print "cl=", cl_p
        print "d=", d_p

        (cl_v,ccp_v,cp_v,d_v) = c.intersect_sphere_point(dir,t.p1)
        print "ccp=", ccp_v
        print "cp=", cp_v
        print "cl=", cl_v
        print "d=", d_v

        (cl_e,ccp_e,cp_e,d_e) = c.intersect_sphere_line(dir,Line(t.p1,t.p2))
        print "ccp=", ccp_e
        print "cp=", cp_e
        print "cl=", cl_e
        print "d=", d_e

        (cl,d) = c.intersect(dir,t)
        print "cl=", cl

    if False:
        samples = 50
        x0 = -5.0
        x1 = +5.0
        y0 = -5.0
        y1 = +5.0
        z = 10
        pathlist = []
        for i in range(0,samples):
            x = x0 + i * ((x1-x0) / samples)
            p = Path()
            for j in range(0,samples):
                y = y0 + j * ((y1-y0) / samples)
        print "d=", d_p

        (cl_v, ccp_v, cp_v, d_v) = c.intersect_sphere_point(dir, t.p1)
        print "ccp=", ccp_v
        print "cp=", cp_v
        print "cl=", cl_v
        print "d=", d_v

        (cl_e, ccp_e, cp_e,
         d_e) = c.intersect_sphere_line(dir, Line(t.p1, t.p2))
        print "ccp=", ccp_e
        print "cp=", cp_e
        print "cl=", cl_e
        print "d=", d_e

        (cl, d) = c.intersect(dir, t)
        print "cl=", cl

    if False:
        samples = 50
        x0 = -5.0
        x1 = +5.0
        y0 = -5.0
        y1 = +5.0
        z = 10
        pathlist = []
        for i in range(0, samples):
            x = x0 + i * ((x1 - x0) / samples)
            p = Path()
            for j in range(0, samples):
                y = y0 + j * ((y1 - y0) / samples)