from turtle import Turtle, Screen
import random
import time
SIZE = 20
class Square:
def __init__(self, x, y):
self.x = x
self.y = y
def drawself(self, turtle):
""" draw a black box at its coordinates, leaving a small gap between cubes """
turtle.goto(self.x - SIZE // 2 - 1, self.y - SIZE // 2 - 1)
turtle.begin_fill()
for _ in range(4):
turtle.forward(SIZE - SIZE // 10)
turtle.left(90)
turtle.end_fill()
class Food:
def __init__(self, x, y):
self.x = x
self.y = y
self.is_blinking = True
def changelocation(self):
# I haven't programmed it to spawn outside the snake's body yet
self.x = random.randint(0, SIZE) * SIZE - 200
self.y = random.randint(0, SIZE) * SIZE - 200
def drawself(self, turtle):
# similar to the Square drawself, but blinks on and off
if self.is_blinking:
turtle.goto(self.x - SIZE // 2 - 1, self.y - SIZE // 2 - 1)
turtle.begin_fill()
for _ in range(4):
turtle.forward(SIZE - SIZE // 10)
turtle.left(90)
turtle.end_fill()
def changestate(self):
# controls the blinking
self.is_blinking = not self.is_blinking
class Snake:
def __init__(self):
self.headposition = [SIZE, 0] # keeps track of where it needs to go next
self.body = [Square(-SIZE, 0), Square(0, 0), Square(SIZE, 0)] # body is a list of squares
self.nextX = 1 # tells the snake which way it's going next
self.nextY = 0
self.crashed = False # I'll use this when I get around to collision detection
self.nextposition = [self.headposition[0] + SIZE * self.nextX, self.headposition[1] + SIZE * self.nextY]
# prepares the next location to add to the snake
def moveOneStep(self):
if Square(self.nextposition[0], self.nextposition[1]) not in self.body:
# attempt (unsuccessful) at collision detection
self.body.append(Square(self.nextposition[0], self.nextposition[1]))
# moves the snake head to the next spot, deleting the tail
del self.body[0]
self.headposition[0], self.headposition[1] = self.body[-1].x, self.body[-1].y
# resets the head and nextposition
self.nextposition = [self.headposition[0] + SIZE * self.nextX, self.headposition[1] + SIZE * self.nextY]
else:
self.crashed = True # more unsuccessful collision detection
def moveup(self): # pretty obvious what these do
self.nextX, self.nextY = 0, 1
def moveleft(self):
self.nextX, self.nextY = -1, 0
def moveright(self):
self.nextX, self.nextY = 1, 0
def movedown(self):
self.nextX, self.nextY = 0, -1
def eatFood(self):
# adds the next spot without deleting the tail, extending the snake by 1
self.body.append(Square(self.nextposition[0], self.nextposition[1]))
self.headposition[0], self.headposition[1] = self.body[-1].x, self.body[-1].y
self.nextposition = [self.headposition[0] + SIZE * self.nextX, self.headposition[1] + SIZE * self.nextY]
def drawself(self, turtle): # draws the whole snake when called
for segment in self.body:
segment.drawself(turtle)
class Game:
def __init__(self):
# game object has a screen, a turtle, a basic snake and a food
self.screen = Screen()
self.artist = Turtle(visible=False)
self.artist.up()
self.artist.speed("slowest")
self.snake = Snake()
self.food = Food(100, 0)
self.counter = 0 # this will be used later
self.commandpending = False # as will this
self.screen.tracer(0) # follow it so far?
self.screen.listen()
self.screen.onkey(self.snakedown, "Down")
self.screen.onkey(self.snakeup, "Up")
self.screen.onkey(self.snakeleft, "Left")
self.screen.onkey(self.snakeright, "Right")
def nextFrame(self):
self.artist.clear()
if (self.snake.nextposition[0], self.snake.nextposition[1]) == (self.food.x, self.food.y):
self.snake.eatFood()
self.food.changelocation()
else:
self.snake.moveOneStep()
if self.counter == 10:
self.food.changestate() # makes the food flash slowly
self.counter = 0
else:
self.counter += 1
self.food.drawself(self.artist) # show the food and snake
self.snake.drawself(self.artist)
self.screen.update()
self.screen.ontimer(lambda: self.nextFrame(), 100)
def snakeup(self):
if not self.commandpending:
self.commandpending = True
self.snake.moveup()
self.commandpending = False
def snakedown(self):
if not self.commandpending:
self.commandpending = True
self.snake.movedown()
self.commandpending = False
def snakeleft(self):
if not self.commandpending:
self.commandpending = True
self.snake.moveleft()
self.commandpending = False
def snakeright(self):
if not self.commandpending:
self.commandpending = True
self.snake.moveright()
self.commandpending = False
game = Game()
screen = Screen()
screen.ontimer(lambda: game.nextFrame(), 100)
screen.mainloop()
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