My objective is to make a space invaders type of game, where the spaceship can move up, down, left and right, and fire bullets at the alien.
I've yet to make the collision part of the code as I am stuck at the firing bullets part.
I've assigned spacebar to fire bullets yet I'm unable to see any bullet firing. Please help me out.
import pygame
import random
# for initialising pygame (req for every pygame app)
pygame.init()
# making the basic window (dimensions must be written inside a tuple )
screen = pygame.display.set_mode((500, 500))
# background
background = pygame.image.load('C:/Users/aryan/Downloads/background.jpg')
# load and set the logo
logo = pygame.image.load('C:/Users/aryan/Downloads/bp.png') # directory of logo
pygame.display.set_icon(logo)
pygame.display.set_caption("space wars") # program name
# define a variable to control the main loop
running = True
# player
playerimg = pygame.image.load('C:/Users/aryan/Downloads/spaceship.png')
playerX = 218 # x and y coordinates of image
playerY = 350
playerxchange = 0 # this will be the change in movement in x direction of our image
playerychange = 0 # this will be the change in movement in y direction of our image
def player(x, y):
screen.blit(playerimg, (x, y)) # blit draws our image on the surface(basically the background)
# syntax for blit(imagename, (xcoordinate,ycoordinate))
# enemy
enemyimg = pygame.image.load('C:/Users/aryan/Downloads/enemy.png')
enemyX = random.randint(0, 476)
enemyY = 20
enemyxchange = 0.2
enemyychange = 40
# game over
overimg = pygame.image.load('C:/Users/aryan/Downloads/gameover.png')
# bullet
bulletimg = pygame.image.load('C:/Users/aryan/Downloads/bullet.png')
bulletX = 0
bulletY = 350
bulletxchange = 0
bulletychange = 7
bullet_state = "ready" # "ready" you cant see bullet on screen
# "fire" you can see bullet firing
def enemy(x, y):
screen.blit(enemyimg, (x, y)) # blit draws our image on the surface(basically the background)
# syntax for blit(imagename, (xcoordinate,ycoordinate))
def firebullet(x, y):
global bullet_state
bullet_state = "ready"
screen.blit(bulletimg, (x+12, y+6))
# main loop
while running:
screen.fill((120, 120, 120)) # in order (r, g, b) . (0, 0, 0) is black (255, 0, 0) is red...
screen.blit(background, (0, 0))
# event handling, gets all event from the event queue
for event in pygame.event.get():
# only do something if the event is of type QUIT
if event.type == pygame.QUIT:
# change the value to False, to exit the main loop
running = False
# checking keystroke
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT:
playerxchange += 0.2 # change in movement will be 0.2 towards the right
if event.key == pygame.K_LEFT:
playerxchange -= 0.2 # change in movement will be 0.2 towards the right
#if event.key == pygame.K_UP:
# playerychange -= 0.2
#if event.key == pygame.K_DOWN:
# playerychange += 0.2
if event.key == pygame.K_SPACE:
bullet_state = "fire"
firebullet(playerX, bulletY)
if event.type == pygame.KEYUP:
if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT: #or event.key == pygame.K_DOWN or event.key == pygame.K_UP:
playerxchange = 0
playerychange = 0
playerY += playerychange
playerX += playerxchange # the value of playerx changes by +- 0.1 depending on keystroke
if playerX <= -64: # this teleports the spaceship from left end to right end
playerX = 564
elif playerX >= 564: # this teleports spaceship from right end to left
playerX = -64
if playerY >= 436: # this prevents spaceship from leaving vertically
playerY = 436
if playerY <= 0:
playerY = 0
# enemy movement
enemyX += enemyxchange
if enemyY >= 476:
enemyY = 476
enemyYchange = 0
enemyXchange = 0
if enemyX <= 0:
enemyxchange = 0.1
enemyY += enemyychange
elif enemyX >= 465:
enemyxchange = -0.1
enemyY += enemyychange
# bullet movement
if bullet_state is "fire":
firebullet(playerX, bulletY)
bulletY -= bulletychange
player(playerX, playerY) # player method is called AFTER screen.fill otherwise the screen will fill after image has been blitted
enemy(enemyX, enemyY)
pygame.display.update() # necessary for events to keep updating
Also, the comments may seem trivial, but I am a beginner.
You don't see the bullet firing because you only call screen.blit(bulletimg, (x+12, y+6)) once in your firebullet function. After this, a new loop begins and the background gets printed over it with screen.blit(background, (0, 0)), and no code is called to render your bullet anymore. What you need is to keep each bullet in memory and call .blit() every loop iteration so that they're all printed correctly.
Here's a basic solution:
...
bullets = [] #Array to store the position of the bullets
...
def firebullet(x, y):
global bullet_state
bullet_state = "ready"
bullets.append([x + 12, y + 6]) # Creating a new bullet
...
while running:
...
if bullet_state is "fire":
firebullet(playerX, bulletY)
# bulletY -= bulletychange # No longer necessary, we'll do this right afterwards
for bullet in bullets:
screen.blit(bulletimg, (bullet[0], bullet[1])) # Print a bullet
bullet[0] -= bulletxchange # Updates its position
bullet[1] -= bulletychange
if bullet[1] < 0:
bullets.remove(bullet) # If the bullet goes offscreen, delete it from the array