73adac987d
* clutter/clutter-alpha.c: (clutter_alpha_get_alpha): Do not return the cached value but just compute the current alpha value. The use case is pretty much straightforward: stop a timeline, advance it, and retrieve the alpha value before starting the timeline to adjust an animation dependent on the alpha. Caching the alpha value is not needed because the behaviours will always pass the alpha value inside the ::alpha-notify virtual function anyway, so there is no need for them to call clutter_alpha_get_alpha(). This change makes it also possible to reliably unit-test ClutterAlpha. (timeline_new_frame_cb): Call clutter_alpha_get_alpha().
1025 lines
24 KiB
C
1025 lines
24 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>
|
|
* Tomas Frydrych <tf@openedhand.com>
|
|
*
|
|
* Copyright (C) 2006, 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-alpha
|
|
* @short_description: A class for calculating an alpha value as a function
|
|
* of time.
|
|
*
|
|
* #ClutterAlpha is a class for calculating an integer value between
|
|
* 0 and %CLUTTER_ALPHA_MAX_ALPHA as a function of time. You should
|
|
* provide a #ClutterTimeline and bind it to the #ClutterAlpha object;
|
|
* you should also provide a function returning the alpha value depending
|
|
* on the position inside the timeline; this function will be executed
|
|
* each time a new frame in the #ClutterTimeline is reached. Since the
|
|
* alpha function is controlled by the timeline instance, you can pause
|
|
* or stop the #ClutterAlpha from calling the alpha function by controlling
|
|
* the #ClutterTimeline object.
|
|
*
|
|
* #ClutterAlpha is used to "drive" a #ClutterBehaviour instance.
|
|
*
|
|
* <figure id="alpha-functions">
|
|
* <title>Graphic representation of some alpha functions</title>
|
|
* <graphic fileref="alpha-func.png" format="PNG"/>
|
|
* </figure>
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#include <math.h>
|
|
|
|
#include "clutter-alpha.h"
|
|
#include "clutter-main.h"
|
|
#include "clutter-marshal.h"
|
|
#include "clutter-private.h"
|
|
#include "clutter-debug.h"
|
|
|
|
G_DEFINE_TYPE (ClutterAlpha, clutter_alpha, G_TYPE_INITIALLY_UNOWNED);
|
|
|
|
|
|
struct _ClutterAlphaPrivate
|
|
{
|
|
ClutterTimeline *timeline;
|
|
guint timeline_new_frame_id;
|
|
|
|
guint32 alpha;
|
|
|
|
GClosure *closure;
|
|
};
|
|
|
|
enum
|
|
{
|
|
PROP_0,
|
|
|
|
PROP_TIMELINE,
|
|
PROP_ALPHA
|
|
};
|
|
|
|
static void
|
|
timeline_new_frame_cb (ClutterTimeline *timeline,
|
|
guint current_frame_num,
|
|
ClutterAlpha *alpha)
|
|
{
|
|
ClutterAlphaPrivate *priv = alpha->priv;
|
|
|
|
/* Update alpha value and notify */
|
|
priv->alpha = clutter_alpha_get_alpha (alpha);
|
|
g_object_notify (G_OBJECT (alpha), "alpha");
|
|
}
|
|
|
|
static void
|
|
clutter_alpha_set_property (GObject *object,
|
|
guint prop_id,
|
|
const GValue *value,
|
|
GParamSpec *pspec)
|
|
{
|
|
ClutterAlpha *alpha;
|
|
ClutterAlphaPrivate *priv;
|
|
|
|
alpha = CLUTTER_ALPHA (object);
|
|
priv = alpha->priv;
|
|
|
|
switch (prop_id)
|
|
{
|
|
case PROP_TIMELINE:
|
|
clutter_alpha_set_timeline (alpha, g_value_get_object (value));
|
|
break;
|
|
default:
|
|
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void
|
|
clutter_alpha_get_property (GObject *object,
|
|
guint prop_id,
|
|
GValue *value,
|
|
GParamSpec *pspec)
|
|
{
|
|
ClutterAlpha *alpha;
|
|
ClutterAlphaPrivate *priv;
|
|
|
|
alpha = CLUTTER_ALPHA (object);
|
|
priv = alpha->priv;
|
|
|
|
switch (prop_id)
|
|
{
|
|
case PROP_TIMELINE:
|
|
g_value_set_object (value, priv->timeline);
|
|
break;
|
|
case PROP_ALPHA:
|
|
g_value_set_uint (value, priv->alpha);
|
|
break;
|
|
default:
|
|
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void
|
|
clutter_alpha_finalize (GObject *object)
|
|
{
|
|
ClutterAlphaPrivate *priv = CLUTTER_ALPHA (object)->priv;
|
|
|
|
if (priv->closure)
|
|
g_closure_unref (priv->closure);
|
|
|
|
G_OBJECT_CLASS (clutter_alpha_parent_class)->finalize (object);
|
|
}
|
|
|
|
static void
|
|
clutter_alpha_dispose (GObject *object)
|
|
{
|
|
ClutterAlpha *self = CLUTTER_ALPHA(object);
|
|
|
|
clutter_alpha_set_timeline (self, NULL);
|
|
|
|
G_OBJECT_CLASS (clutter_alpha_parent_class)->dispose (object);
|
|
}
|
|
|
|
|
|
static void
|
|
clutter_alpha_class_init (ClutterAlphaClass *klass)
|
|
{
|
|
GObjectClass *object_class = G_OBJECT_CLASS (klass);
|
|
|
|
object_class->set_property = clutter_alpha_set_property;
|
|
object_class->get_property = clutter_alpha_get_property;
|
|
object_class->finalize = clutter_alpha_finalize;
|
|
object_class->dispose = clutter_alpha_dispose;
|
|
|
|
g_type_class_add_private (klass, sizeof (ClutterAlphaPrivate));
|
|
|
|
/**
|
|
* ClutterAlpha:timeline:
|
|
*
|
|
* A #ClutterTimeline instance used to drive the alpha function.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
g_object_class_install_property (object_class,
|
|
PROP_TIMELINE,
|
|
g_param_spec_object ("timeline",
|
|
"Timeline",
|
|
"Timeline",
|
|
CLUTTER_TYPE_TIMELINE,
|
|
CLUTTER_PARAM_READWRITE));
|
|
/**
|
|
* ClutterAlpha:alpha:
|
|
*
|
|
* The alpha value as computed by the alpha function.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
g_object_class_install_property (object_class,
|
|
PROP_ALPHA,
|
|
g_param_spec_uint ("alpha",
|
|
"Alpha value",
|
|
"Alpha value",
|
|
0,
|
|
CLUTTER_ALPHA_MAX_ALPHA,
|
|
0,
|
|
CLUTTER_PARAM_READABLE));
|
|
}
|
|
|
|
static void
|
|
clutter_alpha_init (ClutterAlpha *self)
|
|
{
|
|
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
|
|
CLUTTER_TYPE_ALPHA,
|
|
ClutterAlphaPrivate);
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_get_alpha:
|
|
* @alpha: A #ClutterAlpha
|
|
*
|
|
* Query the current alpha value.
|
|
*
|
|
* Return Value: The current alpha value for the alpha
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
guint32
|
|
clutter_alpha_get_alpha (ClutterAlpha *alpha)
|
|
{
|
|
ClutterAlphaPrivate *priv;
|
|
guint32 retval = 0;
|
|
|
|
g_return_val_if_fail (CLUTTER_IS_ALPHA (alpha), 0);
|
|
|
|
priv = alpha->priv;
|
|
|
|
if (G_LIKELY (priv->closure))
|
|
{
|
|
GValue params = { 0, };
|
|
GValue result_value = { 0, };
|
|
|
|
g_object_ref (alpha);
|
|
|
|
g_value_init (&result_value, G_TYPE_UINT);
|
|
|
|
g_value_init (¶ms, CLUTTER_TYPE_ALPHA);
|
|
g_value_set_object (¶ms, alpha);
|
|
|
|
g_closure_invoke (priv->closure,
|
|
&result_value,
|
|
1,
|
|
¶ms,
|
|
NULL);
|
|
|
|
retval = g_value_get_uint (&result_value);
|
|
|
|
g_value_unset (&result_value);
|
|
g_value_unset (¶ms);
|
|
|
|
g_object_unref (alpha);
|
|
}
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_set_closure:
|
|
* @alpha: A #ClutterAlpha
|
|
* @closure: A #GClosure
|
|
*
|
|
* Sets the #GClosure used to compute
|
|
* the alpha value at each frame of the #ClutterTimeline
|
|
* bound to @alpha.
|
|
*
|
|
* Since: 0.8
|
|
*/
|
|
void
|
|
clutter_alpha_set_closure (ClutterAlpha *alpha,
|
|
GClosure *closure)
|
|
{
|
|
ClutterAlphaPrivate *priv;
|
|
|
|
g_return_if_fail (CLUTTER_IS_ALPHA (alpha));
|
|
g_return_if_fail (closure != NULL);
|
|
|
|
priv = alpha->priv;
|
|
|
|
if (priv->closure)
|
|
g_closure_unref (priv->closure);
|
|
|
|
priv->closure = g_closure_ref (closure);
|
|
g_closure_sink (closure);
|
|
|
|
if (G_CLOSURE_NEEDS_MARSHAL (closure))
|
|
{
|
|
GClosureMarshal marshal = clutter_marshal_UINT__VOID;
|
|
|
|
g_closure_set_marshal (closure, marshal);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_set_func:
|
|
* @alpha: A #ClutterAlpha
|
|
* @func: A #ClutterAlphaAlphaFunc
|
|
* @data: user data to be passed to the alpha function, or %NULL
|
|
* @destroy: notify function used when disposing the alpha function
|
|
*
|
|
* Sets the #ClutterAlphaFunc function used to compute
|
|
* the alpha value at each frame of the #ClutterTimeline
|
|
* bound to @alpha.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
void
|
|
clutter_alpha_set_func (ClutterAlpha *alpha,
|
|
ClutterAlphaFunc func,
|
|
gpointer data,
|
|
GDestroyNotify destroy)
|
|
{
|
|
GClosure *closure;
|
|
|
|
g_return_if_fail (CLUTTER_IS_ALPHA (alpha));
|
|
g_return_if_fail (func != NULL);
|
|
|
|
closure = g_cclosure_new (G_CALLBACK (func), data, (GClosureNotify) destroy);
|
|
clutter_alpha_set_closure (alpha, closure);
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_set_timeline:
|
|
* @alpha: A #ClutterAlpha
|
|
* @timeline: A #ClutterTimeline
|
|
*
|
|
* Binds @alpha to @timeline.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
void
|
|
clutter_alpha_set_timeline (ClutterAlpha *alpha,
|
|
ClutterTimeline *timeline)
|
|
{
|
|
ClutterAlphaPrivate *priv;
|
|
|
|
g_return_if_fail (CLUTTER_IS_ALPHA (alpha));
|
|
g_return_if_fail (timeline == NULL || CLUTTER_IS_TIMELINE (timeline));
|
|
|
|
priv = alpha->priv;
|
|
|
|
if (priv->timeline)
|
|
{
|
|
g_signal_handlers_disconnect_by_func (priv->timeline,
|
|
timeline_new_frame_cb,
|
|
alpha);
|
|
|
|
g_object_unref (priv->timeline);
|
|
priv->timeline = NULL;
|
|
}
|
|
|
|
if (timeline)
|
|
{
|
|
priv->timeline = g_object_ref (timeline);
|
|
|
|
g_signal_connect (priv->timeline, "new-frame",
|
|
G_CALLBACK (timeline_new_frame_cb),
|
|
alpha);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_get_timeline:
|
|
* @alpha: A #ClutterAlpha
|
|
*
|
|
* Gets the #ClutterTimeline bound to @alpha.
|
|
*
|
|
* Return value: a #ClutterTimeline instance
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
ClutterTimeline *
|
|
clutter_alpha_get_timeline (ClutterAlpha *alpha)
|
|
{
|
|
g_return_val_if_fail (CLUTTER_IS_ALPHA (alpha), NULL);
|
|
|
|
return alpha->priv->timeline;
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_new:
|
|
*
|
|
* Creates a new #ClutterAlpha instance. You must set a function
|
|
* to compute the alpha value using clutter_alpha_set_func() and
|
|
* bind a #ClutterTimeline object to the #ClutterAlpha instance
|
|
* using clutter_alpha_set_timeline().
|
|
*
|
|
* You should use the newly created #ClutterAlpha instance inside
|
|
* a #ClutterBehaviour object.
|
|
*
|
|
* Return value: the newly created empty #ClutterAlpha instance.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
ClutterAlpha *
|
|
clutter_alpha_new (void)
|
|
{
|
|
return g_object_new (CLUTTER_TYPE_ALPHA, NULL);
|
|
}
|
|
|
|
/**
|
|
* clutter_alpha_new_full:
|
|
* @timeline: #ClutterTimeline timeline
|
|
* @func: #ClutterAlphaFunc alpha function
|
|
* @data: data to be passed to the alpha function
|
|
* @destroy: notify to be called when removing the alpha function
|
|
*
|
|
* Creates a new #ClutterAlpha instance and sets the timeline
|
|
* and alpha function.
|
|
*
|
|
* Return Value: the newly created #ClutterAlpha
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
ClutterAlpha *
|
|
clutter_alpha_new_full (ClutterTimeline *timeline,
|
|
ClutterAlphaFunc func,
|
|
gpointer data,
|
|
GDestroyNotify destroy)
|
|
{
|
|
ClutterAlpha *retval;
|
|
|
|
g_return_val_if_fail (CLUTTER_IS_TIMELINE (timeline), NULL);
|
|
g_return_val_if_fail (func != NULL, NULL);
|
|
|
|
retval = clutter_alpha_new ();
|
|
|
|
clutter_alpha_set_timeline (retval, timeline);
|
|
clutter_alpha_set_func (retval, func, data, destroy);
|
|
|
|
return retval;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_RAMP_INC:
|
|
*
|
|
* Convenience symbol for clutter_ramp_inc_func().
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
/**
|
|
* clutter_ramp_inc_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a monotonic increasing ramp. You
|
|
* can use this function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
guint32
|
|
clutter_ramp_inc_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
return (current_frame_num * CLUTTER_ALPHA_MAX_ALPHA) / n_frames;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_RAMP_DEC:
|
|
*
|
|
* Convenience symbol for clutter_ramp_dec_func().
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
/**
|
|
* clutter_ramp_dec_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a monotonic decreasing ramp. You
|
|
* can use this function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
guint32
|
|
clutter_ramp_dec_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
return (n_frames - current_frame_num)
|
|
* CLUTTER_ALPHA_MAX_ALPHA
|
|
/ n_frames;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_RAMP:
|
|
*
|
|
* Convenience symbol for clutter_ramp_func().
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
/**
|
|
* clutter_ramp_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a full ramp function (increase for
|
|
* half the time, decrease for the remaining half). You can use this
|
|
* function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
guint32
|
|
clutter_ramp_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
if (current_frame_num > (n_frames / 2))
|
|
{
|
|
return (n_frames - current_frame_num)
|
|
* CLUTTER_ALPHA_MAX_ALPHA
|
|
/ (n_frames / 2);
|
|
}
|
|
else
|
|
{
|
|
return current_frame_num
|
|
* CLUTTER_ALPHA_MAX_ALPHA
|
|
/ (n_frames / 2);
|
|
}
|
|
}
|
|
|
|
static guint32
|
|
sincx1024_func (ClutterAlpha *alpha,
|
|
ClutterAngle angle,
|
|
ClutterFixed offset)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
ClutterAngle x;
|
|
unsigned int sine;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = angle * current_frame_num / n_frames;
|
|
|
|
x -= (512 * 512 / angle);
|
|
|
|
sine = ((clutter_sini (x) + offset)/2) * CLUTTER_ALPHA_MAX_ALPHA;
|
|
|
|
sine = sine >> CFX_Q;
|
|
|
|
return sine;
|
|
}
|
|
#if 0
|
|
/*
|
|
* The following two functions are left in place for reference
|
|
* purposes.
|
|
*/
|
|
static guint32
|
|
sincx_func (ClutterAlpha *alpha,
|
|
ClutterFixed angle,
|
|
ClutterFixed offset)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
ClutterFixed x, sine;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = angle * current_frame_num / n_frames;
|
|
x = CLUTTER_FIXED_MUL (x, CFX_PI) - CLUTTER_FIXED_DIV (CFX_PI, angle);
|
|
|
|
sine = (clutter_fixed_sin (x) + offset)/2;
|
|
|
|
CLUTTER_NOTE (ALPHA, "sine: %2f\n", CLUTTER_FIXED_TO_DOUBLE (sine));
|
|
|
|
return CLUTTER_FIXED_TO_INT (sine * CLUTTER_ALPHA_MAX_ALPHA);
|
|
}
|
|
|
|
/* NB: angle is not in radians but in muliples of PI, i.e., 2.0
|
|
* represents full circle.
|
|
*/
|
|
static guint32
|
|
sinc_func (ClutterAlpha *alpha,
|
|
float angle,
|
|
float offset)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
gdouble x, sine;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
/* FIXME: fixed point, and fixed point sine() */
|
|
|
|
x = (gdouble) (current_frame_num * angle * G_PI) / n_frames ;
|
|
sine = (sin (x - (G_PI / angle)) + offset) * 0.5f;
|
|
|
|
CLUTTER_NOTE (ALPHA, "sine: %2f\n",sine);
|
|
|
|
return CLUTTER_FLOAT_TO_INT ((sine * (gdouble) CLUTTER_ALPHA_MAX_ALPHA));
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SINE:
|
|
*
|
|
* Convenience symbol for clutter_sine_func().
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
/**
|
|
* clutter_sine_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a sine wave. You can use this
|
|
* function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
guint32
|
|
clutter_sine_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
#if 0
|
|
return sinc_func (alpha, 2.0, 1.0);
|
|
#else
|
|
/* 2.0 above represents full circle */
|
|
return sincx1024_func (alpha, 1024, CFX_ONE);
|
|
#endif
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SINE_INC:
|
|
*
|
|
* Convenience symbol for clutter_sine_inc_func().
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
/**
|
|
* clutter_sine_inc_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a sine wave over interval [0, pi / 2].
|
|
* You can use this function as the alpha function for
|
|
* clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
guint32
|
|
clutter_sine_inc_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline * timeline;
|
|
gint frame;
|
|
gint n_frames;
|
|
ClutterAngle x;
|
|
ClutterFixed sine;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
frame = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = 256 * frame / n_frames;
|
|
|
|
sine = clutter_sini (x) * CLUTTER_ALPHA_MAX_ALPHA;
|
|
|
|
return ((guint32)sine) >> CFX_Q;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SINE_DEC:
|
|
*
|
|
* Convenience symbol for clutter_sine_dec_func().
|
|
*
|
|
* Since: 0.2
|
|
*/
|
|
|
|
/**
|
|
* clutter_sine_dec_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a sine wave over interval [pi / 2, pi].
|
|
* You can use this function as the alpha function for
|
|
* clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_sine_dec_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline * timeline;
|
|
gint frame;
|
|
gint n_frames;
|
|
ClutterAngle x;
|
|
ClutterFixed sine;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
frame = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = 256 * frame / n_frames + 256;
|
|
|
|
sine = clutter_sini (x) * CLUTTER_ALPHA_MAX_ALPHA;
|
|
|
|
return ((guint32)sine) >> CFX_Q;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SINE_HALF:
|
|
*
|
|
* Convenience symbol for clutter_sine_half_func().
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
|
|
/**
|
|
* clutter_sine_half_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a sine wave over interval [0, pi].
|
|
* You can use this function as the alpha function for
|
|
* clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_sine_half_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline * timeline;
|
|
gint frame;
|
|
gint n_frames;
|
|
ClutterAngle x;
|
|
ClutterFixed sine;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
frame = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = 512 * frame / n_frames;
|
|
|
|
sine = clutter_sini (x) * CLUTTER_ALPHA_MAX_ALPHA;
|
|
|
|
return ((guint32)sine) >> CFX_Q;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SQUARE:
|
|
*
|
|
* Convenience symbol for clutter_square_func().
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
|
|
/**
|
|
* clutter_square_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a square wave. You can use this
|
|
* function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_square_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint current_frame_num, n_frames;
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
|
|
current_frame_num = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
return (current_frame_num > (n_frames / 2)) ? CLUTTER_ALPHA_MAX_ALPHA
|
|
: 0;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SMOOTHSTEP_INC:
|
|
*
|
|
* Convenience symbol for clutter_smoothstep_inc_func().
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
|
|
/**
|
|
* clutter_smoothstep_inc_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused
|
|
*
|
|
* Convenience alpha function for a smoothstep curve. You can use this
|
|
* function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_smoothstep_inc_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline *timeline;
|
|
gint frame;
|
|
gint n_frames;
|
|
guint32 r;
|
|
guint32 x;
|
|
|
|
/*
|
|
* The smoothstep function uses f(x) = -2x^3 + 3x^2 where x is from <0,1>,
|
|
* and precission is critical -- we use 8.24 fixed format for this operation.
|
|
* The earlier operations involve division, which we cannot do in 8.24 for
|
|
* numbers in <0,1> we use ClutterFixed.
|
|
*/
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
frame = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
/*
|
|
* Convert x to 8.24 for next step.
|
|
*/
|
|
x = CFX_DIV (frame, n_frames) << 8;
|
|
|
|
/*
|
|
* f(x) = -2x^3 + 3x^2
|
|
*
|
|
* Convert result to ClutterFixed to avoid overflow in next step.
|
|
*/
|
|
r = ((x >> 12) * (x >> 12) * 3 - (x >> 15) * (x >> 16) * (x >> 16)) >> 8;
|
|
|
|
return CFX_INT (r * CLUTTER_ALPHA_MAX_ALPHA);
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_SMOOTHSTEP_DEC:
|
|
*
|
|
* Convenience symbol for clutter_smoothstep_dec_func().
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
|
|
/**
|
|
* clutter_smoothstep_dec_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused
|
|
*
|
|
* Convenience alpha function for a downward smoothstep curve. You can use
|
|
* this function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_smoothstep_dec_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
return CLUTTER_ALPHA_MAX_ALPHA - clutter_smoothstep_inc_func (alpha, dummy);
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_EXP_INC:
|
|
*
|
|
* Convenience symbol for clutter_exp_inc_func()
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
|
|
/**
|
|
* clutter_exp_inc_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a 2^x curve. You can use this function as the
|
|
* alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_exp_inc_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline * timeline;
|
|
gint frame;
|
|
gint n_frames;
|
|
ClutterFixed x;
|
|
ClutterFixed x_alpha_max = 0x100000;
|
|
guint32 result;
|
|
|
|
/*
|
|
* Choose x_alpha_max such that
|
|
*
|
|
* (2^x_alpha_max) - 1 == CLUTTER_ALPHA_MAX_ALPHA
|
|
*/
|
|
#if CLUTTER_ALPHA_MAX_ALPHA != 0xffff
|
|
#error Adjust x_alpha_max to match CLUTTER_ALPHA_MAX_ALPHA
|
|
#endif
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
frame = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = x_alpha_max * frame / n_frames;
|
|
|
|
result = CLAMP (clutter_pow2x (x) - 1, 0, CLUTTER_ALPHA_MAX_ALPHA);
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* CLUTTER_ALPHA_EXP_DEC:
|
|
*
|
|
* Convenience symbold for clutter_exp_dec_func().
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
|
|
/**
|
|
* clutter_exp_dec_func:
|
|
* @alpha: a #ClutterAlpha
|
|
* @dummy: unused argument
|
|
*
|
|
* Convenience alpha function for a decreasing 2^x curve. You can use this
|
|
* function as the alpha function for clutter_alpha_set_func().
|
|
*
|
|
* Return value: an alpha value.
|
|
*
|
|
* Since: 0.4
|
|
*/
|
|
guint32
|
|
clutter_exp_dec_func (ClutterAlpha *alpha,
|
|
gpointer dummy)
|
|
{
|
|
ClutterTimeline * timeline;
|
|
gint frame;
|
|
gint n_frames;
|
|
ClutterFixed x;
|
|
ClutterFixed x_alpha_max = 0x100000;
|
|
guint32 result;
|
|
|
|
/*
|
|
* Choose x_alpha_max such that
|
|
*
|
|
* (2^x_alpha_max) - 1 == CLUTTER_ALPHA_MAX_ALPHA
|
|
*/
|
|
#if CLUTTER_ALPHA_MAX_ALPHA != 0xffff
|
|
#error Adjust x_alpha_max to match CLUTTER_ALPHA_MAX_ALPHA
|
|
#endif
|
|
|
|
timeline = clutter_alpha_get_timeline (alpha);
|
|
frame = clutter_timeline_get_current_frame (timeline);
|
|
n_frames = clutter_timeline_get_n_frames (timeline);
|
|
|
|
x = (x_alpha_max * (n_frames - frame)) / n_frames;
|
|
|
|
result = CLAMP (clutter_pow2x (x) - 1, 0, CLUTTER_ALPHA_MAX_ALPHA);
|
|
|
|
return result;
|
|
}
|