BBC micro:bit car game

car_game.py

from microbit import *
from random import randint

SCENE_WIDTH = 4
INITIAL_DELAY = 500

POSSIBLE_ROADSIDE_ROWS = [
    [False, False, True, True, True, ], 
    [True, False, False, True, True, ], 
    [True, True, False, False, True, ], 
    [True, True, True, False, False, ], 
    ]
    
roadside_row_indices = None
car_x = None
time_of_last_advance = None
time_of_last_move = None
time_of_last_speedup = None
delay = None

def init():
	global roadside_row_indices
	global car_x
	global time_of_last_advance
	global time_of_last_move, time_of_last_speedup, delay
	roadside_row_indices = [2, 2, 2, 2, 2]
	car_x = 2
	time_of_last_advance = None
	time_of_last_move = None
	time_of_last_speedup = None
	delay = INITIAL_DELAY
	button_a.was_pressed()
	button_b.was_pressed()

def did_detect_collision_while_drawing_scene():
    has_collided = False
    car_y = 3
    display.set_pixel(car_x, car_y, 9)
    for y, state_index in enumerate(roadside_row_indices):
        row = POSSIBLE_ROADSIDE_ROWS[state_index]
        for x, px in enumerate(row):
            if x == car_x and y == car_y:
                has_collided = px
            else:
                display.set_pixel(x, y, 5 if px else 0)
    return has_collided

def roadside_row_indices_by_scrolling():
    next_state_index = roadside_row_indices[0] + randint(-1, 1)
    if next_state_index == -1 or next_state_index == len(POSSIBLE_ROADSIDE_ROWS):
        return roadside_row_indices
    new_roadside = roadside_row_indices[:-1]
    new_roadside.insert(0, next_state_index)
    return new_roadside

def car_x_by_detecting_inputs():
    direction = 0
    if button_a.was_pressed(): direction -= 1
    if button_b.was_pressed(): direction += 1
    return max(min(car_x + direction, SCENE_WIDTH), 0)

init()

while True:
    
    now = running_time()
    if time_of_last_advance == None: time_of_last_advance = now
    if time_of_last_move == None: time_of_last_move = now
    if time_of_last_speedup == None: time_of_last_speedup = now
    
    if now - time_of_last_move >= 100: 
        car_x = car_x_by_detecting_inputs()
        time_of_last_move = now
    
    if now - time_of_last_advance >= delay:
        roadside_row_indices = roadside_row_indices_by_scrolling()
        time_of_last_advance = now
    
    if now - time_of_last_speedup >= 1000:
        delay -= 10
        time_of_last_speedup = now
        
    collided = did_detect_collision_while_drawing_scene()
    if collided:
        score = INITIAL_DELAY - delay
        display.scroll('Game Over', delay=50, wait=True, loop=False)
        display.scroll(str(score), delay=150, wait=True, loop=False)
        init()

microbit_car_game.gif