main.py

import pygame
import random 
#initialize pygame
pygame.init()
pygame.font.init()

#screen dimensions
width = 750
height = 750
screen = pygame.display.set_mode((width,height))

#Game info/Icon
pygame.display.set_caption("Space Invaders")
icon = pygame.image.load("spaceship.png")
pygame.display.set_icon(icon)

#import player
playerImg = pygame.image.load("player.png")
playerX = 370
playerY = 480
playerXchange = 0


#import enemy
enemyImg = pygame.image.load("enemy.png")
enemy2Img = pygame.image.load("enemy2.png")
enemy3Img = pygame.image.load("enemy3.png")



#import lasers
red_laser = pygame.image.load("pixel_laser_red.png")
yellow_laser = pygame.image.load("pixel_laser_yellow.png")
green_laser = pygame.image.load("pixel_laser_green.png")
blue_laser = pygame.image.load("pixel_laser_blue.png")


#import background
background = pygame.transform.scale(pygame.image.load("background.gif"), (width,height))

class Laser:
    def __init__(self, x,y, img):
        self.x = x
        self.y = y
        self.img = img
        self.mask = pygame.mask.from_surface(self.img)
    def draw(self,window):
        window.blit(self.img,(self.x,self.y))
    def move(self,vel):
        self.y+=vel
    def off_screen(self,height):
        return not (self.y <= height and self.y >= 0)
    def collision(self,obj):
        return collide(self,obj)   

class Ship:
    COOLDOWN = 30
    def __init__(self,x,y, health=100):
        self.x = x
        self.y = y
        self.health = health
        self.ship_image = None
        self.laser_image = None
        self.lasers = []
        self.cool_down_counter = 0
    
    def draw(self,window):
        window.blit(self.ship_image,(self.x,self.y))
        for laser in self.lasers:
            laser.draw(window)

    def move_lasers(self,vel,obj):
        self.cooldown()
        for laser in self.lasers:
            laser.move(vel)
            if laser.off_screen(height):
                self.lasers.remove(laser)
            elif laser.collision(obj):
                obj.health -= 10
                self.lasers.remove(laser)

    def get_width(self):
        return self.ship_image.get_width()
    
    def get_height(self):
        return self.ship_image.get_height()
    def shoot(self):
        if self.cool_down_counter == 0:
            laser = Laser(self.x,self.y,self.laser_image)
            self.lasers.append(laser)
            self.cool_down_counter = 1

    def cooldown(self):
        if self.cool_down_counter >= self.COOLDOWN:
            self.cool_down_counter = 0
        elif self.cool_down_counter > 0:
            self.cool_down_counter +=1

class Player(Ship):
    def __init__(self,x,y,health = 100):
        super().__init__(x,y,health)
        self.ship_image = playerImg
        self.laser_image = red_laser
        self.mask = pygame.mask.from_surface(self.ship_image)
        self.max_health = health
    def draw(self,window):
        super().draw(window)
        self.healthbar(window)
    def healthbar(self,window):
        pygame.draw.rect(window, (255,0,0), (self.x,self.y + self.ship_image.get_height()+10, self.ship_image.get_width(),10))
        pygame.draw.rect(window, (0,255,0), (self.x,self.y + self.ship_image.get_height()+10, self.ship_image.get_width()*(self.health/self.max_health),10))

    def move_lasers(self,vel,objs):
        self.cooldown()
        for laser in self.lasers:
            laser.move(vel)
            if laser.off_screen(height):
                self.lasers.remove(laser)
            else:
                for obj in objs:
                    if laser.collision(obj):
                        objs.remove(obj)
                        if laser in self.lasers:
                            self.lasers.remove(laser)

class Enemy(Ship):
    COLOR_MAP = {"blue": (enemyImg,blue_laser), "white":(enemy2Img,yellow_laser),"red":(enemy3Img, green_laser)}
    def __init__(self,x,y,color,health = 100):
        super().__init__(x,y,health)
        self.ship_image, self.laser_image = self.COLOR_MAP[color]
        self.mask = pygame.mask.from_surface(self.ship_image)
    def move(self,vel):
        self.y +=vel
    def shoot(self):
        if self.cool_down_counter == 0:
            laser = Laser(self.x-20,self.y,self.laser_image)
            self.lasers.append(laser)
            self.cool_down_counter = 1    




def collide(obj1,obj2):
    offset_x = obj2.x - obj1.x
    offset_y = obj2.y - obj1.y
    return obj1.mask.overlap(obj2.mask,(offset_x,offset_y)) != None 


def main():
    # Game loop running 
    running = True
    FPS = 60
    level = 0
    lives = 5
    player_vel = 5
    lost = False
    lost_count = 0
    main_font = pygame.font.SysFont("comicsans", 30)
    lost_font = pygame.font.SysFont("comicsans", 60)
    player = Player(300,630)
    clock = pygame.time.Clock()
    
    enemies = []
    enemy_vel =1
    laser_vel = 5
    wave_length = 5

    def redraw_window():
        screen.blit(background,(0,0))

        lives_label = main_font.render(f"Lives: {lives}", 1, (255,255,255))
        levels_label = main_font.render(f"Levels: {level}", 1, (255,255,255))
        screen.blit(lives_label, (10,10))
        screen.blit(levels_label, (width-10-levels_label.get_width(),10))


        for enemy in enemies:
            enemy.draw(screen)


        player.draw(screen)
        if lost:
            lost_label = lost_font.render("You Lost!!",1,(255,255,255))
            screen.blit(lost_label, (width/2 - lost_label.get_width()/2,350))


        pygame.display.update()


    while running:
        clock.tick(FPS)
        redraw_window()

        if lives <=0 or player.health <=0:
            lost =True
            lost_count += 1
        
        if lost:
            if lost_count > FPS * 3:
                running = False
            else:
                continue

        if len(enemies)==0:
            level+=1
            wave_length += 5
            for i in range(wave_length):
                enemy = Enemy(random.randrange(50,width-100), random.randrange(-1500,-100),random.choice(["blue","white","red"]))
                enemies.append(enemy)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                quit()
        keys = pygame.key.get_pressed()
        if keys[pygame.K_a] and player.x - player_vel > 0: #left
            player.x -=player_vel
        if keys[pygame.K_d] and player.x + player_vel + player.get_width()  < width: #right
            player.x +=player_vel
        if keys[pygame.K_w] and player.y - player_vel > 0: #up
            player.y -=player_vel
        if keys[pygame.K_s] and player.y + player_vel + player.get_height() +15 < height: #down
            player.y +=player_vel
        if keys[pygame.K_SPACE]:
            player.shoot()
        
        for enemy in enemies[:]:
            enemy.move(enemy_vel)
            enemy.move_lasers(laser_vel,player)
            if random.randrange(0,2*60) ==1:
                enemy.shoot()
            
            if collide(enemy, player):
                player.health -=10
                enemies.remove(enemy)

            elif enemy.y + enemy.get_height() > height:
                lives-=1
                enemies.remove(enemy)
           
        player.move_lasers(-laser_vel, enemies)

        

def main_menu():
    title_font = pygame.font.SysFont("comicsans",70)
    run = True
    while run:
        screen.blit(background,(0,0))
        title_label = title_font.render("Press the mouse to begin...",1,(255,255,255))
        screen.blit(title_label,(width/2 - title_label.get_width()/2,350))
        pygame.display.update()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run = False
            if event.type == pygame.MOUSEBUTTONDOWN:
                main()
    pygame.quit()
main_menu()