main.py

import math
import random

import pygame
from pygame import mixer

# Initialize the pygame
pygame.init()

# create the screen
screen = pygame.display.set_mode((800, 600))

# background
background = pygame.image.load("assets/background-800x600.png")
mixer.music.load("assets/music/background.wav")
mixer.music.play(-1)

# Tittle and icon
pygame.display.set_caption("Invasores del Espacio")
icon = pygame.image.load('assets/001-ufo.png')
pygame.display.set_icon(icon)

# Player
playerImg = pygame.image.load("assets/64/016-space-invaders-64.png")
playerX = 370
playerY = 480
playerX_change = 0
playerY_change = 0

# Enemy
enemyImg = []
enemyX = []
enemyY = []
enemyX_change = []
enemyY_change = []
num_of_enemies = 10

for i in range(num_of_enemies):
    enemyImg.append(pygame.image.load("assets/64/012-ufo-4.png"))
    enemyX.append(random.randint(0, 735))
    enemyY.append(random.randint(50, 150))
    enemyX_change.append(2.5)
    enemyY_change.append(30)

# Bullet
bulletImg = pygame.image.load("assets/001-bullet.png")
bulletX = 0
bulletY = 480
bulletX_change = 0
bulletY_change = 4
bullet_state = "ready"

# score
score = 0
font = pygame.font.Font('freesansbold.ttf', 35)
textX = 10
textY = 10


def show_score(x, y):
    score_font = font.render("Score: " + str(score), True, (255, 255, 255))
    screen.blit(score_font, (x, y))


def fire_bullet(x, y):
    global bullet_state
    bullet_state = "fire"
    screen.blit(bulletImg, (x + 16, y + 10))


def enemy(x, y, i_element):
    screen.blit(enemyImg[i_element], (x, y))


def player(x, y):
    screen.blit(playerImg, (x, y))


def is_collision(enemy_x, enemy_y, bullet_x, bullet_y):
    distance = math.sqrt((enemy_x - bullet_x) ** 2 + (enemy_y - bullet_y) ** 2)
    if distance < 27:
        return True
    return False


def game_over():
    go_text = pygame.font.Font('freesansbold.ttf', 64).render("Game Over!", True, (255, 255, 255))
    
    screen.blit(go_text, (200, 250))


running = True
while running:
    # RGB
    screen.fill((0, 0, 0))

    # Background
    screen.blit(background, (0, 0))

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

        # if keystroke is pressed
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                playerX_change = -4
            if event.key == pygame.K_RIGHT:
                playerX_change = 4
            if event.key == pygame.K_SPACE:
                if bullet_state is "ready":
                    bullet_sound = mixer.Sound("assets/music/laser.wav")
                    bullet_sound.play()
                    bulletX = playerX
                    fire_bullet(bulletX, bulletY)

        if event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                playerX_change = 0

    playerX += playerX_change

    if playerX <= 0:
        playerX = 0
    elif playerX >= 736:
        playerX = 736

    # 3n3my movement
    for i in range(num_of_enemies):
        # Game over

        if enemyY[i] > 440:
            for j in range(num_of_enemies):
                enemyY[j] = 2000
                game_over()
                break

        enemyX[i] += enemyX_change[i]
        if enemyX[i] <= 0:
            enemyX_change[i] = 2.5
            enemyY[i] += enemyY_change[i]
        elif enemyX[i] >= 736:
            enemyX_change[i] = -2.5
            enemyY[i] += enemyY_change[i]

        # Collision
        collision = is_collision(enemyX[i], enemyY[i], bulletX, bulletY)
        if collision:
            mixer.Sound("assets/music/explosion.wav").play()
            bulletY = 480
            bullet_state = "ready"
            score += 1
            enemyX[i] = random.randint(0, 735)
            enemyY[i] = random.randint(50, 150)
            print(score)
        enemy(enemyX[i], enemyY[i], i)

    # bullet movement
    if bulletY <= 0:
        bulletY = 480
        bullet_state = "ready"

    if bullet_state is "fire":
        fire_bullet(bulletX, bulletY)
        bulletY -= bulletY_change

    player(playerX, playerY)
    show_score(textX, textY)
    pygame.display.update()