polygons.py
from math import sin, cos, tan, pi, atan2
import cairo
import random
COLORS = [
0x477984,
0xEEAA4D,
0xC03C44,
0xFEF5EB,
]
def color(value):
r = ((value >> 16) & 0xff) / 255.0
g = ((value >> 8) & 0xff) / 255.0
b = ((value >> 0) & 0xff) / 255.0
return (r, g, b)
class Shape(object):
def __init__(self, sides, x=0, y=0, rotation=0, **kwargs):
self.sides = sides
self.x = x
self.y = y
self.rotation = rotation
self.color = COLORS[(self.sides - 3) % len(COLORS)]
for key, value in kwargs.items():
setattr(self, key, value)
def points(self, scale=1, margin=0):
angle = 2 * pi / self.sides
rotation = self.rotation - pi / 2
if self.sides % 2 == 0:
rotation += angle / 2
angles = [angle * i + rotation for i in range(self.sides)]
angles.append(angles[0])
d = 0.5 / sin(angle / 2) * scale - margin * sin(angle / 2)
return [(self.x + cos(a) * d, self.y + sin(a) * d) for a in angles]
def adjacent(self, sides, edge, **kwargs):
(x1, y1), (x2, y2) = self.points()[edge:edge + 2]
angle = 2 * pi / sides
a = atan2(y2 - y1, x2 - x1)
b = a - pi / 2
d = 0.5 / tan(angle / 2)
x = x1 + (x2 - x1) / 2.0 + cos(b) * d
y = y1 + (y2 - y1) / 2.0 + sin(b) * d
a += angle * ((sides - 1) / 2)
return Shape(sides, x, y, a, **kwargs)
def render(self, dc):
points = self.points(margin=0.2)
dc.move_to(*points[0])
for point in points[1:]:
dc.line_to(*point)
dc.set_source_rgb(*color(self.color))
dc.fill_preserve()
dc.set_source_rgb(*color(0x313E4A))
dc.stroke()
def render_edge_labels(self, dc):
points = self.points(margin=0.15)
for edge in range(self.sides):
(x1, y1), (x2, y2) = points[edge:edge + 2]
text = str(edge)
tw, th = dc.text_extents(text)[2:4]
x = x1 + (x2 - x1) / 2.0 - tw / 2.0
y = y1 + (y2 - y1) / 2.0 + th / 2.0
dc.set_source_rgb(1, 1, 1)
dc.move_to(x, y)
dc.show_text(text)
def render_label(self, dc, text):
text = str(text)
tw, th = dc.text_extents(text)[2:4]
x = self.x - tw / 2.0
y = self.y + th / 2.0
dc.set_source_rgb(1, 1, 1)
dc.move_to(x, y)
dc.show_text(text)
class Model(object):
def __init__(self):
self.shapes = []
def append(self, shape):
self.shapes.append(shape)
def add(self, index, edge, sides, **kwargs):
parent = self.shapes[index]
shape = parent.adjacent(sides, edge, **kwargs)
self.append(shape)
def render(self, dc, dx=0, dy=0):
dc.save()
dc.translate(dx, dy)
for index, shape in enumerate(self.shapes):
shape.render(dc)
dc.restore()
def recursive_render(self, dc, indexes, depth, x=0, y=0, memo=None):
if depth < 0:
return
memo = memo or {}
key = (round(x, 3), round(y, 3))
previous_depth = memo.get(key, -1)
if previous_depth >= depth:
return
memo[key] = max(depth, previous_depth)
if previous_depth < 0:
self.render(dc, x, y)
for index in indexes:
shape = self.shapes[index]
self.recursive_render(
dc, indexes, depth - 1, x + shape.x, y + shape.y, memo)
def main():
width = height = 1024
scale = 48
surface = cairo.ImageSurface(cairo.FORMAT_RGB24, width, height)
dc = cairo.Context(surface)
dc.set_line_cap(cairo.LINE_CAP_ROUND)
dc.set_line_join(cairo.LINE_JOIN_ROUND)
dc.set_line_width(3.0 / scale)
dc.set_font_size(10.0 / scale)
dc.translate(width / 2, height / 2)
dc.scale(scale, scale)
dc.set_source_rgb(0, 0, 0)
dc.paint()
model = Model()
model.append(Shape(6, color=COLORS[0]))
for i in range(6):
model.add(0, i, 4)
for i in range(6):
model.add(i + 1, 1, 3, color=COLORS[2])
for i in range(6):
model.add(i + 7, 2, 4)
for i in range(6):
model.add(i + 13, 3, 6, color=COLORS[0])
model.recursive_render(dc, range(19, 25), 6)
surface.write_to_png('output.png')
if __name__ == '__main__':
main()