# Gingerbread man fractal with generativepy

Martin McBride, 2020-11-01
Categories generativepy generative art

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The Gingerbread man fractal is based on an iterated function. Here we will look at an implementation using generativepy.

The basic algorithm is similar to the King's Dream fractal. It is best to read that article first, as this section mainly highlights the differences between them.

The fractal equations for Gingerbread Man are:

xnext = 1 - y + abs(x)
ynext = x


There are no parameters, and the required initial values are:

x = -0.01  # Initial value
y = 0      # Initial value


The code also modifies the scaling factors (in the Scaler constructor) to fit the size of the fractal.

Notice that the code is based on the uncoloured version of Kings Dream. For this fractal, the shape is quite interesting, but the distribution of counts within the shape is just random noise that doesn't really add anything.

Here is the result:

## The code

Here is the full code for the image above:

from generativepy.bitmap import make_bitmap, Scaler
from generativepy.color import Color
import numpy as np
import math

MAX_COUNT = 1000000
BLACK = Color(0)
WHITE = Color(1)

def paint(image, pixel_width, pixel_height, frame_no, frame_count):
scaler = Scaler(pixel_width, pixel_height, width=11, startx=-3, starty=-3)

counts = np.zeros([pixel_height, pixel_width], np.int32)

x = -0.1
y = 0
for i in range(MAX_COUNT):
x, y =1 - y + abs(x), x
px, py = scaler.user_to_device(x, y)
counts[py, px] += 1

for px in range(pixel_width):
for py in range(pixel_height):
col = BLACK if counts[py, px]==0 else WHITE
image.putpixel((px, py), col.as_rgb_bytes())