ClutterKeyframeTransition

Keyframe property transition

ClutterKeyframeTransition allows animating a property by defining “key frames”: values at a normalized position on the transition duration.

The ClutterKeyframeTransition interpolates the value of the property to which it’s bound across these key values.

Setting up a ClutterKeyframeTransition means providing the times, values, and easing modes between these key frames, for instance:

  ClutterTransition *keyframe;

  keyframe = clutter_keyframe_transition_new ("opacity");
  clutter_transition_set_from (keyframe, G_TYPE_UINT, 255);
  clutter_transition_set_to (keyframe, G_TYPE_UINT, 0);
  clutter_keyframe_transition_set (CLUTTER_KEYFRAME_TRANSITION (keyframe),
                                   G_TYPE_UINT,
                                   1, /* number of key frames */
                                   0.5, 128, CLUTTER_EASE_IN_OUT_CUBIC);

The example above sets up a keyframe transition for the ClutterActor:opacity property of a ClutterActor; the transition starts and sets the value of the property to fully transparent; between the start of the transition and its mid point, it will animate the property to half opacity, using an easy in/easy out progress. Once the transition reaches the mid point, it will linearly fade the actor out until it reaches the end of the transition.

The ClutterKeyframeTransition will add an implicit key frame between the last and the 1.0 value, to interpolate to the final value of the transition’s interval..