130 lines
3.6 KiB
Python
130 lines
3.6 KiB
Python
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import axi
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import random
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from collections import defaultdict
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from math import pi, sin, cos, hypot, floor
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from shapely.geometry import LineString
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class Grid(object):
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def __init__(self, r):
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self.r = r
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self.size = r / 2 ** 0.5
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self.points = {}
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self.lines = {}
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def normalize(self, x, y):
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i = int(floor(x / self.size))
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j = int(floor(y / self.size))
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return (i, j)
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def nearby(self, x, y):
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points = []
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lines = []
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i, j = self.normalize(x, y)
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for p in range(i - 2, i + 3):
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for q in range(j - 2, j + 3):
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if (p, q) in self.points:
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points.append(self.points[(p, q)])
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if (p, q) in self.lines:
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lines.append(self.lines[(p, q)])
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return points, lines
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def insert(self, x, y, line=None):
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points, lines = self.nearby(x, y)
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for bx, by in points:
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if hypot(x - bx, y - by) < self.r:
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return False
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i, j = self.normalize(x, y)
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if line:
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for other in lines:
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if line.crosses(other):
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return False
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self.lines[(i, j)] = line
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self.points[(i, j)] = (x, y)
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return True
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def remove(self, x, y):
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i, j = self.normalize(x, y)
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self.points.pop((i, j))
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self.lines.pop((i, j))
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def max_angle(i, d):
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a1 = 2 * pi
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a2 = pi / 2
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p = min(1, d / 20.0)
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p = p ** 0.5
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return a1 + (a2 - a1) * p
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def choice(items):
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# return random.choice(items)
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p = random.random() ** 0.1
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return items[int(p * len(items))]
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def poisson_disc(x1, y1, x2, y2, r, n):
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grid = Grid(r)
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active = []
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for i in range(1):
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x = x1 + random.random() * (x2 - x1)
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y = y1 + random.random() * (y2 - y1)
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x = (x1 + x2) / 2.0
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y = (y1 + y2) / 2.0
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a = random.random() * 2 * pi
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if grid.insert(x, y):
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active.append((x, y, a, 0, 0, i))
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pairs = []
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while active:
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ax, ay, aa, ai, ad, ag = record = choice(active)
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for i in range(n):
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# a = random.random() * 2 * pi
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a = aa + (random.random() - 0.5) * max_angle(ai, ad)
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# a = random.gauss(aa, pi / 8)
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d = random.random() * r + r
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x = ax + cos(a) * d
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y = ay + sin(a) * d
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if x < x1 or y < y1 or x > x2 or y > y2:
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continue
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if ad + d > 4.25:
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continue
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pair = ((ax, ay), (x, y))
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line = LineString(pair)
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if not grid.insert(x, y, line):
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continue
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pairs.append(pair)
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active.append((x, y, a, ai + 1, ad + d, ag))
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active.sort(key=lambda x: -x[4])
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# if random.random() < 0.5:
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# active.remove(record)
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break
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else:
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active.remove(record)
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return grid.points.values(), pairs
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def make_path(pairs):
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lookup = defaultdict(list)
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for parent, child in pairs:
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lookup[parent].append(child)
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root = pairs[0][0]
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path = []
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stack = []
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stack.append(root)
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while stack:
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point = stack[-1]
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path.append(point)
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if not lookup[point]:
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stack.pop()
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continue
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child = lookup[point].pop()
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stack.append(child)
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return path
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def main():
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random.seed(1182)
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points, pairs = poisson_disc(0, 0, 11, 8.5, 0.05, 24)
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path = make_path(pairs)
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drawing = axi.Drawing([path]).scale_to_fit(11, 8.5)
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# drawing.render().write_to_png('out.png')
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axi.draw(drawing)
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if __name__ == '__main__':
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main()
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