Just for curiosity ...

When you move the trashcan, this is a nice and smooth move. But when
you move a complex morph this is quite bumpy.

I once looked at the WarpBitBlt and it did pixel operations in no
time. So I thought: it can't be the foreground pixel moves that use up
the CPU it must be the background.

But this isn't true either, because a plain rectangle moves faster
than a complex morph of the same size.

Why is this ?