Snake.py

import pygame
import Grid
class Snake:
    up = 1
    down = 2
    left = 3
    right = 4
    black=(0,0,0)
    head = 0 #collumn for head of snake
    x = 0 # key for x position of snake head
    y = 1 # key for y position of snake head 
    bodyCoordinates = [[2,0],[3,0],[4,0]] #starting body coordinates
    white = (200,200,200)
    def __init__(self):
        self.length = 1
        self.direction = self.right

    
    def eat(self,animal):
        print("Snake eats animal")
        self.length += animal.points #one point per animal (score == length)
        self.bodyCoordinates.append([-1,-1])
    
    def drawSnake(self,grid:Grid):
        for x,y in self.bodyCoordinates:
            # x and y are values between 1 and 22 (grid is 500px in 22 blocks)
            # steps / division by 22 also means that the distance or length of each square is also 22(.7)
            #so you can approximate and use 22 as the multiplier for the coordinate
            grid.drawRect(x*grid.steps, y*grid.steps, 20, 20, self.black) #in steps of 22 pixels to allow the gaps
    
    #changes 'head' coordinate trajectory
    def turnSnakeHead(self):
        x = self.bodyCoordinates[self.head][self.x]
        y = self.bodyCoordinates[self.head][self.y]
        keyPressed = pygame.key.get_pressed()
        if keyPressed[pygame.K_UP] and (self.direction != self.up):
            y -= 1; # move the head of the snake up
            self.direction = self.up 

        if keyPressed[pygame.K_DOWN] and (self.direction != self.down): 
            y += 1; #turn snake head down
            self.direction = self.down 

        if keyPressed[pygame.K_LEFT] and (self.direction != self.left): 
            x -= 1; #turn snake head down
            self.direction = self.left 
        
        if keyPressed[pygame.K_RIGHT] and (self.direction != self.right): 
            x += 1; #turn snake head down
            self.direction = self.right 
        
        # update bodyCoordinates with changes
        self.bodyCoordinates[self.head][self.x] = x
        self.bodyCoordinates[self.head][self.y] = y


    def getSnakeHead(self):
        x = self.bodyCoordinates[self.head][self.x]
        y = self.bodyCoordinates[self.head][self.y]
        return x,y
    
    def getDirection(self):
        return self.direction

    def setSnakeHead(self, x, y):
        self.bodyCoordinates[self.head][self.x] = x
        self.bodyCoordinates[self.head][self.y] = y

    #places new head block at the new coordinates
    #assumes coordinates for head have been already changed
    def placeHead(self):
        #get head coordinates
        x,y = self.getSnakeHead()

        #get head direction
        if self.direction == self.right:
            # move right
            x += 1
            # if you go to far right - come back thorugh left of screen
            if x >= 23:
                x = 0

        if self.direction == self.left:
            # move left
            x -= 1
            # if you go to far left - come out from right side of the screen
            if x < 0:
                x = 23
        if self.direction == self.up:
            # move up
            y -= 1
            # if you got to far up - come out from bottom of the screen
            if y <= 0:
                y = 23

        if self.direction == self.down:
            # move down
            y += 1
            # if you move to far down - come out from the top of the screen
            if y >= 23:
                y = 0
        
                #stop snake movement
        #insert head at front of array of body coordinates
        self.bodyCoordinates.insert(0,[x,y])
    
    #pop tail
    def popTail(self):
        self.bodyCoordinates.pop()

    #moves the snake a block forward in the current trajectory
    def move(self):
        self.placeHead()
        self.popTail()
        
    def displayScore(self, window):
        font = pygame.font.Font(None, 100)
        text = font.render("Score:" + str(self.length), True, self.white)
        textX = 800
        textY = 50
        window.blit(text,(textX,textY))