Spiral Lines

# Spiral Graphics for Pimoroni Pico Display 2 320x240 pixels
# Uses Pimoroni Pico Graphics system
# Tony Goodhew 6th Febrary 2023

import time
import math

from picographics import PicoGraphics, DISPLAY_PICO_DISPLAY_2, PEN_P4
from pimoroni import RGBLED
# Reduced colours to save RAM
display = PicoGraphics(display=DISPLAY_PICO_DISPLAY_2, pen_type=PEN_P4, rotate=0)
display.set_backlight(0.8)
display.set_font("bitmap8") # Lower case included

led = RGBLED(6, 7, 8)
led.set_rgb(0,0,0)     # Turn RGBLED OFF

# ==== Board now setup ====
def end_point(theta, long): # Calculate end of line offsets - angle & length
    theta_rad = math.radians(theta)
    theta_rad = math.radians(theta)
    xx = int(long * math.sin(theta_rad))
    yy = -int(long * math.cos(theta_rad))
    return xx,yy

# === Main Program ===
BLACK = display.create_pen(0,0,0)
w = display.create_pen(255,255,255)
r = display.create_pen(255,0,0)
g = display.create_pen(0,255,0)
b = display.create_pen(0,0,255)
y = display.create_pen(255,255,0)
c = display.create_pen(0,255,255)
m = display.create_pen(255,0,255)
gr = display.create_pen(180,180,180)
o = display.create_pen(255,128,30)

display.set_pen(BLACK)
display.clear()
display.update()
display.set_font("bitmap8")
display.set_pen(g)
display.text("Spiral Lines", 20, 70, 200, 4)
display.set_pen(w)
display.text("Tony Goodhew", 20, 120, 200, 2)
display.update()
time.sleep(1.5)
colours = [r,y,g,c,b,m,w,o,gr]
alpha = [0,1,2,119,89,72,59,51,43] # Turn angles
dl = [0,0,0,2,1,1,1,1,1]           # Extra length

for cc in range(3,9,1):
    display.set_pen(BLACK)
    display.clear()  # Clear the screen
    display.update()
    xold = 159  # Coordinates of start point
    yold = 119
    l = 1
    theta = 0
    for i in range(120):
        xx, yy = end_point(theta, l) # Get offset
        xnext = xold+xx
        ynext = yold+yy
        display.set_pen(colours[i % cc])
        display.line(xold,yold,xnext,ynext)
        display.update()
        xold = xnext
        yold = ynext
        l = l + dl[cc]
        theta = theta + alpha[cc]
        time.sleep(0.01)
    time.sleep(1.5)

# Finish & tidy up
display.set_pen(BLACK)
display.clear()
display.set_pen(g)
display.text("All Done!", 50, 70, 200, 4)
display.update()
time.sleep(2)
display.set_pen(BLACK)
display.clear()
display.update()