Sprite Track Property Atoms 8

The following section describes sprite track property atoms. Track property atoms are applied to the whole track, not just to a single sample. See "Authoring Wired Movies and Sprite Animations," for information on other track property atoms and how to add them to the sprite track's media.

Constant descriptions

kSpriteTrackPropertyHasActions: You must add an atom of this type with its leaf data set to true if you want the movie controller to execute the actions in your sprite track's media. The atom's leaf data is of type Boolean . The default value is false , so it is very important to add an atom of this type if you want interactivity to take place.
kSpriteTrackPropertyQTIdleEventsFrequency: You must add an atom of this type if you want the Sprites in your sprite track to receive kQTEventIdle QuickTime events. The atom's leaf data is of type UInt32 . The value is the mimimum number of ticks that must pass before the next QTIdle event is sent . Each tick is 1/60th of one second. To specify "Idle as fast as possible," set the value to 0. The default value is kNoQTIdleEvents which means don't send any idle events.; It is possible that for small idle event frequencies, the movie will not be able to keep up, in which case they will be sent as fast as possible.; Since sending idle events takes up some time, it is best to specify the largest frequency that produces the results that you desire, or kNoQTIdleEvents if you do not need them.
kSpriteTrackPropertyVisible: You may cause the entire sprite track to be invisible by setting the value of this Boolean property to false . This is useful for using a sprite track as a hidden button track--for example, placing an invisible sprite track over a Video Track would allow the characters in the video to be clicked on. The default value is visible ( true ).
kSpriteTrackPropertyScaleSpritesToScaleWorld: You may cause each sprite to be rescaled when the sprite track is resized by setting the value of this Boolean property to true . Setting this property can improve the drawing performance and quality of a scaled sprite track. This is particularly useful for sprite images compressed with codecs which are resolution-independent, such as the Curve codec. The default value for this property is false .