--- a/pkg/octree/vertex.go	Tue Jun 11 18:20:41 2019 +0200
+++ b/pkg/octree/vertex.go	Wed Jun 12 12:56:18 2019 +0200
@@ -413,6 +413,41 @@
 	}
 }
 
+func (ls LineStringZ) BBox() Box2D {
+
+	min := Vertex{math.MaxFloat64, math.MaxFloat64, math.MaxFloat64}
+	max := Vertex{-math.MaxFloat64, -math.MaxFloat64, -math.MaxFloat64}
+
+	for _, v := range ls {
+		min.Minimize(v)
+		max.Maximize(v)
+	}
+
+	return Box2D{
+		X1: min.X,
+		Y1: min.Y,
+		X2: max.X,
+		Y2: max.Y,
+	}
+}
+
+func (ls LineStringZ) Area() float64 {
+	var result float64
+	for i := 0; i < len(ls); i += 3 {
+		p0 := ls[i+0]
+		p1 := ls[i+1]
+		p2 := ls[i+2]
+		result += area(p0, p1, p2)
+	}
+	return result / 2
+}
+
+func (ls LineStringZ) Reverse() {
+	for i, j := 0, len(ls)-1; i < j; i, j = i+1, j-1 {
+		ls[i], ls[j] = ls[j], ls[i]
+	}
+}
+
 func (ls LineStringZ) order(position func(Vertex) float64) {
 	type posVertex struct {
 		pos float64
@@ -738,6 +773,10 @@
 	}
 }
 
+func (a Box2D) Area() float64 {
+	return (a.X2 - a.X1) * (a.Y2 - a.Y1)
+}
+
 // NewPlane2D creates a new Plane2D from two given points.
 func NewPlane2D(x1, y1, x2, y2 float64) Plane2D {
 	b := x2 - x1