由于Java可以很輕易的完成比較復雜的數學運算，所以我們經常能看到物理領域的問題借助Java實現效果演示，下面我給出一個桌球碰撞的處理及繪制實例。
package org.test.mail;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Panel;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
/**
* <p>
* Title: LoonFramework
* </p>
* <p>
* Description:Java桌球演示
* </p>
* <p>
* Copyright: Copyright (c) 2007
* </p>
* <p>
* Company: LoonFramework
* </p>
*
* @author chenpeng
* @email：ceponline@yahoo.com.cn
* @version 0.1
*/
public class JavaBilliards extends Panel implements Runnable, MouseListener,
MouseMotionListener {
/**
*
*/
private static final long serialVersionUID = -5019885590391523441L;
// 球
private double _ball;
// 緩存用背景
private Image _screen;
// 畫布
private Graphics _graphics;
// 臺桌
private Image _table;
private double c[];
private double d[];
private double e[];
private double f[];
private int countBall;
private int h;
private double i[];
private double j[];
private double k[];
private double l[];
private double m[];
private double n[];
private double o[];
private double p[];
private boolean q[];
private double r;
private int a;
private int u;
private int v;
private int w;
private int x;
private boolean y;
private int z;
private int A;
/**
* 初始化
*
*/
public JavaBilliards() {
a = 0;
r = 10D;
z = 300;
A = 0;
setBounds(50, 50, 700, 350);
Frame frame = new Frame("Java桌球演示");
frame.add(this);
frame.setBounds(0, 0, 700, 380);
frame.setResizable(false);
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
requestFocus();
initialize();
}
public void initialize() {
// 基礎數據
base();
// 注入實例
immit();
// 緩存背景
_screen = new BufferedImage(this.getWidth(), this.getHeight(), 1);
// 背景圖形
_graphics = _screen.getGraphics();
// 繪制臺桌
makeTable();
// 設置監聽
addMouseListener(this);
addMouseMotionListener(this);
// 啟動
new Thread(this).start();
}
/**
* 初始化數據
*
*/
public void base() {
// 球體
_ball = 16D;
c = (new double[] { 40D, (double) (getWidth() - 40) });
d = (new double[] { c[0], (double) getHeight() - c[0] });
e = (new double[] { c[0] + 20D, (double) (getWidth() / 2), c[1] - 20D });
f = (new double[] { d[0] + 20D, d[1] - 20D });
}
/**
* 注入實例
*
*/
public void immit() {
countBall = 16;
i = new double[countBall];
j = new double[countBall];
k = new double[countBall];
l = new double[countBall];
m = new double[countBall];
n = new double[countBall];
o = new double[countBall];
p = new double[countBall];
q = new boolean[countBall];
// 打擊對象
hitObject();
// 打擊用球
hitBall();
}
/**
* 打擊用球數值
*
*/
public void hitBall() {
i[0] = (1.0D * (e[2] - e[0])) / 3D;
j[0] = this.getHeight() / 2;
k[0] = 0.0D;
l[0] = 0.0D;
q[0] = true;
}
/**
* 打擊對象
*
*/
public void hitObject() {
int il = 1;
h = countBall - 1;
// 求平方根
double dl = Math.sqrt(3.5D);
for (int j1 = 0; j1 < 5; j1++) {
double d2 = ((double) getWidth() * 2D) / 3D + (double) j1 * dl * r;
double d3 = (double) (getHeight() / 2) - (double) j1 * r;
for (int k1 = 0; k1 <= j1; k1++) {
i[il] = d2;
j[il] = d3;
k[il] = 0.0D;
l[il] = 0.0D;
q[il] = true;
d3 += 2D * r;
il++;
}
}
}
這么點代碼居然不能一次都發了……
/**
* 繪制臺球桌
*
*/
public void makeTable() {
_table = new BufferedImage(this.getWidth(), this.getHeight(), 1);
Graphics g = _table.getGraphics();
g.setColor(Color.GRAY);
g.fillRect(0, 0, getWidth(), getHeight());
g.setColor((new Color(200, 100, 50)).darker());
g.fill3DRect((int) c[0], (int) d[0], (int) (c[1] - c[0]),
(int) (d[1] - d[0]), true);
g.setColor(Color.BLACK);
g.fill3DRect((int) e[0], (int) f[0], (int) (e[2] - e[0]),
(int) (f[1] - f[0]), false);
g.setColor(Color.GREEN.darker());
g.drawLine((int) ((1.0D * (e[2] - e[0])) / 3D), (int) f[0],
(int) ((1.0D * (e[2] - e[0])) / 3D), (int) f[1]);
g.fillOval((int) ((1.0D * (e[2] - e[0])) / 3D) - 2,
(int) ((f[1] + f[0]) / 2D) - 2, 4, 4);
g.drawArc((int) ((1.0D * (e[2] - e[0])) / 3D) - 20,
(int) ((f[1] + f[0]) / 2D) - 20, 40, 40, 90, 180);
g.setColor(Color.BLACK);
double d1 = _ball - 2D;
for (int i1 = 0; i1 < 3; i1++) {
for (int j1 = 0; j1 < 2; j1++) {
g.fillOval((int) (e[i1] - d1), (int) (f[j1] - d1),
(int) (2D * d1), (int) (2D * d1));
}
}
}
/**
* 線程處理
*/
public void run() {
long timeStart;
timeStart = System.currentTimeMillis();
// 死循環反復處理
for (;;) {
long timeEnd = System.currentTimeMillis();
switch (a) {
default:
break;
case 1:
// 根據時間換算運動軌跡
conversion(timeEnd - timeStart);
// 過程處理
course();
break;
case 2:
conversion(timeEnd - timeStart);
// 過程處理
course();
boolean flag = true;
for (int i1 = 0; flag && i1 < countBall; i1++)
flag = k[i1] == 0.0D && l[i1] == 0.0D;
if (flag) {
a = 1;
// 擊球
if (!q[0]) {
hitBall();
}
}
if (h == 0)
a = 3;
break;
case 3:
hitObject();
hitBall();
a = 0;
break;
}
repaint();
timeStart = timeEnd;
try {
Thread.sleep(10L);
} catch (InterruptedException e1) {
e1.printStackTrace();
}
}
}
public void course() {
// 限制區域
limit();
// 入袋處理
pocket();
// 運動演算
play();
for (int i1 = 0; i1 < countBall; i1++)
if (q[i1]) {
i[i1] = m[i1];
j[i1] = n[i1];
}
}
/**
* 變換時間為動作數據
*
* @param value
*/
public void conversion(long value) {
double d1 = (double) value / 1000D;
for (int i1 = 0; i1 < countBall; i1++)
if (q[i1]) {
m[i1] = i[i1] + k[i1] * d1;
n[i1] = j[i1] + l[i1] * d1;
k[i1] *= 0.98999999999999999D;
l[i1] *= 0.98999999999999999D;
if (Math.abs(Math.hypot(k[i1], l[i1])) < 2D) {
k[i1] = 0.0D;
l[i1] = 0.0D;
}
}
}
public void pocket() {
for (int i1 = 0; i1 < countBall; i1++)
if (q[i1]) {
for (int j1 = 0; j1 < 3; j1++) {
for (int k1 = 0; k1 < 2; k1++)
if (Math.hypot(e[j1] - i[i1], f[k1] - j[i1]) < _ball) {
q[i1] = false;
if (i1 != 0) {
h--;
}
k[i1] = 0.0D;
l[i1] = 0.0D;
}
}
}
}
public void play() {
for (int i1 = 0; i1 < countBall; i1++)
if (q[i1]) {
for (int j1 = i1 + 1; j1 < countBall; j1++) {
boolean flag;
if (q[j1] && (flag = randball(i1, j1))) {
for (int k1 = 0; k1 < 10 && flag; k1++) {
m[i1] = (m[i1] + i[i1]) / 2D;
n[i1] = (n[i1] + j[i1]) / 2D;
m[j1] = (m[j1] + i[j1]) / 2D;
n[j1] = (n[j1] + j[j1]) / 2D;
flag = randball(i1, j1);
}
if (flag) {
m[i1] = i[i1];
n[i1] = j[i1];
m[j1] = i[j1];
n[j1] = j[j1];
}
double d1 = m[j1] - m[i1];
double d2 = n[j1] - n[i1];
double d3 = Math.hypot(m[i1] - m[j1], n[i1] - n[j1]);
double d4 = d1 / d3;
double d5 = d2 / d3;
o[j1] = k[j1] - k[j1] * d4 * d4;
o[j1] -= l[j1] * d4 * d5;
o[j1] += k[i1] * d4 * d4;
o[j1] += l[i1] * d4 * d5;
p[j1] = l[j1] - l[j1] * d5 * d5;
p[j1] -= k[j1] * d4 * d5;
p[j1] += k[i1] * d4 * d5;
p[j1] += l[i1] * d5 * d5;
o[i1] = k[i1] - k[i1] * d4 * d4;
o[i1] -= l[i1] * d4 * d5;
o[i1] += k[j1] * d4 * d4;
o[i1] += l[j1] * d4 * d5;
p[i1] = l[i1] - l[i1] * d5 * d5;
p[i1] -= k[i1] * d4 * d5;
p[i1] += k[j1] * d4 * d5;
p[i1] += l[j1] * d5 * d5;
k[i1] = o[i1];
l[i1] = p[i1];
k[j1] = o[j1];
l[j1] = p[j1];
}
}
}
}
public boolean randball(int i1, int j1) {
// hypot隨機決定兩值之一
return Math.hypot(m[i1] - m[j1], n[i1] - n[j1]) < 2D * r;
}
/**
* 限制區域
*
*/
public void limit() {
for (int i = 0; i < countBall; i++)
if (q[i]) {
if (m[i] - r < e[0]) {
m[i] = e[0] + r;
k[i] *= -1D;
} else if (m[i] + r > e[2]) {
m[i] = e[2] - r;
k[i] *= -1D;
}
if (n[i] - r < f[0]) {
n[i] = f[0] + r;
l[i] *= -1D;
} else if (n[i] + r > f[1]) {
n[i] = f[1] - r;
l[i] *= -1D;
}
}
}
public void makeScreen(Graphics screenGraphics) {
screenGraphics.drawImage(_table, 0, 0, null);
if (q[0]) {
_graphics.setColor(Color.WHITE);
_graphics.fillOval((int) (i[0] - r), (int) (j[0] - r),
(int) (r * 2D), (int) (r * 2D));
}
screenGraphics.setColor(Color.RED);
for (int i1 = 1; i1 < countBall; i1++)
if (q[i1])
screenGraphics.fillOval((int) (i[i1] - r), (int) (j[i1] - r),
(int) (r * 2D), (int) (r * 2D));
screenGraphics.setColor(Color.BLACK);
for (int j1 = 0; j1 < countBall; j1++)
if (q[j1]) {
screenGraphics.drawOval((int) (i[j1] - r), (int) (j[j1] - r),
(int) (r * 2D), (int) (r * 2D));
}
if (a == 1){
makeHelper(screenGraphics);
}
if (a == 0) {
int k1 = getWidth() / 2 - 85;
int l1 = getHeight() / 2;
screenGraphics.setColor(Color.BLACK);
screenGraphics.drawString("點擊畫面開始", k1 + 2, l1 + 2);
if ((System.currentTimeMillis() / 1000L & 1L) == 0L){
screenGraphics.setColor(Color.YELLOW);
}
else{
screenGraphics.setColor(Color.CYAN);
}
screenGraphics.drawString("點擊畫面開始", k1, l1);
}
}
/**
* 繪制球桿及輔助線
*
* @param screenGraphics
*/
public void makeHelper(Graphics screenGraphics) {
double d1 = Math.hypot(i[0] - (double) u, j[0] - (double) v);
double d2 = ((double) u - i[0]) / d1;
double d3 = ((double) v - j[0]) / d1;
double d4 = y ? n() / 10D : 1.0D;
double d5 = i[0] + d2 * (r + d4);
double d6 = i[0] + d2 * (r + (double) z + d4);
double d7 = j[0] + d3 * (r + d4);
double d8 = j[0] + d3 * (r + (double) z + d4);
screenGraphics.setColor(Color.ORANGE);
screenGraphics.drawLine((int) d5, (int) d7, (int) d6, (int) d8);
int i1 = 0;
int j1 = y ? (int) (150D * (d4 / 1000D)) : 15;
double d9;
double d10 = (d9 = 30D) * d2;
double d11 = d9 * d3;
double d12 = i[0] + (double) A * d2;
double d13 = j[0] + (double) A * d3;
A--;
A %= d9;
screenGraphics.setColor(Color.WHITE);
for (; i1 < j1; i1++) {
if (d12 < e[0]) {
d12 = e[0] - d12;
d12 = e[0] + d12;
d10 *= -1D;
} else if (d12 > e[2]) {
d12 -= e[2];
d12 = e[2] - d12;
d10 *= -1D;
}
if (d13 < f[0]) {
d13 = f[0] - d13;
d13 = f[0] + d13;
d11 *= -1D;
} else if (d13 > f[1]) {
d13 -= f[1];
d13 = f[1] - d13;
d11 *= -1D;
}
screenGraphics.fillOval((int) d12 - 2, (int) d13 - 2, 4, 4);
d12 -= d10;
d13 -= d11;
}
}
public double n() {
if (y) {
return Math.min(1000D, 10D * Math.hypot(i[0] - (double) w, j[0]
- (double) x));
} else {
return Math.min(1000D, 10D * Math.hypot(u - w, v - x));
}
}
public void update(Graphics g) {
paint(g);
}
public void paint(Graphics g) {
makeScreen(_graphics);
g.drawImage(_screen, 0, 0, null);
}
public void mousePressed(MouseEvent mouseevent) {
y = true;
}
public void mouseReleased(MouseEvent mouseevent) {
if (a == 1) {
double d1 = Math.hypot(i[0] - (double) u, j[0] - (double) v);
double d2 = (i[0] - (double) u) / d1;
double d3 = (j[0] - (double) v) / d1;
double d4;
if ((d4 = n()) > 0.0D) {
a = 2;
k[0] = d4 * d2;
l[0] = d4 * d3;
}
}
y = false;
}
public void mouseClicked(MouseEvent mouseevent) {
if (a == 0)
a = 1;
}
public void mouseEntered(MouseEvent mouseevent) {
}
public void mouseExited(MouseEvent mouseevent) {
}
public void mouseMoved(MouseEvent mouseevent) {
w = mouseevent.getX();
x = mouseevent.getY();
u = w;
v = x;
}
public void mouseDragged(MouseEvent mouseevent) {
w = mouseevent.getX();
x = mouseevent.getY();
}
public static void main(String args[]) {
new JavaBilliards();
}
}
運行結果如下：
PS:本來今天想寫個關于javamail方面的，后來覺得要寫的東西太多臨時改主意了……
package org.test.mail;import java.awt.Color;import java.awt.Frame;import java.awt.Graphics;import java.awt.Image;import java.awt.Panel;import java.awt.event.MouseEvent;import java.awt.event.MouseListener;import java.awt.event.MouseMotionListener;import java.awt.event.WindowAdapter;import java.awt.event.WindowEvent;import java.awt.image.BufferedImage;/**
* <p> * Title: LoonFramework * </p> * <p> * Description:Java桌球演示 * </p> * <p> * Copyright: Copyright (c) 2007 * </p> * <p> * Company: LoonFramework * </p> * * @author chenpeng * @email：ceponline@yahoo.com.cn * @version 0.1 */public class JavaBilliards extends Panel implements Runnable, MouseListener, MouseMotionListener { /**
* */ private static final long serialVersionUID = -5019885590391523441L; // 球 private double _ball; // 緩存用背景 private Image _screen; // 畫布 private Graphics _graphics; // 臺桌 private Image _table; private double c[]; private double d[]; private double e[]; private double f[]; private int countBall; private int h; private double i[]; private double j[]; private double k[]; private double l[]; private double m[]; private double n[]; private double o[]; private double p[]; private boolean q[]; private double r; private int a; private int u; private int v; private int w; private int x; private boolean y; private int z; private int A; /** * 初始化 * */ public JavaBilliards() { a = 0; r = 10D; z = 300; A = 0; setBounds(50, 50, 700, 350); Frame frame = new Frame("Java桌球演示"); frame.add(this); frame.setBounds(0, 0, 700, 380); frame.setResizable(false); frame.setVisible(true); frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); requestFocus(); initialize(); } public void initialize() { // 基礎數據 base(); // 注入實例 immit(); // 緩存背景 _screen = new BufferedImage(this.getWidth(), this.getHeight(), 1); // 背景圖形 _graphics = _screen.getGraphics(); // 繪制臺桌 makeTable(); // 設置監聽 addMouseListener(this); addMouseMotionListener(this); // 啟動 new Thread(this).start(); } /** * 初始化數據 * */ public void base() { // 球體 _ball = 16D; c = (new double[] { 40D, (double) (getWidth() - 40) }); d = (new double[] { c[0], (double) getHeight() - c[0] }); e = (new double[] { c[0] + 20D, (double) (getWidth() / 2), c[1] - 20D }); f = (new double[] { d[0] + 20D, d[1] - 20D }); } /** * 注入實例 * */ public void immit() { countBall = 16; i = new double[countBall]; j = new double[countBall]; k = new double[countBall]; l = new double[countBall]; m = new double[countBall]; n = new double[countBall]; o = new double[countBall]; p = new double[countBall]; q = new boolean[countBall]; // 打擊對象 hitObject(); // 打擊用球 hitBall(); } /** * 打擊用球數值 * */ public void hitBall() { i[0] = (1.0D * (e[2] - e[0])) / 3D; j[0] = this.getHeight() / 2; k[0] = 0.0D; l[0] = 0.0D; q[0] = true; } /** * 打擊對象 * */ public void hitObject() { int il = 1; h = countBall - 1; // 求平方根 double dl = Math.sqrt(3.5D); for (int j1 = 0; j1 < 5; j1++) { double d2 = ((double) getWidth() * 2D) / 3D + (double) j1 * dl * r; double d3 = (double) (getHeight() / 2) - (double) j1 * r; for (int k1 = 0; k1 <= j1; k1++) { i[il] = d2; j[il] = d3; k[il] = 0.0D; l[il] = 0.0D; q[il] = true; d3 += 2D * r; il++; } } } 這么點代碼居然不能一次都發了……
/** * 繪制臺球桌 * */ public void makeTable() { _table = new BufferedImage(this.getWidth(), this.getHeight(), 1); Graphics g = _table.getGraphics(); g.setColor(Color.GRAY); g.fillRect(0, 0, getWidth(), getHeight()); g.setColor((new Color(200, 100, 50)).darker()); g.fill3DRect((int) c[0], (int) d[0], (int) (c[1] - c[0]), (int) (d[1] - d[0]), true); g.setColor(Color.BLACK); g.fill3DRect((int) e[0], (int) f[0], (int) (e[2] - e[0]), (int) (f[1] - f[0]), false); g.setColor(Color.GREEN.darker()); g.drawLine((int) ((1.0D * (e[2] - e[0])) / 3D), (int) f[0], (int) ((1.0D * (e[2] - e[0])) / 3D), (int) f[1]); g.fillOval((int) ((1.0D * (e[2] - e[0])) / 3D) - 2, (int) ((f[1] + f[0]) / 2D) - 2, 4, 4); g.drawArc((int) ((1.0D * (e[2] - e[0])) / 3D) - 20, (int) ((f[1] + f[0]) / 2D) - 20, 40, 40, 90, 180); g.setColor(Color.BLACK); double d1 = _ball - 2D; for (int i1 = 0; i1 < 3; i1++) { for (int j1 = 0; j1 < 2; j1++) { g.fillOval((int) (e[i1] - d1), (int) (f[j1] - d1), (int) (2D * d1), (int) (2D * d1)); } } } /** * 線程處理 */ public void run() { long timeStart; timeStart = System.currentTimeMillis(); // 死循環反復處理 for (;;) { long timeEnd = System.currentTimeMillis(); switch (a) { default: break; case 1: // 根據時間換算運動軌跡 conversion(timeEnd - timeStart); // 過程處理 course(); break; case 2: conversion(timeEnd - timeStart); // 過程處理 course(); boolean flag = true; for (int i1 = 0; flag && i1 < countBall; i1++) flag = k[i1] == 0.0D && l[i1] == 0.0D; if (flag) { a = 1; // 擊球 if (!q[0]) { hitBall(); } } if (h == 0) a = 3; break; case 3: hitObject(); hitBall(); a = 0; break; } repaint(); timeStart = timeEnd; try { Thread.sleep(10L); } catch (InterruptedException e1) { e1.printStackTrace(); } } } public void course() { // 限制區域 limit(); // 入袋處理 pocket(); // 運動演算 play(); for (int i1 = 0; i1 < countBall; i1++) if (q[i1]) { i[i1] = m[i1]; j[i1] = n[i1]; } } /** * 變換時間為動作數據 * * @param value */ public void conversion(long value) { double d1 = (double) value / 1000D; for (int i1 = 0; i1 < countBall; i1++) if (q[i1]) { m[i1] = i[i1] + k[i1] * d1; n[i1] = j[i1] + l[i1] * d1; k[i1] *= 0.98999999999999999D; l[i1] *= 0.98999999999999999D; if (Math.abs(Math.hypot(k[i1], l[i1])) < 2D) { k[i1] = 0.0D; l[i1] = 0.0D; } } } public void pocket() { for (int i1 = 0; i1 < countBall; i1++) if (q[i1]) { for (int j1 = 0; j1 < 3; j1++) { for (int k1 = 0; k1 < 2; k1++) if (Math.hypot(e[j1] - i[i1], f[k1] - j[i1]) < _ball) { q[i1] = false; if (i1 != 0) { h--; } k[i1] = 0.0D; l[i1] = 0.0D; } } } } public void play() { for (int i1 = 0; i1 < countBall; i1++) if (q[i1]) { for (int j1 = i1 + 1; j1 < countBall; j1++) { boolean flag; if (q[j1] && (flag = randball(i1, j1))) { for (int k1 = 0; k1 < 10 && flag; k1++) { m[i1] = (m[i1] + i[i1]) / 2D; n[i1] = (n[i1] + j[i1]) / 2D; m[j1] = (m[j1] + i[j1]) / 2D; n[j1] = (n[j1] + j[j1]) / 2D; flag = randball(i1, j1); } if (flag) { m[i1] = i[i1]; n[i1] = j[i1]; m[j1] = i[j1]; n[j1] = j[j1]; } double d1 = m[j1] - m[i1]; double d2 = n[j1] - n[i1]; double d3 = Math.hypot(m[i1] - m[j1], n[i1] - n[j1]); double d4 = d1 / d3; double d5 = d2 / d3; o[j1] = k[j1] - k[j1] * d4 * d4; o[j1] -= l[j1] * d4 * d5; o[j1] += k[i1] * d4 * d4; o[j1] += l[i1] * d4 * d5; p[j1] = l[j1] - l[j1] * d5 * d5; p[j1] -= k[j1] * d4 * d5; p[j1] += k[i1] * d4 * d5; p[j1] += l[i1] * d5 * d5; o[i1] = k[i1] - k[i1] * d4 * d4; o[i1] -= l[i1] * d4 * d5; o[i1] += k[j1] * d4 * d4; o[i1] += l[j1] * d4 * d5; p[i1] = l[i1] - l[i1] * d5 * d5; p[i1] -= k[i1] * d4 * d5; p[i1] += k[j1] * d4 * d5; p[i1] += l[j1] * d5 * d5; k[i1] = o[i1]; l[i1] = p[i1]; k[j1] = o[j1]; l[j1] = p[j1]; } } } } public boolean randball(int i1, int j1) { // hypot隨機決定兩值之一 return Math.hypot(m[i1] - m[j1], n[i1] - n[j1]) < 2D * r; } /** * 限制區域 * */ public void limit() { for (int i = 0; i < countBall; i++) if (q[i]) { if (m[i] - r < e[0]) { m[i] = e[0] + r; k[i] *= -1D; } else if (m[i] + r > e[2]) { m[i] = e[2] - r; k[i] *= -1D; } if (n[i] - r < f[0]) { n[i] = f[0] + r; l[i] *= -1D; } else if (n[i] + r > f[1]) { n[i] = f[1] - r; l[i] *= -1D; } } } public void makeScreen(Graphics screenGraphics) { screenGraphics.drawImage(_table, 0, 0, null); if (q[0]) { _graphics.setColor(Color.WHITE); _graphics.fillOval((int) (i[0] - r), (int) (j[0] - r), (int) (r * 2D), (int) (r * 2D)); } screenGraphics.setColor(Color.RED); for (int i1 = 1; i1 < countBall; i1++) if (q[i1]) screenGraphics.fillOval((int) (i[i1] - r), (int) (j[i1] - r), (int) (r * 2D), (int) (r * 2D)); screenGraphics.setColor(Color.BLACK); for (int j1 = 0; j1 < countBall; j1++) if (q[j1]) { screenGraphics.drawOval((int) (i[j1] - r), (int) (j[j1] - r), (int) (r * 2D), (int) (r * 2D)); } if (a == 1){ makeHelper(screenGraphics); } if (a == 0) { int k1 = getWidth() / 2 - 85; int l1 = getHeight() / 2; screenGraphics.setColor(Color.BLACK); screenGraphics.drawString("點擊畫面開始", k1 + 2, l1 + 2); if ((System.currentTimeMillis() / 1000L & 1L) == 0L){ screenGraphics.setColor(Color.YELLOW); } else{ screenGraphics.setColor(Color.CYAN); } screenGraphics.drawString("點擊畫面開始", k1, l1); } } /** * 繪制球桿及輔助線 * * @param screenGraphics */ public void makeHelper(Graphics screenGraphics) { double d1 = Math.hypot(i[0] - (double) u, j[0] - (double) v); double d2 = ((double) u - i[0]) / d1; double d3 = ((double) v - j[0]) / d1; double d4 = y ? n() / 10D : 1.0D; double d5 = i[0] + d2 * (r + d4); double d6 = i[0] + d2 * (r + (double) z + d4); double d7 = j[0] + d3 * (r + d4); double d8 = j[0] + d3 * (r + (double) z + d4); screenGraphics.setColor(Color.ORANGE); screenGraphics.drawLine((int) d5, (int) d7, (int) d6, (int) d8); int i1 = 0; int j1 = y ? (int) (150D * (d4 / 1000D)) : 15; double d9; double d10 = (d9 = 30D) * d2; double d11 = d9 * d3; double d12 = i[0] + (double) A * d2; double d13 = j[0] + (double) A * d3; A--; A %= d9; screenGraphics.setColor(Color.WHITE); for (; i1 < j1; i1++) { if (d12 < e[0]) { d12 = e[0] - d12; d12 = e[0] + d12; d10 *= -1D; } else if (d12 > e[2]) { d12 -= e[2]; d12 = e[2] - d12; d10 *= -1D; } if (d13 < f[0]) { d13 = f[0] - d13; d13 = f[0] + d13; d11 *= -1D; } else if (d13 > f[1]) { d13 -= f[1]; d13 = f[1] - d13; d11 *= -1D; } screenGraphics.fillOval((int) d12 - 2, (int) d13 - 2, 4, 4); d12 -= d10; d13 -= d11; } } public double n() { if (y) { return Math.min(1000D, 10D * Math.hypot(i[0] - (double) w, j[0] - (double) x)); } else { return Math.min(1000D, 10D * Math.hypot(u - w, v - x)); } } public void update(Graphics g) { paint(g); } public void paint(Graphics g) { makeScreen(_graphics); g.drawImage(_screen, 0, 0, null); } public void mousePressed(MouseEvent mouseevent) { y = true; } public void mouseReleased(MouseEvent mouseevent) { if (a == 1) { double d1 = Math.hypot(i[0] - (double) u, j[0] - (double) v); double d2 = (i[0] - (double) u) / d1; double d3 = (j[0] - (double) v) / d1; double d4; if ((d4 = n()) > 0.0D) { a = 2; k[0] = d4 * d2; l[0] = d4 * d3; } } y = false; } public void mouseClicked(MouseEvent mouseevent) { if (a == 0) a = 1; } public void mouseEntered(MouseEvent mouseevent) { } public void mouseExited(MouseEvent mouseevent) { } public void mouseMoved(MouseEvent mouseevent) { w = mouseevent.getX(); x = mouseevent.getY(); u = w; v = x; } public void mouseDragged(MouseEvent mouseevent) { w = mouseevent.getX(); x = mouseevent.getY(); } public static void main(String args[]) { new JavaBilliards(); }}運行結果如下：
PS:本來今天想寫個關于javamail方面的，后來覺得要寫的東西太多臨時改主意了……
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