Useful for cases where you have a tileset but only want some of the tiles in your multi frame image. This means that multiple different MultiFrameImages can be created using different, possibly overlapping subsets of the same shared tileset.

git-svn-id: svn+ssh://src.earth.threerings.net/nenya/trunk@782 ed5b42cb-e716-0410-a449-f6a68f950b19

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

@@ -0,0 +1,63 @@
+package com.threerings.media.tile;
+
+import java.awt.Graphics2D;
+
+import com.threerings.media.image.Colorization;
+
+/**
+ * A {@link MultiFrameImage} implementation that obtains its image frames
+ * from a tileset but that only uses a subset of the tiles available.
+ */
+public class TileSubsetMultiFrameImage extends TileMultiFrameImage
+{
+    /**
+     * Creates a tile MFI which will obtain its image frames from the
+     * specified source tileset.
+     */
+    public TileSubsetMultiFrameImage (TileSet source, int startIdx, int numTiles)
+    {
+        super(source);
+        if (startIdx + numTiles > source.getTileCount()) {
+            throw new IllegalArgumentException("Invalid tile range specified.");
+        }
+        _tileCount = numTiles;
+        _startIdx = startIdx;
+    }
+
+    /**
+     * Creates a recoolored tile MFI which will obtain its image frames
+     * from the specified source tileset.
+     */
+    public TileSubsetMultiFrameImage (TileSet source, Colorization[] zations,
+        int startIdx, int numTiles)
+    {
+        this(source.clone(zations), startIdx, numTiles);
+    }
+
+    @Override
+    public int getWidth (int index)
+    {
+        return super.getWidth(index + _startIdx);
+    }
+
+    @Override
+    public int getHeight (int index)
+    {
+        return super.getHeight(index + _startIdx);
+    }
+
+    @Override
+    public void paintFrame (Graphics2D g, int index, int x, int y)
+    {
+        super.paintFrame(g, index + _startIdx, x, y);
+    }
+
+    @Override
+    public boolean hitTest (int index, int x, int y)
+    {
+        return super.hitTest(index + _startIdx, x, y);
+    }
+
+    /** Index of the tile with which we begin this subset. */
+    protected int _startIdx;
+}