touchpad: require a <45 degree movement for a palm to become a touch

[platform/upstream/libinput.git] / src / evdev-mt-touchpad.c

diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index 830e9fe..2cf8b56 100644 (file)
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -363,15 +363,20 @@ static void
 tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
 {
        const int PALM_TIMEOUT = 200; /* ms */
+       const int DIRECTIONS = NE|E|SE|SW|W|NW;
 
        /* If labelled a touch as palm, we unlabel as palm when
-          we move out of the palm edge zone within the timeout.
+          we move out of the palm edge zone within the timeout, provided
+          the direction is within 45 degrees of the horizontal.
         */
        if (t->palm.is_palm) {
                if (time < t->palm.time + PALM_TIMEOUT &&
                    (t->x > tp->palm.left_edge && t->x < tp->palm.right_edge)) {
-                       t->palm.is_palm = false;
-                       tp_set_pointer(tp, t);
+                       int dirs = vector_get_direction(t->x - t->palm.x, t->y - t->palm.y);
+                       if ((dirs & DIRECTIONS) && !(dirs & ~DIRECTIONS)) {
+                               t->palm.is_palm = false;
+                               tp_set_pointer(tp, t);
+                       }
                }
                return;
        }
@@ -391,6 +396,8 @@ tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
 
        t->palm.is_palm = true;
        t->palm.time = time;
+       t->palm.x = t->x;
+       t->palm.y = t->y;
 }
 
 static void