Introduce activation hold time

Do not activate a drag, pinch or rotate immediately, even
if the activation threshold is met. This allows for a smoother
transition between fingers.

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

1 files changed, 4 insertions, 1 deletions

diff --git a/src/grail-gestures.c b/src/grail-gestures.c
index efadde5..458f60d 100644
--- a/src/grail-gestures.c
+++ b/src/grail-gestures.c
@@ -27,6 +27,7 @@
 static const float FM_SN[DIM_FM] = { 1000, 1000, 200, 1000 };
 static const float FM_BAR[DIM_FM] = { 50, 50, 30, 50 };
 static const grail_time_t FM_BAR_MS[DIM_FM] = { 300, 300, 10000, 10000 };
+static const grail_time_t FM_HOLD_MS[DIM_FM] = { 60, 60, 60, 60 };
 static const grail_time_t SAMPLE_MS = 10;
 static const float EPS = 1e-3;
 
@@ -133,7 +134,8 @@ static void move_update(struct move_model *m, int i, float x, grail_time_t t)
         if (m->active & (1 << i))
                 return;
         fm->action_delta = x - fm->original;
-        if (fabs(fm->action_delta) > fm->bar) {
+        if (t - fm->original_ms > fm->hold_ms &&
+            fabs(fm->action_delta) > fm->bar) {
                 m->active |= (1 << i);
         } else if (t - fm->original_ms > fm->bar_ms) {
                 m->active |= (1 << i);
@@ -157,6 +159,7 @@ void gru_init_motion(struct grail *ge)
         for (i = 0; i < DIM_FM; i++) {
                 m->fm[i].fuzz = D[i] / FM_SN[i];
                 m->fm[i].bar = D[i] / FM_BAR[i];
+                m->fm[i].hold_ms = FM_HOLD_MS[i];
                 m->fm[i].bar_ms = FM_BAR_MS[i];
         }
 }