Box2D.Collision.Shapes.PolygonShape.SetAsEdge C# (CSharp) Method

        public void SetAsEdge(Vec2 v1, Vec2 v2)
        {
            VertexCount = 2;
            Vertices[0].Set(v1);
            Vertices[1].Set(v2);
            Centroid.Set(v1).AddLocal(v2).MulLocal(0.5f);
            // = 0.5f * (v1 + v2);
            Normals[0].Set(v2).SubLocal(v1);
            Vec2.CrossToOut(Normals[0], 1f, Normals[0]);
            // m_normals[0] = Cross(v2 - v1, 1.0f);
            Normals[0].Normalize();
            Normals[1].Set(Normals[0]).NegateLocal();
        }