/*
* 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.
*
* A #ClutterAlpha binds a #ClutterTimeline to a progress function which
* translates the time T into an adimensional factor alpha. The factor can
* then be used to drive a #ClutterBehaviour, which will translate the
* alpha value into something meaningful for a #ClutterActor.
*
* You should provide a #ClutterTimeline and bind it to the #ClutterAlpha
* instance using clutter_alpha_set_timeline(); you should also provide a
* function returning the alpha value depending on the progress of the
* timeline, using clutter_alpha_set_func() or clutter_alpha_set_closure().
* The alpha 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, stop or resume the #ClutterAlpha from calling the alpha function by
* using the appropriate functions of 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-debug.h"
#include "clutter-enum-types.h"
#include "clutter-main.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
G_DEFINE_TYPE (ClutterAlpha, clutter_alpha, G_TYPE_INITIALLY_UNOWNED);
struct _ClutterAlphaPrivate
{
ClutterTimeline *timeline;
guint timeline_new_frame_id;
guint32 alpha;
GClosure *closure;
ClutterAnimationMode mode;
};
enum
{
PROP_0,
PROP_TIMELINE,
PROP_ALPHA,
PROP_MODE
};
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;
case PROP_MODE:
clutter_alpha_set_mode (alpha, g_value_get_enum (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;
case PROP_MODE:
g_value_set_enum (value, priv->mode);
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));
/**
* ClutterAlpha:mode:
*
* The progress function as a #ClutterAnimationMode enumeration
* value. If %CLUTTER_CUSTOM_MODE is used then the function set
* using clutter_alpha_set_closure() or clutter_alpha_set_func()
* will be used.
*
* Since: 1.0
*/
g_object_class_install_property (object_class,
PROP_MODE,
g_param_spec_enum ("mode",
"Mode",
"Progress mode",
CLUTTER_TYPE_ANIMATION_MODE,
CLUTTER_CUSTOM_MODE,
G_PARAM_CONSTRUCT |
CLUTTER_PARAM_READWRITE));
}
static void
clutter_alpha_init (ClutterAlpha *self)
{
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
CLUTTER_TYPE_ALPHA,
ClutterAlphaPrivate);
self->priv->mode = CLUTTER_CUSTOM_MODE;
}
/**
* 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);
}
priv->mode = CLUTTER_CUSTOM_MODE;
g_object_notify (G_OBJECT (alpha), "mode");
}
/**
* clutter_alpha_set_func:
* @alpha: A #ClutterAlpha
* @func: A #ClutterAlphaFunc
* @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);
}
g_object_notify (G_OBJECT (alpha), "timeline");
}
/**
* 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_new_for_mode:
* @mode: a #ClutterAnimationMode value
*
* Creates a new #ClutterAlpha using @mode to set the
* progress function using its symbolic name.
*
* Return value: the newly created #ClutterAlpha
*
* Since: 1.0
*/
ClutterAlpha *
clutter_alpha_new_for_mode (ClutterAnimationMode mode)
{
return g_object_new (CLUTTER_TYPE_ALPHA,
"mode", mode,
NULL);
}
/**
* clutter_alpha_get_mode:
* @alpha: a #ClutterAlpha
*
* Retrieves the #ClutterAnimatioMode used by @alpha.
*
* Return value: the animation mode
*
* Since: 1.0
*/
ClutterAnimationMode
clutter_alpha_get_mode (ClutterAlpha *alpha)
{
g_return_val_if_fail (CLUTTER_IS_ALPHA (alpha), CLUTTER_CUSTOM_MODE);
return alpha->priv->mode;
}
/* XXX - keep in sync with ClutterAnimationMode */
static const struct {
ClutterAnimationMode mode;
ClutterAlphaFunc func;
} animation_modes[] = {
{ CLUTTER_CUSTOM_MODE, NULL },
{ CLUTTER_LINEAR, clutter_ramp_inc_func },
{ CLUTTER_SINE_IN, clutter_sine_in_func },
{ CLUTTER_SINE_OUT, clutter_sine_out_func },
{ CLUTTER_SINE_IN_OUT, clutter_sine_in_out_func },
{ CLUTTER_EASE_IN, clutter_ease_in_func },
{ CLUTTER_EASE_OUT, clutter_ease_out_func },
{ CLUTTER_EASE_IN_OUT, clutter_ease_in_out_func },
{ CLUTTER_EXPO_IN, clutter_exp_in_func },
{ CLUTTER_EXPO_OUT, clutter_exp_out_func },
{ CLUTTER_EXPO_IN_OUT, clutter_exp_in_out_func },
{ CLUTTER_SMOOTH_IN_OUT, clutter_smoothstep_inc_func }
};
/**
* clutter_alpha_set_mode:
* @alpha: a #ClutterAlpha
* @mode: a #ClutterAnimationMode
*
* Sets the progress function of @alpha using the symbolic value
* of @mode, as taken by the #ClutterAnimationMode enumeration
*
* Since: 1.0
*/
void
clutter_alpha_set_mode (ClutterAlpha *alpha,
ClutterAnimationMode mode)
{
ClutterAlphaPrivate *priv;
g_return_if_fail (CLUTTER_IS_ALPHA (alpha));
priv = alpha->priv;
priv->mode = mode;
/* sanity check to avoid getting an out of sync enum/function mapping */
g_assert (animation_modes[mode].mode == mode);
if (G_LIKELY (animation_modes[mode].func != NULL))
clutter_alpha_set_func (alpha, animation_modes[mode].func, NULL, NULL);
g_object_notify (G_OBJECT (alpha), "mode");
}
/**
* 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;
ClutterFixed 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 = ((cogl_angle_sin (x) + offset) / 2)
* CLUTTER_ALPHA_MAX_ALPHA;
sine = sine >> COGL_FIXED_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 = COGL_FIXED_FAST_MUL (x, COGL_FIXED_PI)
- COGL_FIXED_FAST_DIV (COGL_FIXED_PI, angle);
sine = (cogl_fixed_sin (x) + offset) / 2;
CLUTTER_NOTE (ALPHA, "sine: %2f\n", COGL_FIXED_TO_DOUBLE (sine));
return COGL_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 COGL_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, COGL_FIXED_1);
#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 = cogl_angle_sin (x) * CLUTTER_ALPHA_MAX_ALPHA;
return ((guint32) sine) >> COGL_FIXED_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 = cogl_angle_sin (x) * CLUTTER_ALPHA_MAX_ALPHA;
return ((guint32) sine) >> COGL_FIXED_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 = cogl_angle_sin (x) * CLUTTER_ALPHA_MAX_ALPHA;
return ((guint32) sine) >> COGL_FIXED_Q;
}
/**
* clutter_sine_in_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for (sin(x) + 1) over the
* interval [-pi/2, 0].
*
* You can use this function as the alpha function for
* clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 1.0
*/
guint32
clutter_sine_in_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);
/* XXX- if we use 768 we overflow */
x = 256 * frame / n_frames + 767;
sine = (cogl_angle_sin (x) + 1) * CLUTTER_ALPHA_MAX_ALPHA;
return ((guint32) sine) >> COGL_FIXED_Q;
}
/**
* clutter_sine_in_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for sin(x) over the interval [0, pi/2].
*
* You can use this function as the alpha function for
* clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 1.0
*/
guint32
clutter_sine_out_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 = cogl_angle_sin (x) * CLUTTER_ALPHA_MAX_ALPHA;
return ((guint32) sine) >> COGL_FIXED_Q;
}
/**
* clutter_sine_in_out_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for (sin(x) + 1) / 2 over the
* interval [-pi/2, pi/2].
*
* You can use this function as the alpha function for
* clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 1.0
*/
guint32
clutter_sine_in_out_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 = (cogl_angle_sin (x) + 1) / 2 * CLUTTER_ALPHA_MAX_ALPHA;
return ((guint32) sine) >> COGL_FIXED_Q;
}
/**
* CLUTTER_ALPHA_SQUARE:
*
* Convenience symbol for clutter_square_func().
*
* Since: 0.4
*
* Deprecated: 1.0: Use clutter_square_func() instead
*/
/**
* 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 = COGL_FIXED_FAST_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 COGL_FIXED_TO_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 (cogl_fixed_pow2 (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 (cogl_fixed_pow2 (x) - 1, 0, CLUTTER_ALPHA_MAX_ALPHA);
return result;
}
static inline gdouble
clutter_cubic_bezier (ClutterAlpha *alpha,
gdouble x_1,
gdouble y_1,
gdouble x_2,
gdouble y_2)
{
ClutterTimeline *timeline;
gdouble t, b_t, res;
/* the cubic bezier has a parametric form of:
*
* B(t) = (1 - t)^3 * P_0
* + 3t * (1 - t)^2 * P_1
* + 3t^2 * (1 - t) * P_2
* + 3t^3 * P_3 (with t included in [0, 1])
*
* the P_0 and P_3 points are set to (0, 0) and (1, 1) respectively,
* and the curve never passes through P_1 and P_2 - with these two
* points merely acting as control points for the curve starting
* from P_0 and ending at P_3.
*
* since the starting point is (0, 0) we can simplify the previous
* parametric form to:
*
* B(t) = 3t * (1 - t)^2 * P_1
* + 3t^2 * (1 - t) * P_2
* + 3t^3 * P_3 (with t included in [0, 1])
*
* and, similarly, since the final point is (1, 1) we can simplify
* it further to:
*
* B(t) = 3t * (1 - t)^2 * P_1
* + 3t^2 * (1 - t) * P_2
* + 3t^3 (with t included in [0, 1])
*
* since an alpha function has only a time parameter and we have two
* coordinates for each point, we pass the time as the first
* coordinate for the point and then we solve the cubic beziér curve
* for the second coordinate at the same point.
*/
timeline = clutter_alpha_get_timeline (alpha);
t = clutter_timeline_get_progress (timeline);
b_t = 3 * t * pow (1 - t, 2) * x_1
+ 3 * pow (t, 2) * (1 - t) * x_2
+ 3 * pow (t, 3);
res = 3 * b_t * pow (1 - b_t, 2) * y_1
+ 3 * pow (b_t, 2) * (1 - b_t) * y_2
+ 3 * pow (b_t, 3);
return res;
}
/**
* clutter_ease_in_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for a cubic Beziér curve with control
* points at (0.42, 0) and (1, 0). You can use this function as the
* alpha function for clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 1.0
*/
guint32
clutter_ease_in_func (ClutterAlpha *alpha,
gpointer dummy)
{
gdouble res;
res = clutter_cubic_bezier (alpha, 0.42, 0, 1, 0);
return CLAMP (res * CLUTTER_ALPHA_MAX_ALPHA, 0, CLUTTER_ALPHA_MAX_ALPHA);
}
/**
* clutter_ease_out_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for a cubic Beziér curve with control
* points at (0, 0) and (0.58, 1). You can use this function as the
* alpha function for clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 1.0
*/
guint32
clutter_ease_out_func (ClutterAlpha *alpha,
gpointer dummy)
{
gdouble res;
res = clutter_cubic_bezier (alpha, 0, 0, 0.58, 1);
return CLAMP (res * CLUTTER_ALPHA_MAX_ALPHA, 0, CLUTTER_ALPHA_MAX_ALPHA);
}
/**
* clutter_ease_in_out_func:
* @alpha: a #ClutterAlpha
* @dummy: unused argument
*
* Convenience alpha function for a cubic Beziér curve with control
* points at (0.42, 0) and (0.58, 1). You can use this function as
* the alpha function for clutter_alpha_set_func().
*
* Return value: an alpha value.
*
* Since: 1.0
*/
guint32
clutter_ease_in_out_func (ClutterAlpha *alpha,
gpointer dummy)
{
gdouble res;
res = clutter_cubic_bezier (alpha, 0.42, 0, 0.58, 1);
return CLAMP (res * CLUTTER_ALPHA_MAX_ALPHA, 0, CLUTTER_ALPHA_MAX_ALPHA);
}
guint32
clutter_exp_in_func (ClutterAlpha *alpha,
gpointer dummy)
{
ClutterTimeline *timeline;
gdouble progress, res;
timeline = clutter_alpha_get_timeline (alpha);
progress = clutter_timeline_get_progress (timeline);
res = pow (2, 10 * (progress - 1));
res = CLAMP (res * CLUTTER_ALPHA_MAX_ALPHA, 0, CLUTTER_ALPHA_MAX_ALPHA);
return res;
}
guint32
clutter_exp_out_func (ClutterAlpha *alpha,
gpointer dummy)
{
ClutterTimeline *timeline;
gdouble progress, res;
timeline = clutter_alpha_get_timeline (alpha);
progress = clutter_timeline_get_progress (timeline);
res = -pow (2, (-10 * progress)) + 1;
res = CLAMP (res * CLUTTER_ALPHA_MAX_ALPHA, 0, CLUTTER_ALPHA_MAX_ALPHA);
return res;
}
guint32
clutter_exp_in_out_func (ClutterAlpha *alpha,
gpointer dummy)
{
ClutterTimeline *timeline;
gdouble progress, res;
timeline = clutter_alpha_get_timeline (alpha);
progress = clutter_timeline_get_progress (timeline);
if (progress < 0.5)
res = 0.5 * pow (2, (10 * (progress - 1)));
else
res = 0.5 * -pow (2, (-10 * progress)) + 1;
res = CLAMP (res * CLUTTER_ALPHA_MAX_ALPHA, 0, CLUTTER_ALPHA_MAX_ALPHA);
return res;
}