More work on object placement, removal, and rendering within scenes.

git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@479 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/miso/client/DisplayMisoSceneImpl.java

@@ -1,5 +1,5 @@
 //
-// $Id: DisplayMisoSceneImpl.java,v 1.40 2001/10/13 01:08:59 shaper Exp $
+// $Id: DisplayMisoSceneImpl.java,v 1.41 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene;
 
@@ -54,13 +54,10 @@ public class MisoSceneImpl implements EditableMisoScene
      * initialized to contain tiles of the specified default tileset and
      * tile id.
      *
-     * <em>Note:</em> Be sure to call {@link #prepareAllObjectTiles}
+     * <em>Note:</em> Be sure to call {@link
-     * before the scene is first used so that the base layer will be
+     * #generateAllObjectShadows} before the scene is first used so
-     * properly populated with shadow tiles in the footprint of all
+     * that the base layer will be properly populated with shadow
-     * object tiles.  Similarly, any addition of tiles to or removal
+     * tiles in the footprint of all object tiles.
-     * of tiles from the object layer of the scene should be followed
-     * by a call to {@link #prepareObjectTile} or {@link
-     * #unprepareObjectTile}, respectively.
      *
      * @param model the iso scene view model.
      * @param deftile the default tile.
@@ -94,6 +91,26 @@ public class MisoSceneImpl implements EditableMisoScene
         _deftile = tile;
     }
 
+    // documentation inherited
+    public void setTile (int lnum, int x, int y, Tile tile)
+    {
+        // if the tile being replaced is an object tile, clear out its
+        // shadow tiles
+        Tile otile = tiles[lnum][x][y];
+        if (otile instanceof ObjectTile) {
+            removeObjectShadow(x, y);
+        }
+
+        // place the new tile
+        tiles[lnum][x][y] = tile;
+
+        // if the tile being placed is an object tile, create the
+        // shadow tiles that lie in its footprint
+        if (tile instanceof ObjectTile) {
+            generateObjectShadow(x, y);
+        }
+    }
+
     // documentation inherited
     public int getId ()
     {
@@ -293,12 +310,12 @@ public class MisoSceneImpl implements EditableMisoScene
      * fully populated, but before the scene is used in any other
      * meaningful capacity.
      */
-    public void prepareAllObjectTiles ()
+    public void generateAllObjectShadows ()
     {
         for (int xx = 0; xx < _model.scenewid; xx++) {
             for (int yy = 0; yy < _model.scenehei; yy++) {
                 if (objectTiles[xx][yy] != null) {
-                    prepareObjectTile(xx, yy);
+                    generateObjectShadow(xx, yy);
                 }
             }
         }
@@ -312,9 +329,9 @@ public class MisoSceneImpl implements EditableMisoScene
      * @param x the tile x-coordinate.
      * @param y the tile y-coordinate.
      */
-    public void prepareObjectTile (int x, int y)
+    protected void generateObjectShadow (int x, int y)
     {
-        setObjectTileFootprint(x, y, ShadowTile.TILE);
+        setObjectTileFootprint(x, y, new ShadowTile(x, y));
     }
 
     /**
@@ -325,7 +342,7 @@ public class MisoSceneImpl implements EditableMisoScene
      * @param x the tile x-coordinate.
      * @param y the tile y-coordinate.
      */
-    public void unprepareObjectTile (int x, int y)
+    protected void removeObjectShadow (int x, int y)
     {
         setObjectTileFootprint(x, y, _deftile);
     }

src/java/com/threerings/miso/client/IsoSceneView.java

@@ -1,5 +1,5 @@
 //
-// $Id: IsoSceneView.java,v 1.60 2001/10/13 01:08:59 shaper Exp $
+// $Id: IsoSceneView.java,v 1.61 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene;
 
@@ -35,7 +35,8 @@ public class IsoSceneView implements SceneView
     {
         _spritemgr = spritemgr;
 
-        setModel(model);
+        _model = model;
+        _model.precalculate();
 
         // create our polygon arrays and create polygons for each of the
         // tiles. we use these repeatedly, so we go ahead and make 'em all
@@ -49,8 +50,6 @@ public class IsoSceneView implements SceneView
 
         // create the array used to mark dirty tiles
         _dirty = new boolean[model.scenewid][model.tilehei];
-
-	clearDirtyRegions();
     }
 
     // documentation inherited
@@ -58,8 +57,14 @@ public class IsoSceneView implements SceneView
     {
         _scene = scene;
 
+        // clear all dirty lists and tile array
+	clearDirtyRegions();
+
         // generate all object shadow tiles and polygons
-        prepareAllObjectTiles();
+        initAllObjectBounds();
+
+        // invalidate the entire screen as there's a new scene in town
+        invalidate();
     }
 
     // documentation inherited
@@ -88,6 +93,11 @@ public class IsoSceneView implements SceneView
         // draw frames of dirty tiles and rectangles
         // drawDirtyRegions(gfx);
 
+        // draw tile coordinates
+        if (_model.showCoords) {
+            paintCoordinates(gfx);
+        }
+
         // clear out the dirty tiles and rectangles
         clearDirtyRegions();
 
@@ -127,6 +137,10 @@ public class IsoSceneView implements SceneView
         invalidateRects(rects);
     }
 
+    /**
+     * Clears the dirty rectangles and items lists, and the array of
+     * dirty tiles.
+     */
     protected void clearDirtyRegions ()
     {
 	_dirtyRects.clear();
@@ -140,6 +154,9 @@ public class IsoSceneView implements SceneView
 	}
     }
 
+    /**
+     * Draws highlights around the dirty tiles and rectangles.
+     */
     protected void drawDirtyRegions (Graphics2D gfx)
     {
 	// draw the dirty tiles
@@ -178,45 +195,26 @@ public class IsoSceneView implements SceneView
      */
     protected void renderTiles (Graphics2D gfx)
     {
-	int numDrawn = 0;
         Tile[][][] tiles = _scene.getTiles();
 
         // render the base and fringe layers
 	for (int yy = 0; yy < _model.scenehei; yy++) {
 	    for (int xx = 0; xx < _model.scenewid; xx++) {
+		if (_dirty[xx][yy]) {
 
-		// skip this tile if it's not marked dirty
+                    // draw both layers at this tile position
-		if (!_dirty[xx][yy]) {
+                    for (int kk = MisoScene.LAYER_BASE;
-		    continue;
+                         kk < MisoScene.LAYER_FRINGE; kk++) {
-		}
 
-		// get the tile's screen position
+                        // get the tile at these coordinates and layer
-		Polygon poly = _polys[xx][yy];
+                        Tile tile = tiles[kk][xx][yy];
+                        if (tile != null) {
+                            // draw the tile image
+                            tile.paint(gfx, _polys[xx][yy]);
+                        }
+                    }
 
-		// draw both layers at this tile position
-		for (int kk = MisoScene.LAYER_BASE;
-                     kk < MisoScene.LAYER_FRINGE; kk++) {
-
-		    // get the tile at these coordinates and layer
-		    Tile tile = tiles[kk][xx][yy];
-		    if (tile == null) {
-			continue;
-		    }
-
-		    // draw the tile image
-		    renderTile(gfx, tile, xx, yy, poly);
-		}
-
-		// paint the tile coordinate if desired
-  		if (_model.showCoords) {
-                    paintCoords(gfx, xx, yy, poly.xpoints[0],
-				poly.ypoints[0] - _model.tilehhei);
                 }
-
-		// bail early if we know we've drawn all dirty tiles
-		if (++numDrawn == _numDirty) {
-		    break;
-		}
 	    }
 	}
     }
@@ -233,61 +231,38 @@ public class IsoSceneView implements SceneView
         // render dirty sprites and objects
         int size = _dirtyItems.size();
         for (int ii = 0; ii < size; ii++) {
-            DirtyItemList.DirtyItem di =
+            ((DirtyItemList.DirtyItem)_dirtyItems.get(ii)).paint(gfx);
-                (DirtyItemList.DirtyItem)_dirtyItems.get(ii);
-
-            if (di.obj instanceof Sprite) {
-                ((Sprite)di.obj).paint(gfx);
-
-            } else {
-                Polygon poly = (Polygon)
-                    _objpolys.get(getCoordinateKey(di.x, di.y));
-                ((ObjectTile)di.obj).paint(gfx, poly);
-            }
         }
     }
 
     /**
-     * Renders the given tile in the scene to the given graphics
+     * Generates and stores bounding polygons for all object tiles in
-     * context.
+     * the scene for later use while rendering.
      */
-    protected void renderTile (
+    protected void initAllObjectBounds ()
-        Graphics2D gfx, Tile tile, int x, int y, Polygon poly)
     {
-        if (tile instanceof ObjectTile) {
+        // clear out any previously existing object polygons
-            poly = (Polygon)_objpolys.get(getCoordinateKey(x, y));
+        _objpolys.clear();
-        }
 
-        tile.paint(gfx, poly);
+        // generate bounding polygons for all objects
-    }
-
-    /**
-     * Pre-processes all object tiles in the scene to create bounding
-     * polygons.
-     */
-    protected void prepareAllObjectTiles ()
-    {
         ObjectTile[][] tiles = _scene.getObjectLayer();
         for (int xx = 0; xx < _model.scenewid; xx++) {
             for (int yy = 0; yy < _model.scenehei; yy++) {
                 ObjectTile tile = tiles[xx][yy];
-                if (tile == null) {
+                if (tile != null) {
-                    continue;
+                    generateObjectBounds(tile, xx, yy);
                 }
-
-                prepareObjectTile(tile, xx, yy);
             }
         }
     }
 
     /**
-     * Pre-processes a single object tile.  Creates the bounding
+     * Generates and stores the bounding polygon for the object which
-     * polygon for the object which is used when invalidating dirty
+     * is used when invalidating dirty rectangles or tiles, and when
-     * rectangles or tiles, and when rendering the object to a
+     * rendering the object to a graphics context.  This method should
-     * graphics context.  This method should be called when an object
+     * be called when an object tile is added to a scene.
-     * tile is added to a scene.
      */
-    protected void prepareObjectTile (ObjectTile tile, int x, int y)
+    protected void generateObjectBounds (ObjectTile tile, int x, int y)
     {
         // create the bounding polygon for this object
         int key = getCoordinateKey(x, y);
@@ -308,16 +283,11 @@ public class IsoSceneView implements SceneView
     }
 
     /**
-     * Paint the tile coordinate numbers in tile (x, y) whose top-left
+     * Paints tile coordinate numbers on all dirty tiles.
-     * corner is at screen pixel coordinates (sx, sy).
      *
      * @param gfx the graphics context.
-     * @param x the tile x-position coordinate.
-     * @param y the tile y-position coordinate.
-     * @param sx the screen x-position pixel coordinate.
-     * @param sy the screen y-position pixel coordinate.
      */
-    protected void paintCoords (Graphics2D gfx, int x, int y, int sx, int sy)
+    protected void paintCoordinates (Graphics2D gfx)
     {
         FontMetrics fm = gfx.getFontMetrics(_font);
 
@@ -327,13 +297,27 @@ public class IsoSceneView implements SceneView
         int cx = _model.tilehwid, cy = _model.tilehhei;
         int fhei = fm.getAscent();
 
-        // draw x-coordinate
+        for (int yy = 0; yy < _model.scenehei; yy++) {
-        String str = "" + x;
+            for (int xx = 0; xx < _model.scenewid; xx++) {
-        gfx.drawString(str, sx + cx - (fm.stringWidth(str)/2), sy + cy);
+                if (_dirty[xx][yy]) {
 
-        // draw y-coordinate
+                    // get the top-left screen coordinates of the tile
-        str = "" + y;
+                    Rectangle bounds = _polys[xx][yy].getBounds();
-        gfx.drawString(str, sx + cx - (fm.stringWidth(str)/2), sy + cy + fhei);
+                    int sx = bounds.x, sy = bounds.y;
+
+                    // draw x-coordinate
+                    String str = "" + xx;
+                    int xpos = sx + cx - (fm.stringWidth(str) / 2);
+                    gfx.drawString(str, xpos, sy + cy);
+
+                    // draw y-coordinate
+                    str = "" + yy;
+                    xpos = sx + cx - (fm.stringWidth(str) / 2);
+                    gfx.drawString(str, xpos, sy + cy + fhei);
+
+                }
+            }
+        }
     }
 
     /**
@@ -417,7 +401,7 @@ public class IsoSceneView implements SceneView
 
 	    // save the rectangle for potential display later
 	    _dirtyRects.add(r);
-	}
+        }
     }
 
     /**
@@ -570,7 +554,7 @@ public class IsoSceneView implements SceneView
             Point tpos = new Point();
             IsoUtil.screenToTile(_model, sprite.getX(), sprite.getY(), tpos);
 
-            if (_dirtyItems.appendDirtyItem(sprite, tpos.x, tpos.y)) {
+            if (_dirtyItems.appendDirtySprite(sprite, tpos.x, tpos.y)) {
                 // Log.info("Dirtied item: " + sprite);
             }
         }
@@ -585,7 +569,8 @@ public class IsoSceneView implements SceneView
 
             if (poly.intersects(r)) {
                 int tx = coord >> 16, ty = coord & 0x0000FFFF;
-                if (_dirtyItems.appendDirtyItem(tiles[tx][ty], tx, ty)) {
+                if (_dirtyItems.appendDirtyObject(
+                    tiles[tx][ty], poly, tx, ty)) {
                     // Log.info("Dirtied item: Object(" + tx + ", " +
                     // ty + ")");
                 }
@@ -613,12 +598,6 @@ public class IsoSceneView implements SceneView
         }
     }
 
-    public void setModel (IsoSceneViewModel model)
-    {
-        _model = model;
-        _model.precalculate();
-    }
-
     // documentation inherited
     public Path getPath (AmbulatorySprite sprite, int x, int y)
     {

src/java/com/threerings/miso/client/IsoSceneViewModel.java

@@ -1,5 +1,5 @@
 //
-// $Id: IsoSceneViewModel.java,v 1.13 2001/10/11 16:21:09 shaper Exp $
+// $Id: IsoSceneViewModel.java,v 1.14 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene;
 
@@ -7,18 +7,19 @@ import java.awt.Dimension;
 import java.awt.Point;
 
 import com.samskivert.util.Config;
+
 import com.threerings.miso.Log;
 import com.threerings.miso.scene.util.IsoUtil;
 import com.threerings.miso.util.MisoUtil;
 
 /**
- * This class provides a holding place for the myriad parameters and
+ * The iso scene view model provides a holding place for the myriad
- * bits of data that describe the details of an isometric view of a
+ * parameters and bits of data that describe the details of an
- * scene.
+ * isometric view of a scene.
  *
  * <p> The member data are public to facilitate speedy referencing by
- * the {@link IsoSceneView} class.  The model should only be
+ * the {@link IsoSceneView} class.  The model should only be modified
- * configured through the constructor's passed-in {@link
+ * through the constructor's passed-in {@link
  * com.samskivert.util.Config} object and the accessor methods.
  */
 public class IsoSceneViewModel

src/java/com/threerings/miso/client/MisoScene.java

@@ -1,5 +1,5 @@
 //
-// $Id: MisoScene.java,v 1.5 2001/10/11 00:41:27 shaper Exp $
+// $Id: MisoScene.java,v 1.6 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene;
 
@@ -7,6 +7,7 @@ import java.util.List;
 
 import com.threerings.media.tile.Tile;
 import com.threerings.media.tile.ObjectTile;
+
 import com.threerings.miso.tile.MisoTile;
 
 /**
@@ -43,26 +44,35 @@ public interface MisoScene
 
     /**
      * Returns an array of the tile layers that comprise the scene.
+     * The array returned by this method should <em>not</em> be
+     * modified.
      */
     public Tile[][][] getTiles ();
 
     /**
-     * Returns the tile layer for the specified layer index.
+     * Returns the tile layer for the specified layer index.  The
+     * array returned by this method should <em>not</em> be modified.
      */
     public Tile[][] getTiles (int lnum);
 
     /**
      * Returns the tiles that comprise the base layer of this scene.
+     * The array returned by this method should <em>not</em> be
+     * modified.
      */
     public MisoTile[][] getBaseLayer ();
 
     /**
      * Returns the tiles that comprise the fringe layer of this scene.
+     * The array returned by this method should <em>not</em> be
+     * modified.
      */
     public Tile[][] getFringeLayer ();
 
     /**
      * Returns the tiles that comprise the object layer of this scene.
+     * The array returned by this method should <em>not</em> be
+     * modified.
      */
     public ObjectTile[][] getObjectLayer ();
 

src/java/com/threerings/miso/client/SceneViewPanel.java

@@ -1,5 +1,5 @@
 //
-// $Id: SceneViewPanel.java,v 1.15 2001/10/11 00:41:27 shaper Exp $
+// $Id: SceneViewPanel.java,v 1.16 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene;
 
@@ -8,6 +8,7 @@ import java.util.List;
 import javax.swing.*;
 
 import com.samskivert.util.Config;
+
 import com.threerings.media.sprite.*;
 import com.threerings.miso.util.MisoUtil;
 
@@ -16,11 +17,10 @@ import com.threerings.miso.util.MisoUtil;
  * SceneView}, rendering it to the screen, and handling view-related
  * UI events.
  */
-public class SceneViewPanel
+public class SceneViewPanel extends AnimatedPanel
-    extends JPanel implements AnimatedView
 {
     /**
-     * Construct the panel and initialize it with a context.
+     * Constructs the scene view panel.
      */
     public SceneViewPanel (Config config, SpriteManager spritemgr)
     {
@@ -29,10 +29,6 @@ public class SceneViewPanel
 
 	// create the scene view
         _view = newSceneView(spritemgr, _smodel);
-
-	// set our attributes for optimal display performance
-        setDoubleBuffered(false);
-        setOpaque(true);
     }
 
     /**
@@ -45,7 +41,7 @@ public class SceneViewPanel
     }
 
     /**
-     * Set the scene managed by the panel.
+     * Sets the scene managed by the panel.
      */
     public void setScene (MisoScene scene)
     {
@@ -53,24 +49,17 @@ public class SceneViewPanel
     }
 
     /**
-     * Get the scene managed by the panel.
+     * Gets the scene managed by the panel.
      */
     public SceneView getSceneView ()
     {
 	return _view;
     }
 
-    /**
+    // documentation inherited
-     * Render the panel and the scene view to the given graphics object.
+    protected void render (Graphics g)
-     */
-    public void render (Graphics g)
     {
-	if (_offimg == null) {
+        _view.paint(g);
-	    createOffscreen();
-	}
-
-	_view.paint(_offg);
-	g.drawImage(_offimg, 0, 0, null);
     }
 
     // documentation inherited
@@ -81,48 +70,7 @@ public class SceneViewPanel
     }
 
     /**
-     * Paints this panel immediately. Since we know that we are always
+     * Returns the desired size for the panel based on the requested
-     * opaque and not dependent on Swing's double-buffering, we bypass the
-     * antics that <code>JComponent.paintImmediately()</code> performs in
-     * the interest of better performance.
-     */
-    public void paintImmediately ()
-    {
-        Graphics g = null;
-
-        try {
-            Graphics pcg = getGraphics();
-            g = pcg.create();
-            pcg.dispose();
-            paint(g);
-
-        } catch (NullPointerException e) {
-            e.printStackTrace();
-        }
-    }
-
-    public JComponent getComponent ()
-    {
-	return this;
-    }
-
-    public void paintComponent (Graphics g)
-    {
-	render(g);
-
-//          Rectangle bounds = getBounds();
-//          g.drawRect(bounds.x, bounds.y, bounds.width-1, bounds.height-1);
-    }
-
-    protected void createOffscreen ()
-    {
-	Rectangle bounds = getBounds();
-	_offimg = createImage(bounds.width, bounds.height);
-	_offg = _offimg.getGraphics();
-    }
-
-    /**
-     * Return the desired size for the panel based on the requested
      * and calculated bounds of the scene view.
      */
     public Dimension getPreferredSize ()
@@ -132,12 +80,6 @@ public class SceneViewPanel
 	return psize;
     }
 
-    /** The offscreen image used for double-buffering. */
-    protected Image _offimg;
-
-    /** The graphics context for the offscreen image. */
-    protected Graphics _offg;
-
     /** The scene view data model. */
     protected IsoSceneViewModel _smodel;
 

src/java/com/threerings/miso/client/util/IsoUtil.java

@@ -1,5 +1,5 @@
 //
-// $Id: IsoUtil.java,v 1.8 2001/10/13 01:08:59 shaper Exp $
+// $Id: IsoUtil.java,v 1.9 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene.util;
 
@@ -7,7 +7,7 @@ import java.awt.*;
 import java.util.Comparator;
 
 import com.threerings.media.sprite.Sprite;
-import com.threerings.media.sprite.DirtyItemList;
+import com.threerings.media.sprite.DirtyItemList.DirtyItem;
 import com.threerings.media.tile.ObjectTile;
 import com.threerings.media.util.MathUtil;
 
@@ -20,16 +20,66 @@ import com.threerings.miso.scene.*;
  */
 public class IsoUtil
 {
-    /** The comparator used to sort dirty items in ascending render order. */
+    /** The dirty item comparator used to sort dirty items back to front. */
     public static final Comparator DIRTY_COMP = new DirtyItemComparator();
 
+    /**
+     * Returns a polygon bounding all footprint tiles of the given
+     * object tile.
+     *
+     * @param model the scene view model.
+     * @param root the polygon for the root tile at which the object
+     * is located.
+     * @param tile the object tile.
+     *
+     * @return the bounding polygon.
+     */
+    public static Polygon getObjectFootprint (
+        IsoSceneViewModel model, Polygon root, ObjectTile tile)
+    {
+	Rectangle bounds = root.getBounds();
+        int sx = bounds.x - ((tile.baseWidth - 1) * model.tilehwid);
+        int sy = bounds.y - tile.height + model.tilehei;
+
+        Polygon boundsPoly = new Polygon();
+        int rx = sx, ry = sy;
+
+        // right point
+        rx = sx + tile.width;
+        ry = bounds.y - ((tile.baseHeight - 2) * model.tilehhei);
+        boundsPoly.addPoint(rx, ry);
+
+        // bottom-middle point
+        rx = bounds.x + model.tilehwid;
+        ry = bounds.y + model.tilehei;
+        boundsPoly.addPoint(rx, ry);
+
+        // left point
+        rx = sx;
+        ry = bounds.y - ((tile.baseWidth - 2) * model.tilehhei);
+        boundsPoly.addPoint(rx, ry);
+
+        // top-middle point
+        rx += (tile.baseHeight * model.tilehwid);
+        ry -= (tile.baseHeight * model.tilehhei);
+        boundsPoly.addPoint(rx, ry);
+
+        // right point
+        rx = sx + tile.width;
+        ry = bounds.y - ((tile.baseHeight - 2) * model.tilehhei);
+        boundsPoly.addPoint(rx, ry);
+
+        return boundsPoly;
+    }
+
     /**
      * Returns a polygon bounding the given object tile display image,
      * with the bottom of the polygon shaped to conform to the known
      * object dimensions.
      *
      * @param model the scene view model.
-     * @param root the root tile at which the object is located.
+     * @param root the polygon for the root tile at which the object
+     * is located.
      * @param tile the object tile.
      *
      * @return the bounding polygon.
@@ -345,18 +395,26 @@ public class IsoUtil
     protected static final int FULL_TILE_FACTOR = 100;
 
     /**
-     * A comparator class to facilitate sorting the dirty items in
+     * A comparator class for use in sorting the dirty sprites and
-     * ascending x- and y-coordinate order suitable for rendering in
+     * objects in a scene in ascending x- and y-coordinate order
-     * the isometric view with proper visual results.
+     * suitable for rendering in the isometric view with proper visual
+     * results.
      */
-    protected static class DirtyItemComparator implements Comparator
+    public static class DirtyItemComparator implements Comparator
     {
         public int compare (Object a, Object b)
         {
-            DirtyItemList.DirtyItem da = (DirtyItemList.DirtyItem)a;
+            DirtyItem da = (DirtyItem)a;
-            DirtyItemList.DirtyItem db = (DirtyItemList.DirtyItem)b;
+            DirtyItem db = (DirtyItem)b;
 
-            if (da.y <= db.y && da.x <= db.x) {
+            // check whether right edge of a overlaps with left edge of b
+            int comp = getRightOverlap(da, db);
+            if (comp != 0) {
+                return comp;
+            }
+
+            // determine ordering based purely on coordinates
+            if (da.x <= db.x && da.y <= db.y) {
                 return -1;
             }
 
@@ -367,5 +425,52 @@ public class IsoUtil
         {
 	    return (obj == this);
         }
+
+        /**
+         * Checks the right edge of <code>da</code> to see whether it
+         * overlaps with the left edge of <code>db</code>.
+         *
+         * @return -1 if <code>da</code> should be rendered behind
+         * <code>db</code>, 0 if the right edge of <code>da</code>
+         * does not overlap with <code>db</code>, and 1 if
+         * <code>da</code> should be rendered in front of
+         * <code>db</code>.
+         */
+        protected int getRightOverlap (DirtyItem da, DirtyItem db)
+        {
+            int ax = da.x, bx = db.x;
+            int ay = da.y, by = db.y;
+
+            // get da's rightmost corner coordinate
+            if (da.obj instanceof ObjectTile) {
+                ay -= (((ObjectTile)da.obj).baseHeight - 1);
+            }
+
+            // get db's leftmost corner coordinate
+            if (db.obj instanceof ObjectTile) {
+                bx -= (((ObjectTile)db.obj).baseWidth - 1);
+            }
+
+            // Log.info("getOverlap [ax=" + ax + ", ay=" + ay +
+            // ", bx=" + bx + ", by=" + by + "].");
+
+            if (ax > bx && ay < by) {
+                // we most certainly don't overlap
+                return 0;
+            }
+
+
+            // calculate inequality constant for db's leftmost corner
+            int k = (bx + by);
+
+            // we need to determine whether to render da in front of
+            // db, so we check whether da's rightmost corner is above
+            // or below db's leftmost corner.
+            if (ay <= k - ax) {
+                return -1;
+            } else {
+                return 1;
+            }
+        }
     }
 }

src/java/com/threerings/miso/tools/EditableMisoScene.java

@@ -1,8 +1,10 @@
 //
-// $Id: EditableMisoScene.java,v 1.3 2001/10/13 01:08:59 shaper Exp $
+// $Id: EditableMisoScene.java,v 1.4 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene;
 
+import com.threerings.media.tile.Tile;
+
 import com.threerings.miso.tile.MisoTile;
 
 /**
@@ -30,6 +32,11 @@ public interface EditableMisoScene
      */
     public void setDefaultTile (MisoTile tile);
 
+    /**
+     * Updates the specified tile in the scene.
+     */
+    public void setTile (int lnum, int x, int y, Tile tile);
+
     /**
      * Set the default entrance portal for this scene.
      *

src/java/com/threerings/miso/tools/xml/XMLSceneGroupParser.java

@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneGroupParser.java,v 1.6 2001/10/15 23:53:43 shaper Exp $
+// $Id: XMLSceneGroupParser.java,v 1.7 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -40,7 +40,7 @@ public class XMLSceneGroupParser extends SimpleParser
 	} else if (qName.equals("portal")) {
 	    // pull out the portal data
 	    String src = attributes.getValue("src");
-	    String destScene = attributes.getValue("destScene");
+	    String destScene = attributes.getValue("destscene");
 	    String dest = attributes.getValue("dest");
 
 	    // construct a new portal info object

src/java/com/threerings/miso/tools/xml/XMLSceneParser.java

@@ -1,5 +1,5 @@
 //
-// $Id: XMLSceneParser.java,v 1.20 2001/10/15 23:53:43 shaper Exp $
+// $Id: XMLSceneParser.java,v 1.21 2001/10/17 22:21:22 shaper Exp $
 
 package com.threerings.miso.scene.xml;
 
@@ -258,7 +258,7 @@ public class XMLSceneParser extends SimpleParser
 	_info = new SceneInfo();
         parseFile(fname);
         // place shadow tiles for any objects in the scene
-        _info.scene.prepareAllObjectTiles();
+        _info.scene.generateAllObjectShadows();
         // return the final scene object
         return _info.scene;
     }