mutter/clutter/clutter-behaviour-ellipse.c

/* -*- mode:C; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Clutter.
 *
 * An OpenGL based 'interactive canvas' library.
 *
 * Authored By Tomas Frydrych  <tf@openedhand.com>
 *
 * Copyright (C) 2007 OpenedHand
 *
 * 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, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:clutter-behaviour-ellipse
 * @short_description: elliptic path behaviour.
 *
 * #ClutterBehaviourEllipse interpolates actors along a path defined by
 *  an ellipse.
 *
 * Since: 0.4
 */

#include "clutter-fixed.h"
#include "clutter-marshal.h"
#include "clutter-behaviour-ellipse.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-private.h"

#include <stdlib.h>
#include <memory.h>

/****************************************************************************
 *                                                                          *
 * ClutterBehaviourEllipse                                                  *
 *                                                                          *
 ****************************************************************************/

G_DEFINE_TYPE (ClutterBehaviourEllipse, 
               clutter_behaviour_ellipse,
	       CLUTTER_TYPE_BEHAVIOUR);

#define CLUTTER_BEHAVIOUR_ELLIPSE_GET_PRIVATE(obj)    \
              (G_TYPE_INSTANCE_GET_PRIVATE ((obj),    \
               CLUTTER_TYPE_BEHAVIOUR_ELLIPSE,        \
               ClutterBehaviourEllipsePrivate))

enum
{
  PROP_0,

  PROP_CENTER,
  PROP_WIDTH,
  PROP_HEIGHT,
  PROP_ANGLE_BEGIN,
  PROP_ANGLE_END,
  PROP_ANGLE_TILT,
};

struct _ClutterBehaviourEllipsePrivate
{
  ClutterKnot  center;
  
  gint         a;
  gint         b;
  
  ClutterAngle angle_begin;
  ClutterAngle angle_end;
  ClutterAngle angle_tilt;
};

static void
clutter_behaviour_ellipse_advance (ClutterBehaviourEllipse *e,
                                   ClutterAngle             angle,
                                   ClutterKnot             *knot)
{
  ClutterBehaviourEllipsePrivate *priv = e->priv;
  gint x, y;
  
  x = CLUTTER_FIXED_INT (priv->a * clutter_cosi (angle));
  y = CLUTTER_FIXED_INT (priv->b * clutter_sini (angle));

  if (e->priv->angle_tilt)
    {
      /*
       * x2 = r * cos (angle + tilt)
       * y2 = r * sin (angle + tilt)
       *
       * These can be trasformed to the formulas below using properties of
       * sin (a + b) and cos (a + b)
       *
       */
      ClutterFixed x2, y2;

      x2 = x * clutter_cosi (priv->angle_tilt)
           - y * clutter_sini (priv->angle_tilt);

      y2 = y * clutter_cosi (priv->angle_tilt)
           + x * clutter_sini (priv->angle_tilt);
      
      knot->x = CLUTTER_FIXED_INT (x2);
      knot->y = CLUTTER_FIXED_INT (y2);
    }
  else
    {
      knot->x = x;
      knot->y = y;
    }
  
  CLUTTER_NOTE (BEHAVIOUR, "advancing to angle %d [%d, %d] (a: %d, b: %d)", 
                angle,
                knot->x, knot->y,
                priv->a, priv->b);
}


static void
actor_apply_knot_foreach (ClutterBehaviour *behave,
                          ClutterActor     *actor,
                          gpointer          data)
{
  ClutterKnot *knot = data;

  clutter_actor_set_position (actor, knot->x, knot->y);
}

static void
clutter_behaviour_ellipse_alpha_notify (ClutterBehaviour *behave,
                                        guint32           alpha)
{
  ClutterBehaviourEllipse *self = CLUTTER_BEHAVIOUR_ELLIPSE (behave);
  ClutterBehaviourEllipsePrivate *priv = self->priv;
  ClutterKnot knot;
  ClutterAngle angle;

  if (priv->angle_end >= priv->angle_begin)
    {
      angle = (priv->angle_end - priv->angle_begin)
              * alpha
              / CLUTTER_ALPHA_MAX_ALPHA
              + priv->angle_begin;
    }
  else
    {
      angle = priv->angle_begin
              - ((priv->angle_begin - priv->angle_end) * alpha)
              / CLUTTER_ALPHA_MAX_ALPHA;
    }

  clutter_behaviour_ellipse_advance (self, angle, &knot);

  knot.x += priv->center.x;
  knot.y += priv->center.y;
  
  clutter_behaviour_actors_foreach (behave, actor_apply_knot_foreach, &knot);
}

static void
clutter_behaviour_ellipse_set_property (GObject      *gobject,
                                        guint         prop_id,
                                        const GValue *value,
                                        GParamSpec   *pspec)
{
  ClutterBehaviourEllipse *el = CLUTTER_BEHAVIOUR_ELLIPSE (gobject);
  ClutterBehaviourEllipsePrivate *priv = el->priv;

  switch (prop_id)
    {
    case PROP_ANGLE_BEGIN:
      priv->angle_begin = CLUTTER_ANGLE_FROM_DEG (g_value_get_double (value));
      break;
    case PROP_ANGLE_END:
      priv->angle_end = CLUTTER_ANGLE_FROM_DEG (g_value_get_double (value));
      break;
    case PROP_ANGLE_TILT:
      priv->angle_tilt = CLUTTER_ANGLE_FROM_DEG (g_value_get_double (value));
      break;
    case PROP_WIDTH:
      priv->a = g_value_get_int (value) >> 1;
      break;
    case PROP_HEIGHT:
      priv->b = g_value_get_int (value) >> 1;
      break;
    case PROP_CENTER:
      {
        ClutterKnot *knot = g_value_get_boxed (value);
        if (knot)
          clutter_behaviour_ellipse_set_center (el, knot->x, knot->y);
      }
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
      break;
    }
}

static void
clutter_behaviour_ellipse_get_property (GObject    *gobject,
                                        guint       prop_id,
                                        GValue     *value,
                                        GParamSpec *pspec)
{
  ClutterBehaviourEllipsePrivate *priv;

  priv = CLUTTER_BEHAVIOUR_ELLIPSE (gobject)->priv;

  switch (prop_id)
    {
    case PROP_ANGLE_BEGIN:
      g_value_set_double (value, CLUTTER_ANGLE_TO_DEG (priv->angle_begin));
      break;
    case PROP_ANGLE_END:
      g_value_set_double (value, CLUTTER_ANGLE_TO_DEG (priv->angle_end));
      break;
    case PROP_ANGLE_TILT:
      g_value_set_double (value, CLUTTER_ANGLE_TO_DEG (priv->angle_tilt));
      break;
    case PROP_WIDTH:
      g_value_set_int (value, (priv->a << 1));
      break;
    case PROP_HEIGHT:
      g_value_set_int (value, (priv->b << 1));
      break;
    case PROP_CENTER:
      g_value_set_boxed (value, &priv->center);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
      break;
    }
}

static void
clutter_behaviour_ellipse_applied (ClutterBehaviour *behave,
                                   ClutterActor     *actor)
{
  ClutterBehaviourEllipse *e = CLUTTER_BEHAVIOUR_ELLIPSE (behave);
  ClutterKnot knot;
  
  clutter_behaviour_ellipse_advance (e, e->priv->angle_begin, &knot);

  clutter_actor_set_position (actor, knot.x, knot.y);

#if 0
  /* no need to chain up: ClutterBehaviourEllipse's parent class does
   * not have a class closure for ::apply
   */
  if (CLUTTER_BEHAVIOUR_CLASS (clutter_behaviour_ellipse_parent_class)->apply)
    CLUTTER_BEHAVIOUR_CLASS (clutter_behaviour_ellipse_parent_class)->apply (behave, actor);
#endif
}

static void
clutter_behaviour_ellipse_class_init (ClutterBehaviourEllipseClass *klass)
{
  GObjectClass          *object_class = G_OBJECT_CLASS (klass);
  ClutterBehaviourClass *behave_class = CLUTTER_BEHAVIOUR_CLASS (klass);

  object_class->set_property = clutter_behaviour_ellipse_set_property;
  object_class->get_property = clutter_behaviour_ellipse_get_property;

  behave_class->alpha_notify = clutter_behaviour_ellipse_alpha_notify;
  behave_class->applied = clutter_behaviour_ellipse_applied;
  
  /**
   * ClutterBehaviourEllipse:angle-begin:
   *
   * The initial angle from where the rotation should begin.
   *
   * Since: 0.4
   */
  g_object_class_install_property (object_class,
                                   PROP_ANGLE_BEGIN,
                                   g_param_spec_double ("angle-begin",
                                                        "Angle Begin",
                                                        "Initial angle",
                                                        0.0, 360.0, 0.0,
                                                        CLUTTER_PARAM_READWRITE));
  /**
   * ClutterBehaviourEllipse:angle-end:
   *
   * The final angle to where the rotation should end.
   * 
   * Since: 0.4
   */
  g_object_class_install_property (object_class,
                                   PROP_ANGLE_END,
                                   g_param_spec_double ("angle-end",
                                                        "Angle End",
                                                        "Final angle",
                                                        0.0, 360.0, 360.0,
                                                        CLUTTER_PARAM_READWRITE));
  /**
   * ClutterBehaviourEllipse:angle-tilt:
   *
   * The tilt angle for the rotation
   * 
   * Since: 0.4
   */
  g_object_class_install_property (object_class,
                                   PROP_ANGLE_TILT,
                                   g_param_spec_double ("angle-tilt",
                                                        "Angle Tilt",
                                                        "Tilt of the ellipse",
                                                        0.0, 360.0, 360.0,
                                                        CLUTTER_PARAM_READWRITE));
  /**
   * ClutterBehaviourEllipse:width:
   *
   * Width of the ellipse.
   * 
   * Since: 0.4
   */
  g_object_class_install_property (object_class,
                                   PROP_WIDTH,
                                   g_param_spec_int ("width",
                                                     "Width",
                                                     "Width of ellipse",
                                                     0, G_MAXINT, 100,
                                                     CLUTTER_PARAM_READWRITE));
  /**
   * ClutterBehaviourEllipse:height:
   *
   * Height of the ellipse.
   * 
   * Since: 0.4
   */
  g_object_class_install_property (object_class,
                                   PROP_HEIGHT,
                                   g_param_spec_int ("height",
                                                     "Height",
                                                     "Height of ellipse",
                                                     0, G_MAXINT, 50,
                                                     CLUTTER_PARAM_READWRITE));
  /**
   * ClutterBehaviourEllipse:center:
   *
   * The center of the ellipse.
   *
   * Since: 0.4
   */
  g_object_class_install_property (object_class,
                                   PROP_CENTER,
                                   g_param_spec_boxed ("center",
                                                       "Center",
                                                       "Center of ellipse",
                                                       CLUTTER_TYPE_KNOT,
                                                       CLUTTER_PARAM_READWRITE));
  
  g_type_class_add_private (klass, sizeof (ClutterBehaviourEllipsePrivate));
}

static void
clutter_behaviour_ellipse_init (ClutterBehaviourEllipse * self)
{
  ClutterBehaviourEllipsePrivate *priv;

  self->priv = priv = CLUTTER_BEHAVIOUR_ELLIPSE_GET_PRIVATE (self);
}

/**
 * clutter_behaviour_ellipse_new:
 * @alpha: a #ClutterAlpha, or %NULL
 * @x: x coordinace of the center
 * @y: y coordiance of the center
 * @width: width of the ellipse
 * @height: height of the ellipse
 * @begin: angle in degrees at which movement begins
 * @end: angle in degrees at which movement ends
 * @tilt: angle in degrees with which the ellipse should be tilted around its
 * center
 *
 * Creates a behaviour that drives actors along an elliptical path with
 * given center, width and height; the movement begins at angle_begin (with 0
 * corresponding to 12 o'clock) and ends at angle_end; if angle_end > angle_begin,
 * the movement is in clockwise direction, counter-clockwise otherwise.
 *
 * Return value: a #ClutterBehaviour
 *
 * Since: 0.4
 */
ClutterBehaviour *
clutter_behaviour_ellipse_new (ClutterAlpha          *alpha,
                               gint                   x,
                               gint                   y,
                               gint                   width,
                               gint                   height,
                               gdouble                begin,
                               gdouble                end,
                               gdouble                tilt)
{
  ClutterKnot center;

  g_return_val_if_fail (alpha == NULL || CLUTTER_IS_ALPHA (alpha), NULL);

  center.x = x;
  center.y = y;
  
  return g_object_new (CLUTTER_TYPE_BEHAVIOUR_ELLIPSE, 
                       "alpha", alpha,
                       "center", &center,
                       "width", width,
                       "height", height,
                       "angle-begin", begin,
                       "angle-end", end,
                       "angle-tilt", tilt,
                       NULL);
}

/**
 * clutter_behaviour_ellipse_newx:
 * @alpha: a #ClutterAlpha, or %NULL
 * @x: x coordinace of the center
 * @y: y coordiance of the center
 * @width: width of the ellipse
 * @height: height of the ellipse
 * @begin: #ClutterFixed angle in degrees at which movement begins
 * @end: #ClutterFixed angle in degrees at which movement ends
 * @tilt: #ClutterFixed angle in degrees with which the ellipse should be
 * tilted around its center
 *
 * Creates a behaviour that drives actors along an elliptical path with
 * given center, width and height; the movement begins at angle_begin (with 0
 * corresponding to 12 o'clock) and ends at angle_end; if angle_end > angle_begin,
 * the movement is in clockwise direction, counter-clockwise otherwise.
 *
 * Return value: a #ClutterBehaviour
 *
 * Since: 0.4
 */
ClutterBehaviour *
clutter_behaviour_ellipse_newx (ClutterAlpha          * alpha,
                                gint                    x,
                                gint                    y,
                                gint                    width,
                                gint                    height,
                                ClutterFixed            begin,
                                ClutterFixed            end,
                                ClutterFixed            tilt)
{
  ClutterKnot center;

  g_return_val_if_fail (alpha == NULL || CLUTTER_IS_ALPHA (alpha), NULL);

  center.x = x;
  center.y = y;
  
  return g_object_new (CLUTTER_TYPE_BEHAVIOUR_ELLIPSE, 
                       "alpha", alpha,
                       "center", &center,
                       "width", width,
                       "height", height,
                       "angle-begin", CLUTTER_ANGLE_FROM_DEGX (begin),
                       "angle-end", CLUTTER_ANGLE_FROM_DEGX (end),
                       "angle-tilt", CLUTTER_ANGLE_FROM_DEGX (tilt),
                       NULL);
}


/**
 * clutter_behaviour_ellipse_set_center
 * @self: a #ClutterBehaviourEllipse
 * @x: x coordinace of centre
 * @y: y coordinace of centre
 *
 * Sets the center of the elliptical path to the point represented by knot.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_center (ClutterBehaviourEllipse *self,
                                      gint                     x,
                                      gint                     y)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;

  if (priv->center.x != x || priv->center.y != y)
    {
      priv->center.x = x;
      priv->center.y = y;
      
      g_object_notify (G_OBJECT (self), "center");
    }
}

/**
 * clutter_behaviour_ellipse_get_center
 * @self: a #ClutterBehaviourEllipse
 * @x: location to store the x coordinace of the center, or NULL
 * @y: location to store the y coordinace of the center, or NULL
 *
 * Gets the center of the elliptical path path.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_get_center (ClutterBehaviourEllipse  *self,
                                      gint                     *x,
                                      gint                     *y)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;

  if (x)
    *x = priv->center.x;

  if (y)
    *y = priv->center.y;
}


/**
 * clutter_behaviour_ellipse_set_width
 * @self: a #ClutterBehaviourEllipse
 * @width: width of the ellipse
 *
 * Sets the width of the elliptical path.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_width (ClutterBehaviourEllipse * self,
                                     gint                      width)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;

  if (priv->a != width >> 1)
    {
      priv->a = width >> 1;
      
      g_object_notify (G_OBJECT (self), "width");
    }
}

/**
 * clutter_behaviour_ellipse_get_width
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the width of the elliptical path.
 *
 * Return value: the width of the path
 * 
 * Since: 0.4
 */
gint
clutter_behaviour_ellipse_get_width (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0);

  return self->priv->a << 1;
}

/**
 * clutter_behaviour_ellipse_set_height
 * @self: a #ClutterBehaviourEllipse
 * @height: height of the ellipse
 *
 * Sets the height of the elliptical path.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_height (ClutterBehaviourEllipse *self,
                                      gint                     height)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;

  if (priv->b != height >> 1)
    {
      priv->b = height >> 1;
      
      g_object_notify (G_OBJECT (self), "height");
    }
}

/**
 * clutter_behaviour_ellipse_get_height
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the height of the elliptical path.
 *
 * Return value: the height of the path
 * 
 * Since: 0.4
 */
gint
clutter_behaviour_ellipse_get_height (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0);

  return self->priv->b << 1;
}

/**
 * clutter_behaviour_ellipse_set_angle_begin
 * @self: a #ClutterBehaviourEllipse
 * @angle_begin: angle at which movement begins in degrees
 *
 * Sets the angle at which movement begins.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_angle_begin (ClutterBehaviourEllipse *self,
                                           gdouble                  angle_begin)
{
  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  clutter_behaviour_ellipse_set_angle_beginx (self,
                                              CLUTTER_ANGLE_FROM_DEG (angle_begin));
}

/**
 * clutter_behaviour_ellipse_set_angle_beginx
 * @self: a #ClutterBehaviourEllipse
 * @angle_begin: #ClutterAngle at which movement begins
 *
 * Sets the angle at which movement begins.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_angle_beginx (ClutterBehaviourEllipse *self,
                                            ClutterAngle             angle_begin)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;
  if (priv->angle_begin != angle_begin)
    {
      priv->angle_begin = angle_begin;
      g_object_notify (G_OBJECT (self), "angle-begin");
    }
}

/**
 * clutter_behaviour_ellipse_get_angle_begin
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the angle at which movements begins.
 *
 * Return value: angle in degrees
 * 
 * Since: 0.4
 */
gdouble
clutter_behaviour_ellipse_get_angle_begin (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0.0);

  return CLUTTER_ANGLE_TO_DEG (self->priv->angle_begin);
}

/**
 * clutter_behaviour_ellipse_get_angle_beginx
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the angle at which movements begins.
 *
 * Return value: a #ClutterAngle
 * 
 * Since: 0.4
 */
ClutterAngle
clutter_behaviour_ellipse_get_angle_beginx (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0);

  return self->priv->angle_begin;
}

/**
 * clutter_behaviour_ellipse_set_angle_end
 * @self: a #ClutterBehaviourEllipse
 * @angle_end: angle at which movement ends in degrees.
 *
 * Sets the angle at which movement ends.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_angle_end (ClutterBehaviourEllipse *self,
                                         gdouble                  angle_end)
{
  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  clutter_behaviour_ellipse_set_angle_endx (self,
                                            CLUTTER_ANGLE_FROM_DEG (angle_end));
}

/**
 * clutter_behaviour_ellipse_set_angle_endx
 * @self: a #ClutterBehaviourEllipse
 * @angle_end: #ClutterAngle at which movement ends
 *
 * Sets the angle at which movement ends.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_angle_endx (ClutterBehaviourEllipse *self,
                                          ClutterAngle             angle_end)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;

  if (priv->angle_end != angle_end)
    {
      priv->angle_end = angle_end;
      
      g_object_notify (G_OBJECT (self), "angle-end");
    }
}

/**
 * clutter_behaviour_ellipse_get_angle_end
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the at which movements ends.
 *
 * Return value: angle in degrees
 * 
 * Since: 0.4
 */
gdouble
clutter_behaviour_ellipse_get_angle_end (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0.0);

  return CLUTTER_ANGLE_TO_DEG (self->priv->angle_end);
}

/**
 * clutter_behaviour_ellipse_get_angle_endx
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the angle at which movements ends.
 *
 * Return value: a #ClutterAngle
 * 
 * Since: 0.4
 */
ClutterAngle
clutter_behaviour_ellipse_get_angle_endx (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0);

  return self->priv->angle_end;
}

/**
 * clutter_behaviour_ellipse_set_angle_tilt
 * @self: a #ClutterBehaviourEllipse
 * @angle_tilt: tilt of the elipse around the center in degrees.
 *
 * Sets the angle at which the ellipse should be tilted around it's center.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_angle_tilt (ClutterBehaviourEllipse *self,
                                          gdouble                  angle_tilt)
{
  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  clutter_behaviour_ellipse_set_angle_tiltx (self,
                                             CLUTTER_ANGLE_FROM_DEG (angle_tilt));
}

/**
 * clutter_behaviour_ellipse_set_angle_tiltx
 * @self: a #ClutterBehaviourEllipse
 * @angle_tilt: #ClutterAngle tilt of the elipse around the center
 *
 * Sets the angle at which the ellipse should be tilted around it's center.
 * 
 * Since: 0.4
 */
void
clutter_behaviour_ellipse_set_angle_tiltx (ClutterBehaviourEllipse *self,
                                           ClutterAngle             angle_tilt)
{
  ClutterBehaviourEllipsePrivate *priv;

  g_return_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self));

  priv = self->priv;

  if (priv->angle_tilt != angle_tilt)
    {
      priv->angle_tilt = angle_tilt;
      
      g_object_notify (G_OBJECT (self), "angle-tilt");
    }
}

/**
 * clutter_behaviour_ellipse_get_angle_tilt
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the tilt of the ellipse around the center.
 *
 * Return value: angle in degrees.
 * 
 * Since: 0.4
 */
gdouble
clutter_behaviour_ellipse_get_angle_tilt (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0.0);

  return CLUTTER_ANGLE_TO_DEG (self->priv->angle_tilt);
}

/**
 * clutter_behaviour_ellipse_get_angle_tiltx
 * @self: a #ClutterBehaviourEllipse
 *
 * Gets the tilt of the ellipse around the center.
 *
 * Return value: a #ClutterAngle
 * 
 * Since: 0.4
 */
ClutterAngle
clutter_behaviour_ellipse_get_angle_tiltx (ClutterBehaviourEllipse *self)
{
  g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR_ELLIPSE (self), 0);

  return self->priv->angle_tilt;
}