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Second version of snake game in python with computer AI and without cheat codes
# Snake Game Version 2.0
# By virtualanup
# http://www.virtualanup.com
import pygame,random
from pygame.locals import *
from sys import exit
import math
fps=150 #frames per second. The higher, the harder
#direction of snake
left=-1,0
right=1,0
up=0,-1
down=0,1
directions=[up,down,right,left]
class Snake:
def __init__(self,body , direction, color,speed):
self.speed=speed
self.body=body #initially located here
self.color=color
self.direction=self.newdirection=direction
self.IsDead=False
def UpdateDirection(self,game):
self.direction=self.newdirection #the next direction is stored in newdirection....logic is updated here
def Update(self,game):
if self.IsDead:
fadestep=5
self.color=(max(self.color[0]-fadestep,0),max(self.color[1]-fadestep,0),max(self.color[2]-fadestep,0))
if self.color[0]==0 and self.color[1]==0 and self.color[2]==0:
self.color=(0,0,0)
game.players.remove(self)
else:
#updates the snake...
head=self.body[0]#head of snake
head=(head[0]+self.direction[0],head[1]+self.direction[1])
#wrap the snake around the window
headx=game.hortiles if head[0]<0 else 0 if head[0]>game.hortiles else head[0]
heady=game.verttiles if head[1]<0 else 0 if head[1]>game.verttiles else head[1]
head=(headx,heady)
#update the body and see if the snake is dead
alivelist=[snake for snake in reversed(game.players) if not snake.IsDead]
for snake in alivelist:
if head in snake.body:
if head == snake.body[0]:#in case of head to head collision, kill both of the snakes
snake.IsDead=True
self.IsDead=True
return
if head in game.obstacles:#hit an obstacle
self.IsDead=True
return
elif head == game.foodpos:
#the snake ate the food
game.foodpos=0,0
self.body.append((self.body[0]))
#the snake hasnot collided....move along
self.body=[head]+[self.body[i-1] for i in range(1,len(self.body))]
def Draw(self,screen,game):
for part in self.body:
pygame.draw.rect(screen,self.color,(part[0]*game.tilesize,part[1]*game.tilesize,game.tilesize,game.tilesize),0)
def processkey(self,key):
pass #nothing to do here
class HumanSnake(Snake):
def __init__(self,body=[(0,0)] , direction=(1,0),upkey=K_UP,downkey=K_DOWN,rightkey=K_RIGHT,leftkey=K_LEFT,color=(0,255,0)):
super().__init__(body,direction,color,1)#speed is always 1
#assign the keys to control the human snake
self.upkey=upkey
self.downkey=downkey
self.rightkey=rightkey
self.leftkey=leftkey
def processkey(self,key):
#we check the old direction not the new direction.
if key==self.upkey:
if self.direction != down:
self.newdirection=up
elif key==self.downkey:
if self.direction != up:
self.newdirection=down
elif key==self.rightkey:
if self.direction != left:
self.newdirection=right
elif key==self.leftkey:
if self.direction != right:
self.newdirection=left
class ComputerSnake(Snake):
def __init__(self,body=[(0,0)] , direction=(1,0),color=(255,0,0),speed=1):
super().__init__(body,direction,color,speed)
def pathlen(self,a,b):
return int( ((a[0]-b[0])**2 + (a[1]-b[1])**2 )**0.5)
def add(self,a,b):
return a[0]+b[0],a[1]+b[1]
def UpdateDirection(self,game):
#this is the brain of the snake player
olddir=self.direction
position=self.body[0]
#new direction can't be up if current direction is down...and so on
complement=[(up,down),(down,up),(right,left),(left,right)]
invaliddir=[x for (x,y) in complement if y==olddir]
validdir=[dir for dir in directions if not ( dir in invaliddir )]
#get the list of valid directions for us
validdir=[dir for dir in validdir if not (self.add(position,dir) in game.obstacles or self.add(position,dir) in game.playerpos)]
#if we collide then set olddir to first move of validdir (if validdir is empty then leave it to olddir)
olddir= olddir if olddir in validdir or len(validdir)==0 else validdir[0]
#shortest path.....we assume that the direction we are currently going now gives the shortest path
shortest=self.pathlen(self.add(position,olddir) , game.foodpos)#length in shortest path
for dir in validdir:
newpos=self.add(position,dir)
newlen=self.pathlen(newpos , game.foodpos)#length in shortest path
if newlen < shortest:
if not ( newpos in game.obstacles or newpos in game.playerpos):
olddir=dir
shortest=newlen
self.direction=olddir
class SnakeGame:
tilesize=20
hortiles=60
verttiles=40
def __init__(self):
#create the window and do other stuff
pygame.init()
self.screen = pygame.display.set_mode(((self.hortiles+1)*self.tilesize,(self.verttiles+1)*self.tilesize+25))
pygame.display.set_caption('Python Snake')
#load the font
self.font = pygame.font.Font(None, 30)
self.obstacles=[]
self.obscolor=(0,0,255)
self.foodcolor=(0,255,255)
self.foodpos=(0,0)
self.playercount=0
def GenerateFood(self):
if(self.foodpos == (0,0)):
self.foodpos=random.randrange(1,self.hortiles),random.randrange(1,self.verttiles)
while (self.foodpos in self.playerpos or self.foodpos in self.obstacles):
self.foodpos=random.randrange(1,self.hortiles),random.randrange(1,self.verttiles)
def SetObstacles(self,level):
for i in range(1,level+1):
lo=random.randrange(1,self.hortiles),random.randrange(1,self.verttiles) #last obstacle
self.obstacles.append(lo)
for j in range(1,random.randint(1,int(level/2))):
if(random.randint(1,2) == 1):
lo=(lo[0]+1,lo[1])
else:
lo=(lo[0],lo[1]+1)
if( 0<lo[0]<=self.hortiles and 0<lo[1]<=self.verttiles ):
self.obstacles.append(lo)
def setplayers(self,players):
self.playercount+=len(players)
self.players=players
def printstatus(self):
if(len(self.players) >0):
text = self.font.render(str(len(self.players))+" players playing", 1,(255,255,255))
else:
text=self.font.render("All players dead....press c for new computer snake or h for new human snake",1,(255,0,0))
textpos = text.get_rect(centerx=self.screen.get_width()/2,y=(self.verttiles+1)*self.tilesize)
self.screen.blit(text, textpos)
def UpdatePlayerInfo(self):
#update where the players are in the board just before updating the logic
self.playerpos=[]
for player in self.players:
self.playerpos+=player.body
def start(self):
clock = pygame.time.Clock()
count=0
while True:
clock.tick(fps)
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit();exit()
elif event.type == pygame.KEYDOWN:
for player in self.players:
player.processkey(event.key)
if event.key == K_h:
pass
self.players.append(HumanSnake())
self.playercount+=1
elif event.key == K_c:
pass
self.players.append(ComputerSnake())
self.playercount+=1
count+=1
self.screen.fill((0,0,0))
#game logic is updated in the code below
self.UpdatePlayerInfo()
self.GenerateFood() #generate food if necessary
for player in [a for a in self.players if not a.IsDead]:
player.UpdateDirection(self) #update game logic (only for alive players)
for player in [a for a in self.players if count%a.speed == 0]:
player.Update(self)
#print all the content in the screen
for player in self.players:
player.Draw(self.screen,self)
for obstacle in self.obstacles:
pygame.draw.rect(self.screen,self.obscolor,(obstacle[0]*self.tilesize,obstacle[1]*self.tilesize,self.tilesize,self.tilesize),0)
pygame.draw.rect(self.screen,self.foodcolor,(self.foodpos[0]*self.tilesize,self.foodpos[1]*self.tilesize,self.tilesize,self.tilesize),0)
self.printstatus()
pygame.display.update()
#start the game
if(__name__ == "__main__"):
snake=SnakeGame()
snake.SetObstacles(15) #level of obstacles
snake.setplayers([
#HumanSnake([(12,14)])
#,ComputerSnake(),
#ComputerSnake([(17,14)]*2,up)
])
snake.start()
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