Codedrop for CoderDojo #36 (September 21st 2019)
This is written in Python, and uses the excellent PyGame engine.
For installation instructions, go here:
# Import the libraries
#
import pygame
import random
# Initialise PyGame
#
pygame.init()
# Some global variables
#
win_w = 1024 # Window width
win_h = 768 # Window height
image_files = [ # List of images to load
"robot.jpg",
"space_invader.png"
]
# Variables used by this game engine we're writing
#
sprites = [] # List of sprites
images = {} # Hashtable of images
# Create a screen surface to draw on, and a clock
#
screen = pygame.display.set_mode((win_w, win_h))
clock = pygame.time.Clock()
# Set the key repeat to 1ms delay, 1ms repeat
#
pygame.key.set_repeat(1,1)
# Load some images -------------------------------------------------------------
for image_file in image_files:
image = pygame.image.load("../Graphics/" + image_file).convert()
image.set_colorkey((255,255,255))
images[image_file] = image
# The Sprite class -------------------------------------------------------------
class Sprite:
#
# Some basic variables, just for this sprite
#
active = None # Whether the sprite is active or off
xp = None # X position of the sprite
yp = None # Y position of the sprite
image = None # Sprite image
type = None # Sprite type (string)
fn_move = None # Function to move the sprite
#
# This is called when we initialise the Sprite class
#
def __init__(self):
self.active = False
#
# A class function to move the sprite
#
def move(self):
if(self.active and self.fn_move is not None):
self.fn_move(self)
return
#
# A class function to draw the sprite
#
def draw(self):
if(self.active):
screen.blit(self.image, (self.xp, self.yp))
# Set up a list of Sprites
#
max_sprites = 200 # Number of sprites we want to create
sprites = [Sprite() for i in range(max_sprites)] # Create a list of Sprites
# Helper functions ------------------------------------------------------------
# Find index of next available free sprite slot in list
# Returns sprite object, or None if no slots left
# Start from 2, as 0 and 1 are reserved for player and player missile
#
def find_next_available_sprite():
for sprite in sprites:
if sprite.active == False:
return sprite
return None
# Movement functions ----------------------------------------------------------
# Move the player
#
def move_player(self):
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.xp -= 4
if keys[pygame.K_RIGHT]:
self.xp += 4
if keys[pygame.K_UP]:
self.yp -= 4
if keys[pygame.K_DOWN]:
self.yp += 4
# Move the invader
#
def move_invader_1(self):
px = sprites[0].xp # The player's X position
py = sprites[0].yp # The player's Y position
if px < self.xp: # If the player is to the left of this sprite
self.xp -= 1 # Move this sprite left
if px > self.xp: # Similarly, move the sprite right if the player is to the right
self.xp += 1
if py < self.yp: # And up..
self.yp -= 1
if py > self.yp: # And down..
self.yp += 1
if px == self.xp and py == self.yp:
self.xp = random.randint(0, win_w)
self.yp = random.randint(0, win_h)
self.counter -=1
if self.counter < 0:
self.counter = random.randint(60, 120)
self.fn_move = move_invader_2
return
def move_invader_2(self):
self.counter -=1
if self.counter < 0:
self.counter = random.randint(60, 120)
self.fn_move = move_invader_1
return
# Stubbed functions ------------------------------------------------------------
# Called when the game initialises
#
def Initialise_Game():
# Create the player sprite
#
s = find_next_available_sprite()
s.sprite_type = "player" # This is the sprite type
s.active = True # Set the sprite to be active
s.xp = win_w//2 # Set X position to centre of screen
s.yp = win_h//2 # Set Y position to centre of screen
s.image = images["robot.jpg"] # Set image (loaded previously)
s.fn_move = move_player # Set function to move sprite
return
# Called when the level initialises
#
def Initialise_Level():
for c in range(10): # Do this 10 times!
s = find_next_available_sprite() # Get next available slot for the sprite
if(s != None):
s.sprite_type = "invader" # This is the sprite type
s.active = True # Set the sprite to be active
s.xp = random.randint(0, win_w) # Set X position to centre of screen
s.yp = random.randint(0, win_h) # Set Y position to centre of screen
s.image = images["space_invader.png"] # Set image (loaded previously)
s.counter = random.randint(60, 120)
s.fn_move = move_invader_1 # Set function to move sprite
return
# Called when the level ends
#
def End_Level():
return
# Called when the game ends
#
def End_Game():
return
# Main Game Loop ---------------------------------------------------------------
Initialise_Game()
# This outer loop keeps going until end_game is True
#
end_game = False
while not end_game:
Initialise_Level()
# This outer loop keeps going until end_level is True
#
end_level = False
while not end_level:
#
# Pygame event handler
#
for event in pygame.event.get():
# Check for window close
if event.type == pygame.QUIT:
end_level = True
end_game = True
# Move everything by calling the Sprite's move function
#
for sprite in sprites:
sprite.move()
# Clear the screen
#
screen.fill((255,255,255))
# Draw the Sprites by calling their draw function
#
for sprite in sprites:
sprite.draw()
# Update the surface to the screen and lock at 60fps
#
pygame.display.flip()
clock.tick(60)
# Level over
#
End_Level()
# Game over!
#
End_Game()
pygame.quit()