Ok, let's me say my problem, i have a .png displayed by Surface object.
So, this .PNG is only transparent via an Alpha Channel.

So for win to redrawn the picture (.png) in Surface object, i destroyed the Alpha Channel, then recreated.

It works, the Ellipse i drawn every "X" position destroy the given position for replacing by an Alpha Channel.

Then, it become Transparent at this place.

My question is, "How" i can check if Surface object is entirely transparent?