Add velocity estimate

The per-touch velocity is useful in many contexts. This patch
adds a simple estimator of the velocity, which also smooths out
position jumps caused by course-grained event updates.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/frame-mtdev.c b/src/frame-mtdev.c
index caf90ae..1d9976d 100644
--- a/src/frame-mtdev.c
+++ b/src/frame-mtdev.c
@@ -154,9 +154,11 @@ static int handle_abs_event(utouch_frame_handle fh,
                 return 1;
         case ABS_MT_POSITION_X:
                 t->x = ev->value;
+                t->vx = 0;
                 return 1;
         case ABS_MT_POSITION_Y:
                 t->y = ev->value;
+                t->vy = 0;
                 return 1;
         case ABS_MT_TOUCH_MAJOR:
                 t->touch_major = ev->value;