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clutter/clutter/clutter-page-turn-effect.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2010 Intel Corporation.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*
* Based on MxDeformPageTurn, written by:
* Chris Lord <chris@linux.intel.com>
*/
/**
* SECTION:clutter-page-turn-effect
* @Title: ClutterPageTurnEffect
* @Short_Description: A page turning effect
*
* A simple page turning effect
*
* #ClutterPageTurnEffect is available since Clutter 1.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <math.h>
#include "clutter-page-turn-effect.h"
#include "clutter-debug.h"
#include "clutter-private.h"
#define CLUTTER_PAGE_TURN_EFFECT_CLASS(k) (G_TYPE_CHECK_CLASS_CAST ((k), CLUTTER_TYPE_PAGE_TURN_EFFECT, ClutterPageTurnEffectClass))
#define CLUTTER_IS_PAGE_TURN_EFFECT_CLASS(k) (G_TYPE_CHECK_CLASS_TYPE ((k), CLUTTER_TYPE_PAGE_TURN_EFFECT))
#define CLUTTER_PAGE_TURN_EFFECT_GET_CLASS(o) (G_TYPE_INSTANCE_GET_CLASS ((o), CLUTTER_TYPE_PAGE_TURN_EFFECT, ClutterPageTurnEffectClass))
struct _ClutterPageTurnEffect
{
ClutterDeformEffect parent_instance;
gdouble period;
gdouble angle;
gfloat radius;
};
struct _ClutterPageTurnEffectClass
{
ClutterDeformEffectClass parent_class;
};
enum
{
PROP_0,
PROP_PERIOD,
PROP_ANGLE,
PROP_RADIUS,
PROP_LAST
};
static GParamSpec *obj_props[PROP_LAST];
G_DEFINE_TYPE (ClutterPageTurnEffect,
clutter_page_turn_effect,
CLUTTER_TYPE_DEFORM_EFFECT);
static void
clutter_page_turn_effect_deform_vertex (ClutterDeformEffect *effect,
gfloat width,
gfloat height,
CoglTextureVertex *vertex)
{
ClutterPageTurnEffect *self = CLUTTER_PAGE_TURN_EFFECT (effect);
gfloat cx, cy, rx, ry, radians, turn_angle;
guint shade;
if (self->period == 0.0)
return;
radians = self->angle / (180.0f / G_PI);
/* Rotate the point around the centre of the page-curl ray to align it with
* the y-axis.
*/
cx = (1.f - self->period) * width;
cy = (1.f - self->period) * height;
rx = ((vertex->x - cx) * cos (- radians))
- ((vertex->y - cy) * sin (- radians))
- self->radius;
ry = ((vertex->x - cx) * sin (- radians))
+ ((vertex->y - cy) * cos (- radians));
turn_angle = 0.f;
if (rx > self->radius * -2.0f)
{
/* Calculate the curl angle as a function from the distance of the curl
* ray (i.e. the page crease)
*/
turn_angle = (rx / self->radius * G_PI_2) - G_PI_2;
shade = (sin (turn_angle) * 96.0f) + 159.0f;
/* Add a gradient that makes it look like lighting and hides the switch
* between textures.
*/
cogl_color_init_from_4ub (&vertex->color, shade, shade, shade, 0xff);
}
if (rx > 0)
{
/* Make the curl radius smaller as more circles are formed (stops
* z-fighting and looks cool). Note that 10 is a semi-arbitrary
* number here - divide it by two and it's the amount of space
* between curled layers of the texture, in pixels.
*/
gfloat small_radius;
small_radius = self->radius
- MIN (self->radius, (turn_angle * 10) / G_PI);
/* Calculate a point on a cylinder (maybe make this a cone at some
* point) and rotate it by the specified angle.
*/
rx = (small_radius * cos (turn_angle)) + self->radius;
vertex->x = (rx * cos (radians)) - (ry * sin (radians)) + cx;
vertex->y = (rx * sin (radians)) + (ry * cos (radians)) + cy;
vertex->z = (small_radius * sin (turn_angle)) + self->radius;
}
}
static void
clutter_page_turn_effect_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterPageTurnEffect *effect = CLUTTER_PAGE_TURN_EFFECT (gobject);
switch (prop_id)
{
case PROP_PERIOD:
clutter_page_turn_effect_set_period (effect, g_value_get_double (value));
break;
case PROP_ANGLE:
clutter_page_turn_effect_set_angle (effect, g_value_get_double (value));
break;
case PROP_RADIUS:
clutter_page_turn_effect_set_radius (effect, g_value_get_float (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_page_turn_effect_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterPageTurnEffect *effect = CLUTTER_PAGE_TURN_EFFECT (gobject);
switch (prop_id)
{
case PROP_PERIOD:
g_value_set_double (value, effect->period);
break;
case PROP_ANGLE:
g_value_set_double (value, effect->angle);
break;
case PROP_RADIUS:
g_value_set_float (value, effect->radius);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_page_turn_effect_class_init (ClutterPageTurnEffectClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterDeformEffectClass *deform_class = CLUTTER_DEFORM_EFFECT_CLASS (klass);
GParamSpec *pspec;
gobject_class->set_property = clutter_page_turn_effect_set_property;
gobject_class->get_property = clutter_page_turn_effect_get_property;
/**
* ClutterPageTurnEffect:period:
*
* The period of the page turn, between 0.0 (no curling) and
* 1.0 (fully curled)
*
* Since: 1.4
*/
pspec = g_param_spec_double ("period",
"Period",
"The period of the page turn",
0.0, 1.0,
0.0,
CLUTTER_PARAM_READWRITE);
obj_props[PROP_PERIOD] = pspec;
g_object_class_install_property (gobject_class, PROP_PERIOD, pspec);
/**
* ClutterPageTurnEffect:angle:
*
* The angle of the page rotation, in degrees, between 0.0 and 360.0
*
* Since: 1.4
*/
pspec = g_param_spec_double ("angle",
"Angle",
"The angle of the page rotation, in degrees",
0.0, 360.0,
0.0,
CLUTTER_PARAM_READWRITE);
obj_props[PROP_ANGLE] = pspec;
g_object_class_install_property (gobject_class, PROP_ANGLE, pspec);
/**
* ClutterPageTurnEffect:radius:
*
* The radius of the page curl, in pixels
*
* Since: 1.4
*/
pspec = g_param_spec_float ("radius",
"Radius",
"The radius of the page curl",
-G_MAXFLOAT, G_MAXFLOAT,
24.0,
CLUTTER_PARAM_READWRITE);
obj_props[PROP_RADIUS] = pspec;
g_object_class_install_property (gobject_class, PROP_RADIUS, pspec);
deform_class->deform_vertex = clutter_page_turn_effect_deform_vertex;
}
static void
clutter_page_turn_effect_init (ClutterPageTurnEffect *self)
{
self->period = 0.0;
self->angle = 0.0;
self->radius = 24.0f;
}
/**
* clutter_page_turn_effect_new:
* @period: the period of the page curl, between 0.0 and 1.0
* @angle: the angle of the page curl, between 0.0 and 360.0
* @radius: the radius of the page curl, in pixels
*
* Creates a new #ClutterPageTurnEffect instance with the given parameters
*
* Return value: the newly created #ClutterPageTurnEffect
*
* Since: 1.4
*/
ClutterEffect *
clutter_page_turn_effect_new (gdouble period,
gdouble angle,
gfloat radius)
{
g_return_val_if_fail (period >= 0.0 && period <= 1.0, NULL);
g_return_val_if_fail (angle >= 0.0 && angle <= 360.0, NULL);
return g_object_new (CLUTTER_TYPE_PAGE_TURN_EFFECT,
"period", period,
"angle", angle,
"radius", radius,
NULL);
}
/**
* clutter_page_turn_effect_set_period:
* @effect: a #ClutterPageTurnEffect
* @period: the period of the page curl, between 0.0 and 1.0
*
* Sets the period of the page curling, between 0.0 (no curling)
* and 1.0 (fully curled)
*
* Since: 1.4
*/
void
clutter_page_turn_effect_set_period (ClutterPageTurnEffect *effect,
gdouble period)
{
g_return_if_fail (CLUTTER_IS_PAGE_TURN_EFFECT (effect));
g_return_if_fail (period >= 0.0 && period <= 1.0);
effect->period = period;
clutter_deform_effect_invalidate (CLUTTER_DEFORM_EFFECT (effect));
g_object_notify_by_pspec (G_OBJECT (effect), obj_props[PROP_PERIOD]);
}
/**
* clutter_page_turn_effect_get_period:
* @effect: a #ClutterPageTurnEffect
*
* Retrieves the value set using clutter_page_turn_effect_get_period()
*
* Return value: the period of the page curling
*
* Since: 1.4
*/
gdouble
clutter_page_turn_effect_get_period (ClutterPageTurnEffect *effect)
{
g_return_val_if_fail (CLUTTER_IS_PAGE_TURN_EFFECT (effect), 0.0);
return effect->period;
}
/**
* clutter_page_turn_effect_set_angle:
* @effect: #ClutterPageTurnEffect
* @angle: the angle of the page curl, in degrees
*
* Sets the angle of the page curling, in degrees
*
* Since: 1.4
*/
void
clutter_page_turn_effect_set_angle (ClutterPageTurnEffect *effect,
gdouble angle)
{
g_return_if_fail (CLUTTER_IS_PAGE_TURN_EFFECT (effect));
g_return_if_fail (angle >= 0.0 && angle <= 360.0);
effect->angle = angle;
clutter_deform_effect_invalidate (CLUTTER_DEFORM_EFFECT (effect));
g_object_notify_by_pspec (G_OBJECT (effect), obj_props[PROP_ANGLE]);
}
/**
* clutter_page_turn_effect_get_angle:
* @effect: a #ClutterPageTurnEffect:
*
* Retrieves the value set using clutter_page_turn_effect_get_angle()
*
* Return value: the angle of the page curling
*
* Since: 1.4
*/
gdouble
clutter_page_turn_effect_get_angle (ClutterPageTurnEffect *effect)
{
g_return_val_if_fail (CLUTTER_IS_PAGE_TURN_EFFECT (effect), 0.0);
return effect->angle;
}
/**
* clutter_page_turn_effect_set_radius:
* @effect: a #ClutterPageTurnEffect:
* @radius: the radius of the page curling, in pixels
*
* Sets the radius of the page curling
*
* Since: 1.4
*/
void
clutter_page_turn_effect_set_radius (ClutterPageTurnEffect *effect,
gfloat radius)
{
g_return_if_fail (CLUTTER_IS_PAGE_TURN_EFFECT (effect));
effect->radius = radius;
clutter_deform_effect_invalidate (CLUTTER_DEFORM_EFFECT (effect));
g_object_notify_by_pspec (G_OBJECT (effect), obj_props[PROP_RADIUS]);
}
/**
* clutter_page_turn_effect_get_radius:
* @effect: a #ClutterPageTurnEffect
*
* Retrieves the value set using clutter_page_turn_effect_set_radius()
*
* Return value: the radius of the page curling
*
* Since: 1.4
*/
gfloat
clutter_page_turn_effect_get_radius (ClutterPageTurnEffect *effect)
{
g_return_val_if_fail (CLUTTER_IS_PAGE_TURN_EFFECT (effect), 0.0);
return effect->radius;
}
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