Used to keep around all visible (or nearly visible) objects in a scene.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1741 542714f4-19e9-0310-aa3c-eee0fc999fb1
2002-09-23 21:53:23 +00:00
parent f7e383d667
commit 552d73de59
1 changed files with 132 additions and 0 deletions
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+//
+// $Id: ObjectSet.java,v 1.1 2002/09/23 21:53:23 mdb Exp $
+
+package com.threerings.miso.scene.util;
+
+import java.util.Arrays;
+import java.util.Comparator;
+
+import com.samskivert.util.ArrayUtil;
+import com.samskivert.util.ListUtil;
+
+import com.threerings.miso.scene.SceneObject;
+
+/**
+ * Used to store an (arbitrarily) ordered, low-impact iteratable (doesn't
+ * require object creation), set of {@link SceneObject} instances.
+ */
+public class ObjectSet
+{
+    /**
+     * Inserts the supplied scene object into the set.
+     *
+     * @return true if it was inserted, false if the object was already in
+     * the set.
+     */
+    public boolean insert (SceneObject scobj)
+    {
+        // bail if it's already in the set
+        int ipos = indexOf(scobj);
+        if (ipos >= 0) {
+            return false;
+        }
+
+        // otherwise insert it
+        ipos = -(ipos+1);
+        _scobjs = ListUtil.insert(_scobjs, ipos, scobj);
+        _size++;
+        return true;
+    }
+
+    /**
+     * Returns true if the specified object is in the set, false if it is
+     * not.
+     */
+    public boolean contains (SceneObject scobj)
+    {
+        return (indexOf(scobj) >= 0);
+    }
+
+    /**
+     * Returns the number of scene objects in this set.
+     */
+    public int size ()
+    {
+        return _size;
+    }
+
+    /**
+     * Returns the scene object with the specified index. The index must &
+     * be between <code>0</code> and {@link #size}<code>-1</code>.
+     */
+    public SceneObject get (int index)
+    {
+        return (SceneObject)_scobjs[index];
+    }
+
+    /**
+     * Removes the object at the specified index.
+     */
+    public void remove (int index)
+    {
+        ListUtil.remove(_scobjs, index);
+        _size--;
+    }
+
+    /**
+     * Removes the specified scene object from the set.
+     *
+     * @return true if it was removed, false if it was not in the set.
+     */
+    public boolean remove (SceneObject scobj)
+    {
+        int opos = indexOf(scobj);
+        if (opos >= 0) {
+            remove(opos);
+            return true;
+        } else {
+            return false;
+        }
+    }
+
+    /**
+     * Clears out the contents of this set.
+     */
+    public void clear ()
+    {
+        _size = 0;
+        Arrays.fill(_scobjs, null);
+    }
+
+    /**
+     * Returns the index of the object or it's insertion index if it is
+     * not in the set.
+     */
+    protected final int indexOf (SceneObject scobj)
+    {
+        return ArrayUtil.binarySearch(_scobjs, 0, _size, scobj, SCOBJ_COMP);
+    }
+
+    /** Our sorted array of scene objects. */
+    protected Object[] _scobjs = new Object[DEFAULT_SIZE];
+
+    /** The number of objects in the set. */
+    protected int _size;
+
+    /** We simply sort the scene objects in order of their hash code. We
+     * don't care about their orderer, it simply needs to exist to support
+     * binary search. */
+    protected static final Comparator SCOBJ_COMP = new Comparator() {
+        public int compare (Object o1, Object o2) {
+            return o1.hashCode() - o2.hashCode();
+        }
+
+        public boolean equals (Object other) {
+            return this == other;
+        }
+    };
+
+    /** We start big because we know these will in general contain at
+     * least in the tens of objects. */
+    protected static final int DEFAULT_SIZE = 16;
+}