Mandelbrot set, on Micropython Makerfab

micro_mandelbrot.py

# this will be the mandelbrot set, written in python
import sys
import machine
import st7789py as st7789
import random
from machine import Pin

def scale_x(px):
  #scaled x coordinate of pixel (scaled to lie in the Mandelbrot X scale (-2.5, 1))  
  return -2.5 + px * 3.5 / 239
def scale_y(py):
  #scaled y coordinate of pixel (scaled to lie in the Mandelbrot Y scale (-1, 1))
  return -1 + py * 2 / 239
def mandelbrot_pixel(px, py):
  x0 = scale_x(px)
  y0 = scale_y(py)
  
  max_iteration = 20
  x2 = 0
  y2 = 0
  w = 0
  iteration = 0
  while x2 + y2 <= 4 and iteration < max_iteration:
    x = x2 - y2 + x0
    y = w - x2 - y2 + y0
    x2 = x * x
    y2 = y * y
    w = (x + y) * (x + y)
    iteration += 1
  return iteration


class Render:
  """Abstracts rendering out from mandelbrot logic"""
  def __init__(self, display, buffered=True):
    self.buffered = buffered
    self.display = display
    if buffered:
      self.pallete = build_byte_pallete()
    else:
      self.pallete = build_colors_pallete()
    self.buffer = bytearray()
  
  def plot(self, i, j, iter):
    if not self.buffered:
      self.display.pixel(i, j, self.pallete[iter])
      return 
    
    self.buffer.append(self.pallete[iter*2])
    self.buffer.append(self.pallete[iter*2+1])
    if j % 10 == 9 and i == 239:
      self.display.blit_buffer(self.buffer, 0, j-9, 240, 10)
      self.buffer = bytearray()

  def build_colors_pallete():
    colors = bytearray()
    for i in range(21):
      colors.append(st7789.color565(
      random.getrandbits(8),
      random.getrandbits(8),
      random.getrandbits(8)))
    return colors

  def build_byte_pallete():
    colors = bytearray()
    for i in range(21):
      colors.append(random.getrandbits(8))
      colors.append(random.getrandbits(8))
    return colors

def mandelbrot(render):
  for j in range(240):
    for i in range(240):
      iter = mandelbrot_pixel(i, j)
      render.plot(i, j, iter)

bl = machine.Pin(5, machine.Pin.OUT)
bl.value(1) 
spi = machine.SPI(1, baudrate=80000000, polarity=1, phase=0, sck=machine.Pin(14), mosi=machine.Pin(13), miso=machine.Pin(12))#HSPI


display = st7789.ST7789(
  spi, 240, 240,
  reset=machine.Pin(21, machine.Pin.OUT),
  dc=machine.Pin(22, machine.Pin.OUT),
  cs=machine.Pin(15, machine.Pin.OUT),
  backlight=machine.Pin(5, machine.Pin.OUT),
  )


display.fill(st7789.BLACK)

render = Render(display, buffered=True)
mandelbrot(render)
print("done")