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Diffstat (limited to 'src/classes/com/sun/opengl/impl/packrect/RectanglePacker.java')
-rwxr-xr-x | src/classes/com/sun/opengl/impl/packrect/RectanglePacker.java | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/src/classes/com/sun/opengl/impl/packrect/RectanglePacker.java b/src/classes/com/sun/opengl/impl/packrect/RectanglePacker.java new file mode 100755 index 000000000..3a77b3bd1 --- /dev/null +++ b/src/classes/com/sun/opengl/impl/packrect/RectanglePacker.java @@ -0,0 +1,295 @@ +/* + * 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.sun.opengl.impl.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 BackingStoreManager manager; + private Object backingStore; + private LevelSet levels; + private float EXPANSION_FACTOR = 0.5f; + private float SHRINK_FACTOR = 0.3f; + + private int initialWidth; + private int initialHeight; + + private int maxWidth = -1; + private int maxHeight = -1; + + static class RectHComparator implements Comparator { + public int compare(Object o1, Object o2) { + Rect r1 = (Rect) o1; + Rect r2 = (Rect) o2; + return r2.h() - r1.h(); + } + + public boolean equals(Object obj) { + return this == obj; + } + } + private static final Comparator rectHComparator = new RectHComparator(); + + public RectanglePacker(BackingStoreManager manager, + int initialWidth, + 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(int maxWidth, 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. */ + public void add(Rect rect) { + // 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; + + // 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++); + } while (tryAgain); + + compactImpl(rect); + + // Retry the addition of the incoming rectangle + add(rect); + // Done + } + + /** Removes the given rectangle from this RectanglePacker. */ + public void remove(Rect rect) { + levels.remove(rect); + } + + /** Visits all Rects contained in this RectanglePacker. */ + public void visit(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(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 + List/*<Rect>*/ newRects = new ArrayList/*<Rect>*/(); + for (Iterator i1 = levels.iterator(); i1.hasNext(); ) { + Level level = (Level) i1.next(); + for (Iterator i2 = level.iterator(); i2.hasNext(); ) { + Rect cur = (Rect) i2.next(); + 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 (Iterator iter = newRects.iterator(); iter.hasNext(); ) { + if (!nextLevelSet.add((Rect) 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. + Object newBackingStore = manager.allocateBackingStore(nextLevelSet.w(), + nextLevelSet.h()); + manager.beginMovement(backingStore, newBackingStore); + for (Iterator i1 = levels.iterator(); i1.hasNext(); ) { + Level level = (Level) i1.next(); + for (Iterator i2 = level.iterator(); i2.hasNext(); ) { + Rect cur = (Rect) 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; + } +} |