| Interface | Description | 
|---|---|
| Animatable | An Animatable object is one that may be incorporated into an Animation as
 one of its frames. | 
| Drawable | A Drawable object is one that visually represents itself with an image
 that is contextless by itself but can be drawn to a Graphics context. | 
| Event<T extends CellGame,U extends GameState<T,U,?>> | An Event represents a sequence of actions that can be taken as part of the
 mechanics of a GameState. | 
| Filter | A Filter represents an operation that transforms an image, such as
 replacing some of its colors with others. | 
| Loadable | A Loadable object is an asset, such as an image or sound effect, that can
 be manually loaded and unloaded into and out of memory. | 
| SafeIterator<E> | A SafeIterator is an Iterator whose Collection can be safely modified by
 some means other than the Iterator's own remove() method while the Iterator
 is active. | 
| Class | Description | 
|---|---|
| Animation | An Animation is a sequence of one or more Animatable frames that
 may be instantiated in an AnimationInstance in order to be displayed one
 after another and/or smoothly transitioned between. | 
| AnimationInstance | An AnimationInstance is an instance of an Animation that represents a
 point in the Animation and rates at which that point progresses through the
 Animation. | 
| CellGame | A CellGame is a game made with Cell2D. | 
| CellVector | A CellVector represents a point in continuous space as a two-dimensional
 vector. | 
| Color | A Color represents a color in RGBA format. | 
| ColorFilter | A ColorFilter is a Filter that blends the RGB value of each pixel in the
 original image with that of a single Color that it uses. | 
| ColorMapFilter | A ColorMapFilter is a Filter that uses a Map<Color,Color> to replace
 some RGB values with others in the filtered image. | 
| ColorMultiplyFilter | A ColorMultiplyFilter is a Filter that multiplies the red, green, blue,
 and alpha values of each pixel in the original image with those of a single
 Color that it uses. | 
| EventGroup<T extends CellGame,U extends GameState<T,U,?>> | An EventGroup is an ordered group of Events. | 
| Frac | The Frac class contains constants and methods related to fracunits,
 Cell2D's units of "continuous" length and time. | 
| GameState<T extends CellGame,U extends GameState<T,U,V>,V extends SubThinker<T,U,V>> | A GameState represents one state that a CellGame can be in, such as the
 main menu, the options menu, in the middle of a level, etc. | 
| Music | A Music track is a piece of music that can be played in the background of
 a CellGame. | 
| Sound | A Sound is a sound effect. | 
| Sprite | A Sprite is a static image that can be drawn to a Graphics context. | 
| SpriteSheet | A SpriteSheet is a rectangular grid of Sprites. | 
| SubThinker<T extends CellGame,U extends GameState<T,U,V>,V extends SubThinker<T,U,V>> | A SubThinker is a type of Thinker that contributes to the mechanics of
 another Thinker to which it is assigned. | 
| Thinker<T extends CellGame,U extends GameState<T,U,V>,V extends SubThinker<T,U,V>> | A Thinker is a collection of methods that contributes to the mechanics of
 a GameState to which it is assigned. | 
| Enum | Description | 
|---|---|
| Direction | A Direction is one of the four orthogonal directions. |