particle.java

面向对象技术

//定义particle类
public class Particle
{
	float velocityX, velocityY, x, y;
        public Particle()
	{
	}
	//initialize方法，负责初始化
	public void initialize(int mx, int my)
	{
		velocityX = (float)((Math.random()*0.5)-0.25f);
		velocityY = (float)((Math.random()*0.5)-0.25f);
		x = (float)(mx+velocityX);
		y = (float)(my+velocityY);
	}
	//update方法
	public void update(float[] v1, float[] v2, float[] v3, float[] v4, float[] v5, int i, boolean chaseMouse)
	{
		velocityX+=(v1[0]+v2[0]+v3[0]+v4[0]+v5[0]);
		velocityY+=(v1[1]+v2[1]+v3[1]+v4[1]+v5[1]);	
		x+=velocityX;
		y+=velocityY;      
		if(i==0 && !chaseMouse)
		{
			x+=velocityX*1.6f;
	                y+=velocityY*1.6f;
		}	
		if(Math.abs(velocityX) > 5.0f)
			velocityX = (velocityX/Math.abs(velocityX))*5.0f;
		if(Math.abs(velocityY) > 5.0f)
			velocityY = (velocityY/Math.abs(velocityY))*5.0f;
	}			
}