diff --git a/src/java/com/threerings/media/sprite/SpriteManager.java b/src/java/com/threerings/media/sprite/SpriteManager.java
index 70d348b58..dde2507f0 100644
--- a/src/java/com/threerings/media/sprite/SpriteManager.java
+++ b/src/java/com/threerings/media/sprite/SpriteManager.java
@@ -1,5 +1,5 @@
 //
-// $Id: SpriteManager.java,v 1.22 2002/02/19 03:58:37 mdb Exp $
+// $Id: SpriteManager.java,v 1.23 2002/02/19 07:41:36 mdb Exp $
 
 package com.threerings.media.sprite;
 
@@ -35,6 +35,21 @@ public class SpriteManager
         _dirty = new ArrayList();
     }
 
+    /**
+     * Specifies the viewport offset of the view into which the sprites
+     * are being rendered. This is an annoying hack, but the sprite
+     * manager needs to create dirty rectangles and communicate them to
+     * the animation manager who deals in untranslated coordinates,
+     * whereas the sprites remain in translated coordinates; but only the
+     * view itself knows what the translation should be, so it has to tell
+     * the sprite manager about it using this method.
+     */
+    public void setViewportOffset (int tx, int ty)
+    {
+        _tx = tx;
+        _ty = ty;
+    }
+
     /**
      * Add a rectangle to the dirty rectangle list.
      *
@@ -42,6 +57,8 @@ public class SpriteManager
      */
     public void addDirtyRect (Rectangle rect)
     {
+        // translate the rectangle according to our viewport offset
+        rect.translate(-_tx, -_ty);
         _dirty.add(rect);
     }
 
@@ -309,6 +326,9 @@ public class SpriteManager
     /** The list of pending sprite notifications. */
     protected ArrayList _notify;
 
+    /** Our viewport offset. */
+    protected int _tx, _ty;
+
     protected static class SpriteComparator implements Comparator
     {
 	public int compare (Object o1, Object o2)