X-Git-Url: https://git.sesse.net/?p=tcxmerge;a=blobdiff_plain;f=opt.cc;h=87b632e62e7ac5fd042abe9c0ff1ae9988273417;hp=bd70b4173443c9765d689e534e5fc24d5dd46f6f;hb=5e162abbf9da991f67661149b686714535e0fa1d;hpb=a282bfeb16f1554da043752a3bb90e2ec42ae27d

diff --git a/opt.cc b/opt.cc
index bd70b41..87b632e 100644
--- a/opt.cc
+++ b/opt.cc
@@ -93,8 +93,8 @@ BSPTreeNode* make_bsp_tree(const vector<int>& remaining_roads)
 		const LineSegment& ls = roads[remaining_roads[i]];
 
 		// find the normal
-		double a = -(ls.to.x - ls.from.x);
-		double b =  ls.to.y - ls.from.y;
+		double a =   ls.to.y - ls.from.y;
+		double b = -(ls.to.x - ls.from.x);
 		double invlen = 1.0 / hypot(a, b);
 		a *= invlen, b *= invlen;
 
@@ -128,6 +128,13 @@ BSPTreeNode* make_bsp_tree(const vector<int>& remaining_roads)
 		}
 	}
 
+	if (left.empty() || right.empty()) {
+		node->is_leaf = true;
+		node->left = node->right = NULL;
+		node->roads_this_node = remaining_roads;
+		return node;
+	}
+
 	if (left.size() == 0) {
 		node->left = NULL;
 	} else {