[cairo] Image drawing questions

[Ian Britten]

Hi all,
I'm trying to get our existing framework to draw it's images
using Cairo, but am not having much success, mostly in getting
the image positioned/scaled/rotated correctly...

I see two separate possible approaches, and am not sure of the
pros/cons of them, and was wondering if someone could clarify,
so I could focus on just one.  (sigh - The *vast* majority of
my time seems to be going into transformation problems, rather
than functionality...  :(  )

For both cases, I have my ImageSurface populated correctly (I
believe) with the raw image data.
[ BTW - What way do the rows increase in the image surface?  Is
it top-to-bottom, or bottom-to-top? ]

Case 1:  In this case, I'm working toward calling
Context::set_source(Surface, x, y), and am mucking about with
the transformation of the context itself.

Case 1:  In this case, I'm working toward calling
Context::set_source(Pattern), and am making a SurfacePattern
from my Surface, and am trying to configure the Matrix on it.

What, if anything, is the difference?
Thanks for any info!
Ian