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() == 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)
