多彩泡泡屏保特效(JAVA版)

• 一個多彩泡泡屏保特效(JS+CSS版) https://my.oschina.net/darkness/blog/360394 

  package screensaver;
  import java.awt.AlphaComposite;
  import java.awt.Composite;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.Image;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Timer;
  import java.util.TimerTask;
  
  import javax.swing.ImageIcon;
  import javax.swing.JFrame;
  import javax.swing.JPanel;
  
  import com.abigdreamer.infinity.common.util.IntegerValue;
  import com.sun.awt.AWTUtilities;
  
  @SuppressWarnings("restriction")
  public class BubblesScreensaver {
  	// 常量
  	static int D = 222; // 泡泡直徑
  	static double K = 0.999;
  
  	static double POW_RATE = 0.0001; // 補償機率
  	static double POW_RANGE = 0.8; // 補償範圍(基於誕生速度)
  
  	public static double SPEED_X() {
  		return 8 + (RND() * 4);
  	}
  
  	public static double SPEED_Y() {
  		return 6 + (RND() * 2);
  	}
  
  	static List<Bubble> arrBubs = new ArrayList<>();
  
  	static double iBottom;
  	static double iRight;
  
  	public static double SQRT(double a) {
  		return Math.sqrt(a);
  	}
  
  	public static double RND() {
  		return Math.random();
  	}
  
  	static int clientWidth;
  	static int clientHeight;
  
  	public static void main(String[] args) {
  		JFrame frame = new JFrame();
  		frame.setAlwaysOnTop(true);
  		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  		frame.setUndecorated(true);
  		frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
  		AWTUtilities.setWindowOpaque(frame, false);
  
  		final JPanel pane = new JPanel() {
  
  			private static final long serialVersionUID = 1L;
  
  			@Override
  			public void paint(Graphics g) {
  				super.paint(g);
  
  				Graphics2D g2d = (Graphics2D) g;
  
  				int n = arrBubs.size();
  
  				for (int j = 0; j < n; j++) {
  					Bubble bub = arrBubs.get(j);
  
  					float v;
  					g2d.translate(bub.x, bub.y);
  
  					g2d.drawImage(bub.images[3], 0, 0, null);
  
  					Composite old = g2d.getComposite();
  
  					for (int i = 0; i < 3; i++) {
  
  						v = (float) Math.abs(Math.sin(bub.kOpa[i] += bub.kStp[i] * Math.random()));
  						v *= bub.POW[i];
  
  						// v = ((v * 1e4) >> 0) / 1e4;
  
  						AlphaComposite alphaComposite = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, v);
  						g2d.setComposite(alphaComposite);// 透明度
  
  						g2d.drawImage(bub.images[i], 0, 0, null);// 背景
  					}
  
  					g2d.setComposite(old);
  
  					g2d.translate(-bub.x, -bub.y);
  				}
  
  			}
  		};
  
  		pane.setOpaque(false);
  		frame.setContentPane(pane);
  		frame.setVisible(true);
  
  		clientHeight = frame.getHeight();
  		clientWidth = frame.getWidth();
  
  		int MAX = 5;
  
  		IntegerValue integerValue = new IntegerValue();
  
  		Timer timer1 = new Timer();
  		timer1.schedule(new TimerTask() {
  			public void run() {
  				if (integerValue.get() < MAX) {
  					integerValue.add();
  					CreateBubble(frame);
  				} else {
  					timer1.cancel();
  				}
  			}
  		}, 10, 1000);// delay=2000毫秒 後執行該任務
  
  		Timer timer = new Timer();
  		timer.schedule(new TimerTask() {
  			public void run() {
  				update();
  				pane.repaint();
  			}
  		}, 10, 17);// delay=2000毫秒 後執行該任務
  
  	}
  
  	public static void CreateBubble(JFrame frame) {
  		Bubble bub = new Bubble();
  
  		bub.setX(0);
  		bub.setY(0);
  		bub.vx = SPEED_X();
  		bub.vy = SPEED_Y();
  
  		arrBubs.add(bub);
  	};
  
  	public static void update() {
  		int n = arrBubs.size();
  		int i, j;
  
  		updateWall();
  
  		for (i = 0; i < n; i++) {
  			Bubble bub = arrBubs.get(i);
  
  			bub.vx *= K;
  			bub.vy *= K;
  
  			if (RND() < POW_RATE) {
  				bub.vx = SPEED_X() * (1 + RND() * POW_RANGE);
  				bub.vy = SPEED_Y() * (1 + RND() * POW_RANGE);
  			}
  
  			bub.setX(bub.x + bub.vx);
  			bub.setY(bub.y + bub.vy);
  
  			checkWalls(bub);
  		}
  
  		Bubble bub, bub2;
  		for (i = 0; i < n - 1; i++) {
  			bub = arrBubs.get(i);
  
  			for (j = i + 1; j < n; j++) {
  				bub2 = arrBubs.get(j);
  				checkCollision(bub, bub2);
  			}
  		}
  	}
  
  	public static void updateWall() {
  		iRight = clientWidth - D;
  		iBottom = clientHeight - D;
  	}
  
  	public static void checkWalls(Bubble bub) {
  		if (bub.x < 0) {
  			bub.setX(0);
  			bub.vx *= -1;
  		} else if (bub.x > iRight) {
  			bub.setX(iRight);
  			bub.vx *= -1;
  		}
  
  		if (bub.y < 0) {
  			bub.setY(0);
  			bub.vy *= -1;
  		} else if (bub.y > iBottom) {
  			bub.setY(iBottom);
  			bub.vy *= -1;
  		}
  	}
  
  	static class Position {
  		public double x;
  		public double y;
  
  		public Position(double x, double y) {
  			this.x = x;
  			this.y = y;
  		}
  	}
  
  	public static Position rotate(double x, double y, double sin, double cos, boolean reverse) {
  		if (reverse)
  			return new Position((x * cos + y * sin), (y * cos - x * sin));
  		else
  			return new Position((x * cos - y * sin), (y * cos + x * sin));
  	}
  
  	public static void checkCollision(Bubble bub0, Bubble bub1) {
  		double dx = bub1.x - bub0.x;
  		double dy = bub1.y - bub0.y;
  		double dist = SQRT(dx * dx + dy * dy);
  
  		if (dist < D) {
  			// 計算角度和正餘弦值
  			double angle = Math.atan2(dy, dx);
  			double sin = Math.sin(angle);
  			double cos = Math.cos(angle);
  
  			// 旋轉 bub0 的位置
  			Position pos0 = new Position(0, 0);
  
  			// 旋轉 bub1 的速度
  			Position pos1 = rotate(dx, dy, sin, cos, true);
  
  			// 旋轉 bub0 的速度
  			Position vel0 = rotate(bub0.vx, bub0.vy, sin, cos, true);
  
  			// 旋轉 bub1 的速度
  			Position vel1 = rotate(bub1.vx, bub1.vy, sin, cos, true);
  
  			// 碰撞的做用力
  			double vxTotal = vel0.x - vel1.x;
  			vel0.x = vel1.x;
  			vel1.x = vxTotal + vel0.x;
  
  			// 更新位置
  			double absV = Math.abs(vel0.x) + Math.abs(vel1.x);
  			double overlap = D - Math.abs(pos0.x - pos1.x);
  
  			pos0.x += vel0.x / absV * overlap;
  			pos1.x += vel1.x / absV * overlap;
  
  			// 將位置旋轉回來
  			Position pos0F = rotate(pos0.x, pos0.y, sin, cos, false);
  			Position pos1F = rotate(pos1.x, pos1.y, sin, cos, false);
  
  			// 將位置調整爲屏幕的實際位置
  			bub1.setX(bub0.x + pos1F.x);
  			bub1.setY(bub0.y + pos1F.y);
  			bub0.setX(bub0.x + pos0F.x);
  			bub0.setY(bub0.y + pos0F.y);
  
  			// 將速度旋轉回來
  			Position vel0F = rotate(vel0.x, vel0.y, sin, cos, false);
  			Position vel1F = rotate(vel1.x, vel1.y, sin, cos, false);
  
  			bub0.vx = vel0F.x;
  			bub0.vy = vel0F.y;
  			bub1.vx = vel1F.x;
  			bub1.vy = vel1F.y;
  		}
  	}
  
  }
  
  class Bubble {
  
  	static int D = 222; // 泡泡直徑
  
  	double APLHA = 0.8;
  	double[] POW = new double[] { 1.0, APLHA, APLHA * APLHA };
  
  	double vx;
  	double vy;
  
  	double x;
  	double y;
  
  	double[] kOpa;
  	double[] kStp;
  
  	Image[] images = new Image[4];
  
  	public Bubble() {
  		double[] kOpa = new double[4];
  		double[] kStp = new double[4];
  
  		for (int i = 0; i < 4; i++) {
  			// 泡泡頂層
  			if (i == 3) {
  				ImageIcon imageIcon = new ImageIcon(getClass().getResource("heart.png"));
  				images[i] = imageIcon.getImage();
  
  			} else {
  				ImageIcon imageIcon = new ImageIcon(getClass().getResource("ch" + i + ".png"));
  				images[i] = imageIcon.getImage();
  			}
  
  			kOpa[i] = 3 * Math.random();
  			kStp[i] = 0.02 * Math.random();
  		}
  
  		this.kOpa = kOpa;
  		this.kStp = kStp;
  	}
  
  	public void setX(double x) {
  		this.x = x;
  	}
  
  	public void setY(double y) {
  		this.y = y;
  	}
  
  }