/**
* Creates an immutable image using pixel data from the specified region of a source image,
* transformed as specified.
*
* <p>The source image may be mutable or immutable. For immutable source images, transparency
* information, if any, is copied to the new image unchanged.
*
* <p>On some devices, pre-transformed images may render more quickly than images that are
* transformed on the fly using <code>drawRegion</code>. However, creating such images does
* consume additional heap space, so this technique should be applied only to images whose
* rendering speed is critical.
*
* <p>The transform function used must be one of the following, as defined in the {@link
* javax.microedition.lcdui.game.Sprite Sprite} class:<br>
* <code>Sprite.TRANS_NONE</code> - causes the specified image region to be copied unchanged<br>
* <code>Sprite.TRANS_ROT90</code> - causes the specified image region to be rotated clockwise by
* 90 degrees.<br>
* <code>Sprite.TRANS_ROT180</code> - causes the specified image region to be rotated clockwise by
* 180 degrees.<br>
* <code>Sprite.TRANS_ROT270</code> - causes the specified image region to be rotated clockwise by
* 270 degrees.<br>
* <code>Sprite.TRANS_MIRROR</code> - causes the specified image region to be reflected about its
* vertical center.<br>
* <code>Sprite.TRANS_MIRROR_ROT90</code> - causes the specified image region to be reflected
* about its vertical center and then rotated clockwise by 90 degrees.<br>
* <code>Sprite.TRANS_MIRROR_ROT180</code> - causes the specified image region to be reflected
* about its vertical center and then rotated clockwise by 180 degrees.<br>
* <code>Sprite.TRANS_MIRROR_ROT270</code> - causes the specified image region to be reflected
* about its vertical center and then rotated clockwise by 270 degrees.<br>
*
* <p>The size of the returned image will be the size of the specified region with the transform
* applied. For example, if the region is <code>100 x 50</code> pixels and the transform
* is <code>TRANS_ROT90</code>, the returned image will be <code>50 x 100</code> pixels.
*
* <p><strong>Note:</strong> If all of the following conditions are met, this method may simply
* return the source <code>Image</code> without creating a new one:
*
* <ul>
* <li>the source image is immutable;
* <li>the region represents the entire source image; and
* <li>the transform is <code>TRANS_NONE</code>.
* </ul>
*
* @param dataSource the source image data to be copied from
* @param x the horizontal location of the region to be copied
* @param y the vertical location of the region to be copied
* @param width the width of the region to be copied
* @param height the height of the region to be copied
* @param transform the transform to be applied to the region
* @return the new immutable image data
*/
public ImageData createImmutableImageData(
ImageData dataSource, int x, int y, int width, int height, int transform) {
ImageData dataDest;
if ((transform & Image.TRANSFORM_SWAP_AXIS) != 0x0) {
dataDest = new ImageData(height, width, false);
} else {
dataDest = new ImageData(width, height, false);
}
// Copy native data from the source region
try {
createImmutableImageDataRegion(
dataDest, dataSource, x, y, width, height, transform, dataSource.isMutable());
} catch (OutOfMemoryError e) {
garbageCollectImages(false);
try {
createImmutableImageDataRegion(
dataDest, dataSource, x, y, width, height, transform, dataSource.isMutable());
} catch (OutOfMemoryError e2) {
garbageCollectImages(true);
createImmutableImageDataRegion(
dataDest, dataSource, x, y, width, height, transform, dataSource.isMutable());
}
}
return dataDest;
}
