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How to rotate a bitmap with AffineTransform

I'm trying to create a simple program that displays a bitmap zombie picture and then rotates it around using AffineTransform and Thread. I followed the example I had to accomplish this, but whenever I run the program the zombie bitmap just rotates once and stops. Also, for some reason when I painted the zombie bitmap, the image is partially off the screen along the y-axis.
So my questions are: why is the bitmap not rotating and why is the bitmap off the screen.
Code is as follows:
import java.awt.*;// Graphics class
import java.awt.geom.*;
import java.net.*;//URL navigation
import javax.swing.*;//JFrame
import java.util.*;//Toolkit
public class BitMapZombies2 extends JFrame implements Runnable
{
private Image zombieOneRight;
Thread zombieRun;
public static void main (String[] args)
{
new BitMapZombies2();
}
public BitMapZombies2()
{
super("Bit Map Zombies..RUN FOR YOUR LIFE!!!");
setSize(800,600);
setVisible(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Toolkit Zkit = Toolkit.getDefaultToolkit();
zombieOneLeft = Zkit.getImage(getURL("_images/_production_images/zombie_1_left_75h.png"));
zombieOneRight = Zkit.getImage(getURL("_images/_production_images/zombie_1_right_75h.png"));
zombieRun = new Thread(this);
zombieRun.start();
}
AffineTransform zombieIdentity = new AffineTransform();
private URL getURL(String filename)
{
URL url = null;
try
{
url = this.getClass().getResource(filename);
}
catch (Exception e) {}
return url;
}
public void paint(Graphics z)
{
Graphics2D z2d = (Graphics2D) z;
AffineTransform ZombiePowered = new AffineTransform();
z2d.setColor(Color.BLACK);
z2d.fillRect(0,0, 800, 600);
ZombiePowered.setTransform(zombieIdentity);
ZombiePowered.rotate(2,37.5,37.5);
z2d.drawImage(zombieOneRight,ZombiePowered,this);
}
public void run()
{
Thread zT = Thread.currentThread();
while (zT == zombieRun)
{
try
{
Thread.sleep(500);
}
catch(InterruptedException e)
{
e.printStackTrace();
}
repaint();
}
}
}
Appreciate any help I can get on this.

Commenting your code:
AffineTransform ZombiePowered = new AffineTransform();//Create an Id. transform
ZombiePowered.setTransform(zombieIdentity);//Set it as a copy of an Id. transform
ZombiePowered.rotate(2, 37.5, 37.5);//Concatenate the rotation with the Id. transform
z2d.drawImage(zombieOneRight, ZombiePowered, this);//Apply the rotation
So your always rotating 2rads your image. If you do this assignment at the end of the paint method:
zombieIdentity = ZombiePowered;
the next time you paint the image it will be rotate 2rads more.
About the issues with the position, take a look at rotate javadoc:
Concatenates this transform with a transform that rotates coordinates
around an anchor point. This operation is equivalent to translating
the coordinates so that the anchor point is at the origin (S1), then
rotating them about the new origin (S2), and finally translating so
that the intermediate origin is restored to the coordinates of the
original anchor point (S3).
This operation is equivalent to the following sequence of calls:
translate(anchorx, anchory); // S3: final translation
rotate(theta); // S2: rotate around anchor
translate(-anchorx, -anchory); // S1: translate anchor to origin
Hope it helps.

Once you've created your transformation, you need to apply it to the graphics context...
public void paint(Graphics z)
{
//...
z2d.setTransform(ZombiePowered);
//...
}
Once you apply a transformation, it will effect everything painted to the Graphics context after it so you need to reset it or referse it. There's lots of ways to do this, but the simplest would be to create a copy of the Graphics context and simply dispose of it when you no longer need it...
public void paint(Graphics z)
{
Graphics2D z2d = (Graphics2D) z.create();
//...
z2d.dispose();
}
Also, this is just me, but I'd be creating a new instance of the AffineTransform, these things are to easy to completely screw up...

Resize an image to fit the entirety of a JLabel adapting to its size

before you ask, I've looked up this issue in the website and the solutions provided have, unfortunately, not worked for me, so I must resort to asking it once more to see what could I be doing wrong.
Closest achievement I've had with the code I've got is this (I should most definitely use a try and catch when I retrieve the image, I'll save that for later on):
private void asignarTile(Tile tile, JPanel panel){
if(tile.getTipo() == 0){
ImageIcon ii = new ImageIcon("pasto.png");
Image image = ii.getImage();
Image newimg = image.getScaledInstance(32, 32, java.awt.Image.SCALE_SMOOTH);
ii = new ImageIcon(newimg);
tile.setIcon(ii);
panel.add(tile);
}
}
Now, as oblivious as it is, I must mention that the code does work for a specific size, but it won't adapt the size of the image to the JLabel afterwards, that means that first I'll have this:
But after I resize it I'll have this:
I think it would be useful to note that Tile extends JLabel, and these are the changes (columna means column, fila means row, maybe I should start writing my code entirely in english)
package gui;
import javax.swing.JLabel;
public class Tile extends JLabel{
private int fila, columna, tipo;
public int getFila() {
return fila;
}
public void setFila(int x) {
this.fila = x;
}
public int getColumna() {
return columna;
}
public void setColumna(int y) {
this.columna = y;
}
public int getTipo(){
return tipo;
}
public void setTipo(int tipo){
if(tipo >= 0 || tipo <= 6)
this.tipo = tipo;
}
public Tile(int x, int y, int tipo) {
this.setFila(x);
this.setColumna(y);
this.setTipo(tipo);
}
}
As a conclusion I must say that I have considered adding a componentListener to the Tile since it extends a JLabel, but I have also tried to resize the image to the label's dimensions to no avail, as it gave me an exception saying that its dimensions were 0, and well, they can't be 0.
Thank you for reading!

You can try Darryl's Stretch Icon for dynamic resizing.
Otherwise you would extend JComponent (instead of JLabel) and do you own custom painting of the image. See Background Panel for an example of how to paint a scaled image.

I would recommend that you try to create or find a larger tile image. If you try to stretch the image, you will degrade it, but this is not so for shrinking.

This code looks good.
Here's a code review suggestion:
The serializable class Tile.java does not declare a static final serialVersionUID field of type long. Solution: Add a generated serial version ID to the selected type.

Setting multiple icons on JButton

I have a JButton which I have set a custom icon on. Now I want it to display another icon ontop of the one that is already displayed when I drag my mouse cursor over it but I can't figure out how to do it because if I use button.setIcon(icon); it will replace the icon that already is displayed. How would I do this in an as easy way as possible?

I have a JButton which I have set a custom icon on. Now I want it to
display another icon ontop of the one that is already displayed when I
drag my mouse cursor over it but I can't figure out how to do it
because if I use button.setIcon(icon); it will replace the icon that
already is displayed. How would I do this in an as easy way as
possible
I think thats about JButton.setRolloverIcon(myIcon);
JButton has implemented those methods in API
JButton.setIcon(myIcon);
JButton.setRolloverIcon(myIcon);
JButton.setPressedIcon(myIcon);
JButton.setDisabledIcon(myIcon);
for example

If your icons are already transparent you can easily implement your own Icon to combine the two -
public class CombineIcon implements Icon {
private Icon top;
private Icon bottom;
public CombineIcon(Icon top, Icon bottom) {
this.top = top;
this.bottom = bottom;
}
public int getIconHeight() {
return Math.max(top.getIconHeight(), bottom.getIconHeight());
}
public int getIconWidth() {
return Math.max(top.getIconWidth(), bottom.getIconWidth());
}
public void paintIcon(Component c, Graphics g, int x, int y) {
bottom.paintIcon(c, g, x, y);
top.paintIcon(c, g, x, y);
}
}
You use setRolloverIcon(icon) to specify the icon you want to show when the mouse is over the button.

Create a second version of that button icon which contains the overlay. On mouse over switch to the image with the overlay.
Another approach could be to combine the icon with its overlay to a new icon in memory and place it as an icon on the button. This might be a good approach if your icons are frequently changing. If that's not the case I would definitely use the first approach.

I find this pretty easy.
import java.awt.*;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
class CombinedIconButton {
public static BufferedImage getCombinedImage(BufferedImage i1, BufferedImage i2) {
if (i1.getHeight() != i2.getHeight()
|| i1.getWidth() != i2.getWidth()) {
throw new IllegalArgumentException("Images are not the same size!");
}
BufferedImage bi = new BufferedImage(
i1.getHeight(),
i1.getWidth(),
BufferedImage.TYPE_INT_ARGB);
Graphics g = bi.getGraphics();
g.drawImage(i1,0,0,null);
g.drawImage(i2,0,0,null);
g.dispose();
return bi;
}
public static void main(String[] args) throws Exception {
URL url1 = new URL("http://i.stack.imgur.com/gJmeJ.png"); // blue circle
URL url2 = new URL("http://i.stack.imgur.com/5v2TX.png"); // red triangle
final BufferedImage bi1 = ImageIO.read(url1);
final BufferedImage bi2 = ImageIO.read(url2);
final BufferedImage biC = getCombinedImage(bi1,bi2);
Runnable r = new Runnable() {
#Override
public void run() {
JPanel gui = new JPanel(new BorderLayout());
JToggleButton b = new JToggleButton();
b.setIcon(new ImageIcon(bi1));
b.setRolloverIcon(new ImageIcon(biC));
b.setSelectedIcon(new ImageIcon(bi2));
gui.add(b);
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
Images borrowed from this answer.

One way to do that is:
Create an icon which you want to see when the pointer is hovered on top of the button by some image editing tool. And set that image once mousehover event occurs.
p.s. use any pic editing tool and you can easily create a overlay image.
I also saw now that there is a concept of roll over icon in AbsractButton class. You can use that as well.

LWUIT Painter : How to make an image the background?

I am trying to use Painter to make a certain jpg become my background.
mapScreen = new Form("Map");
try
{
Image image = Image.createImage("/res/try.jpg");
map = new Map(image);
mapScreen.addComponent(map);
} catch (Exception e)
{
System.out.print("Error\n\n"+e.getMessage());
mapScreen.addComponent(new Label(e.getMessage()));
}
And for the map class,
public Map(Image image)
{
this.mapImage = image;
painter = new Painter()
{
public void paint(Graphics g, Rectangle clippingRect)
{
g.clipRect(0, 0, getWidth(), getHeight());
g.drawImage(mapImage, getX(), getY());
}
};
}
public void initComponent()
{
setX(0);
setY(0);
getSelectedStyle().setBgTransparency(0);
getSelectedStyle().setBgPainter(painter);
getUnselectedStyle().setBgTransparency(0);
getUnselectedStyle().setBgPainter(painter);
}
The problem with this is that the image doesn't show up at all and when I try to debug, It doesn't even enter the paint(Graphics g, Rectangle clippingRect)...
The code
try
{
Image image = Image.createImage("/res/try.jpg");
map = new Map(image);
mapScreen.addComponent(map);
}
is successful.
Can anyone tell me how to do it properly?
And also, if anyone know how to do panning on an image larger than the size of the screen, Can you help me with that also? Thanks.

Use setBgTransparency to 255 and don't call the clipRect method.
You can look at the bg painter code within Component.java which is pretty flexible.

Creating custom JButton from images containing transparent pixels

Read edit 2 for what I'm actually missing to make it work
I'm currently trying to create some custom JButtons using images created in photoshop that have an alpha parameter.
So far, overriding the paint() method to draw the image has worked in the sense that the button is drawn showing the correct image. I'd like to improve it, though, by making its shape (clickable area) the same as the visible pixels on the image (right now if I draw the button's border, it's a square).
Is there an easy way to do that or do I have to parse the image and find the alpha pixels to make a custom border?
Which methods would I have to override to make it work the way I want?
Also, another question I'm going to have later: would it be better to use some kind of algorithm to change the images' colors to make it seem like it is being clicked when people click on it or am I better off creating a second image and drawing that one while the button is active?
Edit: I just read on some other question that I should redefine paintComponent() instead of paint(), I'd like to know why since redefining paint() works fine?
Edit 2: I changed everything to make sure my JButtons are created using the default constructor with an icon. What I'm trying to do is get the X and Y position of where the click was registered and grab the icon's pixel at that position and check its alpha channel to see if it is 0 (if it is, do nothing, else do the action it is supposed to do).
The thing is, the alpha channel always returns 255 (and blue, red and green are at 238 on transparent pixels). On other pixels, everything returns the value it should be returning.
Here's an example (try it with another image if you want) that recreates my problem:
public class TestAlphaPixels extends JFrame
{
private final File FILECLOSEBUTTON = new File("img\\boutonrondX.png"); //My round button with transparent corners
private JButton closeButton = new JButton(); //Creating it empty to be able to place it and resize the image after the button size is known
public TestAlphaPixels() throws IOException
{
setLayout(null);
setSize(150, 150);
closeButton.setSize(100, 100);
closeButton.setContentAreaFilled(false);
closeButton.setBorderPainted(false);
add(closeButton);
closeButton.addMouseListener(new MouseListener()
{
public void mouseClicked(MouseEvent e)
{
}
public void mousePressed(MouseEvent e)
{
}
public void mouseReleased(MouseEvent e)
{
System.out.println("Alpha value of pixel (" + e.getX() + ", " + e.getY() + ") is: " + clickAlphaValue(closeButton.getIcon(), e.getX(), e.getY()));
}
public void mouseEntered(MouseEvent e)
{
}
public void mouseExited(MouseEvent e)
{
}
});
Image imgCloseButton = ImageIO.read(FILECLOSEBUTTON);
//Resize the image to fit the button
Image newImg = imgCloseButton.getScaledInstance((int)closeButton.getSize().getWidth(), (int)closeButton.getSize().getHeight(), java.awt.Image.SCALE_SMOOTH);
closeButton.setIcon(new ImageIcon(newImg));
}
private int clickAlphaValue(Icon icon, int posX, int posY)
{
int width = icon.getIconWidth();
int height = icon.getIconHeight();
BufferedImage tempImage = (BufferedImage)createImage(width, height);
Graphics2D g = tempImage.createGraphics();
icon.paintIcon(null, g, 0, 0);
g.dispose();
int alpha = (tempImage.getRGB(posX, posY) >> 24) & 0x000000FF;
return alpha;
}
public static void main(String[] args)
{
try
{
TestAlphaPixels testAlphaPixels = new TestAlphaPixels();
testAlphaPixels.setVisible(true);
testAlphaPixels.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
catch(IOException ioe)
{
ioe.printStackTrace();
}
}
}
This is just a wild guess, but is it possible that when my image gets cast to an Icon, it loses its Alpha property and thus doesn't return the correct value? Anyway, I'd really appreciate it if someone could actually help me out and tell me what I should be changing to get the correct value.
I'm guessing that because when I try it with the original image, the alpha channel's value is fine, but I can't actually use that BufferedImage because I resize it, so I actually get the channel values of the image with the original size...

I think you are on the wrong way. You do not have to override neither paint() nor paintComponent() methods. JButton already "knows" to be shown with image only:
ImageIcon cup = new ImageIcon("images/cup.gif");
JButton button2 = new JButton(cup);
See the following tutorial for example: http://www.apl.jhu.edu/~hall/java/Swing-Tutorial/Swing-Tutorial-JButton.html
Moreover swing is fully customized. You can control opacity, border, color etc. You probably should override some mentioned methods to change functionality. But in most cases there is better and simpler solution.

Since there were good elements in multiple answers, but none of the answers were complete on their own, I'll answer my own question so other people that have the same problem can try something similar.
I created my buttons using a new class which extends JButton, with a new constructor that takes a BufferedImage as parameter instead of an icon. The reason for that is that when I did something like myButton.getIcon(), it would return an Icon, then I'd have to make various manipulations on it to make it a BufferedImage of the right size, and it ended up not working anyway because it seems like the first cast to Icon made it lose the alpha data in the pixels, so I couldn't check to see if the user was clicking on transparent pixels or not.
So I did something like this for the constructor:
public class MyButton extends JButton
{
private BufferedImage bufImg;
public MyButton(BufferedImage bufImg)
{
super(new ImageIcon(bufImg));
this.bufImg = bufImg;
}
}
Then I created an accessor for my bufImg that resized the image to fit the JButton using the getSize() method and then returned an image resized at the right size. I do the transformations in the getBufImg() accessor because the image size might change when the window gets resized. When you call the getBufImg(), it's usually because you clicked on the button and thus you're not currently resizing the window.
Something a little bit like this will return the image at the right size:
public BufferedImage getBufImg()
{
BufferedImage newImg = new BufferedImage(getSize().getWidth(), getSize().getHeight(), BufferedImage.TYPE_INT_ARGB); //Create a new buffered image the right size
Graphics2D g2d = newImg.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.drawImage(bufImg, 0, 0, getSize().getWidth(), getSize().getHeight(), null);
g2d.dispose();
return newImg;
}
With that buffered image, you can then code a method like this:
private int clickAlphaValue(BufferedImage bufImg, int posX, int posY)
{
int alpha;
alpha = (bufImg.getRGB(posX, posY) >>24) & 0x000000FF; //Gets the bit that contains alpha information
return alpha;
}
That you call on the button that implements a MouseListener, like this:
myButton.addMouseListener(new MouseListener()
{
public void mouseClicked(MouseEvent e)
{
}
public void mousePressed(MouseEvent e)
{
}
public void mouseReleased(MouseEvent e)
{
if(clickAlphaValue(((myButton)e.getSource()).getBufImg(), e.getX(), e.getY()) != 0) //If alpha is not set to 0
System.exit(0); //Or other things you want your button to do
}
public void mouseEntered(MouseEvent e)
{
}
public void mouseExited(MouseEvent e)
{
}
});
And voila! The button will only do the action if you clicked on non-transparent pixels.
Thanks for the help everyone, I couldn't have come up with this solutions on my own.

If you want to have shape-specific click points, you're better off using Shape and their contains method. If you want, you can create a shape when creating your custom button class as part of it, and implement a contains method by wrapping around the shape's contains method.
As for the custom JButton, create a class that extends JButton, like this:
import java.awt.*;
import javax.swing.*;
public class CustomButton extends JButton{
/** Filename of the image to be used as the button's icon. */
private String fileName;
/** The width of the button */
private int width;
/** The height of the button. */
private int height;
public CustomButton(String fileName, int width, int height){
this.fileName = fileName;
this.width = width;
this.height = height;
createButton();
}
/**
* Creates the button according to the fields set by the constructor.
*/
private void createButton(){
this.setIcon(getImageIcon(filename));
this.setPreferredSize(new Dimension(width, height));
this.setMaximumSize(new Dimension(width, height));
this.setFocusPainted(false);
this.setRolloverEnabled(false);
this.setOpaque(false);
this.setContentAreaFilled(false);
this.setBorderPainted(false);
this.setBorder(BorderFactory.createEmptyBorder(0,0,0,0));
}
}
Here's how you can load the ImageIcon, if you want to do it like this.
public ImageIcon getImageIcon(String fileName){
String imageDirectory = "images/"; //relative to classpath
URL imgURL = getClass().getResource(imageDirectory + fileName);
return new ImageIcon(imgURL);
}
This will give you a button that will at least look like your image.
I asked a similar question regarding Image-based events on click, and Shapes helped wonders.
I guess it comes down to how complex your button images are.
Here's reference anyway:
How can you detect a mouse-click event on an Image object in Java?
PS: Maybe look into generating shapes from images, that go around all the pixels that aren't transparent. No idea if this is possible, but it would mean that a button would only be "pressed" if the user clicks on the image part of it. Just a thought.

If you want your button layout to be that of the non-transparent pixels in your image, then you should redefine the paintComponent() method. It is the most correct way of doing it (overriding paint() worked in old times but is now discouraged).
However I think it is not exactly what you want: you want a click on the button to be detected only if it is on a non-transparent pixel, right? In that case you have to parse your image and when clicked compare mouse coordinates to the pixel alpha channel of your image as JButton does not have such a feature.

If you have a round button, this is exactly what you need:
public class RoundButton extends JButton {
public RoundButton() {
this(null, null);
}
public RoundButton(Icon icon) {
this(null, icon);
}
public RoundButton(String text) {
this(text, null);
}
public RoundButton(Action a) {
this();
setAction(a);
}
public RoundButton(String text, Icon icon) {
setModel(new DefaultButtonModel());
init(text, icon);
if(icon==null) return;
setBorder(BorderFactory.createEmptyBorder(0,0,0,0));
setContentAreaFilled(false);
setFocusPainted(false);
initShape();
}
protected Shape shape, base;
protected void initShape() {
if(!getBounds().equals(base)) {
Dimension s = getPreferredSize();
base = getBounds();
shape = new Ellipse2D.Float(0, 0, s.width, s.height);
}
}
#Override public Dimension getPreferredSize() {
Icon icon = getIcon();
Insets i = getInsets();
int iw = Math.max(icon.getIconWidth(), icon.getIconHeight());
return new Dimension(iw+i.right+i.left, iw+i.top+i.bottom);
}
#Override public boolean contains(int x, int y) {
initShape();
return shape.contains(x, y);
//or return super.contains(x, y) && ((image.getRGB(x, y) >> 24) & 0xff) > 0;
}
}
JButton has a contains() method. Override it and call it on mouseReleased();

paintComponent() instead of paint() depends if you paint() inside XxxButtonUI or just override paintComponent(), but there exists the option JButton#setIcon.