mygame.py

import pygame
import random
import math
from pygame import mixer

# Intialize the pygame
pygame.init()

# Background
background = pygame.image.load('background.png')

# Background sound
mixer.music.load("background.wav")
mixer.music.play(-1)

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

# Title and Icon
pygame.display.set_caption("Space Invaders")
icon = pygame.image.load('game.png')
pygame.display.set_icon(icon)

# Player
playerImg = pygame.image.load('ship.png')
playerX = 360
playerY = 500
new_playerX = 0

# Enemy
enemyImg = []
enemyX = []
enemyY = []
enemyX_change = []
enemyY_change = []
num_of_enemies = 6
for i in range(num_of_enemies):
    enemyImg.append(pygame.image.load('play.png'))
    enemyX.append(random.randint(0, 736))
    enemyY.append(random.randint(30, 200))
    enemyX_change.append(1.5)
    enemyY_change.append(30)

# bullet
# Ready = you can't see the bullet on the screen
# Fire = The bullet is currently moving

bulletImg = pygame.image.load('bullet.png')
bulletX = 0
bulletY = 500
bulletX_change = 0
bulletY_change = 8
bullet_state = "ready"

# Score counter
score_value = 0
font = pygame.font.Font('freesansbold.ttf', 32)
textX = 10
textY = 10

# Game over text
over_font = pygame.font.Font('freesansbold.ttf', 64)


# Creating the score thing on the screen
def show_score(x, y):
    score = font.render("score :" + str(score_value), True, (255, 255, 0))
    screen.blit(score, (x, y))


def game_over_text():
    over_text = over_font.render("GAME OVER", True, (255, 255, 255))
    screen.blit(over_text, (200, 200))


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


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


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


def isCollision(enemyX, enemyY, bulletX, bulletY):
    distance = math.sqrt((math.pow(enemyX - bulletX, 2)) + (math.pow(enemyY - bulletY, 2)))
    if distance < 27:
        return True
    else:
        return False


# Game loop
running = True
while running:

    # Adding RGB = Red, Green, Blue
    screen.fill((255, 128, 255))
    # Background image
    screen.blit(background, (0, 0))

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

        # if keystroke is pressed check whether its right or left
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                new_playerX = -5
            if event.key == pygame.K_RIGHT:
                new_playerX = 5
            if event.key == pygame.K_SPACE:
                if bullet_state is "ready":
                    # Get the current x coordinate of the bullet
                    bulletX = playerX
                    bullet_sound = mixer.Sound('laser.wav')
                    bullet_sound.play()
                    fire_bullet(bulletX, bulletY)
        if event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                new_playerX = 0

    # Checking for boundaries of the ship so it doesn't go out of bounds
    playerX += new_playerX

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

    # Enemy 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_text()
            break

        enemyX[i] += enemyX_change[i]

        if enemyX[i] <= 0:
            enemyX_change[i] = 1.5
            enemyY[i] += enemyY_change[i]
        elif enemyX[i] >= 736:
            enemyX_change[i] = -1.5
            enemyY[i] += enemyY_change[i]

        # Collision
        collision = isCollision(enemyX[i], enemyY[i], bulletX, bulletY)
        if collision is True:
            collision_sound = mixer.Sound('explosion.wav')
            collision_sound.play()
            bulletY = 500
            bullet_state = "ready"
            score_value += 1
            enemyX[i] = random.randint(0, 736)
            enemyY[i] = random.randint(30, 200)

        enemy(enemyX[i], enemyY[i], i)

    # Bullet Movement
    if bullet_state is "fire":
        fire_bullet(bulletX, bulletY)
        bulletY -= bulletY_change
        if bulletY <= 0:
            bulletY = 500
            bullet_state = "ready"

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