The Game API - Beginning J2ME: From Novice to Professional - page 264

Table 14-2. Collision Detection with Sprite

Target Intersecting Rectangle Pixel Level

Sprite Compares collision rectangles Compares pixels inside the collision

rectangles

TiledLayer Compares the Sprite 's collision

rectangle and tiles in the TiledLayer

Compares pixels inside the Sprite 's
collision rectangle with pixels in the
TiledLayer

Image Compares the Sprite 's collision

rectangle and the Image 's bounds

Compares pixels inside the Sprite 's
collision rectangle with pixels in the
Image

Copying Sprites
Sprite includes a copy constructor:

public Sprite(Sprite s)

This is more powerful than you might think. It creates a new Sprite with all of the attributes of
the original, including

• Source image frames

• Frame sequence

• Current frame

• Current transformation

• Reference pixel

• Collision rectangle

Putting It All Together
QuatschCanvas , shown in Listing 14-2, is an example that showcases many of the features of the
Game API. Although it looks long, it's broken into manageable methods and demonstrates
quite a few features of the Game API:

• Using an animation loop in GameCanvas

Polling for key state using GameCanvas •

•Using a LayerManager to maintain multiple layers

Creating a Sprite and TiledLayer s •

Animating a Sprite , including changing frame sequences and transformations •

Using an animated tile in a TiledLayer •