mutter/clutter/clutter-behaviour-opacity.c
Emmanuele Bassi 237496fa75 2006-11-17 Emmanuele Bassi <ebassi@openedhand.com>
* clutter/clutter-behaviour-path.h:
	* clutter/clutter-behaviour-path.c: Add a "knot-reached" signal,
	which is emitted when the path reaches a node in the nodes list;
	flesh out the documentation a bit; sync the parameters names
	so that gtk-doc doesn't complain about missing stuff.

	* clutter/clutter-behaviour.h:
	* clutter/clutter-behaviour.c: Add the alpha value to the
	ClutterBehaviour::alpha_notify vfunc, so you don't have to
	get the value from the alpha inside the behaviour implementations;
	add more documentation.

	* clutter/clutter-alpha.c: Flesh out the description.

	* clutter/clutter-actor.h: Update the header.

	* clutter/clutter-behaviour-opacity.c:
	* clutter/clutter-behaviour-scale.c: Update docs.
2006-11-17 18:45:31 +00:00

156 lines
4.4 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006 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-opacity
* @short_description: A behaviour class interpolating actors opacity between
* two values.
*
* #ClutterBehaviourPath interpolates actors opacity between two values.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-actor.h"
#include "clutter-behaviour.h"
#include "clutter-behaviour-opacity.h"
#include "clutter-enum-types.h"
#include "clutter-main.h"
#include <math.h>
/**
* SECTION:clutter-behaviour-opacity
* @short_description: Behaviour controlling the opacity
*
* #ClutterBehaviourOpacity controls the opacity of a set of actors.
*/
G_DEFINE_TYPE (ClutterBehaviourOpacity,
clutter_behaviour_opacity,
CLUTTER_TYPE_BEHAVIOUR);
struct _ClutterBehaviourOpacityPrivate
{
guint8 opacity_start;
guint8 opacity_end;
};
#define CLUTTER_BEHAVIOUR_OPACITY_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
CLUTTER_TYPE_BEHAVIOUR_OPACITY, \
ClutterBehaviourOpacityPrivate))
static void
opacity_frame_foreach (ClutterActor *actor,
ClutterBehaviourOpacity *behave)
{
guint32 alpha;
guint8 opacity;
ClutterBehaviourOpacityPrivate *priv;
ClutterBehaviour *_behave;
priv = CLUTTER_BEHAVIOUR_OPACITY_GET_PRIVATE (behave);
_behave = CLUTTER_BEHAVIOUR (behave);
alpha = clutter_alpha_get_alpha (clutter_behaviour_get_alpha (_behave));
opacity = (alpha * (priv->opacity_end - priv->opacity_start))
/ CLUTTER_ALPHA_MAX_ALPHA;
opacity += priv->opacity_start;
CLUTTER_DBG ("alpha %i opacity %i\n", alpha, opacity);
clutter_actor_set_opacity (actor, opacity);
}
static void
clutter_behaviour_alpha_notify (ClutterBehaviour *behave,
guint32 alpha_value)
{
clutter_behaviour_actors_foreach (behave,
(GFunc) opacity_frame_foreach,
CLUTTER_BEHAVIOUR_OPACITY (behave));
}
static void
clutter_behaviour_opacity_finalize (GObject *object)
{
G_OBJECT_CLASS (clutter_behaviour_opacity_parent_class)->finalize (object);
}
static void
clutter_behaviour_opacity_class_init (ClutterBehaviourOpacityClass *klass)
{
ClutterBehaviourClass *behave_class;
behave_class = (ClutterBehaviourClass*) klass;
behave_class->alpha_notify = clutter_behaviour_alpha_notify;
g_type_class_add_private (klass, sizeof (ClutterBehaviourOpacityPrivate));
}
static void
clutter_behaviour_opacity_init (ClutterBehaviourOpacity *self)
{
self->priv = CLUTTER_BEHAVIOUR_OPACITY_GET_PRIVATE (self);
}
/**
* clutter_behaviour_opacity_new:
* @alpha: a #ClutterAlpha instance, or %NULL
* @opacity_start: minimum level of opacity
* @opacity_end: maximum level of opacity
*
* Creates a new #ClutterBehaviourOpacity object, driven by @alpha
* which controls the opacity property of every actor, making it
* change in the interval between @opacity_start and @opacity_end.
*
* Return value: the newly created #ClutterBehaviourOpacity
*/
ClutterBehaviour *
clutter_behaviour_opacity_new (ClutterAlpha *alpha,
guint8 opacity_start,
guint8 opacity_end)
{
ClutterBehaviourOpacity *behave;
behave = g_object_new (CLUTTER_TYPE_BEHAVIOUR_OPACITY,
"alpha", alpha,
NULL);
behave->priv->opacity_start = opacity_start;
behave->priv->opacity_end = opacity_end;
return CLUTTER_BEHAVIOUR (behave);
}