[cairo] Clearing up misconceptions

[Jeff Muizelaar]

On Thu, Dec 13, 2007 at 12:55:49PM -0500, Behdad Esfahbod wrote:
> > The relationship between Pattern and Mask is unclear -- right now I
> > think of them as synonyms, they are the same thing.
> 
> A mask is a pattern.  A source is a pattern too.

i.e. 'pattern's more represent the data versus 'source' or 'mask' representing how
that data will be used.

-Jeff