13_pygame_space_war.py

import pygame
import random
import math

pygame.init()

# Main Screen
screen = pygame.display.set_mode((600,957)) 

# load wallpaper 
wallpaper = pygame.image.load('background-wallpaper.jpg')

# Title and Icon
pygame.display.set_caption(".::SPACE WAR::.")
icon = pygame.image.load('icon.png')
pygame.display.set_icon(icon)

# Player 
playerImg = pygame.image.load('player.png')
playerX = 268
playerY = 720
playerX_change = 0 

# enemy 
enemyImg = []
enemyX = []
enemyY = []
enemyX_change = [] 
enemyY_change = [] 
num_of_enemies = 4 

for i in range(num_of_enemies):
    enemyType = random.randint(1,4)
    if enemyType == 1 :
        enemyImg.append(pygame.image.load('enemy1.png'))
    elif enemyType == 2 :
        enemyImg.append(pygame.image.load('enemy2.png'))
    elif enemyType == 3 :
        enemyImg.append(pygame.image.load('enemy3.png'))
    elif enemyType == 4 :
        enemyImg.append(pygame.image.load('enemy4.png'))
    enemyX.append(random.randint(100,400))
    enemyY.append(random.randint(50,150))
    enemyX_change.append(0.5)
    enemyY_change.append(10) 



# bullet 
bulletImg = pygame.image.load('bullet.png')
bulletX = 0
bulletY = 720
bulletX_change = 0.1 
bulletY_change = 1
bullet_state = "ready"

# display score text
score_value = 0 
font = pygame.font.Font('Vazirmatn-Black.ttf',40)
scoreTextX = 10
scoreTextY = 10 

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

def fire_bullet(x,y):
    screen.blit(bulletImg,(x+10,y+20))

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

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

def isCollision(x1,y1,x2,y2):
    # calculate distance between (x1,y1) and (x2,y2)
    distance = math.sqrt(math.pow((x2-x1),2) + math.pow((y2-y1),2))
    if distance < 30 :
        return True
    else :
        return False

# Game Frames 
running = True
while running:
    
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_RIGHT:
                playerX_change = 0.2
            if event.key == pygame.K_LEFT:
                playerX_change = -0.2
            if event.key == pygame.K_SPACE:
                if bullet_state is 'ready':
                    bulletX = playerX
                    bullet_state = "fire"
                    fire_bullet(bulletX,bulletY)

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


    screen.fill((0,128,128))
    screen.blit(wallpaper,(0,0))

    # player movement
    playerX += playerX_change
    if playerX <= 0:
         playerX = 0 
    elif playerX >=536 :
        playerX = 536

    # enemy movement
    for i in range(num_of_enemies):
        enemyX[i] += enemyX_change[i]
        if enemyX[i] <= 0:
            enemyX_change[i] = 0.5
            enemyY[i] += enemyY_change[i]
        elif enemyX[i] >=536 :
            enemyX_change[i] = -0.5
            enemyY[i] += enemyY_change[i]

        # bullet collision 
        collision = isCollision(enemyX[i] , enemyY[i] , bulletX , bulletY )
        if collision:
            bullet_state = 'ready'
            bulletY = 720
            score_value += 1
            enemyX[i] = random.randint(100,400)
            enemyY[i] = random.randint(50,150)

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

    # bullet movement 
    if bullet_state is 'fire':
        if bulletY <= 0 : 
            bullet_state = 'ready'
            bulletY = 720
        
        fire_bullet(bulletX , bulletY)
        bulletY -= bulletY_change

    player(playerX,playerY)
    show_score(scoreTextX,scoreTextY)
    pygame.display.update()