#ifndef __TS_FILTER_H__ #define __TS_FILTER_H__ /* * touchscreen filter * * (c) 2008 Andy Green <andy@openmoko.com> */ #define MAX_TS_FILTER_CHAIN 4 /* max filters you can chain up */ #define MAX_TS_FILTER_COORDS 3 /* Y, Y and Z (pressure) */ struct ts_filter; /* operations that a filter can perform */ struct ts_filter_api { struct ts_filter * (*create)(void *config, int count_coords); void (*destroy)(struct ts_filter *filter); void (*clear)(struct ts_filter *filter); int (*process)(struct ts_filter *filter, int *coords); void (*scale)(struct ts_filter *filter, int *coords); }; /* this is the common part of all filters, the result * we use this type as an otherwise opaque handle on to * the actual filter. Therefore you need one of these * at the start of your actual filter struct */ struct ts_filter { struct ts_filter *next; /* next in chain */ struct ts_filter_api *api; /* operations to use for this object */ int count_coords; int coords[MAX_TS_FILTER_COORDS]; }; /* * helper to create a filter chain from array of API pointers and * array of config ints... leaves pointers to created filters in list * array and fills in ->next pointers to create the chain */ extern int ts_filter_create_chain(struct ts_filter_api **api, void **config, struct ts_filter **list, int count_coords); /* helper to destroy a whole chain from the list of filter pointers */ extern void ts_filter_destroy_chain(struct ts_filter **list); #endif