generativeart/hyphae.py

#!/usr/bin/env python3

import cairo
import math
import random
from utils import circle_fill
from utils import random_color

WIDTH, HEIGHT = 1000, 1000
ANGLE_RANDOM_MIN = -0.6 
ANGLE_RANDOM_MAX = 0.6
# how much to shrink each consecutive circle
SHRINK = 0.00004

class Branch():
    def __init__(self, idx, ctx, x, y, r, ang):
        ctx.set_source_rgb(255, 0, 0)
        self.nodes = [Node(ctx, x, y, r, ang, dry=True)]
        ctx.set_source_rgb(0,0, 0)
        self.idx = idx
        self.ctx = ctx
        self.ended = False
        
    def _last_node(self):
        return self.nodes[-1]
    def place_next(self, branches):
        if not self.ended:
          last = self._last_node()
          next_x = last.r * math.sin(last.ang) + last.x
          next_y = last.r * math.cos(last.ang) + last.y
          next_r = last.r - SHRINK
          # too small?
          if next_r < 0.000000001:
              self.ended = True
              return False
          # did we hit canvas edge?
          if next_x + next_r > 1 or next_x - next_r < 0:
              self.ended = True
              return False
          if next_y + next_r > 1 or next_y - next_r < 0:
              self.ended = True
              return False
          last_nodes = self.nodes[-2:]
          # did we hit another circle?
          for branch in branches:
              for node in branch.nodes:
                  if node not in last_nodes: #!= last and node != self.nodes[-2]:
                      if circles_intersect(node.x, node.y, node.r,
                                            next_x, next_y, next_r):
                          self.ended = True
                          return False

          next_ang = last.ang + random.uniform(ANGLE_RANDOM_MIN, ANGLE_RANDOM_MAX)
          self.nodes.append(Node(self.ctx, next_x, next_y, next_r, next_ang))
          return True

def circles_intersect(x1, y1, r1, x2, y2, r2):
    distance = math.sqrt(math.pow(abs(x2 - x1), 2) + math.pow(abs(y2 - y1), 2))
    combined_r = r1 + r2
    return distance < combined_r


class Node():
    def __init__(self, ctx, x, y, r, ang, dry=False):
        self.x = x
        self.y = y
        self.r = r
        self.ang = ang
        if not dry:
            circle_fill(ctx, x, y, r)
    def __ne__(self, other):
        return self.x != other.x or self.y != other.y or self.r != other.r or self.ang != other.ang

def grow_subs(ctx, subs, branches):
    new_subs = []
    created = False
    for branch in subs:
        # create a sub branch based on length
        sub_branches = len(branch.nodes) // 10
        if sub_branches > 1:
            created = True
        for i in range(sub_branches):
            for n in range(15): # attempts at growing branches
                start_node = random.choice(branch.nodes)
                # start perpendicular to our last angle
                start_angle = start_node.ang + random.choice([90, -90]) + random.uniform(-5, 5)
                start_x = start_node.r * math.sin(start_angle) + start_node.x
                start_y = start_node.r * math.cos(start_angle) + start_node.y
                start_r = start_node.r - 0.002
                new_branch = Branch(i, ctx, start_x, start_y, start_r, start_angle)
                if new_branch.place_next(branches):
                    break
            branches.append(new_branch)
            new_subs.append(new_branch)
    if not created:
        return
    while not all([branch.ended for branch in new_subs]):
        for branch in new_subs:
            branch.place_next(branches)
    return new_subs 
def main():
    
    surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, WIDTH, HEIGHT)
    ctx = cairo.Context(surface)

    ctx.scale(WIDTH, HEIGHT)  # Normalizing the canvas

    # place seeds 
    branches = []
    #for b in range(6):
    #    start_x = random.uniform(0.2, 0.8)
    #    start_y = random.uniform(0.2, 0.8)
    start_r = 0.015
    #    start_angle = random.randint(0, 360)
    #    branches.append(Branch(b, ctx, start_x, start_y, start_r, start_angle))
    branches.append(Branch(0, ctx, 0.5, 0.4, start_r, 180)) 
    branches.append(Branch(1, ctx, 0.4, 0.5, start_r, 270)) 
    branches.append(Branch(2, ctx, 0.6, 0.5, start_r, 90)) 
    branches.append(Branch(3, ctx, 0.5, 0.6, start_r, 0)) 
    # grow initial branches
    while not all([b.ended for b in branches]):
        for branch in branches:
            branch.place_next(branches)
    # start branching off
    #subs = []
    subs = branches
    try:
        for x in range(8):
            if subs == None:
                return
            subs = grow_subs(ctx, subs, branches)
            surface.write_to_png("out/hyphae.png")  # Output to PNG
            input('next')
    finally:
        surface.write_to_png("out/hyphae.png")  # Output to PNG

if __name__ == '__main__':
    main()