持球人带球行走示例（球与人保持一定距离）

来源：互联网发布：js typedarray 编辑：程序博客网时间：2024/04/27 21:57

package runball;

import java.applet.Applet;

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Image;

import java.util.Random;

/**

* 用户模仿球员带球跑动的运动过程

* 球员梯到球后球便会离开持球人脚下，并一开始

* 会以一个最大速度进行，随着摩擦力的增大，球速

* 会慢慢的降下来，此时持球人又追到球，然后踢出，

* 从而达到球一停一走的感觉。

* 要注意的是当球离开持球人的时候此时持球人并没有

* 发生改变；只有在其他球员抢到球后才会更改持球人

* 另外假如要实现球始终在持球人的脚下效果，则直接

* 根据持球人当前跑动的方向调整相应的坐标即可。

* @author Administrator

public class TakeBallRun extends Applet {

private Image offScreen;

private Graphics drawOffScreen;

private int appWidth, appHeight;

private Ball ball;

private Rect rect;

public void init() {

appWidth = 400;

appHeight = 300;

setSize(new Dimension(400, 300));

offScreen = this.createImage(appWidth, appHeight);

drawOffScreen = offScreen.getGraphics();

ball = new Ball(90, 160, 25, 25, appWidth, appHeight);

ball.dir = Entity.RIGHT; //这个方向是测试

rect = new Rect(30, 150, 30, 40, appWidth, appHeight);

new Thread(new PaintThread()).start();

}

public void paint(Graphics g) {

drawOffScreen.setColor(Color.BLACK);

drawOffScreen.fillRect(0, 0, appWidth, appHeight);

rect.draw(drawOffScreen);

ball.draw(drawOffScreen);

ball.move(rect);

rect.move(ball);

g.drawImage(offScreen, 0, 0, this);

}

public void update(Graphics g) {

paint(g);

}

class PaintThread implements Runnable {

@Override

public void run() {

while (true) {

try {

Thread.sleep(41);

} catch (InterruptedException e) {

e.printStackTrace();

}

repaint();

}

/**充当人物*/

class Rect extends Entity{

public Rect(int x, int y, int width, int height, int appWidth, int appHeight){

super(x, y, width, height, appWidth, appHeight);

speed = 4;

}

@Override

public void draw(Graphics g) {

//绘制人物的宽高

g.setColor(Color.RED);

g.fillRect((int)x, (int)y, width, height);

//绘制人物的脚,用于作碰撞检测

g.setColor(Color.GREEN);

g.drawRect((int)x + width / 4, (int)y + height / 4 * 2, width / 2, height / 2); //把宽高分成4等分

}

public void move(Entity entity){

Ball ball = (Ball)entity;

if(ball.isRun()){

return;

}

double spaceX = entity.x - x;

double spaceY = entity.y - y;

double radian = Math.atan2(spaceY, spaceX); //弧度

double angle = Math.abs(radian * 180 / Math.PI); //角度

if(entity.x >= x && entity.y <= y){ //第1象限

getBearing(angle, 7, 7, 1);

}else if(entity.y <= y && entity.x <= x){ //第2象限

getBearing(angle, 5, 5, 1);

}else if(entity.y >= y && entity.x <= x){ //第3象限

getBearing(180-angle,3,6,2);

}else if(entity.y >= y && entity.x >= x){ //第4象限

getBearing(angle,4,8,2);

}

vx = Math.cos(radian) * speed;

vy = Math.sin(radian) * speed;

boolean flag = isCollide(this, entity);

if(flag){

// System.out.println("人碰到了球，球开始移动");

//这里是测试，随机一个开球方向

// int[] dirs = new int[]{1,2,3,4,5,6,7,8};

// int temp = new Random(System.currentTimeMillis()).nextInt(dirs.length - 1);

// ball.setDir(temp);

ball.initDir();

}else{

x += vx;

y += vy;

// System.out.println("x: " + x + ",y: " + y);

}

private boolean isCollide(Entity e1, Entity e2){

if(e1.x + width / 4 < e2.x + e2.width && e1.x + width / 4 + e1.width / 2 > e2.x

&& e1.y + height / 4 * 2 < e2.y + e2.height && e1.y + height / 4 * 2 + e1.height / 2 > e2.height){

return true;

}

return false;

}

/**

* 把象限分成3分：23，23~68，68~90,都是跟X轴为起始旋转的角度

private void getBearing(double angle,int a, int b, int c){

if(angle < 23){

dir = a;

}else if(angle >= 23 && angle < 68){

dir = b;

}else if(angle >= 68){

dir = c;

}

/**Ball球*/

class Ball extends Entity{

private double friction; //摩擦力

private boolean isRun; //是否可以运动

public Ball(int x, int y, int width, int height, int appWidth, int appHeight){

super(x, y, width, height, appWidth, appHeight);

friction = 0.95;

speed = 8;

isRun = true;

changeDir(); //为vx、vy赋值

}

@Override

public void draw(Graphics g) {

g.setColor(Color.BLUE);

g.fillOval((int)x, (int)y, width, height);

}

@Override

public void move(Entity entity) {

vx *= friction;

vy *= friction;

x += vx;

y += vy;

if(vx < 1 && vy < 1){

isRun = false;

}else{

isRun = true;

}

boolean flag = isCollideBorder();

if(flag){

changeDir();

System.out.println("改变方向");

}

/**玩家碰到球后，将向量重置为

* 之前的状态, 还是朝之前的方向走

* 因为人碰到球后，只是朝球原来的方向行走即可

public void initDir(){

isRun = false;

changeDir();

}

private void changeDir(){

switch(dir){

case UP:

vx = 0;

vy = -speed;

break;

case DOWN:

vx = 0;

vy = speed;

break;

case LEFT:

vx = -speed;

vy = 0;

break;

case RIGHT:

vx = speed;

vy = 0;

break;

case LEFT_UP:

vx = -speed;

vy = -speed;

break;

case LEDT_DOWN:

vx = -speed;

vy = speed;

break;

case RIGHT_UP:

vx = speed;

vy = -speed;

break;

case RIGHT_DOWN:

vx = speed;

vy = speed;

break;

}

/**

* 检测是否碰到边界，如果碰到则反弹

* @return

private boolean isCollideBorder(){

System.out.println("x: "+ x);

if(x <= 0){

dir = RIGHT;

return true;

}else if(x + width >= appWidth){

dir = LEFT;

return true;

}

if(y <= 0){

dir = DOWN;

return true;

}else if(y + height >= appHeight){

dir = UP;

return true;

}

return false;

}

public void setDir(int dir){

this.dir = dir;

}

public final boolean isRun() {

return isRun;

}

public final void setRun(boolean isRun) {

this.isRun = isRun;

}

public void setVXY(int vx, int vy){

this.vx = vx;

this.vy = vy;

}

abstract class Entity{

public static final int LEFT = 3;

public static final int RIGHT = 4;

public static final int UP = 1;

public static final int DOWN = 2;

public static final int RIGHT_UP = 7;

public static final int RIGHT_DOWN = 8;

public static final int LEFT_UP = 5;

public static final int LEDT_DOWN = 6;

protected int dir = RIGHT;

protected double x, y, speed, maxSpeed;

protected int width, height;

protected double vx, vy; //速度向量

protected int appWidth, appHeight; //显示区域的宽度和高度

public Entity(int x, int y, int width, int height, int appWidth, int appHeight){

this.x = x;

this.y = y;

this.width = width;

this.height = height;

this.appWidth = appWidth;

this.appHeight = appHeight;

}

abstract public void draw(Graphics g);

abstract public void move(Entity entity);

}