Order of graphical operations and transforms

In reading the Compositing and Blending spec, it mentions the order of
graphical operations for filters, clipping, masking and opacity.

In my head, transforms take place in the same space as these steps, i.e.
when the style calculation is done and the element is moved into some sort
of temp bitmap and then composited onto the page.

I cant seem to find any spec documentation as to where transforms fit into
this chain. Is there any?

//emil