From d83fa334e4a5fc5a9e5e9334391338d0e06c4ed9 Mon Sep 17 00:00:00 2001
From: Lukas Himbert <lukas@2.71828.eu>
Date: Sun, 27 Dec 2020 19:20:16 +0100
Subject: [PATCH] spinning rainbow

---
 spinning-rainbow.py | 133 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 spinning-rainbow.py

diff --git a/spinning-rainbow.py b/spinning-rainbow.py
new file mode 100644
index 0000000..95e0dba
--- /dev/null
+++ b/spinning-rainbow.py
@@ -0,0 +1,133 @@
+# Try to import board and neopixel to run on the real hardware
+try:
+    import board
+    import neopixel
+except ImportError:
+    # Error, try to import the simulation from DutChen18 instead (https://github.com/standupmaths/xmastree2020/pull/5)
+    from sim import board, neopixel
+
+def xmaslight():
+    # This is the code from my 
+    
+    #NOTE THE LEDS ARE GRB COLOUR (NOT RGB)
+    
+    # Here are the libraries I am currently using:
+    import time
+    import re
+    from math import sin, cos, atan2, pi
+    #import board
+    #import neopixel
+
+    # You are welcome to add any of these:
+    import random
+    import numpy
+    # import scipy
+    # import sys
+    
+    # If you want to have user changable values, they need to be entered from the command line
+    # so import sys sys and use sys.argv[0] etc
+    # some_value = int(sys.argv[0])
+    
+    # IMPORT THE COORDINATES (please don't break this bit)
+    
+    coordfilename = "Python/coords.txt"
+	
+    fin = open(coordfilename,'r')
+    coords_raw = fin.readlines()
+    
+    coords_bits = [i.split(",") for i in coords_raw]
+    
+    coords = []
+    
+    for slab in coords_bits:
+        new_coord = []
+        for i in slab:
+            new_coord.append(int(re.sub(r'[^-\d]','', i)))
+        coords.append(new_coord)
+    
+    #set up the pixels (AKA 'LEDs')
+    PIXEL_COUNT = len(coords) # this should be 500
+    
+    pixels = neopixel.NeoPixel(board.D18, PIXEL_COUNT, auto_write=False)
+    
+    
+    # YOU CAN EDIT FROM HERE DOWN
+    
+    # unzip coordinates
+    xs, ys, zs = list(zip(*coords))
+    xs = numpy.array(xs)
+    ys = numpy.array(ys)
+    zs = numpy.array(zs)
+
+    # normalize heights (0 to 1)
+    zs = (zs - zs.min()) / (zs.max() - zs.min())
+
+    # Find center of the tree
+    x0 = numpy.average([x for (x, _, _) in coords])
+    y0 = numpy.average([y for (_, y, _) in coords])
+
+    # normalized radii (0 to 1)
+    radii = numpy.sqrt((xs - x0)**2, (ys - y0)**2)
+    radii = radii / radii.max()
+
+    # azimuths
+    azimuths = numpy.arctan2(ys, xs)
+
+    # VARIOUS SETTINGS
+
+    # rotation speed in radians per second
+    # may be negative to reverse direction
+    speed = pi/2
+
+    # brightness factor:
+    # 0 = black
+    # 1 = maximum brightness
+    brightness_factor = 0.4
+
+    # colours in GRB order
+    white = (255, 255, 255)
+    black = (0, 0, 0)
+    ray_colors = [
+        (0, 255, 0),
+        (165, 255, 0),
+        (255, 255, 0),
+        (128, 0, 0),
+        (0, 0, 255),
+        (0, 75, 130),
+        (130, 238, 238),
+    ]
+    ray_colors = [ (round(brightness_factor * g), round(brightness_factor * r), round(brightness_factor * b)) for (g, r, b) in ray_colors ]
+    # extend the colors so that the rainbow only spans half the circumference tree
+    ray_colors = ray_colors + len(ray_colors) * [black]
+    
+    # ray width; 2*pi/len(ray_colors) is the maximum
+    ray_width = 2*pi/len(ray_colors)
+
+    # INITIALISE SOME VALUES
+    t0 = time.time()
+
+    while True:
+        # Reset all lights to black
+        for i in range(len(coords)):
+            pixels[i] = black
+        # Turn them on again if they are at the "right" position
+        delta = time.time() - t0
+        for (i, (φ, z)) in enumerate(zip(azimuths, zs)):
+            if z > 0.95:
+                # the top stays dark constantly, so it doesn't look too messy
+                continue
+            else:
+                for (j, color) in enumerate(ray_colors):
+                    ray_offset = j * 2*pi / len(ray_colors)
+                    if abs(φ + ray_offset + delta * speed) % (2*pi) <= ray_width:
+                        pixels[i] = color
+        
+        # use the show() option as rarely as possible as it takes ages
+        # do not use show() each time you change a LED but rather wait until you have changed them all
+        pixels.show()
+        
+    return 'DONE'
+
+
+# yes, I just put this at the bottom so it auto runs
+xmaslight()
-- 
2.45.2