Rotate and flip an image
/*
* This snippet was adapted from org.eclipse.draw2d.ImageUtilities in
* http://dev.eclipse.org/viewcvs/index.cgi/org.eclipse.draw2d/?cvsroot=Tools_Project
* by Pratik Shah.
*
* example snippet: rotate and flip an image
*
* For a list of all SWT example snippets see
* http://dev.eclipse.org/viewcvs/index.cgi/%7Echeckout%7E/platform-swt-home/dev.html#snippets
*/
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
public class Snippet139 {
static ImageData rotate(ImageData srcData, int direction) {
int bytesPerPixel = srcData.bytesPerLine / srcData.width;
int destBytesPerLine = (direction == SWT.DOWN) ? srcData.width
* bytesPerPixel : srcData.height * bytesPerPixel;
byte[] newData = new byte[srcData.data.length];
int width = 0, height = 0;
for (int srcY = 0; srcY < srcData.height; srcY++) {
for (int srcX = 0; srcX < srcData.width; srcX++) {
int destX = 0, destY = 0, destIndex = 0, srcIndex = 0;
switch (direction) {
case SWT.LEFT: // left 90 degrees
destX = srcY;
destY = srcData.width - srcX - 1;
width = srcData.height;
height = srcData.width;
break;
case SWT.RIGHT: // right 90 degrees
destX = srcData.height - srcY - 1;
destY = srcX;
width = srcData.height;
height = srcData.width;
break;
case SWT.DOWN: // 180 degrees
destX = srcData.width - srcX - 1;
destY = srcData.height - srcY - 1;
width = srcData.width;
height = srcData.height;
break;
}
destIndex = (destY * destBytesPerLine)
+ (destX * bytesPerPixel);
srcIndex = (srcY * srcData.bytesPerLine)
+ (srcX * bytesPerPixel);
System.arraycopy(srcData.data, srcIndex, newData, destIndex,
bytesPerPixel);
}
}
// destBytesPerLine is used as scanlinePad to ensure that no padding is
// required
return new ImageData(width, height, srcData.depth, srcData.palette,
destBytesPerLine, newData);
}
static ImageData flip(ImageData srcData, boolean vertical) {
int bytesPerPixel = srcData.bytesPerLine / srcData.width;
int destBytesPerLine = srcData.width * bytesPerPixel;
byte[] newData = new byte[srcData.data.length];
for (int srcY = 0; srcY < srcData.height; srcY++) {
for (int srcX = 0; srcX < srcData.width; srcX++) {
int destX = 0, destY = 0, destIndex = 0, srcIndex = 0;
if (vertical) {
destX = srcX;
destY = srcData.height - srcY - 1;
} else {
destX = srcData.width - srcX - 1;
destY = srcY;
}
destIndex = (destY * destBytesPerLine)
+ (destX * bytesPerPixel);
srcIndex = (srcY * srcData.bytesPerLine)
+ (srcX * bytesPerPixel);
System.arraycopy(srcData.data, srcIndex, newData, destIndex,
bytesPerPixel);
}
}
// destBytesPerLine is used as scanlinePad to ensure that no padding is
// required
return new ImageData(srcData.width, srcData.height, srcData.depth,
srcData.palette, destBytesPerLine, newData);
}
public static void main(String[] args) {
Display display = new Display();
// create an image with the word "hello" on it
final Image image0 = new Image(display, 50, 30);
GC gc = new GC(image0);
gc.setBackground(display.getSystemColor(SWT.COLOR_RED));
gc.fillRectangle(image0.getBounds());
gc.drawString("hello", 5, 5, true);
gc.dispose();
ImageData data = image0.getImageData();
// rotate and flip this image
final Image image1 = new Image(display, rotate(data, SWT.LEFT));
final Image image2 = new Image(display, rotate(data, SWT.RIGHT));
final Image image3 = new Image(display, rotate(data, SWT.DOWN));
final Image image4 = new Image(display, flip(data, true));
final Image image5 = new Image(display, flip(data, false));
Shell shell = new Shell(display);
// draw the results on the shell
shell.addPaintListener(new PaintListener() {
public void paintControl(PaintEvent e) {
e.gc.drawText("Original Image:", 10, 10, true);
e.gc.drawImage(image0, 10, 40);
e.gc.drawText("Left, Right, 180:", 10, 80, true);
e.gc.drawImage(image1, 10, 110);
e.gc.drawImage(image2, 50, 110);
e.gc.drawImage(image3, 90, 110);
e.gc.drawText("Flipped Vertical, Horizontal:", 10, 170, true);
e.gc.drawImage(image4, 10, 200);
e.gc.drawImage(image5, 70, 200);
}
});
shell.setSize(300, 300);
shell.open();
while (!shell.isDisposed()) {
if (!display.readAndDispatch())
display.sleep();
}
image0.dispose();
image1.dispose();
image2.dispose();
image3.dispose();
image4.dispose();
image5.dispose();
display.dispose();
}
}
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