import pygame.font
from Class_definitions import *
import sys
from pygame.locals import *
global screen, backbuffer, font, timer, snake, food_group
# TODO
# add pause/resume function into the game
class Snake:
def __init__(self):
self.velocity = Point(-1, 0)
self.old_time = 0
head = SnakeSegment((50, 250, 50)) # segment[0]
head.X = 12 * 32
head.Y = 9 * 32
self.segments = list()
# Original length = 3
self.segments.append(head)
self.add_segment()
self.add_segment()
def update(self, ticks):
global step_time
"""
# accelerate as snake grows longer
if len(snake.segments) % 5 == 0:
step_time += 50
"""
if ticks > self.old_time + step_time:
self.old_time = ticks
# move body segments
for n in range(len(self.segments) - 1, 0, -1):
self.segments[n].X = self.segments[n - 1].X
self.segments[n].Y = self.segments[n - 1].Y
# move snake head
self.segments[0].X += self.velocity.x * 32
self.segments[0].Y += self.velocity.y * 32
def draw(self, surface):
for segment in self.segments:
surface.blit(segment.image, (segment.X, segment.Y))
def add_segment(self):
last = len(self.segments) - 1 # snake tail
# randomize color of the new segment
color_r = random.randint(35, 45)
color_g = random.randint(90, 100)
color_b = random.randint(0, 256)
segment = SnakeSegment(color=(color_r, color_g, color_b))
start = Point(0, 0)
if self.velocity.x < 0:
start.x = 32
elif self.velocity.x > 0:
start.x = -32
if self.velocity.y < 0:
start.y = 32
elif self.velocity.y > 0:
start.y = -32
segment.X = self.segments[last].X + start.x
segment.Y = self.segments[last].Y + start.y
# add segment to body
self.segments.append(segment)
def game_init():
# several global variables
global screen, backbuffer, font, timer, snake, food_group
pygame.init()
screen = pygame.display.set_mode((24 * 32, 18 * 32))
pygame.display.set_caption("Snake Game")
font = pygame.font.Font(None, 30)
timer = pygame.time.Clock()
# create a drawing surface
backbuffer = pygame.Surface((screen.get_rect().width, screen.get_rect().height))
# create snake
snake = Snake()
image = pygame.Surface((60, 60)).convert_alpha()
image.fill((255, 255, 255, 0))
pygame.draw.circle(image, (80, 80, 220, 70), (30, 30), 30, 0)
pygame.draw.circle(image, (80, 80, 250, 255), (30, 30), 30, 4)
# create food
food_group = pygame.sprite.Group()
food = Food()
food_group.add(food)
def get_current_direction():
global head_x, head_y
first_segment_x = snake.segments[1].X // 32
first_segment_y = snake.segments[1].Y // 32
if head_x - 1 == first_segment_x:
return "right"
elif head_x + 1 == first_segment_x:
return "left"
elif head_y - 1 == first_segment_y:
return "down"
elif head_y + 1 == first_segment_y:
return "up"
def get_food_direction():
global head_x, head_y
food = Point(0, 0)
for obj in food_group:
food = Point(obj.X // 32, obj.Y // 32)
if head_x < food.x:
return "right"
elif head_x > food.x:
return "left"
elif head_x == food.x:
if head_y < food.y:
return "down"
elif head_y > food.y:
return "up"
def auto_move():
direction = get_current_direction()
food_dir = get_food_direction()
if food_dir == "left":
if direction != "right":
direction = "left"
elif food_dir == "right":
if direction != "left":
direction = "right"
elif food_dir == "up":
if direction != "down":
direction = "up"
elif food_dir == "down":
if direction != "up":
direction = "down"
# set velocity based on direction
if direction == "up":
snake.velocity = Point(0, -1)
elif direction == "down":
snake.velocity = Point(0, 1)
elif direction == "left":
snake.velocity = Point(-1, 0)
elif direction == "right":
snake.velocity = Point(1, 0)
def print_text(font, x, y, text, color=(255, 255, 255), shadow=True):
if shadow:
imgText = font.render(text, True, (0, 0, 0))
screen.blit(imgText, (x - 2, y - 2))
imgText = font.render(text, True, color)
screen.blit(imgText, (x, y))
# main program begins
game_init()
pygame.mixer.init()
game_over = False
last_time = 0
auto_play = False
step_time = 400
pause = False
# sound effects
game_over_sound = pygame.mixer.Sound("gameover.wav")
eat_sound = pygame.mixer.Sound("eat.wav")
# main loop
while True:
timer.tick(30)
ticks = pygame.time.get_ticks()
# event section
for event in pygame.event.get():
if event.type == QUIT:
sys.exit()
keys = pygame.key.get_pressed()
if keys[K_ESCAPE]:
sys.exit()
elif keys[K_SPACE]:
if auto_play:
auto_play = False
step_time = 400
else:
auto_play = True
step_time = 100
elif keys[K_UP] or keys[K_w]:
snake.velocity = Point(0, -1)
elif keys[K_DOWN] or keys[K_s]:
snake.velocity = Point(0, 1)
elif keys[K_LEFT] or keys[K_a]:
snake.velocity = Point(-1, 0)
elif keys[K_RIGHT] or keys[K_d]:
snake.velocity = Point(1, 0)
# update section
if not game_over:
snake.update(ticks)
food_group.update(ticks)
# try to pick up food
hit_list = pygame.sprite.groupcollide(snake.segments, food_group, False, True)
if len(hit_list) > 0:
play_sound(eat_sound)
food_group.add(Food())
snake.add_segment()
# see if head collides with body
for n in range(1, len(snake.segments)):
if pygame.sprite.collide_rect(snake.segments[0], snake.segments[n]):
game_over = True
# check screen boundary
# use grids of 32 * 32 to judge.
head_x = snake.segments[0].X // 32
head_y = snake.segments[0].Y // 32
if head_x < 0 or head_x > 24 or head_y < 0 or head_y > 17:
game_over = True
# drawing section
backbuffer.fill((20, 50, 20))
snake.draw(backbuffer)
food_group.draw(backbuffer)
screen.blit(backbuffer, (0, 0))
if not game_over:
if auto_play:
auto_move()
print_text(font, 0, 0, "Length " + str(len(snake.segments)))
print_text(font, 0, 20, "Position " + str(snake.segments[0].X // 32) + "," + str(snake.segments[0].Y // 32))
else:
# play_sound(game_over_sound)
print_text(font, 0, 0, "GAME OVER")
pygame.display.update()
