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clutter/clutter/clutter-zoom-action.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2012 Intel Corporation.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*
* Author:
* Lionel Landwerlin <lionel.g.landwerlin@linux.intel.com>
*/
/**
* SECTION:clutter-zoom-action
* @Title: ClutterZoomAction
* @Short_Description: Action enabling zooming on actors
*
* #ClutterZoomAction is a sub-class of #ClutterGestureAction that
* implements all the necessary logic for zooming actors using a "pinch"
* gesture between two touch points.
*
* The simplest usage of #ClutterZoomAction consists in adding it to
* a #ClutterActor and setting it as reactive; for instance, the following
* code:
*
* |[
* clutter_actor_add_action (actor, clutter_zoom_action_new ());
* clutter_actor_set_reactive (actor, TRUE);
* ]|
*
* will automatically result in the actor to be scale according to the
* distance between two touch points.
*
* Since: 1.12
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include "clutter-zoom-action.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-gesture-action-private.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
#include "clutter-stage-private.h"
typedef struct
{
gfloat start_x;
gfloat start_y;
gfloat transformed_start_x;
gfloat transformed_start_y;
gfloat update_x;
gfloat update_y;
gfloat transformed_update_x;
gfloat transformed_update_y;
} ZoomPoint;
struct _ClutterZoomActionPrivate
{
ClutterStage *stage;
ClutterZoomAxis zoom_axis;
ZoomPoint points[2];
ClutterPoint initial_focal_point;
ClutterPoint focal_point;
ClutterPoint transformed_focal_point;
gfloat initial_x;
gfloat initial_y;
gfloat initial_z;
gdouble initial_scale_x;
gdouble initial_scale_y;
gdouble zoom_initial_distance;
};
enum
{
PROP_0,
PROP_ZOOM_AXIS,
PROP_LAST
};
static GParamSpec *zoom_props[PROP_LAST] = { NULL, };
enum
{
ZOOM,
LAST_SIGNAL
};
static guint zoom_signals[LAST_SIGNAL] = { 0, };
G_DEFINE_TYPE_WITH_PRIVATE (ClutterZoomAction, clutter_zoom_action, CLUTTER_TYPE_GESTURE_ACTION)
static void
capture_point_initial_position (ClutterGestureAction *action,
ClutterActor *actor,
gint index,
ZoomPoint *point)
{
clutter_gesture_action_get_motion_coords (action, index,
&point->start_x,
&point->start_y);
point->transformed_start_x = point->update_x = point->start_x;
point->transformed_start_y = point->update_x = point->start_y;
clutter_actor_transform_stage_point (actor,
point->start_x, point->start_y,
&point->transformed_start_x,
&point->transformed_start_y);
point->transformed_update_x = point->transformed_start_x;
point->transformed_update_y = point->transformed_start_y;
}
static void
capture_point_update_position (ClutterGestureAction *action,
ClutterActor *actor,
gint index,
ZoomPoint *point)
{
clutter_gesture_action_get_motion_coords (action, index,
&point->update_x,
&point->update_y);
point->transformed_update_x = point->update_x;
point->transformed_update_y = point->update_y;
clutter_actor_transform_stage_point (actor,
point->update_x, point->update_y,
&point->transformed_update_x,
&point->transformed_update_y);
}
static gboolean
clutter_zoom_action_gesture_begin (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterZoomActionPrivate *priv = ((ClutterZoomAction *) action)->priv;
gfloat dx, dy;
capture_point_initial_position (action, actor, 0, &priv->points[0]);
capture_point_initial_position (action, actor, 1, &priv->points[1]);
dx = priv->points[1].transformed_start_x - priv->points[0].transformed_start_x;
dy = priv->points[1].transformed_start_y - priv->points[0].transformed_start_y;
priv->zoom_initial_distance = sqrt (dx * dx + dy * dy);
clutter_actor_get_translation (actor,
&priv->initial_x,
&priv->initial_y,
&priv->initial_z);
clutter_actor_get_scale (actor,
&priv->initial_scale_x,
&priv->initial_scale_y);
priv->initial_focal_point.x = (priv->points[0].start_x + priv->points[1].start_x) / 2;
priv->initial_focal_point.y = (priv->points[0].start_y + priv->points[1].start_y) / 2;
clutter_actor_transform_stage_point (actor,
priv->initial_focal_point.x,
priv->initial_focal_point.y,
&priv->transformed_focal_point.x,
&priv->transformed_focal_point.y);
clutter_actor_set_pivot_point (actor,
priv->transformed_focal_point.x / clutter_actor_get_width (actor),
priv->transformed_focal_point.y / clutter_actor_get_height (actor));
return TRUE;
}
static gboolean
clutter_zoom_action_gesture_progress (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterZoomActionPrivate *priv = ((ClutterZoomAction *) action)->priv;
gdouble distance, new_scale;
gfloat dx, dy;
gboolean retval;
capture_point_update_position (action, actor, 0, &priv->points[0]);
capture_point_update_position (action, actor, 1, &priv->points[1]);
dx = priv->points[1].update_x - priv->points[0].update_x;
dy = priv->points[1].update_y - priv->points[0].update_y;
distance = sqrt (dx * dx + dy * dy);
if (distance == 0)
return TRUE;
priv->focal_point.x = (priv->points[0].update_x + priv->points[1].update_x) / 2;
priv->focal_point.y = (priv->points[0].update_y + priv->points[1].update_y) / 2;
new_scale = distance / priv->zoom_initial_distance;
g_signal_emit (action, zoom_signals[ZOOM], 0,
actor, &priv->focal_point, new_scale,
&retval);
return TRUE;
}
static void
clutter_zoom_action_gesture_cancel (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterZoomActionPrivate *priv = ((ClutterZoomAction *) action)->priv;
clutter_actor_set_translation (actor,
priv->initial_x,
priv->initial_y,
priv->initial_z);
clutter_actor_set_scale (actor, priv->initial_scale_x, priv->initial_scale_y);
}
static gboolean
clutter_zoom_action_real_zoom (ClutterZoomAction *action,
ClutterActor *actor,
ClutterPoint *focal_point,
gdouble factor)
{
ClutterZoomActionPrivate *priv = action->priv;
gfloat x, y, z;
gdouble scale_x, scale_y;
ClutterVertex out, in;
in.x = priv->transformed_focal_point.x;
in.y = priv->transformed_focal_point.y;
in.z = 0;
clutter_actor_apply_transform_to_point (actor, &in, &out);
clutter_actor_get_scale (actor, &scale_x, &scale_y);
switch (priv->zoom_axis)
{
case CLUTTER_ZOOM_BOTH:
clutter_actor_set_scale (actor, factor, factor);
break;
case CLUTTER_ZOOM_X_AXIS:
clutter_actor_set_scale (actor, factor, scale_y);
break;
case CLUTTER_ZOOM_Y_AXIS:
clutter_actor_set_scale (actor, scale_x, factor);
break;
default:
break;
}
x = priv->initial_x + priv->focal_point.x - priv->initial_focal_point.x;
y = priv->initial_y + priv->focal_point.y - priv->initial_focal_point.y;
clutter_actor_get_translation (actor, NULL, NULL, &z);
clutter_actor_set_translation (actor, x, y, z);
return TRUE;
}
static void
clutter_zoom_action_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterZoomAction *action = CLUTTER_ZOOM_ACTION (gobject);
switch (prop_id)
{
case PROP_ZOOM_AXIS:
clutter_zoom_action_set_zoom_axis (action, g_value_get_enum (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
clutter_zoom_action_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterZoomActionPrivate *priv = CLUTTER_ZOOM_ACTION (gobject)->priv;
switch (prop_id)
{
case PROP_ZOOM_AXIS:
g_value_set_enum (value, priv->zoom_axis);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
clutter_zoom_action_dispose (GObject *gobject)
{
G_OBJECT_CLASS (clutter_zoom_action_parent_class)->dispose (gobject);
}
static void
clutter_zoom_action_constructed (GObject *gobject)
{
ClutterGestureAction *gesture;
gesture = CLUTTER_GESTURE_ACTION (gobject);
clutter_gesture_action_set_threshold_trigger_edge (gesture, CLUTTER_GESTURE_TRIGGER_EDGE_NONE);
}
static void
clutter_zoom_action_class_init (ClutterZoomActionClass *klass)
{
ClutterGestureActionClass *gesture_class =
CLUTTER_GESTURE_ACTION_CLASS (klass);
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->constructed = clutter_zoom_action_constructed;
gobject_class->set_property = clutter_zoom_action_set_property;
gobject_class->get_property = clutter_zoom_action_get_property;
gobject_class->dispose = clutter_zoom_action_dispose;
gesture_class->gesture_begin = clutter_zoom_action_gesture_begin;
gesture_class->gesture_progress = clutter_zoom_action_gesture_progress;
gesture_class->gesture_cancel = clutter_zoom_action_gesture_cancel;
klass->zoom = clutter_zoom_action_real_zoom;
/**
* ClutterZoomAction:zoom-axis:
*
* Constraints the zooming action to the specified axis
*
* Since: 1.12
*/
zoom_props[PROP_ZOOM_AXIS] =
g_param_spec_enum ("zoom-axis",
P_("Zoom Axis"),
P_("Constraints the zoom to an axis"),
CLUTTER_TYPE_ZOOM_AXIS,
CLUTTER_ZOOM_BOTH,
CLUTTER_PARAM_READWRITE);
g_object_class_install_properties (gobject_class,
PROP_LAST,
zoom_props);
/**
* ClutterZoomAction::zoom:
* @action: the #ClutterZoomAction that emitted the signal
* @actor: the #ClutterActor attached to the action
* @focal_point: the focal point of the zoom
* @factor: the initial distance between the 2 touch points
*
* The ::zoom signal is emitted for each series of touch events that
* change the distance and focal point between the touch points.
*
* The default handler of the signal will call
* clutter_actor_set_scale() on @actor using the ratio of the first
* distance between the touch points and the current distance. To
* override the default behaviour, connect to this signal and return
* %FALSE.
*
* Return value: %TRUE if the zoom should continue, and %FALSE if
* the zoom should be cancelled.
*
* Since: 1.12
*/
zoom_signals[ZOOM] =
g_signal_new (I_("zoom"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterZoomActionClass, zoom),
_clutter_boolean_continue_accumulator, NULL,
_clutter_marshal_BOOLEAN__OBJECT_BOXED_DOUBLE,
G_TYPE_BOOLEAN, 3,
CLUTTER_TYPE_ACTOR,
CLUTTER_TYPE_POINT,
G_TYPE_DOUBLE);
}
static void
clutter_zoom_action_init (ClutterZoomAction *self)
{
ClutterGestureAction *gesture;
self->priv = clutter_zoom_action_get_instance_private (self);
self->priv->zoom_axis = CLUTTER_ZOOM_BOTH;
gesture = CLUTTER_GESTURE_ACTION (self);
clutter_gesture_action_set_n_touch_points (gesture, 2);
}
/**
* clutter_zoom_action_new:
*
* Creates a new #ClutterZoomAction instance
*
* Return value: the newly created #ClutterZoomAction
*
* Since: 1.12
*/
ClutterAction *
clutter_zoom_action_new (void)
{
return g_object_new (CLUTTER_TYPE_ZOOM_ACTION, NULL);
}
/**
* clutter_zoom_action_set_zoom_axis:
* @action: a #ClutterZoomAction
* @axis: the axis to constraint the zooming to
*
* Restricts the zooming action to a specific axis
*
* Since: 1.12
*/
void
clutter_zoom_action_set_zoom_axis (ClutterZoomAction *action,
ClutterZoomAxis axis)
{
g_return_if_fail (CLUTTER_IS_ZOOM_ACTION (action));
g_return_if_fail (axis >= CLUTTER_ZOOM_X_AXIS &&
axis <= CLUTTER_ZOOM_BOTH);
if (action->priv->zoom_axis == axis)
return;
action->priv->zoom_axis = axis;
g_object_notify_by_pspec (G_OBJECT (action), zoom_props[PROP_ZOOM_AXIS]);
}
/**
* clutter_zoom_action_get_zoom_axis:
* @action: a #ClutterZoomAction
*
* Retrieves the axis constraint set by clutter_zoom_action_set_zoom_axis()
*
* Return value: the axis constraint
*
* Since: 1.12
*/
ClutterZoomAxis
clutter_zoom_action_get_zoom_axis (ClutterZoomAction *action)
{
g_return_val_if_fail (CLUTTER_IS_ZOOM_ACTION (action),
CLUTTER_ZOOM_BOTH);
return action->priv->zoom_axis;
}
/**
* clutter_zoom_action_get_focal_point:
* @action: a #ClutterZoomAction
* @point: (out): a #ClutterPoint
*
* Retrieves the focal point of the current zoom
*
* Since: 1.12
*/
void
clutter_zoom_action_get_focal_point (ClutterZoomAction *action,
ClutterPoint *point)
{
g_return_if_fail (CLUTTER_IS_ZOOM_ACTION (action));
g_return_if_fail (point != NULL);
*point = action->priv->focal_point;
}
/**
* clutter_zoom_action_get_transformed_focal_point:
* @action: a #ClutterZoomAction
* @point: (out): a #ClutterPoint
*
* Retrieves the focal point relative to the actor's coordinates of
* the current zoom
*
* Since: 1.12
*/
void
clutter_zoom_action_get_transformed_focal_point (ClutterZoomAction *action,
ClutterPoint *point)
{
g_return_if_fail (CLUTTER_IS_ZOOM_ACTION (action));
g_return_if_fail (point != NULL);
*point = action->priv->transformed_focal_point;
}
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