Android粒子效果

ActivityMain.java

 

public class DrawThread extends Thread {
    ParticleView pv;
    SurfaceHolder suraceHolder;
    boolean isRunning;
    int sleepSpan = 15;
    long start = System.nanoTime();
    int count = 0;
    public DrawThread(ParticleView pv, SurfaceHolder suraceHolder) {
        this.isRunning = true;
        this.pv = pv;
        this.suraceHolder = suraceHolder;
    }

    @Override
    public void run() {
        Canvas canvas = null;
        while(isRunning){
            try{
                canvas = suraceHolder.lockCanvas();
                synchronized(suraceHolder){
                    pv.doDraw(canvas);
                }
            }catch(Exception e){
                e.printStackTrace();
            }finally{
                if(canvas!=null){
                    suraceHolder.unlockCanvasAndPost(canvas);
                }
            }
            this.count++;
            if(count == 20){
                count = 0;
                long tempStamp = System.nanoTime(); //获取当前时间
                long span = tempStamp - start;      //获取时间间隔
                start = tempStamp;                  //为start重新赋值
                double fps = Math.round(100000000000.0/span*20)/100.0;//计算帧速率
                pv.fps = "FPS:"+fps;//将计算出的帧速率设置到BallView的相应字符串对象中

            }
            try{
                Thread.sleep(sleepSpan);//线程休眠一段时间
            }
            catch(Exception e){
                e.printStackTrace();//捕获并打印异常
            }
        }
    }

}

DrawThread.java

 

public class ActivityMain extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);      //不显示标题
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        ParticleView lz = new ParticleView(this);
        setContentView(lz);
    }
}

Particle.java

 

public class Particle {
    int color;          //粒子颜色
    int r;              //粒子半径
    double ver_v;       //垂直速度
    double hor_v;       //水平速度
    int startX;         //初始X坐标
    int startY;         //初始Y坐标
    int x;              //实时X坐标
    int y;              //实时Y坐标
    double startTime;   //起始时间

    public Particle(int color, int r, double ver_v, double hor_v, int x, int y, double startTime) {
        super();
        this.color = color;
        this.r = r;
        this.ver_v = ver_v;
        this.hor_v = hor_v;
        this.startX = x;
        this.startY = y;
        this.x = x;
        this.y = y;
        this.startTime = startTime;
    }
}

ParticleSet.java

 

public class ParticleSet {
    ArrayList<Particle> particleSet;
    public ParticleSet(){
        particleSet = new ArrayList<Particle>();
    }

    public void addParticle(int count,double startTime){
        for(int i=0;i<count;i++){
            int color = this.getColor(i);
            int r = 1;
            double ver_v = -30 + 10*(Math.random());
            double hor_v = 10 - 20*(Math.random());
            int x = 160;
            int y = (int)(100 - 10*(Math.random()));
            Particle particle = new Particle(color, r, ver_v, hor_v, x, y, startTime);
            particleSet.add(particle);
        }
    }
    public int getColor(int i){
        int color = Color.RED;
        switch(i%4){
            case 0:
                color = Color.RED;
                break;
            case 1:
                color = Color.BLUE;
                break;
            case 2:
                color = Color.YELLOW;
                break;
            case 3:
                color = Color.GRAY;
                break;
        }
        return color;
    }
}

ParticleThread.java

 

public class ParticleThread extends Thread{
    boolean isRunning;
    ParticleView father;
    int sleepSpan = 80;
    double time = 0;
    double span = 0.15;

    public ParticleThread(ParticleView father) {
        this.isRunning = true;
        this.father = father;
    }

    @Override
    public void run() {
        while(isRunning){
            father.ps.addParticle(5, time);
            ArrayList<Particle> tempSet = father.ps.particleSet;
            int count = tempSet.size();
            for(int i=0;i<count;i++){
                Particle particle = tempSet.get(i);
                double timeSpan = time - particle.startTime;
                //计算X坐标
                int tempx = (int)(particle.startX+particle.hor_v*timeSpan);
                //计算Y坐标
                int tempy = (int)(particle.startY+particle.ver_v*timeSpan+4.9*timeSpan*timeSpan);
                //超过屏幕下边
                if(tempy>300){
                    tempSet.remove(particle);
                    count = tempSet.size();
                }
                particle.x = tempx;
                particle.y = tempy;
            }
            time += span;
            try{
                Thread.sleep(sleepSpan);
            }catch(Exception ex){
                ex.printStackTrace();
            }
        }
        super.run();
    }
}

 

ParticleView.java

 

public class ParticleView extends SurfaceView implements SurfaceHolder.Callback{
    public static final int DIE_OUT_LINE = 300;
    DrawThread dt;
    ParticleSet ps;
    ParticleThread pt;
    String fps="FPS:N/A";


    public ParticleView(Context context) {
        super(context);
        this.getHolder().addCallback(this);
        dt = new DrawThread(this,getHolder());
        ps = new ParticleSet();
        pt = new ParticleThread(this);
    }

    @Override
    public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
        // TODO Auto-generated method stub

    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        if(!dt.isAlive()){
            dt.start();
        }
        if(!pt.isAlive()){
            pt.start();
        }
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        dt.isRunning = false;
        dt = null;
    }

    public void doDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        canvas.drawColor(Color.BLACK);
        ArrayList<Particle> particleSet = ps.particleSet;
        Paint paint = new Paint();
        //绘制粒子
        for(int i=0;i<particleSet.size();i++){
            Particle p = particleSet.get(i);
            paint.setColor(p.color);
            int tempX = p.x;
            int tempY = p.y;
            int tempR = p.r;
            RectF oval = new RectF(tempX,tempY,tempX+2*tempR, tempY+2*tempR);
            canvas.drawOval(oval, paint);
        }
        paint.setColor(Color.WHITE);
        paint.setTextSize(18);              //字体大小
        paint.setAntiAlias(true);           //设置抗锯齿
        canvas.drawText(fps, 15, 15, paint);
    }
}

运行结果