private void AddLineX(MeshBuilder mesh, double x, double minY, double maxY, double thickness)
{
int i0 = mesh.Positions.Count;
mesh.Positions.Add(this.GetPoint(x - thickness / 2, minY));
mesh.Positions.Add(this.GetPoint(x - thickness / 2, maxY));
mesh.Positions.Add(this.GetPoint(x + thickness / 2, maxY));
mesh.Positions.Add(this.GetPoint(x + thickness / 2, minY));
mesh.Normals.Add(this.Normal);
mesh.Normals.Add(this.Normal);
mesh.Normals.Add(this.Normal);
mesh.Normals.Add(this.Normal);
mesh.TriangleIndices.Add(i0);
mesh.TriangleIndices.Add(i0 + 1);
mesh.TriangleIndices.Add(i0 + 2);
mesh.TriangleIndices.Add(i0 + 2);
mesh.TriangleIndices.Add(i0 + 3);
mesh.TriangleIndices.Add(i0);
}