From 91d9d9c4b5e4c0b2c1a5a5796eb3b9323710e74b Mon Sep 17 00:00:00 2001
From: Marius Kintel <marius@kintel.net>
Date: Wed, 21 Dec 2011 22:47:00 +0100
Subject: [PATCH] Added note about tree pruning

---
 src/csgterm.cc | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/csgterm.cc b/src/csgterm.cc
index 49f3dbb5..1b9cb1db 100644
--- a/src/csgterm.cc
+++ b/src/csgterm.cc
@@ -81,6 +81,12 @@ shared_ptr<CSGTerm> CSGTerm::normalize(shared_ptr<CSGTerm> &term)
 
 	if (term->type == TYPE_PRIMITIVE) return term;
 
+	// FIXME: We can optimize the normalized tree by pruning based on bounding boxes
+	// as described in the above mentioned paper:
+	// 1) If the bounding boxes of two intersected nodes don't intersect, prune the 
+	//    intersection node
+	// 2) If the bounding boxes of two subtracted nodes don't intersect, replace the
+	//    difference node with the positive operator
 	do {
 		while (normalize_tail(term)) {}
 		normalize(term->left);