mutter/clutter/clutter-behaviour-scale.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

518 lines
16 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-scale
* @short_description: A behaviour controlling scale
*
* A #ClutterBehaviourScale interpolates actors size between two values.
*
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-actor.h"
#include "clutter-behaviour.h"
#include "clutter-enum-types.h"
#include "clutter-main.h"
#include "clutter-fixed.h"
#include "clutter-behaviour-scale.h"
#include "clutter-private.h"
#include "clutter-debug.h"
#include <math.h>
G_DEFINE_TYPE (ClutterBehaviourScale,
clutter_behaviour_scale,
CLUTTER_TYPE_BEHAVIOUR);
struct _ClutterBehaviourScalePrivate
{
ClutterFixed x_scale_start;
ClutterFixed y_scale_start;
ClutterFixed x_scale_end;
ClutterFixed y_scale_end;
};
#define CLUTTER_BEHAVIOUR_SCALE_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
CLUTTER_TYPE_BEHAVIOUR_SCALE, \
ClutterBehaviourScalePrivate))
enum
{
PROP_0,
PROP_X_SCALE_START,
PROP_Y_SCALE_START,
PROP_X_SCALE_END,
PROP_Y_SCALE_END,
};
typedef struct {
ClutterFixed scale_x;
ClutterFixed scale_y;
} ScaleFrameClosure;
static void
scale_frame_foreach (ClutterBehaviour *behaviour,
ClutterActor *actor,
gpointer data)
{
ScaleFrameClosure *closure = data;
clutter_actor_set_scalex (actor, closure->scale_x, closure->scale_y);
}
static void
clutter_behaviour_scale_alpha_notify (ClutterBehaviour *behave,
gdouble alpha_value)
{
ClutterBehaviourScalePrivate *priv;
ClutterFixed scale_x, scale_y;
ScaleFrameClosure closure = { 0, };
priv = CLUTTER_BEHAVIOUR_SCALE (behave)->priv;
/* Fix the start/end values, avoids potential rounding errors on large
* values.
*/
if (alpha_value == 1.0)
{
scale_x = priv->x_scale_end;
scale_y = priv->y_scale_end;
}
else if (alpha_value == 0)
{
scale_x = priv->x_scale_start;
scale_y = priv->y_scale_start;
}
else
{
ClutterFixed factor;
factor = COGL_FIXED_FROM_FLOAT (alpha_value);
scale_x =
COGL_FIXED_FAST_MUL (factor, (priv->x_scale_end - priv->x_scale_start));
scale_x += priv->x_scale_start;
scale_y =
COGL_FIXED_FAST_MUL (factor, (priv->y_scale_end - priv->y_scale_start));
scale_y += priv->y_scale_start;
}
closure.scale_x = scale_x;
closure.scale_y = scale_y;
clutter_behaviour_actors_foreach (behave,
scale_frame_foreach,
&closure);
}
static void
clutter_behaviour_scale_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterBehaviourScalePrivate *priv;
priv = CLUTTER_BEHAVIOUR_SCALE (gobject)->priv;
switch (prop_id)
{
case PROP_X_SCALE_START:
priv->x_scale_start = COGL_FIXED_FROM_FLOAT (g_value_get_double (value));
break;
case PROP_X_SCALE_END:
priv->x_scale_end = COGL_FIXED_FROM_FLOAT (g_value_get_double (value));
break;
case PROP_Y_SCALE_START:
priv->y_scale_start = COGL_FIXED_FROM_FLOAT (g_value_get_double (value));
break;
case PROP_Y_SCALE_END:
priv->y_scale_end = COGL_FIXED_FROM_FLOAT (g_value_get_double (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_behaviour_scale_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterBehaviourScalePrivate *priv;
priv = CLUTTER_BEHAVIOUR_SCALE (gobject)->priv;
switch (prop_id)
{
case PROP_X_SCALE_START:
g_value_set_double (value, COGL_FIXED_TO_FLOAT (priv->x_scale_start));
break;
case PROP_X_SCALE_END:
g_value_set_double (value, COGL_FIXED_TO_FLOAT (priv->x_scale_end));
break;
case PROP_Y_SCALE_START:
g_value_set_double (value, COGL_FIXED_TO_FLOAT (priv->y_scale_start));
break;
case PROP_Y_SCALE_END:
g_value_set_double (value, COGL_FIXED_TO_FLOAT (priv->y_scale_end));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_behaviour_scale_class_init (ClutterBehaviourScaleClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterBehaviourClass *behave_class = CLUTTER_BEHAVIOUR_CLASS (klass);
gobject_class->set_property = clutter_behaviour_scale_set_property;
gobject_class->get_property = clutter_behaviour_scale_get_property;
/**
* ClutterBehaviourScale:x-scale-start:
*
* The initial scaling factor on the X axis for the actors.
*
* Since: 0.6
*/
g_object_class_install_property (gobject_class,
PROP_X_SCALE_START,
g_param_spec_double ("x-scale-start",
"X Start Scale",
"Initial scale on the X axis",
0.0, G_MAXDOUBLE,
1.0,
CLUTTER_PARAM_READWRITE));
/**
* ClutterBehaviourScale:x-scale-end:
*
* The final scaling factor on the X axis for the actors.
*
* Since: 0.6
*/
g_object_class_install_property (gobject_class,
PROP_X_SCALE_END,
g_param_spec_double ("x-scale-end",
"X End Scale",
"Final scale on the X axis",
0.0, G_MAXDOUBLE,
1.0,
CLUTTER_PARAM_READWRITE));
/**
* ClutterBehaviourScale:y-scale-start:
*
* The initial scaling factor on the Y axis for the actors.
*
* Since: 0.6
*/
g_object_class_install_property (gobject_class,
PROP_Y_SCALE_START,
g_param_spec_double ("y-scale-start",
"Y Start Scale",
"Initial scale on the Y axis",
0.0, G_MAXDOUBLE,
1.0,
CLUTTER_PARAM_READWRITE));
/**
* ClutterBehaviourScale:y-scale-end:
*
* The final scaling factor on the Y axis for the actors.
*
* Since: 0.6
*/
g_object_class_install_property (gobject_class,
PROP_Y_SCALE_END,
g_param_spec_double ("y-scale-end",
"Y End Scale",
"Final scale on the Y axis",
0.0, G_MAXDOUBLE,
1.0,
CLUTTER_PARAM_READWRITE));
behave_class->alpha_notify = clutter_behaviour_scale_alpha_notify;
g_type_class_add_private (klass, sizeof (ClutterBehaviourScalePrivate));
}
static void
clutter_behaviour_scale_init (ClutterBehaviourScale *self)
{
ClutterBehaviourScalePrivate *priv;
self->priv = priv = CLUTTER_BEHAVIOUR_SCALE_GET_PRIVATE (self);
priv->x_scale_start = priv->x_scale_end = COGL_FIXED_1;
priv->y_scale_start = priv->y_scale_end = COGL_FIXED_1;
}
/**
* clutter_behaviour_scale_new:
* @alpha: a #ClutterAlpha
* @x_scale_start: initial scale factor on the X axis
* @y_scale_start: initial scale factor on the Y axis
* @x_scale_end: final scale factor on the X axis
* @y_scale_end: final scale factor on the Y axis
*
* Creates a new #ClutterBehaviourScale instance.
*
* Return value: the newly created #ClutterBehaviourScale
*
* Since: 0.2
*/
ClutterBehaviour *
clutter_behaviour_scale_new (ClutterAlpha *alpha,
gdouble x_scale_start,
gdouble y_scale_start,
gdouble x_scale_end,
gdouble y_scale_end)
{
g_return_val_if_fail (alpha == NULL || CLUTTER_IS_ALPHA (alpha), NULL);
return clutter_behaviour_scale_newx (alpha,
COGL_FIXED_FROM_FLOAT (x_scale_start),
COGL_FIXED_FROM_FLOAT (y_scale_start),
COGL_FIXED_FROM_FLOAT (x_scale_end),
COGL_FIXED_FROM_FLOAT (y_scale_end));
}
/**
* clutter_behaviour_scale_newx:
* @alpha: a #ClutterAlpha
* @x_scale_start: initial scale factor on the X axis
* @y_scale_start: initial scale factor on the Y axis
* @x_scale_end: final scale factor on the X axis
* @y_scale_end: final scale factor on the Y axis
*
* A fixed point implementation of clutter_behaviour_scale_new()
*
* Return value: the newly created #ClutterBehaviourScale
*
* Since: 0.2
*/
ClutterBehaviour *
clutter_behaviour_scale_newx (ClutterAlpha *alpha,
ClutterFixed x_scale_start,
ClutterFixed y_scale_start,
ClutterFixed x_scale_end,
ClutterFixed y_scale_end)
{
ClutterBehaviourScale *behave;
g_return_val_if_fail (alpha == NULL || CLUTTER_IS_ALPHA (alpha), NULL);
behave = g_object_new (CLUTTER_TYPE_BEHAVIOUR_SCALE, "alpha", alpha, NULL);
behave->priv->x_scale_start = x_scale_start;
behave->priv->y_scale_start = y_scale_start;
behave->priv->x_scale_end = x_scale_end;
behave->priv->y_scale_end = y_scale_end;
return CLUTTER_BEHAVIOUR (behave);
}
/**
* clutter_behaviour_scale_set_bounds:
* @scale: a #ClutterBehaviourScale
* @x_scale_start: initial scale factor on the X axis
* @y_scale_start: initial scale factor on the Y axis
* @x_scale_end: final scale factor on the X axis
* @y_scale_end: final scale factor on the Y axis
*
* Sets the bounds used by scale behaviour.
*
* Since: 0.6
*/
void
clutter_behaviour_scale_set_bounds (ClutterBehaviourScale *scale,
gdouble x_scale_start,
gdouble y_scale_start,
gdouble x_scale_end,
gdouble y_scale_end)
{
g_return_if_fail (CLUTTER_IS_BEHAVIOUR_SCALE (scale));
clutter_behaviour_scale_set_boundsx (scale,
COGL_FIXED_FROM_FLOAT (x_scale_start),
COGL_FIXED_FROM_FLOAT (y_scale_start),
COGL_FIXED_FROM_FLOAT (x_scale_end),
COGL_FIXED_FROM_FLOAT (y_scale_end));
}
/**
* clutter_behaviour_scale_get_bounds:
* @scale: a #ClutterBehaviourScale
* @x_scale_start: return location for the initial scale factor on the X
* axis, or %NULL
* @y_scale_start: return location for the initial scale factor on the Y
* axis, or %NULL
* @x_scale_end: return location for the final scale factor on the X axis,
* or %NULL
* @y_scale_end: return location for the final scale factor on the Y axis,
* or %NULL
*
* Retrieves the bounds used by scale behaviour.
*
* Since: 0.4
*/
void
clutter_behaviour_scale_get_bounds (ClutterBehaviourScale *scale,
gdouble *x_scale_start,
gdouble *y_scale_start,
gdouble *x_scale_end,
gdouble *y_scale_end)
{
ClutterBehaviourScalePrivate *priv;
g_return_if_fail (CLUTTER_IS_BEHAVIOUR_SCALE (scale));
priv = scale->priv;
if (x_scale_start)
*x_scale_start = COGL_FIXED_TO_DOUBLE (priv->x_scale_start);
if (x_scale_end)
*x_scale_end = COGL_FIXED_TO_DOUBLE (priv->x_scale_end);
if (y_scale_start)
*y_scale_start = COGL_FIXED_TO_DOUBLE (priv->y_scale_start);
if (y_scale_end)
*y_scale_end = COGL_FIXED_TO_DOUBLE (priv->y_scale_end);
}
/**
* clutter_behaviour_scale_set_boundsx:
* @scale: a #ClutterBehaviourScale
* @x_scale_start: initial scale factor on the X axis
* @y_scale_start: initial scale factor on the Y axis
* @x_scale_end: final scale factor on the X axis
* @y_scale_end: final scale factor on the Y axis
*
* Fixed point version of clutter_behaviour_scale_set_bounds().
*
* Sets the bounds used by scale behaviour.
*
* Since: 0.6
*/
void
clutter_behaviour_scale_set_boundsx (ClutterBehaviourScale *scale,
ClutterFixed x_scale_start,
ClutterFixed y_scale_start,
ClutterFixed x_scale_end,
ClutterFixed y_scale_end)
{
ClutterBehaviourScalePrivate *priv;
g_return_if_fail (CLUTTER_IS_BEHAVIOUR_SCALE (scale));
priv = scale->priv;
g_object_freeze_notify (G_OBJECT (scale));
if (priv->x_scale_start != x_scale_start)
{
priv->x_scale_start = x_scale_start;
g_object_notify (G_OBJECT (scale), "x-scale-start");
}
if (priv->y_scale_start != y_scale_start)
{
priv->y_scale_start = y_scale_start;
g_object_notify (G_OBJECT (scale), "y-scale-start");
}
if (priv->x_scale_end != x_scale_end)
{
priv->x_scale_end = x_scale_end;
g_object_notify (G_OBJECT (scale), "x-scale-end");
}
if (priv->y_scale_end != y_scale_end)
{
priv->y_scale_end = y_scale_end;
g_object_notify (G_OBJECT (scale), "y-scale-end");
}
g_object_thaw_notify (G_OBJECT (scale));
}
/**
* clutter_behaviour_scale_get_boundsx:
* @scale: a #ClutterBehaviourScale
* @x_scale_start: return location for the initial scale factor on the X
* axis, or %NULL
* @y_scale_start: return location for the initial scale factor on the Y
* axis, or %NULL
* @x_scale_end: return location for the final scale factor on the X axis,
* or %NULL
* @y_scale_end: return location for the final scale factor on the Y axis,
* or %NULL
*
* Fixed point version of clutter_behaviour_scale_get_bounds().
*
* Retrieves the bounds used by scale behaviour.
*
* Since: 0.4
*/
void
clutter_behaviour_scale_get_boundsx (ClutterBehaviourScale *scale,
ClutterFixed *x_scale_start,
ClutterFixed *y_scale_start,
ClutterFixed *x_scale_end,
ClutterFixed *y_scale_end)
{
ClutterBehaviourScalePrivate *priv;
g_return_if_fail (CLUTTER_IS_BEHAVIOUR_SCALE (scale));
priv = scale->priv;
if (x_scale_start)
*x_scale_start = priv->x_scale_start;
if (x_scale_end)
*x_scale_end = priv->x_scale_end;
if (y_scale_start)
*y_scale_start = priv->y_scale_start;
if (y_scale_end)
*y_scale_end = priv->y_scale_end;
}