/*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistribution of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
* INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
* MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
* ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
* DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
* DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
* ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
* SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed or intended for use
* in the design, construction, operation or maintenance of any nuclear
* facility.
*
* Sun gratefully acknowledges that this software was originally authored
* and developed by Kenneth Bradley Russell and Christopher John Kline.
*/
package com.jogamp.opengl.util.packrect;
import java.util.*;
/** Packs rectangles supplied by the user (typically representing
image regions) into a larger backing store rectangle (typically
representing a large texture). Supports automatic compaction of
the space on the backing store, and automatic expansion of the
backing store, when necessary. */
public class RectanglePacker {
private final BackingStoreManager manager;
private Object backingStore;
private LevelSet levels;
private static final float EXPANSION_FACTOR = 0.5f;
private static final float SHRINK_FACTOR = 0.3f;
private final int initialWidth;
private final int initialHeight;
private int maxWidth = -1;
private int maxHeight = -1;
static class RectHComparator implements Comparator<Rect> {
@Override
public int compare(final Rect r1, final Rect r2) {
return r2.h() - r1.h();
}
@Override
public boolean equals(final Object obj) {
return this == obj;
}
}
private static final Comparator<Rect> rectHComparator = new RectHComparator();
public RectanglePacker(final BackingStoreManager manager,
final int initialWidth,
final int initialHeight) {
this.manager = manager;
levels = new LevelSet(initialWidth, initialHeight);
this.initialWidth = initialWidth;
this.initialHeight = initialHeight;
}
public Object getBackingStore() {
if (backingStore == null) {
backingStore = manager.allocateBackingStore(levels.w(), levels.h());
}
return backingStore;
}
/** Sets up a maximum width and height for the backing store. These
are optional and if not specified the backing store will grow as
necessary. Setting up a maximum width and height introduces the
possibility that additions will fail; these are handled with the
BackingStoreManager's allocationFailed notification. */
public void setMaxSize(final int maxWidth, final int maxHeight) {
this.maxWidth = maxWidth;
this.maxHeight = maxHeight;
}
/** Decides upon an (x, y) position for the given rectangle (leaving
its width and height unchanged) and places it on the backing
store. May provoke re-layout of other Rects already added. If
the BackingStoreManager does not support compaction, and {@link
BackingStoreManager#preExpand BackingStoreManager.preExpand}
does not clear enough space for the incoming rectangle, then
this method will throw a RuntimeException. */
public void add(final Rect rect) throws RuntimeException {
// Allocate backing store if we don't have any yet
if (backingStore == null)
backingStore = manager.allocateBackingStore(levels.w(), levels.h());
int attemptNumber = 0;
boolean tryAgain = false;
do {
// Try to allocate
if (levels.add(rect))
return;
if (manager.canCompact()) {
// Try to allocate with horizontal compaction
if (levels.compactAndAdd(rect, backingStore, manager))
return;
// Let the manager have a chance at potentially evicting some entries
tryAgain = manager.preExpand(rect, attemptNumber++);
} else {
tryAgain = manager.additionFailed(rect, attemptNumber++);
}
} while (tryAgain);
if (!manager.canCompact()) {
throw new RuntimeException("BackingStoreManager does not support compaction or expansion, and didn't clear space for new rectangle");
}
compactImpl(rect);
// Retry the addition of the incoming rectangle
add(rect);
// Done
}
/** Removes the given rectangle from this RectanglePacker. */
public void remove(final Rect rect) {
levels.remove(rect);
}
/** Visits all Rects contained in this RectanglePacker. */
public void visit(final RectVisitor visitor) {
levels.visit(visitor);
}
/** Returns the vertical fragmentation ratio of this
RectanglePacker. This is defined as the ratio of the sum of the
heights of all completely empty Levels divided by the overall
used height of the LevelSet. A high vertical fragmentation ratio
indicates that it may be profitable to perform a compaction. */
public float verticalFragmentationRatio() {
return levels.verticalFragmentationRatio();
}
/** Forces a compaction cycle, which typically results in allocating
a new backing store and copying all entries to it. */
public void compact() {
compactImpl(null);
}
// The "cause" rect may be null
private void compactImpl(final Rect cause) {
// Have to either expand, compact or both. Need to figure out what
// direction to go. Prefer to expand vertically. Expand
// horizontally only if rectangle being added is too wide. FIXME:
// may want to consider rebalancing the width and height to be
// more equal if it turns out we keep expanding in the vertical
// direction.
boolean done = false;
int newWidth = levels.w();
int newHeight = levels.h();
LevelSet nextLevelSet = null;
int attemptNumber = 0;
boolean needAdditionFailureNotification = false;
while (!done) {
if (cause != null) {
if (cause.w() > newWidth) {
newWidth = cause.w();
} else {
newHeight = (int) (newHeight * (1.0f + EXPANSION_FACTOR));
}
}
// Clamp to maximum values
needAdditionFailureNotification = false;
if (maxWidth > 0 && newWidth > maxWidth) {
newWidth = maxWidth;
needAdditionFailureNotification = true;
}
if (maxHeight > 0 && newHeight > maxHeight) {
newHeight = maxHeight;
needAdditionFailureNotification = true;
}
nextLevelSet = new LevelSet(newWidth, newHeight);
// Make copies of all existing rectangles
final List<Rect> newRects = new ArrayList<Rect>();
for (final Iterator<Level> i1 = levels.iterator(); i1.hasNext(); ) {
final Level level = i1.next();
for (final Iterator<Rect> i2 = level.iterator(); i2.hasNext(); ) {
final Rect cur = i2.next();
final Rect newRect = new Rect(0, 0, cur.w(), cur.h(), null);
cur.setNextLocation(newRect);
// Hook up the reverse mapping too for easier replacement
newRect.setNextLocation(cur);
newRects.add(newRect);
}
}
// Sort them by decreasing height (note: this isn't really
// guaranteed to improve the chances of a successful layout)
Collections.sort(newRects, rectHComparator);
// Try putting all of these rectangles into the new level set
done = true;
for (final Iterator<Rect> iter = newRects.iterator(); iter.hasNext(); ) {
if (!nextLevelSet.add(iter.next())) {
done = false;
break;
}
}
if (done && cause != null) {
// Try to add the new rectangle as well
if (nextLevelSet.add(cause)) {
// We're OK
} else {
done = false;
}
}
// Don't send addition failure notifications if we're only doing
// a compaction
if (!done && needAdditionFailureNotification && cause != null) {
manager.additionFailed(cause, attemptNumber);
}
++attemptNumber;
}
// See whether the implicit compaction that just occurred has
// yielded excess empty space.
if (nextLevelSet.getUsedHeight() > 0 &&
nextLevelSet.getUsedHeight() < nextLevelSet.h() * SHRINK_FACTOR) {
int shrunkHeight = Math.max(initialHeight,
(int) (nextLevelSet.getUsedHeight() * (1.0f + EXPANSION_FACTOR)));
if (maxHeight > 0 && shrunkHeight > maxHeight) {
shrunkHeight = maxHeight;
}
nextLevelSet.setHeight(shrunkHeight);
}
// If we temporarily added the new rectangle to the new LevelSet,
// take it out since we don't "really" add it here but in add(), above
if (cause != null) {
nextLevelSet.remove(cause);
}
// OK, now we have a new layout and a mapping from the old to the
// new locations of rectangles on the backing store. Allocate a
// new backing store, move the contents over and deallocate the
// old one.
final Object newBackingStore = manager.allocateBackingStore(nextLevelSet.w(),
nextLevelSet.h());
manager.beginMovement(backingStore, newBackingStore);
for (final Iterator<Level> i1 = levels.iterator(); i1.hasNext(); ) {
final Level level = i1.next();
for (final Iterator<Rect> i2 = level.iterator(); i2.hasNext(); ) {
final Rect cur = i2.next();
manager.move(backingStore, cur,
newBackingStore, cur.getNextLocation());
}
}
// Replace references to temporary rectangles with original ones
nextLevelSet.updateRectangleReferences();
manager.endMovement(backingStore, newBackingStore);
// Now delete the old backing store
manager.deleteBackingStore(backingStore);
// Update to new versions of backing store and LevelSet
backingStore = newBackingStore;
levels = nextLevelSet;
}
/** Clears all Rects contained in this RectanglePacker. */
public void clear() {
levels.clear();
}
/** Disposes the backing store allocated by the
BackingStoreManager. This RectanglePacker may no longer be used
after calling this method. */
public void dispose() {
if (backingStore != null)
manager.deleteBackingStore(backingStore);
backingStore = null;
levels = null;
}
}