snake.py

import pygame
import time
import random

pygame.init()

white = (255,255,255)
black = (0,0,0)
red = (255,0,0)
green = (0, 155, 0)

display_width = 800
display_height = 600


AppleThickness = 30
block_size = 20
FPS = 30
direction = "right"
gameDisplay = pygame.display.set_mode((display_width,display_height))
pygame.display.set_caption('Slither')
img = pygame.image.load('snakehead.png')
appleimg = pygame.image.load('apple.png')
#pygame.display.set_icon(appleimg)
clock = pygame.time.Clock()

smallfont = pygame.font.SysFont("comicsansms", 25)
medfont = pygame.font.SysFont("comicsansms", 50)
largefont = pygame.font.SysFont("comicsansms", 80)

def pause():

    paused = True
    message_to_screen("Paused", black, -100, size = "large")
    message_to_screen("Press c to continue", black, 25, size = "small")
    pygame.display.update()
    while paused:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_c:
                    paused = False
                elif event.key == pygame.K_q:
                    pygame.quit()
                    quit()

        clock.tick(5)
        
def score(score):
    text = smallfont.render("Score: " + str(score), True, black)
    gameDisplay.blit(text,[0,0])
    
def randAppleGen():
    randAppleX = round(random.randrange(0, display_width - AppleThickness))#/10.0)*10.0
    randAppleY = round(random.randrange(0, display_height - AppleThickness))#/10.0)*10.0
    return randAppleX, randAppleY
     
def game_intro():

    intro = True

    while intro:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                pygame.quit()
                quit()
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_c:
                    intro=False
                if event.key == pygame.K_q:
                    pygame.quit()
                    quit()
                    
        gameDisplay.fill(white)
        message_to_screen("Welcome to the Batcave", black, -100,
                          "medium")
        message_to_screen("Objective of the game is to help the snake eat apple",
                          black, -30,"small")
        message_to_screen("Press C to play, P to pause, Q to Quit",
                          black, 30,"small")
        pygame.display.update()
        clock.tick(5)

def snake(block_size, snakelist):

    if direction == "right":
        head = pygame.transform.rotate(img,270)
        
    if direction == "left":
        head = pygame.transform.rotate(img,90)
        
    if direction == "up":
        head = img
        
    if direction == "down":
        head = pygame.transform.rotate(img,180)
        
    gameDisplay.blit(head, (snakelist[-1][0], snakelist[-1][1]))
    
    for XnY in snakelist[:-1]:
        pygame.draw.rect(gameDisplay, green, [XnY[0], XnY[1],block_size,block_size])

def text_objects(text,color,size):
    if size == "small":
        textSurface = smallfont.render(text, True, color)
    elif size == "medium":
        textSurface = medfont.render(text, True, color)
    elif size == "large":
        textSurface = largefont.render(text, True, color)
    return textSurface, textSurface.get_rect()
    
def message_to_screen(msg,color, y_displace = 0, size = "small"):
    textSurf, textRect = text_objects(msg, color, size)
    textRect.center = (display_width / 2), (display_height / 2) + y_displace
    gameDisplay.blit(textSurf, textRect)

def gameLoop():
    global direction
    direction = "right"
    gameExit = False
    gameOver = False
    lead_x = display_width/2
    lead_y = display_height/2
    lead_x_change = 10
    lead_y_change = 0
    snakeList = []
    snakeLength = 1
    randAppleX, randAppleY = randAppleGen()
    
    while not gameExit:

        if gameOver == True:
            message_to_screen("Game over", red,
                              y_displace=-50, size = "large")
            message_to_screen("Press C to play again or Q to quit", black,
                              50, size = "medium")
            pygame.display.update()
            
        while gameOver == True:
            #gameDisplay.fill(white)
            
            for event in pygame.event.get():
                if event.type == pygame.QUIT:
                    gameOver = False
                    gameExit = True
                if event.type == pygame.KEYDOWN:
                    if event.key == pygame.K_q:
                        gameExit = True
                        gameOver = False
                    if event.key == pygame.K_c:
                        gameLoop()
                        
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                gameExit = True
            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT:
                    lead_x_change = -block_size
                    lead_y_change = 0
                    direction = "left"
                elif event.key == pygame.K_RIGHT:
                    lead_x_change = block_size
                    lead_y_change = 0
                    direction = "right"
                elif event.key == pygame.K_UP:
                    lead_y_change = -block_size
                    lead_x_change = 0
                    direction = "up"
                elif event.key == pygame.K_DOWN:
                    lead_y_change = block_size
                    lead_x_change = 0
                    direction = "down"
                elif event.key == pygame.K_p:
                    pause()
            #print(event)

        if lead_x > display_width - block_size or lead_x < 0 or lead_y > display_height - block_size or lead_y<0:
            gameOver = True
        lead_x += lead_x_change
        lead_y += lead_y_change

        gameDisplay.fill(white)
        #pygame.draw.rect(gameDisplay, red, [randAppleX, randAppleY, AppleThickness, AppleThickness])
        gameDisplay.blit(appleimg, (randAppleX, randAppleY))
        snakeHead = []
        snakeHead.append(lead_x)
        snakeHead.append(lead_y)
        snakeList.append(snakeHead)

        if len(snakeList) > snakeLength:
            del snakeList[0]

        for eachSegment in snakeList[:-1]:
            if eachSegment == snakeHead:
                gameOver = True
        snake(block_size, snakeList)

        score(snakeLength - 1)
        
        pygame.display.update()

        if lead_x > randAppleX and lead_x < randAppleX + AppleThickness or lead_x + block_size > randAppleX and lead_x + block_size < randAppleX + AppleThickness:
            #print("x crossover")
            if lead_y > randAppleY and lead_y < randAppleY + AppleThickness:
                randAppleX, randAppleY = randAppleGen()
                snakeLength+=1
                
            elif lead_y + block_size > randAppleY and lead_y + block_size < randAppleY + AppleThickness:
                randAppleX, randAppleY = randAppleGen()
                snakeLength+=1

        clock.tick(30)

    pygame.quit()
    quit()

game_intro()
gameLoop()