Abuse’s code:
/********************* START Car Image Loading and Generation *****************/
BufferedImage carImage = ImageIO.read(getClass().getResource(STRING_CAR_FILENAME)); //load the car Image
BufferedImage [] carFrames = new BufferedImage[CAR_ROTATIONS];
for(int i = 0;i < CAR_ROTATIONS;i++)
{
carFrames[i] = gc.createCompatibleImage(CAR_SIZE,CAR_SIZE,Transparency.BITMASK);
Graphics2D cfg2d = carFrames[i].createGraphics();
cfg2d.rotate(((Math.PI*2)*i)/CAR_ROTATIONS, CAR_SIZE/2,CAR_SIZE/2);
cfg2d.drawImage(carImage,(CAR_SIZE-CAR_WIDTH)/2,(CAR_SIZE-CAR_HEIGHT)/2 ,null);
}
/********************* END Car Image Loading and Generation *******************/
I tried to do a very similar thing, producing source code:
protected Image loadImage( String filename, GraphicsConfiguration gc )
{
long sTime = System.currentTimeMillis();
BufferedImage loadedImage = null;
try
{
loadedImage = ImageIO.read( getClass().getResource( filename ) );
}
catch( Exception e )
{
System.out.println( "Exception loading image: "+filename+", e = "+e );
}
BufferedImage img = gc.createCompatibleImage( loadedImage.getWidth(), loadedImage.getHeight(), Transparency.BITMASK );
//BufferedImage img = gc.createCompatibleImage( loadedImage.getWidth(), loadedImage.getHeight(), Transparency.OPAQUE );
Graphics2D g = img.createGraphics();
g.drawImage( loadedImage, loadedImage.getWidth(), loadedImage.getHeight(), null );
//return img;
return loadedImage;
}
…but, if you swap the commenting on the last two lines, so that it returns the Compatible Image, which you have drawn the loadedImage onto, you get a blank image.
If you set the transparency to OPAQUE, you get a black image of the same dimenstions as the source.
The way I’m getting the gc is to actually call a wrapper for the above method:
protected Image loadImage( String filename )
{
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gd.getDefaultConfiguration();
System.out.println( "ge = "+ge+", gd = "+gd+", gc = "+gc );
return loadImage( filename, gc );
}
…which seems pretty sensible to me?
But none of this works on linux nor windows for me. So, what the heck am I doing wrong? I’m not getting null devices or anything, no exceptions, just no image! Here’s complete brief source for a tiny Swing app that shows the problem; comment / uncomment the return statements as described above, and you’ll see the application either display your “test.gif” or not.
import net.tmachine.common.*;
import javax.swing.*;
import java.awt.*;
import java.util.*;
import java.io.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.imageio.*;
import java.awt.geom.*;
public class ImageTest extends JComponent
{
public static void main( String[] args )
{
JFrame jf = new JFrame();
jf.getContentPane().add( new ImageTest() );
jf.setSize( 400, 400 );
jf.setVisible( true );
}
Image i;
public ImageTest()
{
i = loadImage( "test.gif" );
}
public void paintComponent( Graphics g )
{
g.drawImage( i, 0, 0, null );
}
protected Image loadImage( String filename )
{
GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
GraphicsDevice gd = ge.getDefaultScreenDevice();
GraphicsConfiguration gc = gd.getDefaultConfiguration();
System.out.println( "ge = "+ge+", gd = "+gd+", gc = "+gc );
return loadImage( filename, gc );
}
protected Image loadImage( String filename, GraphicsConfiguration gc )
{
long sTime = System.currentTimeMillis();
BufferedImage loadedImage = null;
try
{
loadedImage = ImageIO.read( getClass().getResource( filename ) );
}
catch( Exception e )
{
System.out.println( "Exception loading image: "+filename+", e = "+e );
}
BufferedImage img = gc.createCompatibleImage( loadedImage.getWidth(), loadedImage.getHeight(), Transparency.BITMASK );
//BufferedImage img = gc.createCompatibleImage( loadedImage.getWidth(), loadedImage.getHeight(), Transparency.OPAQUE );
Graphics2D g = img.createGraphics();
g.drawImage( loadedImage, loadedImage.getWidth(), loadedImage.getHeight(), null );
//return img;
return loadedImage;
}
}
