man Clutter::Alpha (3): A class for calculating a value as a function of time

DESCRIPTION

The Clutter::Alpha class binds together a Clutter::Timeline and a function. At each frame of the timeline, the Alpha object will call the given function, which will receive the value of the frame and must return a value between -1.0 and 2.0.

This is an example of a simple alpha function that increments linearly:

  sub linear {
      my ($alpha) = shift;
      return $alpha->get_timeline()->get_progress();
  }

A slightly more useful example:

  use Math::Trig;
  sub sine {
      my ($alpha) = @_;
      return sin($alpha->get_timeline()->get_progress() * pi);
  }

Instead of using real functions you can use a logical id for common easing functions, like: Clutter::LINEAR, Clutter::EASE_IN_CUBIC, Clutter::EASE_OUT_BOUNCE, etc. See Clutter::AnimationMode.

Alphas are used by Clutter::Behaviours and Clutter::Animationss to create implicit animations. By changing the alpha function inside a "Clutter::Alpha" object it's possible to change the progress of the animation.

HIERARCHY

  Glib::Object
  +----Glib::InitiallyUnowned
       +----Clutter::Alpha

METHODS

alpha = Clutter::Alpha->new ($timeline=undef, $mode=undef)

$timeline (Clutter::Timeline)
$mode (scalar)

double = $alpha->get_alpha

$alpha->set_func ($func, $data=undef)

$func (scalar) a code reference or undef
$data (scalar) a scalar to pass to func or undef

Sets the alpha function for alpha.

scalar = $alpha->get_mode

$alpha->set_mode ($mode)

$mode (scalar)

unsigned = $class->register_func ($func, $data)

$func (scalar)
$data (scalar)

timeline = $alpha->get_timeline

$alpha->set_timeline ($timeline)

$timeline (Clutter::Timeline)

PROPERTIES

'alpha' (double : readable / private): Alpha value
'mode' (Glib::ULong : readable / writable / construct / private): Progress mode
'timeline' (Clutter::Timeline : readable / writable / private): Timeline used by the alpha

ENUMS AND FLAGS

enum Clutter::AnimationMode

'custom-mode' / 'CLUTTER_CUSTOM_MODE'
'linear' / 'CLUTTER_LINEAR'
'ease-in-quad' / 'CLUTTER_EASE_IN_QUAD'
'ease-out-quad' / 'CLUTTER_EASE_OUT_QUAD'
'ease-in-out-quad' / 'CLUTTER_EASE_IN_OUT_QUAD'
'ease-in-cubic' / 'CLUTTER_EASE_IN_CUBIC'
'ease-out-cubic' / 'CLUTTER_EASE_OUT_CUBIC'
'ease-in-out-cubic' / 'CLUTTER_EASE_IN_OUT_CUBIC'
'ease-in-quart' / 'CLUTTER_EASE_IN_QUART'
'ease-out-quart' / 'CLUTTER_EASE_OUT_QUART'
'ease-in-out-quart' / 'CLUTTER_EASE_IN_OUT_QUART'
'ease-in-quint' / 'CLUTTER_EASE_IN_QUINT'
'ease-out-quint' / 'CLUTTER_EASE_OUT_QUINT'
'ease-in-out-quint' / 'CLUTTER_EASE_IN_OUT_QUINT'
'ease-in-sine' / 'CLUTTER_EASE_IN_SINE'
'ease-out-sine' / 'CLUTTER_EASE_OUT_SINE'
'ease-in-out-sine' / 'CLUTTER_EASE_IN_OUT_SINE'
'ease-in-expo' / 'CLUTTER_EASE_IN_EXPO'
'ease-out-expo' / 'CLUTTER_EASE_OUT_EXPO'
'ease-in-out-expo' / 'CLUTTER_EASE_IN_OUT_EXPO'
'ease-in-circ' / 'CLUTTER_EASE_IN_CIRC'
'ease-out-circ' / 'CLUTTER_EASE_OUT_CIRC'
'ease-in-out-circ' / 'CLUTTER_EASE_IN_OUT_CIRC'
'ease-in-elastic' / 'CLUTTER_EASE_IN_ELASTIC'
'ease-out-elastic' / 'CLUTTER_EASE_OUT_ELASTIC'
'ease-in-out-elastic' / 'CLUTTER_EASE_IN_OUT_ELASTIC'
'ease-in-back' / 'CLUTTER_EASE_IN_BACK'
'ease-out-back' / 'CLUTTER_EASE_OUT_BACK'
'ease-in-out-back' / 'CLUTTER_EASE_IN_OUT_BACK'
'ease-in-bounce' / 'CLUTTER_EASE_IN_BOUNCE'
'ease-out-bounce' / 'CLUTTER_EASE_OUT_BOUNCE'
'ease-in-out-bounce' / 'CLUTTER_EASE_IN_OUT_BOUNCE'
'animation-last' / 'CLUTTER_ANIMATION_LAST'

COPYRIGHT

This module is free software; you can redistribute it and/or modify it under the terms of either:

the GNU Lesser General Public Library version 2.1; or
the Artistic License, version 2.0.