mutter/clutter/clutter-behaviour-depth.c
Emmanuele Bassi 7d7372af43 [animation] Move the alpha value to floating point
The current Alpha value is an unsigned integer that can be used
implicitly as a fixed point value. This makes writing an alpha
function overshooting below and above the current range basically
impossible without complicating an already complex code, and
creating weird corner cases.

For this reason, the Alpha value should be defined as a floating
point normalized value, spanning a range between 0.0 and 1.0; in
order to allow overshooting, the valid range is extended one unit
below and one unit above, thus making it -1.0 .. 2.0.

This commit updates the various users of the ClutterAlpha API
and the tests cases.

This commit also removes all the current alpha functions exposed
in the public API.
2009-01-20 16:42:49 +00:00

290 lines
8.6 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
* Jorn Baayen <jorn@openedhand.com>
* Emmanuele Bassi <ebassi@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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-behaviour-depth.h"
#include "clutter-enum-types.h"
#include "clutter-main.h"
#include "clutter-debug.h"
#include "clutter-private.h"
/**
* SECTION:clutter-behaviour-depth
* @short_description: A behaviour controlling the Z position
*
* #ClutterBehaviourDepth is a simple #ClutterBehaviour controlling the
* depth of a set of actors between a start and end depth.
*
* #ClutterBehaviourDepth is available since Clutter 0.4.
*/
G_DEFINE_TYPE (ClutterBehaviourDepth,
clutter_behaviour_depth,
CLUTTER_TYPE_BEHAVIOUR);
struct _ClutterBehaviourDepthPrivate
{
gint depth_start;
gint depth_end;
};
enum
{
PROP_0,
PROP_DEPTH_START,
PROP_DEPTH_END
};
static void
alpha_notify_foreach (ClutterBehaviour *behaviour,
ClutterActor *actor,
gpointer user_data)
{
clutter_actor_set_depth (actor, GPOINTER_TO_INT (user_data));
}
static void
clutter_behaviour_depth_alpha_notify (ClutterBehaviour *behaviour,
gdouble alpha_value)
{
ClutterFixed factor;
ClutterBehaviourDepthPrivate *priv;
gint depth;
priv = CLUTTER_BEHAVIOUR_DEPTH (behaviour)->priv;
/* Need to create factor as to avoid borking signedness */
factor = COGL_FIXED_FROM_FLOAT (alpha_value);
depth = priv->depth_start
+ COGL_FIXED_TO_INT (factor * (priv->depth_end - priv->depth_start));
CLUTTER_NOTE (BEHAVIOUR, "alpha: %.4f, depth: %d", alpha_value, depth);
clutter_behaviour_actors_foreach (behaviour,
alpha_notify_foreach,
GINT_TO_POINTER (depth));
}
static void
clutter_behaviour_depth_applied (ClutterBehaviour *behaviour,
ClutterActor *actor)
{
ClutterBehaviourDepth *depth = CLUTTER_BEHAVIOUR_DEPTH (behaviour);
clutter_actor_set_depth (actor, depth->priv->depth_start);
}
static void
clutter_behaviour_depth_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterBehaviourDepth *depth = CLUTTER_BEHAVIOUR_DEPTH (gobject);
switch (prop_id)
{
case PROP_DEPTH_START:
depth->priv->depth_start = g_value_get_int (value);
break;
case PROP_DEPTH_END:
depth->priv->depth_end = g_value_get_int (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_behaviour_depth_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterBehaviourDepth *depth = CLUTTER_BEHAVIOUR_DEPTH (gobject);
switch (prop_id)
{
case PROP_DEPTH_START:
g_value_set_int (value, depth->priv->depth_start);
break;
case PROP_DEPTH_END:
g_value_set_int (value, depth->priv->depth_end);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_behaviour_depth_class_init (ClutterBehaviourDepthClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterBehaviourClass *behaviour_class = CLUTTER_BEHAVIOUR_CLASS (klass);
g_type_class_add_private (klass, sizeof (ClutterBehaviourDepthPrivate));
gobject_class->set_property = clutter_behaviour_depth_set_property;
gobject_class->get_property = clutter_behaviour_depth_get_property;
behaviour_class->alpha_notify = clutter_behaviour_depth_alpha_notify;
behaviour_class->applied = clutter_behaviour_depth_applied;
/**
* ClutterBehaviourDepth:depth-start:
*
* Start depth level to apply to the actors.
*
* Since: 0.4
*/
g_object_class_install_property (gobject_class,
PROP_DEPTH_START,
g_param_spec_int ("depth-start",
"Start Depth",
"Initial depth to apply",
G_MININT, G_MAXINT, 0,
CLUTTER_PARAM_READWRITE));
/**
* ClutterBehaviourDepth:depth-end:
*
* End depth level to apply to the actors.
*
* Since: 0.4
*/
g_object_class_install_property (gobject_class,
PROP_DEPTH_END,
g_param_spec_int ("depth-end",
"End Depth",
"Final depth to apply",
G_MININT, G_MAXINT, 0,
CLUTTER_PARAM_READWRITE));
}
static void
clutter_behaviour_depth_init (ClutterBehaviourDepth *depth)
{
depth->priv = G_TYPE_INSTANCE_GET_PRIVATE (depth,
CLUTTER_TYPE_BEHAVIOUR_DEPTH,
ClutterBehaviourDepthPrivate);
}
/**
* clutter_behaviour_depth_new:
* @alpha: a #ClutterAlpha or %NULL
* @depth_start: initial value of the depth
* @depth_end: final value of the depth
*
* Creates a new #ClutterBehaviourDepth which can be used to control
* the ClutterActor:depth property of a set of #ClutterActor<!-- -->s.
*
* Return value: the newly created behaviour
*
* Since: 0.4
*/
ClutterBehaviour *
clutter_behaviour_depth_new (ClutterAlpha *alpha,
gint depth_start,
gint depth_end)
{
g_return_val_if_fail (alpha == NULL || CLUTTER_IS_ALPHA (alpha), NULL);
return g_object_new (CLUTTER_TYPE_BEHAVIOUR_DEPTH,
"alpha", alpha,
"depth-start", depth_start,
"depth-end", depth_end,
NULL);
}
/**
* clutter_behaviour_depth_set_bounds:
* @behaviour: a #ClutterBehaviourDepth
* @depth_start: initial value of the depth
* @depth_end: final value of the depth
*
* Sets the boundaries of the @behaviour.
*
* Since: 0.6
*/
void
clutter_behaviour_depth_set_bounds (ClutterBehaviourDepth *behaviour,
gint depth_start,
gint depth_end)
{
ClutterBehaviourDepthPrivate *priv;
g_return_if_fail (CLUTTER_IS_BEHAVIOUR_DEPTH (behaviour));
priv = behaviour->priv;
g_object_freeze_notify (G_OBJECT (behaviour));
if (priv->depth_start != depth_start)
{
priv->depth_start = depth_start;
g_object_notify (G_OBJECT (behaviour), "depth-start");
}
if (priv->depth_end != depth_end)
{
priv->depth_end = depth_end;
g_object_notify (G_OBJECT (behaviour), "depth-end");
}
g_object_thaw_notify (G_OBJECT (behaviour));
}
/**
* clutter_behaviour_depth_get_bounds:
* @behaviour: a #ClutterBehaviourDepth
* @depth_start: return location for the initial depth value, or %NULL
* @depth_end: return location for the final depth value, or %NULL
*
* Gets the boundaries of the @behaviour
*
* Since: 0.6
*/
void
clutter_behaviour_depth_get_bounds (ClutterBehaviourDepth *behaviour,
gint *depth_start,
gint *depth_end)
{
g_return_if_fail (CLUTTER_IS_BEHAVIOUR_DEPTH (behaviour));
if (depth_start)
*depth_start = behaviour->priv->depth_start;
if (depth_end)
*depth_end = behaviour->priv->depth_end;
}