

What I fix the issue?

Thanks.