diff -r 79b516a3803d -r 76b7bd51d64a ccdemos/spheres_shadow.cc
--- a/ccdemos/spheres_shadow.cc	Fri Nov 30 00:44:51 2007 +0100
+++ b/ccdemos/spheres_shadow.cc	Mon Dec 03 01:49:23 2007 +0100
@@ -4,7 +4,10 @@
 int main()
 {
 	Raytracer rt;
-	rt.setThreads(1);
+	rt.setThreads(2);
+
+	KdTree top;
+	rt.setTop(&top);
 
 	Light light1(Vector3(0.0, 5.0, -5.0), Colour(0.7, 0.3, 0.6));
 	rt.addlight(&light1);
@@ -29,19 +32,21 @@
 	Sphere tinysphere(Vector3(-1.2, 0.0, -2.0), 0.5, &mat3);
 	rt.addshape(&tinysphere);
 
+	top.optimize();
+
 	Camera cam;
 	cam.setEye(Vector3(0,0,15));
 	rt.setCamera(&cam);
 
 	int w = 800;
 	int h = 600;
-	float *fdata = (float *) malloc(w*h*3*sizeof(float));
+	Float *fdata = (Float *) malloc(w*h*3*sizeof(Float));
 	rt.render(w, h, fdata);
 
 	struct image *img;
 	new_image(&img, w, h, 3);
 
-	float *fd = fdata;
+	Float *fd = fdata;
 	for (char *cd = img->data; cd != img->data + w*h*3; cd++, fd++) {
 		if (*fd > 1.0)
 			*cd = 255;