Java Reference
In-Depth Information
Wrapping Up
MIDP 2.0 contains the Mobile Game API in
javax.microedition.lcdui.game
, a robust set of
classes you can use to implement your own games. This interface consists of five classes:
•
GameCanvas
: Lets you poll for keystrokes and structure your game around the notion
of a game loop using Java threads
•
LayerManager
: Responsible for managing visible elements on the screen in a Z-order
you define and draw
•
Layer
: Represents a single plane in the Z-order
•
TiledLayer
: An implementation of
Layer
you can use to create large bitmap images
from small tiles
•
Sprite
: An implementation of
Layer
you can use to create animations
Using the Mobile Game API, you structure your game MIDlet around the notion
of a game loop that runs in its own thread, managing events and updating game state.
Your game loop can poll for keystrokes or respond to events in the traditional manner,
and it draws to the screen as it needs to using the
GameCanvas
's
Graphics
context. The
LayerManager
class simplifies drawing by managing an array of
Layer
s, which each can
paint their own contents. The API defines two specific kinds of layers: the
TiledLayer
,
which is suitable for drawing large regions of a game such as the game level's back-
ground, and the
Sprite
, which helps you organize the frames of an animation for a
specific visible object.
