NSAPI provides a set of C functions that are used to implement SAFs and filters. This section lists the functions that are specific to the development of filters. The public routines are described in detail in Chapter 4, NSAPI Function Reference.
The NSAPI functions specific to the development of filters are:
filter_create — Creates a new filter
filter_insert — Inserts the specified filter into a filter stack
filter_remove — Removes the specified filter from a filter stack
filter_name — Returns the name of the specified filter
filter_find — Finds an existing filter given a filter name
filter_layer — Returns the layer in a filter stack that corresponds to the specified filter