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mutter-performance-source/clutter/clutter-rotate-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-rotate-action
* @Title: ClutterRotateAction
* @Short_Description: Action to rotate an actor
*
* #ClutterRotateAction is a sub-class of #ClutterGestureAction that implements
* the logic for recognizing rotate gestures using two touch points.
*
* Since: 1.12
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include "clutter-rotate-action.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
struct _ClutterRotateActionPrivate
{
gfloat initial_vector[2];
gdouble initial_vector_norm;
gdouble initial_rotation;
};
enum
{
ROTATE,
LAST_SIGNAL
};
static guint rotate_signals[LAST_SIGNAL] = { 0, };
G_DEFINE_TYPE (ClutterRotateAction, clutter_rotate_action,
CLUTTER_TYPE_GESTURE_ACTION);
static gboolean
clutter_rotate_action_real_rotate (ClutterRotateAction *action,
ClutterActor *actor,
gdouble angle)
{
clutter_actor_set_rotation_angle (actor,
CLUTTER_Z_AXIS,
action->priv->initial_rotation + angle);
return TRUE;
}
static gboolean
clutter_rotate_action_gesture_begin (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterRotateActionPrivate *priv = CLUTTER_ROTATE_ACTION (action)->priv;
gfloat p1[2], p2[2];
/* capture initial vector */
clutter_gesture_action_get_motion_coords (action, 0, &p1[0], &p1[1]);
clutter_gesture_action_get_motion_coords (action, 1, &p2[0], &p2[1]);
priv->initial_vector[0] = p2[0] - p1[0];
priv->initial_vector[1] = p2[1] - p1[1];
priv->initial_vector_norm =
sqrt (priv->initial_vector[0] * priv->initial_vector[0] +
priv->initial_vector[1] * priv->initial_vector[1]);
priv->initial_rotation = clutter_actor_get_rotation_angle (actor, CLUTTER_Z_AXIS);
return TRUE;
}
static gboolean
clutter_rotate_action_gesture_progress (ClutterGestureAction *action,
ClutterActor *actor)
{
ClutterRotateActionPrivate *priv = CLUTTER_ROTATE_ACTION (action)->priv;
gfloat p1[2], p2[2];
gfloat vector[2];
gboolean retval;
/* capture current vector */
clutter_gesture_action_get_motion_coords (action, 0, &p1[0], &p1[1]);
clutter_gesture_action_get_motion_coords (action, 1, &p2[0], &p2[1]);
vector[0] = p2[0] - p1[0];
vector[1] = p2[1] - p1[1];
if ((vector[0] == priv->initial_vector[0]) &&
(vector[1] == priv->initial_vector[1]))
{
g_signal_emit (action, rotate_signals[ROTATE], 0,
actor, (gdouble) 0.0,
&retval);
}
else
{
gfloat mult[2];
gfloat norm;
gdouble angle;
/* Computes angle between the 2 initial touch points and the
current position of the 2 touch points. */
norm = sqrt (vector[0] * vector[0] + vector[1] * vector[1]);
norm = (priv->initial_vector[0] * vector[0] +
priv->initial_vector[1] * vector[1]) / (priv->initial_vector_norm * norm);
if ((norm >= -1.0) && (norm <= 1.0))
angle = acos (norm);
else
angle = 0;
/* The angle given is comprise between 0 and 180 degrees, we
need some logic on top to get a value between 0 and 360. */
mult[0] = priv->initial_vector[0] * vector[1] -
priv->initial_vector[1] * vector[0];
mult[1] = priv->initial_vector[1] * vector[0] -
priv->initial_vector[0] * vector[1];
if (mult[0] < 0)
angle = -angle;
/* Convert radians to degrees */
angle = angle * 180.0 / G_PI;
g_signal_emit (action, rotate_signals[ROTATE], 0,
actor, angle,
&retval);
}
return TRUE;
}
static void
clutter_rotate_action_gesture_cancel (ClutterGestureAction *action,
ClutterActor *actor)
{
gboolean retval;
g_signal_emit (action, rotate_signals[ROTATE], 0,
actor, (gdouble) 0.0,
&retval);
}
static void
clutter_rotate_action_class_init (ClutterRotateActionClass *klass)
{
ClutterGestureActionClass *gesture_class =
CLUTTER_GESTURE_ACTION_CLASS (klass);
g_type_class_add_private (klass, sizeof (ClutterRotateActionPrivate));
klass->rotate = clutter_rotate_action_real_rotate;
gesture_class->gesture_begin = clutter_rotate_action_gesture_begin;
gesture_class->gesture_progress = clutter_rotate_action_gesture_progress;
gesture_class->gesture_cancel = clutter_rotate_action_gesture_cancel;
/**
* ClutterRotateAction::rotate:
* @action: the #ClutterRotateAction that emitted the signal
* @actor: the #ClutterActor attached to the @action
* @angle: the difference of angle of rotation between the initial
* rotation and the current rotation
*
* The ::rotate signal is emitted when a rotate gesture is
* recognized on the attached actor and when the gesture is
* cancelled (in this case with an angle value of 0).
*
* Return value: %TRUE if the rotation should continue, and %FALSE if
* the rotation should be cancelled.
*
* Since: 1.12
*/
rotate_signals[ROTATE] =
g_signal_new (I_("rotate"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterRotateActionClass, rotate),
_clutter_boolean_continue_accumulator, NULL,
_clutter_marshal_BOOLEAN__OBJECT_DOUBLE,
G_TYPE_BOOLEAN, 2,
CLUTTER_TYPE_ACTOR,
G_TYPE_DOUBLE);
}
static void
clutter_rotate_action_init (ClutterRotateAction *self)
{
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self, CLUTTER_TYPE_ROTATE_ACTION,
ClutterRotateActionPrivate);
clutter_gesture_action_set_n_touch_points (CLUTTER_GESTURE_ACTION (self), 2);
}
/**
* clutter_rotate_action_new:
*
* Creates a new #ClutterRotateAction instance
*
* Return value: the newly created #ClutterRotateAction
*
* Since: 1.12
*/
ClutterAction *
clutter_rotate_action_new (void)
{
return g_object_new (CLUTTER_TYPE_ROTATE_ACTION, NULL);
}