spiral.py

# tilda example

import ugfx
import buttons
import pyb
import math
from imu import IMU
 
ugfx.init()
buttons.init()
imu = IMU()

ugfx.backlight(50) 
ugfx.enable_tear()
tear_pin = pyb.Pin("TEAR", pyb.Pin.IN)

#ugfx.set_default_font(ugfx.FONT_TITLE)

def wait_for_scanline_pass(height):
    ugfx.set_tear_line(height)
    while(tear_pin.value() == 0):
        pass # wait for LCD to read up to line
    while(tear_pin.value()):
        pass # wait for LCD to read past it

def not_flipped():
    ival = imu.get_acceleration()
    return ival['y'] < 0

if not_flipped():
    ugfx.orientation(0)
    upside = False
else:
    ugfx.orientation(180)
    upside = True

w, h = ugfx.width(), ugfx.height()
tau = 2*math.pi
cx, cy = w//2, h//2

nlines = 4
redraw = True

points = [None]*6*nlines
oldpoints = [None] *6*nlines

angles = [(i*45)%360 for i in range(0, nlines)] # current rotation step
radius, max_radius = list(range(0, 128, 128//nlines)), 128
line_width = 9

cols = [ ugfx.RED, ugfx.BLUE, ugfx.GREEN, ugfx.WHITE ]
def hexpoints(x, y, r, angle, *, into, offset):
    for n in range(offset, offset+6):
        a = ((angle+n*60)%360)/360*tau
        nx = x+int(math.sin(a)*2*r)
        ny = y-int(math.cos(a)*2*r)
        into[n] = (nx,ny)

for n in range(nlines):
    hexpoints(cx, cy, radius[n], angles[n], into=oldpoints, offset=n*6)

while not buttons.is_triggered("BTN_MENU"):
    # Calculate

    for n in range(nlines):
        radius[n] = radius[n] - 2 if radius[n] > 0 else max_radius
        angles[n] = angles[n] + 3 if angles[n] < 360 else 0
        hexpoints(cx, cy, radius[n], angles[n], into=points, offset=n*6)

    if not_flipped():
        ugfx.orientation(0)
        if upside:
            redraw = True
            upside = False
    else:
        ugfx.orientation(180)
        if not upside:
            redraw = True
            upside = True

    # draw text
    if redraw:
        wait_for_scanline_pass(0)
        print("redraw")
        ugfx.clear(ugfx.BLACK)
        redraw=False

    for off in range(0,nlines):
        for n in range(off*6,off*6+6,2):
            ox1, oy1 = oldpoints[n]
            ox2, oy2 = oldpoints[n+1]
            x1, y1 = points[n]
            x2, y2 = points[n+1]
            wait_for_scanline_pass(min(oy1, oy2)-10)
            ugfx.thickline(ox1, oy1, ox2, oy2, ugfx.BLACK,line_width,0)
            ugfx.thickline(x1, y1, x2, y2, cols[off%4],line_width,0)

    pyb.wfi()

    oldpoints, points = points, oldpoints
    
ugfx.disable_tear()