bulletsprite.java

用J2ME开发的射击游戏

import javax.microedition.lcdui.Image;
import javax.microedition.lcdui.game.Sprite;

public class BulletSprite extends Sprite{
	private int m_nSpeedX = 0;
	private int m_nSpeedY = 0;
	BulletSprite(Image image, int frameWidth, int frameHeight){
		super( image, frameWidth, frameHeight );
		defineReferencePixel( frameWidth / 2, frameHeight / 2 );
		setVisible(false);
	}
	public void SetSpeed( int nSpeedX, int nSpeedY ){
		m_nSpeedX = nSpeedX;
		m_nSpeedY = nSpeedY;
	}
	public void Logic(){
		if( isVisible() == false )
			return;
		int nX = getRefPixelX() + m_nSpeedX;
		int nY = getRefPixelY() + m_nSpeedY;
		setRefPixelPosition( nX, nY );
		if( getRefPixelX() < -10 || 
			getRefPixelX() > MainCanvas.m_nScrWidth + 10||
			getRefPixelY() < -10 || 
			getRefPixelY() > MainCanvas.m_nScrHeight + 10 )
				setVisible(false);
	}

}