class Shadow_2d(VGroup):
CONFIG = {
'shadow_color': DARK_GRAY,
'shadow_opacity': 0.6,
'blur_width': 0.25,
'layer_num': 40,
'scale_factor': 1,
'shadow_out': True,
'show_basic_shape': True,
'plot_depth':-1,
'rate_func': lambda t: t ** 0.5,
}
def __init__(self, mob_or_points, **kwargs):
VGroup.__init__(self, **kwargs)
if type(mob_or_points) == list:
self.shape = Polygon(*mob_or_points, stroke_width=0, plot_depth=-1)
else:
self.shape = mob_or_points.set_stroke(width=0)
self.shape.set_fill(color=self.shadow_color, opacity=self.shadow_opacity * (1 if self.show_basic_shape else 0)).scale(self.scale_factor)
self.blur_outline = VGroup()
s = (self.shape.get_height() + self.shape.get_width())/2
if self.blur_width > 1e-4:
for i in range(self.layer_num):
layer_i = self.shape.copy().set_stroke(color=self.shadow_color, width=100 * self.blur_width/self.layer_num, opacity=self.shadow_opacity * (1-self.rate_func(i/self.layer_num))).\
set_fill(opacity=0).scale((s + (1 if self.shadow_out else -1) * self.blur_width/self.layer_num * (i+0.5))/ s).set_plot_depth(-2)
self.blur_outline.add(layer_i)
self.add(self.shape, self.blur_outline)
def init_points(self) -> None:
# Star by creating two of the pentagons, meeting
# back to back on the positive x-axis
phi = (1 + math.sqrt(5)) / 2
x, y, z = np.identity(3)
pentagon1 = Polygon(
[phi, 1 / phi, 0],
[1, 1, 1],
[1 / phi, 0, phi],
[1, -1, 1],
[phi, -1 / phi, 0],
)
pentagon2 = pentagon1.copy().stretch(-1, 2, about_point=ORIGIN)
pentagon2.reverse_points()
x_pair = VGroup(pentagon1, pentagon2)
z_pair = x_pair.copy().apply_matrix(np.array([z, -x, -y]).T)
y_pair = x_pair.copy().apply_matrix(np.array([y, z, x]).T)
self.add(*x_pair, *y_pair, *z_pair)
for pentagon in list(self):
pc = pentagon.copy()
pc.apply_function(lambda p: -p)
pc.reverse_points()
self.add(pc)
