From 436ebb2716b24743b3873aa7b330073c48793b86 Mon Sep 17 00:00:00 2001 From: Emanuele Aina Date: Sat, 25 Aug 2012 16:04:24 +0200 Subject: [PATCH] gesture-action: add _get_motion_delta()/_get_velocity() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add some accessors to simplify common tasks for GestureAction users: • clutter_gesture_action_get_motion_delta() to get the delta on the X and Y axis in stage coordinates since the last motion event, and the scalar distance travelled; • clutter_gesture_action_get_velocity() to get an estimate of the speed of the last motion event along the X and Y axis and as a scalar value in pixels per millisecond. https://bugzilla.gnome.org/show_bug.cgi?id=681648 --- clutter/clutter-gesture-action.c | 121 ++++++++++++++++++++- clutter/clutter-gesture-action.h | 10 ++ clutter/clutter.symbols | 2 + doc/reference/clutter/clutter-sections.txt | 2 + 4 files changed, 131 insertions(+), 4 deletions(-) diff --git a/clutter/clutter-gesture-action.c b/clutter/clutter-gesture-action.c index ace980b86..5994107ef 100644 --- a/clutter/clutter-gesture-action.c +++ b/clutter/clutter-gesture-action.c @@ -62,7 +62,10 @@ #include "clutter-marshal.h" #include "clutter-private.h" +#include + #define MAX_GESTURE_POINTS (10) +#define FLOAT_EPSILON (1e-15) typedef struct { @@ -70,7 +73,10 @@ typedef struct ClutterEventSequence *sequence; gfloat press_x, press_y; + gint64 last_motion_time; gfloat last_motion_x, last_motion_y; + gint64 last_delta_time; + gfloat last_delta_x, last_delta_y; gfloat release_x, release_y; } GesturePoint; @@ -118,6 +124,10 @@ gesture_register_point (ClutterGestureAction *action, ClutterEvent *event) clutter_event_get_coords (event, &point->press_x, &point->press_y); point->last_motion_x = point->press_x; point->last_motion_y = point->press_y; + point->last_motion_time = clutter_event_get_time (event); + + point->last_delta_x = point->last_delta_y = 0; + point->last_delta_time = 0; if (clutter_event_type (event) != CLUTTER_BUTTON_PRESS) point->sequence = clutter_event_get_event_sequence (event); @@ -192,6 +202,8 @@ stage_captured_event_cb (ClutterActor *stage, gint position; gboolean return_value; GesturePoint *point; + gfloat motion_x, motion_y; + gint64 time; if ((point = gesture_find_point (action, event, &position)) == NULL) return CLUTTER_EVENT_PROPAGATE; @@ -218,8 +230,8 @@ stage_captured_event_cb (ClutterActor *stage, case CLUTTER_TOUCH_UPDATE: clutter_event_get_coords (event, - &point->last_motion_x, - &point->last_motion_y); + &motion_x, + &motion_y); if (priv->points->len < priv->requested_nb_points) return CLUTTER_EVENT_PROPAGATE; @@ -233,8 +245,8 @@ stage_captured_event_cb (ClutterActor *stage, "dnd-drag-threshold", &drag_threshold, NULL); - if ((ABS (point->press_y - point->last_motion_y) >= drag_threshold) || - (ABS (point->press_x - point->last_motion_x) >= drag_threshold)) + if ((ABS (point->press_y - motion_y) >= drag_threshold) || + (ABS (point->press_x - motion_x) >= drag_threshold)) { priv->in_gesture = TRUE; @@ -250,6 +262,15 @@ stage_captured_event_cb (ClutterActor *stage, return CLUTTER_EVENT_PROPAGATE; } + point->last_delta_x = motion_x - point->last_motion_x; + point->last_delta_y = motion_y - point->last_motion_y; + point->last_motion_x = motion_x; + point->last_motion_y = motion_y; + + time = clutter_event_get_time (event); + point->last_delta_time = time - point->last_motion_time; + point->last_motion_time = time; + g_signal_emit (action, gesture_signals[GESTURE_PROGRESS], 0, actor, &return_value); if (!return_value) @@ -267,6 +288,12 @@ stage_captured_event_cb (ClutterActor *stage, if (priv->in_gesture && ((priv->points->len - 1) < priv->requested_nb_points)) { + /* Treat the release event as the continuation of the last motion, + * in case the user keeps the pointer still for a while before + * releasing it. */ + time = clutter_event_get_time (event); + point->last_delta_time += time - point->last_motion_time; + priv->in_gesture = FALSE; g_signal_emit (action, gesture_signals[GESTURE_END], 0, actor); } @@ -572,6 +599,49 @@ clutter_gesture_action_get_motion_coords (ClutterGestureAction *action, device).last_motion_y; } +/** + * clutter_gesture_action_get_motion_delta: + * @action: a #ClutterGestureAction + * @device: currently unused, set to 0 + * @delta_x: (out) (allow-none): return location for the X axis + * component of the incremental motion delta + * @delta_y: (out) (allow-none): return location for the Y axis + * component of the incremental motion delta + * + * Retrieves the incremental delta since the last motion event + * during the dragging. + * + * Return value: the distance since last motion event + * + * Since: 1.12 + */ +gfloat +clutter_gesture_action_get_motion_delta (ClutterGestureAction *action, + guint device, + gfloat *delta_x, + gfloat *delta_y) +{ + gfloat d_x, d_y; + + g_return_val_if_fail (CLUTTER_IS_GESTURE_ACTION (action), 0); + g_return_val_if_fail (action->priv->points->len > device, 0); + + d_x = g_array_index (action->priv->points, + GesturePoint, + device).last_delta_x; + d_y = g_array_index (action->priv->points, + GesturePoint, + device).last_delta_y; + + if (delta_x) + *delta_x = d_x; + + if (delta_y) + *delta_y = d_y; + + return sqrt ((d_x * d_x) + (d_y * d_y)); +} + /** * clutter_gesture_action_get_release_coords: * @action: a #ClutterGestureAction @@ -606,6 +676,49 @@ clutter_gesture_action_get_release_coords (ClutterGestureAction *action, device).release_y; } +/** + * clutter_gesture_action_get_velocity: + * @action: a #ClutterGestureAction + * @device: currently unused, set to 0 + * @velocity_x: (out) (allow-none): return location for the latest motion + * event's X velocity + * @velocity_y: (out) (allow-none): return location for the latest motion + * event's Y velocity + * + * Retrieves the velocity, in stage pixels per microseconds, of the + * latest motion event during the dragging + * + * Since: 1.12 + */ +gfloat +clutter_gesture_action_get_velocity (ClutterGestureAction *action, + guint device, + gfloat *velocity_x, + gfloat *velocity_y) +{ + gfloat d_x, d_y, distance, velocity; + gint64 d_t; + + g_return_val_if_fail (CLUTTER_IS_GESTURE_ACTION (action), 0); + g_return_val_if_fail (action->priv->points->len > device, 0); + + distance = clutter_gesture_action_get_motion_delta (action, device, + &d_x, &d_y); + + d_t = g_array_index (action->priv->points, + GesturePoint, + device).last_delta_time; + + if (velocity_x) + *velocity_x = d_t > FLOAT_EPSILON ? d_x / d_t : 0; + + if (velocity_y) + *velocity_y = d_t > FLOAT_EPSILON ? d_y / d_t : 0; + + velocity = d_t > FLOAT_EPSILON ? distance / d_t : 0; + return velocity; +} + /** * clutter_gesture_action_get_n_touch_points: * @action: a #ClutterGestureAction diff --git a/clutter/clutter-gesture-action.h b/clutter/clutter-gesture-action.h index 3aade5b4b..7587bd0ef 100644 --- a/clutter/clutter-gesture-action.h +++ b/clutter/clutter-gesture-action.h @@ -113,10 +113,20 @@ void clutter_gesture_action_get_motion_coords (ClutterGestureA guint device, gfloat *motion_x, gfloat *motion_y); +CLUTTER_AVAILABLE_IN_1_12 +gfloat clutter_gesture_action_get_motion_delta (ClutterGestureAction *action, + guint device, + gfloat *delta_x, + gfloat *delta_y); void clutter_gesture_action_get_release_coords (ClutterGestureAction *action, guint device, gfloat *release_x, gfloat *release_y); +CLUTTER_AVAILABLE_IN_1_12 +gfloat clutter_gesture_action_get_velocity (ClutterGestureAction *action, + guint device, + gfloat *velocity_x, + gfloat *velocity_y); G_END_DECLS diff --git a/clutter/clutter.symbols b/clutter/clutter.symbols index 261ac8351..9991579eb 100644 --- a/clutter/clutter.symbols +++ b/clutter/clutter.symbols @@ -734,10 +734,12 @@ clutter_geometry_get_type clutter_geometry_intersects clutter_geometry_union clutter_gesture_action_get_motion_coords +clutter_gesture_action_get_motion_delta clutter_gesture_action_get_n_touch_points clutter_gesture_action_get_press_coords clutter_gesture_action_get_release_coords clutter_gesture_action_get_type +clutter_gesture_action_get_velocity clutter_gesture_action_set_n_touch_points clutter_gesture_action_new clutter_get_accessibility_enabled diff --git a/doc/reference/clutter/clutter-sections.txt b/doc/reference/clutter/clutter-sections.txt index 1b2a08d4a..72b788965 100644 --- a/doc/reference/clutter/clutter-sections.txt +++ b/doc/reference/clutter/clutter-sections.txt @@ -2941,7 +2941,9 @@ ClutterGestureActionClass clutter_gesture_action_new clutter_gesture_action_get_press_coords clutter_gesture_action_get_motion_coords +clutter_gesture_action_get_motion_delta clutter_gesture_action_get_release_coords +clutter_gesture_action_get_velocity clutter_gesture_action_get_n_touch_points clutter_gesture_action_set_n_touch_points