static void gesture_end (ClutterGestureAction *action, ClutterActor *actor) { ClutterSwipeActionPrivate *priv = CLUTTER_SWIPE_ACTION (action)->priv; gfloat press_x, press_y; gfloat release_x, release_y; ClutterSwipeDirection direction = 0; gboolean can_emit_swipe; clutter_gesture_action_get_press_coords (action, 0, &press_x, &press_y); clutter_gesture_action_get_release_coords (action, 0, &release_x, &release_y); if (release_x - press_x > priv->threshold) direction |= CLUTTER_SWIPE_DIRECTION_RIGHT; else if (press_x - release_x > priv->threshold) direction |= CLUTTER_SWIPE_DIRECTION_LEFT; if (release_y - press_y > priv->threshold) direction |= CLUTTER_SWIPE_DIRECTION_DOWN; else if (press_y - release_y > priv->threshold) direction |= CLUTTER_SWIPE_DIRECTION_UP; /* XXX:2.0 remove */ g_signal_emit (action, swipe_signals[SWIPE], 0, actor, direction, &can_emit_swipe); if (can_emit_swipe) g_signal_emit (action, swipe_signals[SWEPT], 0, actor, direction); }
static void gesture_end (ClutterGestureAction *gesture, ClutterActor *actor) { ClutterPanAction *self = CLUTTER_PAN_ACTION (gesture); ClutterPanActionPrivate *priv = self->priv; gfloat velocity, velocity_x, velocity_y; gfloat delta_x, delta_y; gfloat tau; gint duration; clutter_gesture_action_get_release_coords (CLUTTER_GESTURE_ACTION (self), 0, &priv->release_x, &priv->release_y); if (!priv->should_interpolate) { priv->state = PAN_STATE_INACTIVE; return; } priv->state = PAN_STATE_INTERPOLATING; clutter_gesture_action_get_motion_delta (gesture, 0, &delta_x, &delta_y); velocity = clutter_gesture_action_get_velocity (gesture, 0, &velocity_x, &velocity_y); /* Exponential timing constant v(t) = v(0) * exp(-t/tau) * tau = 1000ms / (frame_per_second * - ln(decay_per_frame)) * with frame_per_second = 60 and decay_per_frame = 0.95, tau ~= 325ms * see http://ariya.ofilabs.com/2011/10/flick-list-with-its-momentum-scrolling-and-deceleration.html */ tau = 1000.0f / (reference_fps * - logf (priv->deceleration_rate)); /* See where the decreasing velocity reaches $min_velocity px/ms * v(t) = v(0) * exp(-t/tau) = min_velocity * t = - tau * ln( min_velocity / |v(0)|) */ duration = - tau * logf (min_velocity / (ABS (velocity) * priv->acceleration_factor)); /* Target point: x(t) = v(0) * tau * [1 - exp(-t/tau)] */ priv->target_x = velocity_x * priv->acceleration_factor * tau * (1 - exp ((float)-duration / tau)); priv->target_y = velocity_y * priv->acceleration_factor * tau * (1 - exp ((float)-duration / tau)); if (ABS (velocity) * priv->acceleration_factor > min_velocity && duration > FLOAT_EPSILON) { priv->interpolated_x = priv->interpolated_y = 0.0f; priv->deceleration_timeline = clutter_timeline_new (duration); clutter_timeline_set_progress_mode (priv->deceleration_timeline, CLUTTER_EASE_OUT_EXPO); g_signal_connect (priv->deceleration_timeline, "new_frame", G_CALLBACK (on_deceleration_new_frame), self); g_signal_connect (priv->deceleration_timeline, "stopped", G_CALLBACK (on_deceleration_stopped), self); clutter_timeline_start (priv->deceleration_timeline); } else { emit_pan_stopped (self, actor); } }