Renamed "w" into "red_cost_matrix" for readability. Add docs and comments to detail what the code is expected to do.
Signed-off-by: Benjamin Tissoires <[email protected]> --- drivers/input/input-mt.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c index b6ee42a..b269113 100644 --- a/drivers/input/input-mt.c +++ b/drivers/input/input-mt.c @@ -359,23 +359,41 @@ static int input_mt_set_matrix(struct input_mt *mt, return w - mt->red; } +/** + * input_mt_set_slots() - assign slots to the list of pos thanks to the reduced + * cost matrix + * @mt: the input_mt handle of the current device + * @slots: the slot assignment to be filled + * @num_pos: number of positions + * + * For each given touch in pos, try to match the touch to a previous one. + * Then, assign new slots to those who were not a match with the previously + * sent slots. + */ static void input_mt_set_slots(struct input_mt *mt, int *slots, int num_pos) { struct input_mt_slot *s; - int *w = mt->red, *p; + int *red_cost_matrix = mt->red; + int *p; + /* first initialise the output values to -1 */ for (p = slots; p != slots + num_pos; p++) *p = -1; + /* for each currently active slot, match it with one of the touch + * in the pos array */ for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { if (!input_mt_is_active(s)) continue; for (p = slots; p != slots + num_pos; p++) - if (*w++ < 0) + if (*red_cost_matrix++ < 0) + /* we have a match, store the slot value + * in pos[i] */ *p = s - mt->slots; } + /* for each unassigned touch in pos, assign a new slot for it */ for (s = mt->slots; s != mt->slots + mt->num_slots; s++) { if (input_mt_is_active(s)) continue; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
