From 7b31827fe39d5496e42fe2e51a2a256f46f1e0ef Mon Sep 17 00:00:00 2001
From: Marius Kintel <marius@kintel.net>
Date: Wed, 25 Dec 2013 14:47:54 -0500
Subject: [PATCH] Implemented intersection_for

---
 src/GeometryEvaluator.cc | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/GeometryEvaluator.cc b/src/GeometryEvaluator.cc
index e78cbf2e..871c3fae 100644
--- a/src/GeometryEvaluator.cc
+++ b/src/GeometryEvaluator.cc
@@ -1087,5 +1087,16 @@ Response GeometryEvaluator::visit(State &state, const RenderNode &node)
 
 Response GeometryEvaluator::visit(State &state, const AbstractIntersectionNode &node)
 {
-	assert(false);
+	if (state.isPrefix() && isCached(node)) return PruneTraversal;
+	if (state.isPostfix()) {
+		shared_ptr<const class Geometry> geom;
+		if (!isCached(node)) {
+			geom = applyToChildren(node, OPENSCAD_INTERSECTION).constptr();
+		}
+		else {
+			geom = GeometryCache::instance()->get(this->tree.getIdString(node));
+		}
+		addToParent(state, node, geom);
+	}
+	return ContinueTraversal;
 }