sine_wave.py

# SPDX-FileCopyrightText: Copyright (c) 2022 Randall Bohn (dexter)
#
# SPDX-License-Identifier: MIT
import math
import time
from vectorio import Circle
import displayio
import board
display = board.DISPLAY

def spread(duration):
    "for _duration_ seconds return a value between 0. and 1."
    end_time = time.monotonic() + duration
    while time.monotonic() < end_time:
        t = end_time - time.monotonic()
        yield 1-t/duration

palette = displayio.Palette(8)
palette[0]=0xFF9933
cc = Circle(radius=48, x=32, y=display.width//2,
    pixel_shader=palette)
    
splash = displayio.Group()
splash.append(cc)

display.show(splash)

while True:
    for x in spread(8):
        cc.x = 32+int((display.width-64)*x)
        cc.y = display.height//2 + int(64*math.sin(4*math.pi*x))