Java开发网 - 经典Robocode例子代码--SnippetBot

Topic: 经典Robocode例子代码--SnippetBot

1.经典Robocode例子代码--SnippetBot

Posted by: luckyboy
Posted on: 2003-01-04 15:22

出处 http://www.robochina.org

经典Robocode例子代码

- -SnippetBot

看过了Robocode的文章，对Robocde有了个大概了解，现在我我们就一个经典的Robocode例子源代码来分析Robocode也java之间是多么的天衣无缝。

经典Robocode新手入门例子，包括了移动，雷达，炮管。。。，看完它并应用它，保你Robocode一日千里。

注：翻译风格有所改变，有部分没有进行翻译，有些加入了天翼.李(Skyala.Li)的心得。我们在此只注重原理，不重形式。

大家可自行看看没有翻译的部分,也正好学习外语嘛！最后引入了About Duelist,快打到世界第一的机器人发展过程的一段文字。

此物出天上，望君好收藏！源代码也可于此下载

package wind;

import robocode.*;

import java.awt.Color;

/**

* SnippetBot - a robot by Alisdair Owens

* This bot includes all sorts of useful snippets. It is not

* designed to be a good fighter (although it does well 1v1),

* just to show how certain things are done

* Bits of code lifted from Nicator and Chrisbot

* Conventions in this bot include: Use of radians throughout

* Storing absolute positions of enemy bots rather than relative ones

* Very little code in events

* These are all good programming practices for robocode

* There may also be methods that arent used; these might just be useful for you.

*/

public class SnippetBot extends AdvancedRobot

{

/**

* run: SnippetBot's default behavior

*/

Enemy target; //our current enemy 代表对手，包括了对手的所有有用参数

final double PI = Math.PI; //just a constant

int direction = 1; //direction we are heading...1 = forward, -1 = backwards

//我们坦克车头的方向

double firePower; //the power of the shot we will be using - set by do firePower() 设置我们的火力

public void run()

{

target = new Enemy(); //实例化Enemy()类

target.distance = 100000; //initialise the distance so that we can select a target

setColors(Color.red,Color.blue,Color.green); //sets the colours of the robot

//the next two lines mean that the turns of the robot, gun and radar are independant

//让gun,radar独立于坦克车

setAdjustGunForRobotTurn(true);

setAdjustRadarForGunTurn(true);

turnRadarRightRadians(2*PI); //turns the radar right around to get a view of the field 以弧度计算旋转一周

while(true)

{

doMovement(); //Move the bot 移动机器人

doFirePower(); //select the fire power to use 选择火力

doScanner(); //Oscillate the scanner over the bot 扫描

doGun(); //move the gun to predict where the enemy will be 预测敌人，调整炮管

out.println(target.distance);

fire(firePower); //所有动作完成后，开火

execute(); //execute all commands 上面使用的都为AdvancedRobot类中的非阻塞调用

//控制权在我们，所有这里用阻塞方法返回控制给机器人

}

}

　

/*

* This simple function calculates the fire power to use (from 0.1 to 3)

* based on the distance from the target. We will investigate the data structure

* holding the target data later.

*/

void doFirePower()

{

firePower = 400/target.distance;//selects a bullet power based on our distance away from the target

//根据敌人距离来选择火力,因为本身前进，后退为300，所以火力不会过大

}

　

/*

* This is the movememnt function. It will cause us

* to circle strafe the enemy (ie move back and forward,

* circling the enemy. if you don't know what strafing means

* play more quake.

* The direction variable is global to the class. Passing a

* negative number to setAhead causes the bot to go backwards

* 以目标主中心来回摆动

*/

void doMovement()

{

if (getTime()%20 == 0) //?过20的倍数时间就反转方向

{

//every twenty 'ticks'

direction *= -1; //reverse direction

setAhead(direction*300); //move in that direction

}

setTurnRightRadians(target.bearing + (PI/2)); //every turn move to circle strafe the enemy

//每一时间周期以敌人为中心绕圆运动

}

/*

* this scanner method allows us to make our scanner track our target.

* it will track to where our target is at the moment, and some further

* in case the target has moved. This way we always get up to the minute

* information on our target 雷达锁定目标

*/

void doScanner()

{

double radarOffset; //雷达偏移量

if (getTime() - target.ctime > 4) //???why来回扫了4个回合都没扫到意味失去了目标，再全扫一遍

{

//if we haven't seen anybody for a bit....

radarOffset = 360; //rotate the radar to find a target

}

else

{

//next is the amount we need to rotate the radar by to scan where the target is now

//通过扫描决定雷达旋转的弧度，"见基本原理方向剖析及目标锁定www.robochina.org".雷达弧度-敌人角度得到两者相差为旋转值

radarOffset = getRadarHeadingRadians() - absbearing(getX(),getY(),target.x,target.y);

//this adds or subtracts small amounts from the bearing for the radar to produce the wobbling

//and make sure we don't lose the target

//在得到的角度中加或减一点角度，让雷达很小的范围内摆而不失去目标

if (radarOffset < 0)

radarOffset -= PI/8; //(0.375)

else

radarOffset += PI/8;

}

//turn the radar

setTurnRadarLeftRadians(NormaliseBearing(radarOffset)); //左转调整转动角度到PI内

}

/*

* This simple method moves the gun to the bearing that we predict the

* enemy will be by the time our bullet will get there.

* the 'absbearing' method can be found in the helper functions section

* the nextX and nextY method can be found in the 'Enemy' class description

*/

void doGun()

{

//works out how long it would take a bullet to travel to where the enemy is *now*

//this is the best estimation we have

//计算子弹到达目标的时间长speed = 20 - 3 * power;有计算公式,距离除速度=时间

long time = getTime() + (int)(target.distance/(20-(3*firePower)));

//offsets the gun by the angle to the next shot based on linear targeting provided by the enemy class

//以直线为目标，偏移子弹下一次发射的角度。（这样让子弹射空的几率减少。但对付不动的和做圆运动的机器人有问题）

//target.guesssX(),target.guessY()为目标移动后的坐标

double gunOffset = getGunHeadingRadians() - absbearing(getX(),getY(),target.guessX(time),target.guessY(time));

setTurnGunLeftRadians(NormaliseBearing(gunOffset)); //调整相对角度到2PI内

}

/*

* This set of helper methods. You may find several of these very useful

* They include the ability to find the angle to a point.

*/

//if a bearing is not within the -pi to pi range, alters it to provide the shortest angle

double NormaliseBearing(double ang)

{

if (ang > PI)

ang -= 2*PI;

if (ang < -PI)

ang += 2*PI;

return ang;

}

//if a heading is not within the 0 to 2pi range, alters it to provide the shortest angle

double NormaliseHeading(double ang)

{

if (ang > 2*PI)

ang -= 2*PI;

if (ang < 0)

ang += 2*PI;

return ang;

}

//returns the distance between two x,y coordinates '**'

//以两边长求得与对手之间的距离

public double getrange( double x1,double y1, double x2,double y2 )

{

double xo = x2-x1;

double yo = y2-y1;

double h = Math.sqrt( xo*xo + yo*yo );

return h;

}

//gets the absolute bearing between to x,y coordinates

//根据x,y的坐标求出绝对角度，见"坐标锁定"利用直角坐标系来反求出角度。？？？

public double absbearing( double x1,double y1, double x2,double y2 )

{

double xo = x2-x1;

double yo = y2-y1;

double h = getrange( x1,y1, x2,y2 );

if( xo > 0 && yo > 0 )

{

//反正弦定义，对边除斜边得弧度.以robocode中的绝对方向系及坐标系参照

//x,y为正右上角为0-90,x正y负右下角为90-180,x,y负左下角180-270,x负，y正右上角270-360

//此处要理解robocode中的绝对角度是上为0,下为180，如以中心为点划分象限则得到下面的结果

return Math.asin( xo / h );

}

if( xo > 0 && yo < 0 )

{

return Math.PI - Math.asin( xo / h ); //x为正,y为负第二象限角

}

if( xo < 0 && yo < 0 )

{

return Math.PI + Math.asin( -xo / h ); //第三象限内180+角度

}

if( xo < 0 && yo > 0 )

{

return 2.0*Math.PI - Math.asin( -xo / h ); //四象限360-角度

}

return 0;

}

/**

* onScannedRobot: What to do when you see another robot

* 扫描事件,也是初始化目标数据的过程

*/

public void onScannedRobot(ScannedRobotEvent e)

{

//if we have found a closer robot....

if ((e.getDistance() < target.distance)||(target.name == e.getName()))

{

//the next line gets the absolute bearing to the point where the bot is

//求得对手的绝对弧度

double absbearing_rad = (getHeadingRadians()+e.getBearingRadians())%(2*PI);

//this section sets all the information about our target

target.name = e.getName();

//求得对手的x,y坐标，见"robocode基本原理之坐标锁定"文章

target.x = getX()+Math.sin(absbearing_rad)*e.getDistance(); //works out the x coordinate of where the target is

target.y = getY()+Math.cos(absbearing_rad)*e.getDistance(); //works out the y coordinate of where the target is

target.bearing = e.getBearingRadians();

target.head = e.getHeadingRadians();

target.ctime = getTime(); //game time at which this scan was produced 扫描到机器人的游戏时间

target.speed = e.getVelocity(); //得到敌人速度

target.distance = e.getDistance();

}

}

public void onRobotDeath(RobotDeathEvent e)

{

if (e.getName() == target.name)

target.distance = 10000; //this will effectively make it search for a new target

}

}

/*

* This class holds scan data so that we can remember where enemies were

* and what they were doing when we last scanned then.

* You could make a hashtable (with the name of the enemy bot as key)

* or a vector of these so that you can remember where all of your enemies are

* in relation to you.

* This class also holds the guessX and guessY methods. These return where our targeting

* system thinks they will be if they travel in a straight line at the same speed

* as they are travelling now. You just need to pass the time at which you want to know

* where they will be.

* 保存我们扫描到的目标的所有有用数据，也可用hashtable，vector方法处理所有和我们有关的目标数据(用于群战)

* 中间的guessX,guessY方法是针对做直线均速运动机器人一个策略

*/

class Enemy

{

/*

* ok, we should really be using accessors and mutators here,

* (i.e getName() and setName()) but life's too short.

*/

String name;

public double bearing;

public double head;

public long ctime; //game time that the scan was produced

public double speed;

public double x,y;

public double distance;

public double guessX(long when)

{

//以扫描时和子弹到达的时间差＊最大速度=距离, 再用对手的坐标加上移动坐标得到敌人移动后的坐标

long diff = when - ctime;

return x+Math.sin(head)*speed*diff; //目标移动后的坐标

}

public double guessY(long when)

{

long diff = when - ctime;

return y+Math.cos(head)*speed*diff;

}

}

要想了解更多的相关资料请参考：

Robocode 中华联盟(http://www.robochina.org)