Java applet code has scale variable for sizing window not sure what it's for

Question

I am having a bit of difficulty understanding what the purpose of this code might be. I put an applet into a Java decompiler and this is the code. Specifically, the line where it is setting the viewCenter is confusing. I am not sure what the purpose of this.scale might be.

import java.applet.Applet;
import java.awt.Color;
import java.awt.Event;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Image;
public class SeekFlee extends Applet implements Runnable {
 private Thread update;
 Seeker seeker;
 Seeker fleer;
 float scale = 15.0F;
 Vector3 viewCenter;
 int framesSinceTouch;
 Image canvasimage;
 Graphics canvasG;
 Graphics myG;
 int wxsize;
 int wysize;
 public void init() {
 super.init();
 this.wxsize = (getSize()).width;
 this.wysize = (getSize()).height;
 resize(this.wxsize, this.wysize);
 this.canvasimage = createImage(this.wxsize, this.wysize);
 this.canvasG = this.canvasimage.getGraphics();
 this.myG = getGraphics();
 this.viewCenter = new Vector3(this.wxsize / 2.0F * this.scale, this.wysize / 2.0F * this.scale, 0.0F);
 this.seeker = new Seeker();
 this.fleer = new Seeker();
 resetSeekers();
 }
 public boolean handleEvent(Event event) {
 boolean returnValue = false;
 return returnValue;
 }
 public static void main(String[] args) {
 Frame f = new Frame();
 SeekFlee app = new SeekFlee();
 app.init();
 app.start();
 f.add("Center", app);
 f.resize(515, 300);
 f.show();
 }
 public void start() {
 if (this.update == null) {
 this.update = new Thread(this);
 this.update.start();
 } 
 }
 public void stop() {
 if (this.update != null && this.update.isAlive())
 this.update.stop(); 
 this.update = null;
 }
 public void run() {
 while (true) {
 repaint();
 try {
 Thread.sleep(33L);
 } catch (InterruptedException interruptedException) {}
 } 
 }
 private void showbuffer() {
 this.myG.drawImage(this.canvasimage, 0, 0, this);
 }
 static final Color bgColor = new Color(0.9F, 0.9F, 0.6F);
 public void paint(Graphics g) {
 this.canvasG.setColor(bgColor);
 this.canvasG.fillRect(0, 0, this.wxsize, this.wysize);
 updateSeekers();
 this.canvasG.setColor(Color.black);
 this.canvasG.drawRect(0, 0, this.wxsize - 1, this.wysize - 1);
 showbuffer();
 }
 public void updateSeekers() {
 this.seeker.update();
 this.seeker.draw(this.canvasG, this.scale);
 this.fleer.update();
 this.fleer.draw(this.canvasG, this.scale);
 this.fleer.touch = this.seeker.touch;
 this.framesSinceTouch = this.seeker.touch ? (this.framesSinceTouch + 1) : 0;
 if (this.framesSinceTouch > 15)
 resetSeekers(); 
 }
 public void resetSeekers() {
 this.seeker.position.setUnitRandom();
 this.seeker.position.setScale(17.0F, this.seeker.position);
 this.seeker.position.setSum(this.viewCenter, this.seeker.position);
 this.seeker.position.z = 0.0F;
 this.seeker.velocity.setUnitRandom();
 this.seeker.velocity.setScale(this.seeker.maxSpeed, this.seeker.velocity);
 this.seeker.velocity.z = 0.0F;
 this.seeker.target.set(this.viewCenter);
 this.seeker.touch = false;
 this.fleer.seek = false;
 this.fleer.position.set(this.seeker.position);
 this.fleer.velocity.set(this.seeker.velocity);
 this.fleer.target.set(this.viewCenter);
 this.fleer.touch = false;
 }
 public void update(Graphics g) {
 paint(g);
 }
}

Vector3 is a class representing a 3D vector.

import java.util.Random;
public class Vector3 {
 public float x;
 public float y;
 public float z;
 public static final Vector3 zero = new Vector3();
 public Vector3() {
 setZero();
 }
 public Vector3(float x, float y, float z) {
 set(x, y, z);
 }
 public void set(Vector3 that) {
 this.x = that.x;
 this.y = that.y;
 this.z = that.z;
 }
 public void set(float x, float y, float z) {
 this.x = x;
 this.y = y;
 this.z = z;
 }
 public void setZero() {
 set(0.0F, 0.0F, 0.0F);
 }
 public boolean equals(Vector3 that) {
 if (this.x != that.x || 
 this.y != that.y || 
 this.z != that.z)
 return false; 
 return true;
 }
 public boolean equalsZero() {
 return !(this.x != 0.0F || this.y != 0.0F || this.z != 0.0F);
 }
 public float magnitude() {
 return (float)Math.sqrt(magnitudeSquared());
 }
 public float magnitudeSquared() {
 return this.x * this.x + 
 this.y * this.y + 
 this.z * this.z;
 }
 public float dot(Vector3 that) {
 return this.x * that.x + 
 this.y * that.y + 
 this.z * that.z;
 }
 static Random generator = new Random();
 public void setUnitRandom() {
 do {
 this.x = generator.nextFloat() * 2.0F - 1.0F;
 this.y = generator.nextFloat() * 2.0F - 1.0F;
 this.z = generator.nextFloat() * 2.0F - 1.0F;
 } while (magnitudeSquared() > 1.0F);
 }
 public float approximateLength() {
 float a = this.x;
 if (a < 0.0F)
 a = -a; 
 float b = this.y;
 if (b < 0.0F)
 b = -b; 
 float c = this.z;
 if (c < 0.0F)
 c = -c; 
 if (a < b) {
 float t = a;
 a = b;
 b = t;
 } 
 if (a < c) {
 float t = a;
 a = c;
 c = t;
 } 
 return a * 0.9375F + (b + c) * 0.375F;
 }
 private static Vector3 distTemp = new Vector3();
 public float distance(Vector3 v) {
 synchronized (distTemp) {
 distTemp.setDiff(this, v);
 return distTemp.magnitude();
 } 
 }
 public float approximateDistance(Vector3 v) {
 synchronized (distTemp) {
 distTemp.setDiff(this, v);
 return distTemp.approximateLength();
 } 
 }
 public void setSum(Vector3 a, Vector3 b) {
 a.x += b.x;
 a.y += b.y;
 a.z += b.z;
 }
 public void setDiff(Vector3 a, Vector3 b) {
 a.x -= b.x;
 a.y -= b.y;
 a.z -= b.z;
 }
 public void setScale(float a, Vector3 b) {
 this.x = a * b.x;
 this.y = a * b.y;
 this.z = a * b.z;
 }
 public void setCross(Vector3 a, Vector3 b) {
 set(a.y * b.z - a.z * b.y, 
 a.z * b.x - a.x * b.z, 
 a.x * b.y - a.y * b.x);
 }
 public void setInterp(float blend, Vector3 v0, Vector3 v1) {
 v0.x += blend * (v1.x - v0.x);
 v0.y += blend * (v1.y - v0.y);
 v0.z += blend * (v1.z - v0.z);
 }
 public void setNormalize() {
 float m = magnitude();
 if (m != 0.0F)
 setScale(1.0F / m, this); 
 }
 public void setApproximateNormalize() {
 float m = approximateLength();
 if (m != 0.0F)
 setScale(1.0F / m, this); 
 }
 public void setApproximateTruncate(float threshold) {
 float length = approximateLength();
 if (length > threshold)
 setScale(threshold / length, this); 
 }
}

edited to provide more details

• Elliott Frisch: Java applets are no longer supported. Not sure why you care.
• milkdrinker: I'm trying to convert some older code into a different language @ElliottFrisch
• Elliott Frisch: Well we can't tell based on one line of code either.
• aled: What package is Vector3? You should provide more details and explain what you are trying to achieve. Edit the question to add details.
• MarsAtomic: Looks like it's trying to establish the dead center of the current context (whatever UI object this is). scale may come from a scaling value associated with some preset size of the overall UI. That having been said... I'm only guessing. If you provided more code, you might get a more definitive answer, as opposed to speculation in a comment.