Key Frames

Every animation handled by a ClutterAnimator can be described in terms of "key frames". For each GObject property there can be multiple key frames, each one defined by the end value for the property to be computed starting from the current value to a specific point in time, using a given easing mode.

The point in time is defined using a value representing the progress in the normalized interval of [ 0, 1 ]. This maps the value returned by clutter_timeline_get_duration().

ClutterAnimator description for ClutterScript

ClutterAnimator defines a custom "properties" key which allows describing the key frames for objects as an array of key frames.

The properties array has the following syntax:

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{
  "properties" : [
    {
      "object" : object_id
      "name" : property_name
      "ease-in" : true_or_false
      "interpolation" : interpolation_value
      "keys" : [
        [ progress, easing_mode, final_value ]
      ]
  ]
}

The following JSON fragment defines a ClutterAnimator with the duration of 1 second and operating on the x and y properties of a ClutterActor named "rect-01", with two frames for each property. The first frame will linearly move the actor from its current position to the 100, 100 position in 20 percent of the duration of the animation; the second will using a cubic easing to move the actor to the 200, 200 coordinates.

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{
  "type" : "ClutterAnimator",
  "duration" : 1000,
  "properties" : [
    {
      "object" : "rect-01",
      "name" : "x",
      "ease-in" : true,
      "keys" : [
        [ 0.2, "linear",       100.0 ],
        [ 1.0, "easeOutCubic", 200.0 ]
      ]
    },
    {
      "object" : "rect-01",
      "name" : "y",
      "ease-in" : true,
      "keys" : [
        [ 0.2, "linear",       100.0 ],
        [ 1.0, "easeOutCubic", 200.0 ]
      ]
    }
  ]
}

clutter_animator_new ()

ClutterAnimator *
clutter_animator_new (void);

Creates a new ClutterAnimator instance

Since: 1.2

clutter_animator_set ()

void
clutter_animator_set (ClutterAnimator *animator,
                      gpointer first_object,
                      const gchar *first_property_name,
                      guint first_mode,
                      gdouble first_progress,
                      ...);

Adds multiple keys to a ClutterAnimator, specifying the value a given property should have at a given progress of the animation. The mode specified is the mode used when going to this key from the previous key of the property_name

If a given (object, property, progress) tuple already exist the mode and value will be replaced with the new values.

Since: 1.2

clutter_animator_set_key ()

ClutterAnimator *
clutter_animator_set_key (ClutterAnimator *animator,
                          GObject *object,
                          const gchar *property_name,
                          guint mode,
                          gdouble progress,
                          const GValue *value);

Sets a single key in the ClutterAnimator for the property_name of object at progress .

See also: clutter_animator_set()

Since: 1.2

clutter_animator_remove_key ()

void
clutter_animator_remove_key (ClutterAnimator *animator,
                             GObject *object,
                             const gchar *property_name,
                             gdouble progress);

Removes all keys matching the conditions specificed in the arguments.

Since: 1.2

clutter_animator_get_keys ()

GList *
clutter_animator_get_keys (ClutterAnimator *animator,
                           GObject *object,
                           const gchar *property_name,
                           gdouble progress);

Returns a list of pointers to opaque structures with accessor functions that describe the keys added to an animator.

Since: 1.2

clutter_animator_start ()

ClutterTimeline *
clutter_animator_start (ClutterAnimator *animator);

Start the ClutterAnimator, this is a thin wrapper that rewinds and starts the animators current timeline.

Since: 1.2

clutter_animator_compute_value ()

gboolean
clutter_animator_compute_value (ClutterAnimator *animator,
                                GObject *object,
                                const gchar *property_name,
                                gdouble progress,
                                GValue *value);

Compute the value for a managed property at a given progress.

If the property is an ease-in property, the current value of the property on the object will be used as the starting point for computation.

Since: 1.2

clutter_animator_set_timeline ()

void
clutter_animator_set_timeline (ClutterAnimator *animator,
                               ClutterTimeline *timeline);

Sets an external timeline that will be used for driving the animation

Since: 1.2

clutter_animator_get_timeline ()

ClutterTimeline *
clutter_animator_get_timeline (ClutterAnimator *animator);

Get the timeline hooked up for driving the ClutterAnimator

Since: 1.2

clutter_animator_set_duration ()

void
clutter_animator_set_duration (ClutterAnimator *animator,
                               guint duration);

Runs the timeline of the ClutterAnimator with a duration in msecs as specified.

Since: 1.2

clutter_animator_get_duration ()

guint
clutter_animator_get_duration (ClutterAnimator *animator);

Retrieves the current duration of an animator

Since: 1.2

clutter_animator_property_set_ease_in ()

void
clutter_animator_property_set_ease_in (ClutterAnimator *animator,
                                       GObject *object,
                                       const gchar *property_name,
                                       gboolean ease_in);

Sets whether a property value is to be eased into the animation.

Since: 1.2

clutter_animator_property_get_ease_in ()

gboolean
clutter_animator_property_get_ease_in (ClutterAnimator *animator,
                                       GObject *object,
                                       const gchar *property_name);

Checks if a property value is to be eased into the animation.

Since: 1.2

clutter_animator_property_set_interpolation ()

void
clutter_animator_property_set_interpolation
                               (ClutterAnimator *animator,
                                GObject *object,
                                const gchar *property_name,
                                ClutterInterpolation interpolation);

Set the interpolation method to use, CLUTTER_INTERPOLATION_LINEAR causes the values to linearly change between the values, and CLUTTER_INTERPOLATION_CUBIC causes the values to smoothly change between the values.

Since: 1.2

clutter_animator_property_get_interpolation ()

ClutterInterpolation
clutter_animator_property_get_interpolation
                               (ClutterAnimator *animator,
                                GObject *object,
                                const gchar *property_name);

Get the interpolation used by animator for a property on a particular object.

Since: 1.2

clutter_animator_key_get_object ()

GObject *
clutter_animator_key_get_object (const ClutterAnimatorKey *key);

Retrieves the object a key applies to.

Since: 1.2

clutter_animator_key_get_property_name ()

const gchar *
clutter_animator_key_get_property_name
                               (const ClutterAnimatorKey *key);

Retrieves the name of the property a key applies to.

Since: 1.2

clutter_animator_key_get_property_type ()

GType
clutter_animator_key_get_property_type
                               (const ClutterAnimatorKey *key);

Retrieves the GType of the property a key applies to

You can use this type to initialize the GValue to pass to clutter_animator_key_get_value()

Since: 1.2

clutter_animator_key_get_mode ()

gulong
clutter_animator_key_get_mode (const ClutterAnimatorKey *key);

Retrieves the mode of a ClutterAnimator key, for the first key of a property for an object this represents the whether the animation is open ended and or curved for the remainding keys for the property it represents the easing mode.

Since: 1.2

clutter_animator_key_get_progress ()

gdouble
clutter_animator_key_get_progress (const ClutterAnimatorKey *key);

Retrieves the progress of an clutter_animator_key

Since: 1.2

clutter_animator_key_get_value ()

gboolean
clutter_animator_key_get_value (const ClutterAnimatorKey *key,
                                GValue *value);

Retrieves a copy of the value for a ClutterAnimatorKey.

The passed in GValue needs to be already initialized for the value type of the key or to a type that allow transformation from the value type of the key.

Use g_value_unset() when done.

Since: 1.2

ClutterAnimator

typedef struct _ClutterAnimator ClutterAnimator;

The ClutterAnimator structure contains only private data and should be accessed using the provided API

Since: 1.2

struct ClutterAnimatorClass

struct ClutterAnimatorClass {
};

The ClutterAnimatorClass structure contains only private data

Since: 1.2

enum ClutterInterpolation

The mode of interpolation between key frames

Since: 1.2

ClutterAnimatorKey

typedef struct _ClutterAnimatorKey ClutterAnimatorKey;

A key frame inside a ClutterAnimator

Since: 1.2

The “duration” property

  “duration”                 guint

The duration of the ClutterTimeline used by the ClutterAnimator to drive the animation

Flags: Read / Write

Default value: 2000

Since: 1.2

The “timeline” property

  “timeline”                 ClutterTimeline *

The ClutterTimeline used by the ClutterAnimator to drive the animation

Flags: Read / Write

Since: 1.2