8章 skier code

import pygame,sys,random
skier_images = ["skier_down.png","skier_right1.png",
                "skier_right2.png","skier_left2.png",
                "skier_left1.png"]
class SkierClass(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.image.load("skier_down.png")
        self.rect = self.image.get_rect()
        self.rect.center = [320,100]
        self.angle = 0
        
    def turn(self,direction):
        self.angle = self.angle + direction
        if self.angle <-2: self.angle = -2
        if self.angle > 2: self.angle = 2
        center = self.rect.center
        self.image = pygame.image.load(skier_images[self.angle])
        self.rect =  self.image.get_rect()
        self.rect.center = center
        speed = [self.angle,6 - abs(self.angle)*2]
        return speed
    
    def move(self, speed):
        self.rect.centerx = self.rect.centerx + speed[0]
        if self.rect.centerx < 20: self.rect.centerx = 20
        if self.rect.centerx > 620:self.rect.centerx = 620

class ObstacleClass(pygame.sprite.Sprite):
    def __init__(self,image_file,location,type):
        pygame.sprite.Sprite.__init__(self)
        self.image_file =image_file
        self.image = pygame.image.load(image_file)
        self.rect = self.image.get_rect()
        self.rect.center = location
        self.type = type
        self.passed = False
        
    def update(self): 
        global speed
        self.rect.centery -= speed[1]
        if self.rect.centery < - 32:
            self.kill()
def create_map():
    global obstacles
    locations = []
    for i in range(10): #10 obstacles per screen
        row = random.randint(0,9)
        col = random.randint(0,9)
        location = [col *64 + 32,row * 64 +32 + 640] #center x,y for abstacle
        if not (location in locations):
            location.append(location)
            type = random.choice(["tree","flag"])
            if type == "tree":  img = "skier_tree.png"
            elif type == "flag": img = "skier_flag.png"
            obstacle = ObstacleClass(img,location, type)
            obstacles.add(obstacle)
            
def animate():
    screen.fill([255,255,255])
    obstacles.draw(screen)
    screen.blit(skier.image,skier.rect)
    screen.blit(score_text,[10,10])
    pygame.display.flip()
    
pygame.init() 
screen = pygame.display.set_mode([640,640])
clock = pygame.time.Clock()
skier = SkierClass()
speed = [0,6]
obstacles = pygame.sprite.Group()#group of obstacle objects
map_position = 0
points = 0
create_map()
font = pygame.font.Font(None,50)
# main pygame event loop
runing = True 
while running:
    clock.tick(30) # screen update 30 times per a second
    for event in pygame.event.get():
        if event.type == pygame.QUIT:runing = False

        if event.type == pygame.KEYDOWN:       #check for key presses
            if event.key == pygame.K_LEFT:     # left arrow turns left
                speed = skier.turn(-1)
            elif event.key == pygame.K_RIGHT:  #righe arrow turns right
                speed = skier.turn(1)
    skier.move(speed)
    map_position += speed[1]


    if map_position >= 640:
        create_map()
        map_position = 0
#check for hitting trees or getting flags                    
    hit = pygame.sprite.spritecollide(skier,obstacles,False)
    if hit:
        if hit[0].type == "tree"and not hit[0].passed:
            points = points - 100
            skier.image = pygame.image.load("skier_crash.png")
            animate()
            pygame.time.delay(1000)
            skier.image = pygame.image.load("skier_down.png")
            skier.angle = 0             
            speed = [0,6]
            hit[0].passed = True
        elif hit[0].type == "flag"and not hit[0].passed:
            points += 10
            hit[0].kill()
                        
        obstacles.update()
        score_text = font.render("Score: " + str(points),1,(0,0,0))
        animate()

pygame.quit()