No subject

won't make any difference to your run time.

> More examples could be given, but these two are in themselves enough 
> for us to require that the application (and not the graphical 
> platform) handles the "last step" in the coordinate pipeline between 
> the multi-dimensional physical reality and the 2D display pixel.

The transformation matrix of a new cairo context is initially the 
identity matrix.  That is, the coordinates you send to cairo are in 
fact in device units of the target surface (which is pixels for image 
surfaces.)

Joonas