I was trying to modify an existing code to rotate an image based on key presses. so far i’ve managed to do the following and I’m stuck. i’ve made use of Affine transform for the first time. The image rotates only once when it’s supposed to rotate as many times as the RIGHT key is pressed.
package aircraftPackage;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
public class RotateImage extends JFrame implements KeyListener {
private static final long serialVersionUID = 1L;
private Image TestImage;
private BufferedImage bf;
private int cordX = 100;
private int cordY = 100;
private double currentAngle;
public RotateImage(Image TestImage) {
this.TestImage = TestImage;
MediaTracker mt = new MediaTracker(this);
mt.addImage(TestImage, 0);
try {
mt.waitForID(0);
}
catch (Exception e) {
e.printStackTrace();
}
setTitle("Testing....");
setSize(500, 500);
imageLoader();
setVisible(true);
}
public void rotate() {
//rotate 5 degrees at a time
currentAngle+=5.0;
if (currentAngle >= 360.0) {
currentAngle = 0;
}
repaint();
}
public void imageLoader() {
try {
String testPath = "test.png";
TestImage = ImageIO.read(getClass().getResourceAsStream(testPath));
} catch (IOException ex) {
ex.printStackTrace();
}
addKeyListener(this);
}
public void update(Graphics g){
paint(g);
}
public void paint(Graphics g){
bf = new BufferedImage( this.getWidth(),this.getHeight(), BufferedImage.TYPE_INT_RGB);
try{
animation(bf.getGraphics());
g.drawImage(bf,0,0,null);
}catch(Exception ex){
}
}
public void animation(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D)g;
AffineTransform origXform = g2d.getTransform();
AffineTransform newXform = (AffineTransform)(origXform.clone());
//center of rotation is center of the panel
int xRot = this.getWidth()/2;
int yRot = this.getHeight()/2;
newXform.rotate(Math.toRadians(currentAngle), xRot, yRot);
g2d.setTransform(newXform);
//draw image centered in panel
int x = (getWidth() - TestImage.getWidth(this))/2;
int y = (getHeight() - TestImage.getHeight(this))/2;
g2d.drawImage(TestImage, x, y, this);
g2d.setTransform(origXform);
g.drawImage(TestImage, cordX, cordY, this);
}
public static void main(String[] args) {
new RotateImage(null);
}
public void keyPressed(KeyEvent ke) {
final RotateImage ri = new RotateImage(TestImage);
switch (ke.getKeyCode()) {
case KeyEvent.VK_RIGHT: {
cordX += 5;
ri.rotate();
}
break;
case KeyEvent.VK_LEFT: {
cordX -= 5;
}
break;
case KeyEvent.VK_DOWN: {
cordY += 5;
}
break;
case KeyEvent.VK_UP: {
cordY -= 3;
}
break;
}
repaint();
}
public void keyTyped(KeyEvent ke) {
}
public void keyReleased(KeyEvent ke) {
}
}
would be helpful if anyone could correct me on where im making the mistake.
Thanks
the problem you are creating new rotate image on each event key so it looks like not working
try to change the place of this line to be none modifiable on each key event
UPDATE:
the reason is because the value of constructor is null you should pass image
modify this on your code
1)make it static
2)define
3)call in main like this
step 4(removed)
UPDATE:
read these question on stack overflow
another question
UPDATE2:
here is the full code it works perfectly ( the right key ) dont foget to include you image in the same package and its the same type .png here is the code