先上图

xz1.gif

xz2.gif

其实比较简单，其实就是canvas绘制图形，步骤就不赘述了，直接上代码

public class Particle {

//火焰粒子坐标

private float x;

private float y;

public float xv = 1;//x轴加速度

public float yv = 1;//y轴加速度

public int alpha;

public Particle(float x, float y) {

this.x = x;

this.y = y;

}

public float getX() {

return x;

}

public void setX(float x) {

this.x = x;

}

public float getY() {

return y;

}

public void setY(float y) {

this.y = y;

//500-200为火焰的y轴左边范围，所以根据这个计算透明度

alpha = (int) ((y-200)*255/300);

}

}

粒子系统类

public class ParticleSystem {

private List particles = new ArrayList<>();

private int border_width = 20;

private Paint paint = new Paint();

private Random random;

public ParticleSystem(int particlesCount) {

paint.setColor(Color.RED);

random = new Random();

for (int i = 0; i < particlesCount; i++) {

Particle particle = new Particle(100 + 100 * random.nextFloat(), 500);

particle.xv = 0.5f - 1 * random.nextFloat();

particles.add(particle);

}

}

public void onDraw(Canvas canvas) {

for (int i = 0; i < particles.size(); i++) {

Particle particle = particles.get(i);

paint.setAlpha(particle.alpha);

canvas.drawRect(particle.getX(), particle.getY(), particle.getX() + border_width, particle.getY() + border_width, paint);

}

}

/**

* 粒子集合更新方法

*

* @param wind wind是风，0时代表无风，粒子不偏移

*/

public void update(float wind) {

for (int i = 0; i < particles.size(); i++) {

Particle particle = particles.get(i);

if (particle.xv > 0) {

//当初始加速度为正，就一直为正

particle.xv += 0.01f + wind;

} else {

//当初始加速度为负，就一直为正

particle.xv += -0.01f + wind;

}

particle.yv = particle.yv + 0.1f;

particle.setX(particle.getX() + particle.xv);

particle.setY(particle.getY() - particle.yv);

}

List list = new ArrayList<>();

list.addAll(particles);

for (Particle particle : list) {

if (particle.getY() < 200) {

particles.remove(particle);

}

}

for (int i = 0; i < 5; i++) {

Particle particle = new Particle(100 + 100 * random.nextFloat(), 500);

particle.xv = 0.5f - 1 * random.nextFloat();

particles.add(particle);

}

}

}

public class MyView extends SurfaceView implements SurfaceHolder.Callback{

private SurfaceHolder holder;

private MyThread thread;

public boolean running = true;

private ParticleSystem particleSystem;

private Paint paint;

public MyView(Context context) {

super(context);

init();

}

public MyView(Context context, AttributeSet attrs) {

super(context, attrs);

init();

}

private void init(){

holder = getHolder();

holder.addCallback(this);

thread = new MyThread();

particleSystem = new ParticleSystem(50);

paint = new Paint();

paint.setColor(Color.BLACK);

}

@Override

public void surfaceCreated(SurfaceHolder holder) {

running = true;

thread.start();

}

@Override

public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

@Override

public void surfaceDestroyed(SurfaceHolder holder) {

running = false;

}

class MyThread extends Thread{

@Override

public void run() {

super.run();

while(true){

if(running){

drawUI();

}

}

}

}

private void drawUI(){

Canvas canvas = holder.lockCanvas();

if(canvas==null){

return;

}

canvas.drawRect(0,0,getWidth(),getHeight(),paint);

particleSystem.onDraw(canvas);

particleSystem.update(new Random().nextFloat()*0.18f);

holder.unlockCanvasAndPost(canvas);

}

}