def plot_ks(segs, nodes, xo, yo, xscale, yscale):
j = 0
cmd = 'moveto'
x = xo
for i in range(len(segs)):
i1 = (i + 1) % len(nodes)
n0 = nodes[i]
n1 = nodes[i1]
x0, y0, t0 = n0.x, n0.y, n0.ty
x1, y1, t1 = n1.x, n1.y, n1.ty
ks = segs[i].ks
chord, ch_th = poly3.integ_chord(ks)
l = chord/segs[i].chord
k0 = l * poly3.eval_cubic(ks[0], ks[1], .5 * ks[2], 1./6 * ks[3], -.5)
print x, yo + yscale * k0, cmd
cmd = 'lineto'
k3 = l * poly3.eval_cubic(ks[0], ks[1], .5 * ks[2], 1./6 * ks[3], .5)
k1 = k0 + l/3 * (ks[1] - 0.5 * ks[2] + .125 * ks[3])
k2 = k3 - l/3 * (ks[1] + 0.5 * ks[2] + .125 * ks[3])
print x + xscale / l / 3., yo + yscale * k1
print x + 2 * xscale / l / 3., yo + yscale * k2
print x + xscale / l, yo + yscale * k3, 'curveto'
x += xscale / l
if t1 == 'v':
j += 2
else:
j += 1
print 'stroke'
print xo, yo, 'moveto', x, yo, 'lineto stroke'
def compute_ends(self, ks):
chord, ch_th = poly3.integ_chord(ks)
l = chord / self.chord
thl = ch_th - (-.5 * ks[0] + .125 * ks[1] - 1./48 * ks[2] + 1./384 * ks[3])
thr = (.5 * ks[0] + .125 * ks[1] + 1./48 * ks[2] + 1./384 * ks[3]) - ch_th
k0l = l * (ks[0] - .5 * ks[1] + .125 * ks[2] - 1./48 * ks[3])
k0r = l * (ks[0] + .5 * ks[1] + .125 * ks[2] + 1./48 * ks[3])
l2 = l * l
k1l = l2 * (ks[1] - .5 * ks[2] + .125 * ks[3])
k1r = l2 * (ks[1] + .5 * ks[2] + .125 * ks[3])
l3 = l2 * l
k2l = l3 * (ks[2] - .5 * ks[3])
k2r = l3 * (ks[2] + .5 * ks[3])
return (thl, k0l, k1l, k2l), (thr, k0r, k1r, k2r), l