cairo:pattern-filter (pattern)

pattern -- a cairo:pattern-t instance
filter -- a cairo:filter-t value describing the filter to use for resizing the pattern

The cairo:pattern-filter function gets the current filter for pattern. The (setf cairo:pattern-filter) function sets the filter to be used for resizing when using the pattern. See the cairo:filter-t enumeration for details on each filter.

Note that you might want to control filtering even when you do not have an explicit cairo:pattern-t instance, for example when using the cairo:set-source-surface function. In these cases, it is convenient to use the cairo:source function to get access to the pattern that Cairo creates implicitly. For example:

(cairo:set-source-surface context image x y)
(setf (cairo:pattern-filter (cairo:source cr)) :nearest)