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Sprites were introducted in QuickTime 2.5 and have since been enhanced in later versions of QuickTime.

The metaphor of a sprite animation as a theatrical play is used, in which sprite tracks are characterized as the boundaries of the stage and a sprite world or a as the stage itself. To extend the metaphor, you may want to think of as actors performing on that stage.

Each has properties that describe its location and appearance at a given time. During an animation sequence, modifying the sprite’s properties causes it to change its appearance and move around the screen. Sprites may be mixed with still–image graphics to produce a wide variety of effects while using relatively little memory.

The QTPlugin provides the developers with the Sprite Framework to add sprite–based animation to their applications. The Sprite Framework, which is a set of classes, handles all the tasks necessary to compose and modify sprites, their backgrounds and properties, in addition to transferring the results to the screen or to an alternate destination.

The QTPlgSpriteProperties class is part of the Sprite Framework and, along with the class defines the basic objects you need to use to implement sprite–based animation. You can use instances of this class whether to setup the initial properties of a or modify its characteristics during the course of the animation (in this case the object represents an override sample).







The QTPlgSpriteProperties class constructors are called when you create a new instance of the class, while the ˜QTPlgSpriteProperties class destructor, is called automatically when the class is no more in use. Also, you can invoke the class destructor by setting the instance of the class to nil.

Once a new class instance is returned, it is good practice to check the class property to be sure that the new object can be used.


The class provides you with the following initializer methods:
()
This is the default class initializer. The properties of the object are set with the following values:
  • =""
  • =0
  • =1
  • =–1
  • =true
  • =
  • =
(other as QTPlgSpriteProperties)
This is the copy constructor. The properties of the object to be copied will be used to initialize the new class instance properties

a descriptive name for the current sprite
specifies the index that identifies the current sprite. This value is set automatically when appropriate
specifies the image the sprite is referring to. This value corresponds to the property of the class and it is set automatically when appropriate. Anyway, you can need to set this value by yourself if you want to add to a more sprites that share the same image
specifies a sprite’s layer in the animation. Sprites with lower layer numbers appear in front of sprites with higher layer numbers. To designate a sprite as a background sprite, you should assign it the special layer number 32767
specifies whether or not the sprite is visible. To make a sprite visible, you set this property to true. By default this property is set to false
specifies the graphics mode and blend color that indicates how to blend a sprite with any sprites behind it and with the background
determines the sprite’s location and scaling within its sprite world or sprite track. By modifying a sprite’s matrix, you can modify the sprite’s location so that it appears to move in a smooth path on the screen or so that it jumps from one place to another. You can modify a sprite’s size, so that it shrinks, grows, or stretches. Depending on which image compressor1 is used to create the sprite images, other transformations, such as rotation, may be supported as well. Translation–only matrices provide the best performance
at time, the plugin uses the Apple’s Animation codec to compress images to add to the

()
use this method to roll all of the class properties back to their initial state (see the for more details)
returns nothing