3d_cube.py

# Rotating 3D cube

# Based on https://github.com/mcauser/micropython-pcd8544/blob/master/examples/3d_cube.py
# Modified to run on CircuitPython

import adafruit_pcd8544
import board,busio,digitalio
import math

backlight = digitalio.DigitalInOut(board.GP12)
backlight.switch_to_output()
backlight.value = True

mosi_pin = board.GP11
clk_pin = board.GP10

spi = busio.SPI(clock=clk_pin, MOSI=mosi_pin)
dc = digitalio.DigitalInOut(board.GP16) # data/command
cs = digitalio.DigitalInOut(board.GP18) # Chip select
reset = digitalio.DigitalInOut(board.GP17) # reset

lcd = adafruit_pcd8544.PCD8544(spi, dc, cs, reset)
lcd.bias = 5
lcd.contrast = 45

pi = math.pi

size = 700
width = 84
height = 48

d = 3
px = [-d,  d,  d, -d, -d,  d,  d, -d]
py = [-d, -d,  d,  d, -d, -d,  d,  d]
pz = [-d, -d, -d, -d,  d,  d,  d,  d]

p2x = [0,0,0,0,0,0,0,0]
p2y = [0,0,0,0,0,0,0,0]
r = [0,0,0]

def drawCube():
    r[0] = r[0] + pi / 180.0
    r[1] = r[1] + pi / 180.0
    r[2] = r[2] + pi / 180.0
    if (r[0] >= 360.0 * pi / 180.0):
        r[0] = 0
    if (r[1] >= 360.0 * pi / 180.0):
        r[1] = 0
    if (r[2] >= 360.0 * pi / 180.0):
        r[2] = 0

    for i in range(8):
        px2 = px[i]
        py2 = math.cos(r[0]) * py[i] - math.sin(r[0]) * pz[i]
        pz2 = math.sin(r[0]) * py[i] + math.cos(r[0]) * pz[i]

        px3 = math.cos(r[1]) * px2 + math.sin(r[1]) * pz2
        py3 = py2
        pz3 = -math.sin(r[1]) * px2 + math.cos(r[1]) * pz2

        ax = math.cos(r[2]) * px3 - math.sin(r[2]) * py3
        ay = math.sin(r[2]) * px3 + math.cos(r[2]) * py3
        az = pz3 - 150

        p2x[i] = width / 2 + ax * size / az
        p2y[i] = height / 2 + ay * size / az

    lcd.fill(0)

    for i in range(3):
        lcd.line(int(p2x[i]),   int(p2y[i]),   int(p2x[i+1]), int(p2y[i+1]), 1)
        lcd.line(int(p2x[i+4]), int(p2y[i+4]), int(p2x[i+5]), int(p2y[i+5]), 1)
        lcd.line(int(p2x[i]),   int(p2y[i]),   int(p2x[i+4]), int(p2y[i+4]), 1)

    lcd.line(int(p2x[3]), int(p2y[3]), int(p2x[0]), int(p2y[0]), 1)
    lcd.line(int(p2x[7]), int(p2y[7]), int(p2x[4]), int(p2y[4]), 1)
    lcd.line(int(p2x[3]), int(p2y[3]), int(p2x[7]), int(p2y[7]), 1)
    lcd.show()
    
while True:
    drawCube()