I am very confuse with my program in Gaphics2D

Question

I tried to draw a GeneralPath onto an image. Initially, I tried with fixed value like:
     float x1Points[]={50,100,200,400,120};
     float y1Points[]={350,100,50,150,400};
it can draw perfectly on an bufferedimage. But when I load a data file containing a set of values, nothing on GeneralPath appears on the image.
The whole class on this is from class A and class B open the data file and calling to this A by:
new A();
Is this possible?
P.S. I tried to post my program code on but no one wants to help me, so I try this way.

Answer 1

Yes, this is actually related to the previous question on something x and y coordinates. Actually, my problem occur when I pass 2 arrays of x and y to class B during I load a file in class A, I can't get it to draw GeneralPath. I have aske answer for maybe error in creating the GeneralPath but my GeneralPath is fine.
I try experimenting with a fixed value of:
float x[]={34.21,45.8976,23.6776,234.678,200};
float y[]={203,458,122.545,45,453};
It can only compile if I insert an "f" at the back of each float value. When I run it, it works and show this line. I was thinking of maybe the missing of "f" in the array, so I try in insert in anyway I can but have syntax error.Is it the "f" thing missing or I try to include in constructing in the bufferimage. The class B code is as follows:
import java.awt.*;
import java.io.*;
import java.util.Hashtable;
import javax.swing.*;
import java.awt.geom.*;
import java.awt.event.*;
import java.awt.image.*;
public class B extends JComponent {
protected float scale = 0.4f;
protected MediaTracker mt;
protected AffineTransform at1, at2;
protected BufferedImage bufferImage = null;
static final Color dblue = new Color(63, 64, 124);
static final Color lgray = new Color(105, 120, 141);
static final GradientPaint grayblue = new GradientPaint(0, 0, dblue,
0, 50, lgray);
protected int cx=0,cy=0;
private Graphics2D context;
private int w,h,sx=0,sy=0;
public B() {
String path = "Map3.jpg";
createImage(path);
addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
          cx=e.getX();
          cy=e.getY();
float value = 1.01f;
if (SwingUtilities.isLeftMouseButton(e)) {
value = 1.01f;
} else {
value = 0.99f;
          sx=getWidth()/2-cx+sx-((int)((float)(w)*scale/(float)(getWidth())*20));
          sy=getHeight()/2-cy+sy-((int)((float)(h)*scale/(float)(getHeight())*20));
          System.out.println((int)((float)(w)*scale/(float)(getWidth())*20));
          System.out.println((int)((float)(h)*scale/(float)(getHeight())*20));
updateComponent(value);
protected void createImage(String path) {
Image ocean = Toolkit.getDefaultToolkit().getImage(path);
try {
mt = new MediaTracker(this);
mt.addImage(ocean, 0);
mt.waitForID(0);
} catch (InterruptedException e) {
e.printStackTrace();
return;
createBufferedImage(ocean);
private BufferedImage createBufferedImage(Image ocean) {
w = ocean.getWidth(this);
h = ocean.getHeight(this);
bufferImage = new BufferedImage(w, h,BufferedImage.TYPE_INT_ARGB_PRE);
if (bufferImage == null) {
throw new NullPointerException(
"BufferedImage could not be created");
context = bufferImage.createGraphics();
     if(A.ix==null||A.iy==null){
context.drawImage(ocean, 0, 0, this);}
     else{
     BasicStroke wideStroke = new BasicStroke(12.0f);
     context.setStroke(wideStroke);
     context.setPaint(Color.blue);
     float x1Points[]=new float[A.ix.length];
     float y1Points[]=new float[A.iy.length];
     for(int i=0;i<GPS3.ix.length;i++){
     x1Points=GPS3.ix[i]*100000-299900;
     y1Points[i]=GPS3.iy[i]*1000-101710;
     System.out.println(x1Points[i]+" "+y1Points[i]);
GeneralPath polygon = new GeneralPath(GeneralPath.WIND_EVEN_ODD/*,x1Points.length*/);
polygon.moveTo(x1Points[0], y1Points[0]);
for ( int i = 1; i < x1Points.length; i++ ) {
polygon.lineTo(x1Points[i], y1Points[i]);
context.drawImage(ocean, 0, 0, this);
context.draw(polygon);
     repaint();
return bufferImage;
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
initMap(g2);
     at1=new AffineTransform();
at1 = AffineTransform.getTranslateInstance(sx,sy);
at2 = AffineTransform.getScaleInstance(scale, scale);
g2.setPaint(grayblue);
g2.fillRect(0, 0, getWidth(), getHeight());
if (!mt.checkID(0)) {
g.clearRect(0, 0, getWidth(), getHeight());
g.drawString("Please wait...", 0, getHeight() / 2);
AffineTransform old = g2.getTransform();
g2.setTransform(at1);
g2.transform(at2);
g2.drawImage(bufferImage, 0, 0, this);
g2.setTransform(old);
     repaint();
private void initMap(Graphics2D g2) {
Hashtable map = new Hashtable();
map.put(RenderingHints.KEY_RENDERING,
RenderingHints.VALUE_RENDER_SPEED);
map.put(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setRenderingHints(map);
public void updateComponent(float value) {
long start = System.currentTimeMillis();
int count = 20;
for (int i = 0; i < count; i++) {
scale *= value;
repaint();
RepaintManager.currentManager(ZoomMap.this).paintDirtyRegions();
getInfo(start, count);
private void getInfo(long start, int count) {
String nl = System.getProperty("line.separator");
long end = System.currentTimeMillis();
long dt = (end - start);
StringBuffer sb = new StringBuffer();
sb.append("Time = ").append(dt).append(", ").append(dt / count)
.append(" ms/count, ").append(count * 1000 / dt).append(" cps")
.append(nl).append("ScaleX : ").append(at2.getScaleX())
.append(", ").append("ScaleY : ").append(at2.getScaleY());
System.out.println(sb.toString());
public Dimension getPreferredSize() {
return new Dimension(bufferImage.getWidth(this) + 200,
bufferImage.getHeight(this) + 200);
Let me remind you that the value I passed to this class (B) is valid as I try to print the value(x and y but not ix and iy) and it really got value.I don't want to draw the GeneralPath in the paintComponent since when I scale the image, the GeneralPath also need to be scale together to see the effect.Thank you