Day 023

Udemy Python Bootcamp Day 023

Turtle Crossing Game

• Check out how the game play works
• Break down the Problem
• Move the turtle with keypress
• Create and move the car
• Detect collision with car
• Detect when turtle reaches the other side
• Create a scoreboard
  
  

Check out how the game play works

• A turtle moves forwards when you press the "Up" key. It can only move forwards, not back, left or right.
• Cars are randomly generated along the y-axis and will move from the right edge of the screen to the left edge.
• When the turtle hits the top edge of the screen, it moves back to the original position and the player levels up. On the next level, the car speed increases.
• When the turtle collides with a car, it's game over and everything stops.
  
  

Break down the Problem

• Create a turtle player that starts at the bottom of the screen and listen for the "Up" keypress to move the turtle north.
• Create cars that are 20px high by 40px wide that are randomly generated along the y-axis and move to the left edge of the screen. No cars should be generated in the top and bottom 50px of the screen (think of it as a safe zone for our little turtle). Hint: generate a new car only every 6th time the game loop runs.
• Detect when the turtle player collides with a car and stop the game if this happens.
• Detect when the turtle player has reached the top edge of the screen (i.e., reached the FINISH_LINE_Y). When this happens, return the turtle to the starting position and increase the speed of the cars. Hint: think about creating an attribute and using the MOVE_INCREMENT to increase the car speed.
• Create a scoreboard that keeps track of which level the user is on. Every time the turtle player does a successful crossing, the level should increase. When the turtle hits a car, GAME OVER should be displayed in the centre.
  
  

Move the turtle with keypress
player.py

from turtle import Turtle

STARTING_POSITION = (0, -280)
MOVE_DISTANCE = 10
FINISH_LINE_Y = 280


class Player(Turtle):
    def __init__(self):
        super().__init__()
        self.shape("turtle")
        self.penup()
        self.goto(STARTING_POSITION)
        self.setheading(90)

    def go_up(self):
        self.forward(MOVE_DISTANCE)

main.py

from player import Player
from car_manager import CarManager
from scoreboard import Scoreboard

screen = Screen()
screen.setup(width=600, height=600)
screen.tracer(0)

player = Player()

screen.listen()
screen.onkey(player.go_up, "Up")

game_is_on = True
while game_is_on:
    time.sleep(0.1)
    screen.update()

Create and move the car
car_manager.py

from turtle import Turtle
import random

COLORS = ["red", "orange", "yellow", "green", "blue", "purple"]
STARTING_MOVE_DISTANCE = 5
MOVE_INCREMENT = 10


class CarManager:

    def __init__(self):
        self.all_cars = []

    def create_car(self):
        random_chance = random.randint(1, 6)
        if random_chance == 1:
            new_car = Turtle("square")
            new_car.penup()
            new_car.shapesize(1, 2)
            new_car.color(random.choice(COLORS))
            random_y = random.randint(-250, 250)
            new_car.goto(300, random_y)
            self.all_cars.append(new_car)

    def move_cars(self):
        for car in self.all_cars:
            car.backward(STARTING_MOVE_DISTANCE)

main.py

import time
from turtle import Screen
from player import Player
from car_manager import CarManager
from scoreboard import Scoreboard

screen = Screen()
screen.setup(width=600, height=600)
screen.tracer(0)

player = Player()
car_manager = CarManager()

screen.listen()
screen.onkey(player.go_up, "Up")

game_is_on = True
while game_is_on:
    time.sleep(0.1)
    screen.update()

    car_manager.create_car()
    car_manager.move_cars()

Detect collision with car
main.py

game_is_on = True
while game_is_on:
    time.sleep(0.1)
    screen.update()

    car_manager.create_car()
    car_manager.move_cars()

    # Detect collision with car
    for car in car_manager.all_cars:
        if car.distance(player) < 20:
            game_is_on = False

Detect when turtle reaches the other side
player.py

from turtle import Turtle

STARTING_POSITION = (0, -280)
MOVE_DISTANCE = 10
FINISH_LINE_Y = 280


class Player(Turtle):
    def __init__(self):
        super().__init__()
        self.shape("turtle")
        self.penup()
        self.go_to_start()
        self.setheading(90)

    def go_up(self):
        self.forward(MOVE_DISTANCE)

    def go_to_start(self):
        self.goto(STARTING_POSITION)

    def is_at_finish_line(self):
        if self.ycor() > FINISH_LINE_Y:
            return True
        else:
            return False

car_manager.py

from turtle import Turtle
import random

COLORS = ["red", "orange", "yellow", "green", "blue", "purple"]
STARTING_MOVE_DISTANCE = 5
MOVE_INCREMENT = 10


class CarManager:

    def __init__(self):
        self.all_cars = []
        self.car_speed = STARTING_MOVE_DISTANCE

    def create_car(self):
        random_chance = random.randint(1, 6)
        if random_chance == 1:
            new_car = Turtle("square")
            new_car.penup()
            new_car.shapesize(1, 2)
            new_car.color(random.choice(COLORS))
            random_y = random.randint(-250, 250)
            new_car.goto(300, random_y)
            self.all_cars.append(new_car)

    def move_cars(self):
        for car in self.all_cars:
            car.backward(STARTING_MOVE_DISTANCE)

    def level_up(self):
        self.car_speed += MOVE_INCREMENT

main.py

game_is_on = True
while game_is_on:
    time.sleep(0.1)
    screen.update()

    car_manager.create_car()
    car_manager.move_cars()

    # Detect collision with car
    for car in car_manager.all_cars:
        if car.distance(player) < 20:
            game_is_on = False

    # Detect successful crossing
    if player.is_at_finish_line():
        player.go_to_start()
        car_manager.level_up()

Create a scoreboard
scoreboard.py

from turtle import Turtle

FONT = ("Courier", 24, "normal")


class Scoreboard(Turtle):
    def __init__(self):
        super().__init__()
        self.penup()
        self.hideturtle()
        self.level = 1
        self.goto(-280, 250)
        self.update_scoreboard()

    def update_scoreboard(self):
        self.clear()
        self.write(f"Level: {self.level}", align="left", font=FONT)

    def increase_level(self):
        self.level += 1
        self.update_scoreboard()

    def game_over(self):
        self.goto(0, 0)
        self.write("GAME OVER", align="center", font=FONT)

main.py

import time
from turtle import Screen
from player import Player
from car_manager import CarManager
from scoreboard import Scoreboard

screen = Screen()
screen.setup(width=600, height=600)
screen.tracer(0)

player = Player()
car_manager = CarManager()
scoreboard = Scoreboard()

screen.listen()
screen.onkey(player.go_up, "Up")

game_is_on = True
while game_is_on:
    time.sleep(0.1)
    screen.update()

    car_manager.create_car()
    car_manager.move_cars()

    # Detect collision with car
    for car in car_manager.all_cars:
        if car.distance(player) < 20:
            game_is_on = False
            scoreboard.game_over()

    # Detect successful crossing
    if player.is_at_finish_line():
        player.go_to_start()
        car_manager.level_up()
        scoreboard.increase_level()

screen.exitonclick()