race1

Attribution

Retro Gaming with Raspberry Pi 2nd Edition, pages 78 - 83.

Retro Gaming with Raspberry Pi, pages 48 - 53.

Licensed under Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported.

Original Python code

from random import randint
import pgzrun

WIDTH = 700 # Width of window
HEIGHT = 800 # Height of window
car = Actor("racecar") # Load in the car Actor image
car.pos = 250, 700 # Set the car screen position
SPEED = 4
trackCount = 0
trackPosition = 250
trackWidth = 120
trackDirection = False
trackLeft = []  # list of track barriers left
trackRight = []  # list of track barriers right
gameStatus = 0

def draw(): # Pygame Zero draw function
    global gameStatus
    screen.fill((128, 128, 128))
    if gameStatus == 0:
        car.draw()
        b = 0
        while b < len(trackLeft):
            trackLeft[b].draw()
            trackRight[b].draw()
            b += 1
    if gameStatus == 1:
        # Red Flag
        screen.blit('rflag', (318, 268))
    if gameStatus == 2:
        # Chequered Flag
        screen.blit('cflag', (318, 268))

def update(): # Pygame Zero update function
    global gameStatus , trackCount
    if gameStatus == 0:
        if keyboard.left: car.x -= 2
        if keyboard.right: car.x += 2
        updateTrack()
    if trackCount > 200: gameStatus = 2 # Chequered flag state

def makeTrack(): # Function to make a new section of track
    global trackCount, trackLeft, trackRight, trackPosition, trackWidth
    trackLeft.append(Actor("barrier", pos = (trackPosition-trackWidth,0)))
    trackRight.append(Actor("barrier", pos = (trackPosition+trackWidth,0)))
    trackCount += 1

def updateTrack(): # Function to update where the track blocks appear
    global trackCount, trackPosition, trackDirection, trackWidth, gameStatus
    b = 0
    while b < len(trackLeft):
        if car.colliderect(trackLeft[b]) or car.colliderect(trackRight[b]):
            gameStatus = 1  # Red flag state
        trackLeft[b].y += SPEED
        trackRight[b].y += SPEED
        b += 1
    if trackLeft[len(trackLeft)-1].y > 32:
        if trackDirection == False: trackPosition += 16
        if trackDirection == True: trackPosition -= 16
        if randint(0, 4) == 1: trackDirection = not trackDirection
        if trackPosition > 700-trackWidth: trackDirection = True
        if trackPosition < trackWidth: trackDirection = False
        makeTrack()

# End of functions
makeTrack() # Make first block of track

pgzrun.go()