import random stage.set_background_color("grey") stage.set_background_scale(1.5) #####GLOBAL VARIABLES##### #the size/diameter of each sprite being drawn size = 15 #this is the list of coordinate pairs (x,y) for the snake segments snake = [] #this is the list of sprites representing each segment of the snake segs = [] #snake x and y movement speeds snakeDx = 0 snakeDy = -1 #determines how many segments the snake should grow when you eat an apple growth = 5 #boolean for whether game is running or not game_over = False #apple's x and y positions apple_x = random.randint(-24, 24) apple_y = random.randint(-24, 24) #display the score score = 0 score_display = codesters.Text("Score: 0", 180, 225, "black") #display the segment count segment_count = 0 segment_display = codesters.Text("Segments: 0", 160, 200, "black") #player controls change the dx and dy variables def up_key(): global snakeDx, snakeDy snakeDx = 0 snakeDy = 1 stage.event_key("up", up_key) def down_key(): global snakeDx, snakeDy snakeDx = 0 snakeDy = -1 #remove_segment() stage.event_key("down", down_key) def left_key(): global snakeDx, snakeDy snakeDx = -1 snakeDy = 0 stage.event_key("left", left_key) def right_key(): global snakeDx, snakeDy snakeDx = 1 snakeDy = 0 stage.event_key("right", right_key) def remove_segment(): global game_over if(len(segs) == 0): segment_display.set_text("Segments: 0") game_over = True else: snake.pop(0) stage.remove_sprite(segs[0]) segs.pop(0) #calculate and add a new head to the list of snake positions def add_head(head): global size snake_x = head[0] + snakeDx snake_y = head[1] + snakeDy snake.append((snake_x, snake_y)) #get the new head of the snake head = snake[len(snake) - 1] #draw the new head circle = codesters.Circle(head[0] * size, head[1] * size, size, "orange") #add the new head to the list of snake sprites segs.append(circle) update_display() def update_display(): global segment_count, score, segment_display, score_display #take the length of the list of segments, minus 1, as the segment count segment_count = len(segs)-1 #update the display on the game board segment_display.set_text("Segments: " + str(segment_count)) score_display.set_text("Score: " + str(score)) #check if snake is eating apple def check_apple(head, apple): global apple_x, apple_y, size, growth, score if head[0] == apple_x and head[1] == apple_y: score += 1 #make new randomized coordinates for the apple apple_x = random.randint(-24, 24) apple_y = random.randint(-24, 24) #increase the growth of the snake growth += 3 #check if the snake should be growing and grow, if not remove the last sprite and last segment position from snake. def check_grow(): global growth #check to see if the snake is growing, if so let it grow if growth > 0: growth -= 1 #otherwise remove the tail from both lists and remove the sprite from the screen else: remove_segment() #check if the snake has bitten itself and the game should end def check_state(head): global game_over #if you want the player's game to be over when they hit the walls... #if head[0] > 25 or head[0] < -25 or head[1] > 25 or head[1] < -25: #game_over = True #if you want the player to continue to play, even if they hit the walls if head[0] > 24: left_key() if head[0] < -24: right_key() if head[1] > 24: down_key() if head[1] < -24: up_key() #comment this back in if you want the snake to die when it overlaps on itself #check for snake biting itself #for seg in snake: #if seg is not head and head[0] == seg[0] and head[1] == seg[1]: #game_over = True #break #main game function def main(): #get global variables global game_over, size, growth #add first head to the list of snake positions snake.append((0, 0)) seg = snake[0] #draw the first head circle = codesters.Circle(seg[0] * size, seg[1] * size, size, "orange") #add the first head to the list of snake sprites segs.append(circle) #add in the apple sprite apple = codesters.Circle(apple_x * size, apple_y * size, size, "red") #main game loop while game_over is False: #get the head of the snake if(len(snake) > 0): head = snake[len(snake) - 1] add_head(head) new_head = snake[len(snake) - 1] check_apple(new_head, apple) check_state(new_head) check_grow() #remove the previous apple and add the new one stage.remove_sprite(apple) apple = codesters.Circle(apple_x * size, apple_y * size, size, "red") stage.wait(0.1) #change the background color if the snake is really small if len(snake) < 2: stage.set_background_color("yellow") else: stage.set_background_color("grey") #the game has ended here, display the game over screen text = codesters.Text("Game Over", 0, 0, "red") #run the main function to run the game main()