Initial work on support for objects whose images span multiple tiles.

Made TileSet an interface.  Throw exceptions for unknown tile or tile
set requests.  General clean-up and documentation.


git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@427 542714f4-19e9-0310-aa3c-eee0fc999fb1

src/java/com/threerings/media/tile/ObjectTile.java

@@ -0,0 +1,40 @@
+//
+// $Id: ObjectTile.java,v 1.1 2001/10/11 00:41:26 shaper Exp $
+
+package com.threerings.media.tile;
+
+import java.awt.Graphics2D;
+import java.awt.Shape;
+
+/**
+ * An object tile extends the base tile to provide support for objects
+ * whose image spans more than one tile.  The object has dimensions
+ * that represent its footprint or "shadow", which the scene
+ * containing the tile can reference to do things like make the
+ * footprint tiles impassable.
+ */
+public class ObjectTile extends Tile
+{
+    /** The object footprint dimensions in unit tile units. */
+    public int baseWidth, baseHeight;
+
+    /**
+     * Constructs a new object tile.
+     */
+    public ObjectTile (int tsid, int tid, int baseWidth, int baseHeight)
+    {
+	super(tsid, tid);
+
+	this.baseWidth = baseWidth;
+	this.baseHeight = baseHeight;
+    }
+
+    // documentation inherited
+    public void paint (Graphics2D gfx, Shape dest)
+    {
+	super.paint(gfx, dest);
+
+	// TODO: draw the object image offset to account for its
+	// actual dimensions
+    }
+}