Separated path code from sprite code so that we can have other things

follow a path (specifically, I want to allow the media panel to be
"scrolled" along a path).


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@1409 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/sprite/ImageSprite.java

@@ -1,5 +1,5 @@
 //
-// $Id: ImageSprite.java,v 1.5 2002/05/04 19:35:31 mdb Exp $
+// $Id: ImageSprite.java,v 1.6 2002/05/31 03:38:03 mdb Exp $
 
 package com.threerings.media.sprite;
 
@@ -145,6 +145,12 @@ public class ImageSprite extends Sprite
             return;
         }
 
+        // if these are the same frames we already had, no need to do a
+        // bunch of pointless business
+        if (frames == _frames) {
+            return;
+        }
+
         // start with our old bounds
         Rectangle dirty = new Rectangle(_bounds);
 
@@ -203,7 +209,7 @@ public class ImageSprite extends Sprite
 
         // move the sprite along toward its destination, if any 
         if (_path != null) {
-            moved = _path.updatePosition(this, timestamp);
+            moved = _path.tick(this, timestamp);
         }
 
         // increment the display image if performing image animation

src/java/com/threerings/media/sprite/PathCompletedEvent.java

@@ -1,8 +1,10 @@
 //
-// $Id: PathCompletedEvent.java,v 1.1 2001/09/13 19:36:20 mdb Exp $
+// $Id: PathCompletedEvent.java,v 1.2 2002/05/31 03:38:03 mdb Exp $
 
 package com.threerings.media.sprite;
 
+import com.threerings.media.util.Path;
+
 /**
  * A path completed event is dispatched when a sprite completes a path
  * along which it has been requested to move.

src/java/com/threerings/media/sprite/Sprite.java

@@ -1,5 +1,5 @@
 //
-// $Id: Sprite.java,v 1.44 2002/05/29 23:27:14 mdb Exp $
+// $Id: Sprite.java,v 1.45 2002/05/31 03:38:03 mdb Exp $
 
 package com.threerings.media.sprite;
 
@@ -12,6 +12,8 @@ import java.util.ArrayList;
 import com.threerings.util.DirectionCodes;
 
 import com.threerings.media.Log;
+import com.threerings.media.util.Path;
+import com.threerings.media.util.Pathable;
 
 /**
  * The sprite class represents a single moveable object in an animated
@@ -19,7 +21,7 @@ import com.threerings.media.Log;
  * be moved along a path.
  */
 public abstract class Sprite
-    implements DirectionCodes
+    implements DirectionCodes, Pathable
 {
     /**
      * Constructs a sprite with a default initial location of <code>(0,
@@ -332,7 +334,7 @@ public abstract class Sprite
     {
         // if we've a path, move the sprite along toward its destination
         if (_path != null) {
-            _path.updatePosition(this, tickStamp);
+            _path.tick(this, tickStamp);
         }
     }