/**
* This method is called on a destination SurfaceData to choose the best SurfaceData from a source
* Image for an imaging operation, with help from its SurfaceManager. The method may determine
* that the default SurfaceData was really the best choice in the first place, or it may decide to
* use a cached surface. Some general decisions about whether acceleration is enabled are made by
* this method, but any decision based on the type of the source image is made in the makeProxyFor
* method below when it comes up with the appropriate SurfaceDataProxy instance. The parameters
* describe the type of imaging operation being performed.
*
* <p>If a blitProxyKey was supplied by the subclass then it is used to potentially override the
* choice of source SurfaceData. The outline of this process is:
*
* <ol>
* <li>Image pipeline asks destSD to find an appropriate srcSD for a given source Image object.
* <li>destSD gets the SurfaceManager of the source Image and first retrieves the default SD
* from it using getPrimarySurfaceData()
* <li>destSD uses its "blit proxy key" (if set) to look for some cached data stored in the
* source SurfaceManager
* <li>If the cached data is null then makeProxyFor() is used to create some cached data which
* is stored back in the source SurfaceManager under the same key for future uses.
* <li>The cached data will be a SurfaceDataProxy object.
* <li>The SurfaceDataProxy object is then consulted to return a replacement SurfaceData object
* (typically a cached copy if appropriate, or the original if not).
* </ol>
*/
public SurfaceData getSourceSurfaceData(
Image img, int txtype, CompositeType comp, Color bgColor) {
SurfaceManager srcMgr = SurfaceManager.getManager(img);
SurfaceData srcData = srcMgr.getPrimarySurfaceData();
if (img.getAccelerationPriority() > 0.0f && blitProxyKey != null) {
SurfaceDataProxy sdp = (SurfaceDataProxy) srcMgr.getCacheData(blitProxyKey);
if (sdp == null || !sdp.isValid()) {
if (srcData.getState() == State.UNTRACKABLE) {
sdp = SurfaceDataProxy.UNCACHED;
} else {
sdp = makeProxyFor(srcData);
}
srcMgr.setCacheData(blitProxyKey, sdp);
}
srcData = sdp.replaceData(srcData, txtype, comp, bgColor);
}
return srcData;
}
/**
* Restores the contents of the given Image and then returns the new SurfaceData object in use by
* the Image's SurfaceManager.
*/
public static SurfaceData restoreContents(Image img) {
SurfaceManager sMgr = SurfaceManager.getManager(img);
return sMgr.restoreContents();
}
/**
* Extracts the SurfaceManager from the given Image, and then returns the SurfaceData object that
* would best be suited as the destination surface in some rendering operation.
*/
public static SurfaceData getPrimarySurfaceData(Image img) {
SurfaceManager sMgr = SurfaceManager.getManager(img);
return sMgr.getPrimarySurfaceData();
}