--- a/include/kdtree.h	Thu May 08 09:21:25 2008 +0200
+++ b/include/kdtree.h	Sat May 10 14:29:37 2008 +0200
@@ -69,7 +69,7 @@
 	KdNode* getRightChild() const { return (KdNode*)(((size_t)children & ~3) + 16); };
 
 	ShapeList* getShapes() const { return (ShapeList*)((size_t)shapes & ~3); };
-	void addShape(Shape* aShape) { getShapes()->push_back(aShape); };
+	void addShape(const Shape* aShape) { getShapes()->push_back(aShape); };
 };
 
 /**
@@ -88,19 +88,19 @@
 	KdTree(): Container(), mempool(64), root(NULL), max_depth(32), built(false) {};
 	KdTree(int maxdepth): Container(), mempool(64), root(NULL), max_depth(maxdepth), built(false) {};
 	~KdTree() { if (root) delete root; };
-	void addShape(Shape* aShape) { Container::addShape(aShape); built = false; };
-	Shape *nearest_intersection(const Shape *origin_shape, const Ray &ray,
+	void addShape(const Shape* aShape) { Container::addShape(aShape); built = false; };
+	const Shape *nearest_intersection(const Shape *origin_shape, const Ray &ray,
 		Float &nearest_distance);
 #ifndef NO_SIMD
 	void packet_intersection(const Shape* const* origin_shapes, const RayPacket &rays,
-		Float *nearest_distances, Shape **nearest_shapes);
+		Float *nearest_distances, const Shape **nearest_shapes);
 #endif
 	void optimize() { build(); };
 	void build();
 	bool isBuilt() const { return built; };
 	KdNode *getRootNode() const { return root; };
 
-	ostream & dump(ostream &st);
+	ostream & dump(ostream &st) const;
 	istream & load(istream &st, Material *mat);
 };