import collections
import itertools
import numpy as np
from ... import draw, mesh
from ...draw import internal
LightInfo = collections.namedtuple(
'LightInfo', ['normal', 'magnitude'])
[docs]@internal.ShapeDecorator
class Spheres(draw.Spheres):
__doc__ = draw.Spheres.__doc__
_ATTRIBUTES = draw.Spheres._ATTRIBUTES + list(itertools.starmap(
internal.ShapeAttribute, [
('light_levels', np.uint32, 3, 0, False,
'Number of quantized light levels to use'),
]))
def render(self, rotation=(1, 0, 0, 0), name_suffix='', illo_id='illo',
ambient_light=0.4, directional_light=[], **kwargs):
# in the zdog coordinate system, x is to the right, y is down,
# and z is toward you
lines = []
light_levels = np.linspace(0, 1, self.light_levels + 2)[1:-1]
directional_light = np.atleast_2d(directional_light)
light_info = []
for light in directional_light:
mag = np.linalg.norm(light)
normal = light/mag
light_info.append(LightInfo(normal, mag))
particles = zip(*mesh.unfoldProperties([
self.positions*(1, -1, 1), self.diameters, self.colors*255]))
for i, (position, (diameter,), color) in enumerate(particles):
group_index = 'sphere_{}_{}'.format(name_suffix, i)
lines.append("""
let {group_index} = new Zdog.Group({{
addTo: {illo_id},
translate: {{x: {pos[0]}, y: {pos[1]}, z: {pos[2]}}},
updateSort: true,
}});""".format(
group_index=group_index, illo_id=illo_id, pos=position))
(r, g, b) = map(int, ambient_light*color[:3])
color_str = '"rgba({}, {}, {}, {})"'.format(r, g, b, color[3]/255)
lines.append("""
new Zdog.Shape({{
addTo: {group_index},
stroke: {diameter},
color: {color},
}});""".format(group_index=group_index, pos=position,
diameter=diameter, color=color_str))
for (light, level_fraction) in itertools.product(
light_info, light_levels):
offset = -0.5*diameter*(1 - level_fraction)*light.normal*(1, -1, 1)
this_color = color.copy()
light_level = 1 - level_fraction
this_color[:3] *= ambient_light + light_level*light.magnitude
this_color.clip(0, 255, this_color)
(r, g, b) = map(int, this_color[:3])
# RGB components are 0-255, A component is a float 0-1
color_str = '"rgba({}, {}, {}, {})"'.format(r, g, b, color[3]/255)
lines.append("""
new Zdog.Shape({{
addTo: {group_index},
translate: {{x: {pos[0]}, y: {pos[1]}, z: {pos[2]}}},
color: {color},
stroke: {diameter},
fill: true,
}});
""".format(
group_index=group_index, pos=offset,
diameter=diameter*level_fraction, color=color_str))
return lines