Develop Reference

Send obstacles from right side of screen in Pygame

I'm making a basic dodger game where you play as a fish and need to avoid getting hit by obstacles. I want the obstacles to come from the right side of the screen at a random velocity (from a certain range, let's just say 4 to 6). I already have the fish/underwater gravity mechanics working. But I have no idea where to start with the obstacles.
This is my main python script:
import pygame
from assets.player import Bob
# Screen properties
pygame.init()
# Important Variables
run = True
game_speed = 0
SCREEN_WIDTH, SCREEN_HEIGHT = 900, 600
screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
clock = pygame.time.Clock()
FPS = 60
# Properties
bg_game_surface = pygame.image.load('images/game-background.png')
player = Bob(game_speed)
#############
# Functions #
#############
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
screen.blit(bg_game_surface, (0, 0))
player.update(screen)
pygame.display.update()
clock.tick(FPS)
pygame.quit()
And this is the class for my player:
import pygame
class Bob:
def __init__(self, game_speed):
self.img = pygame.image.load('images/player/bob.png').convert_alpha()
self.img_up = pygame.image.load('images/player/bob_up.png').convert_alpha()
self.rect = self.img.get_rect()
self.game_speed = game_speed
def update(self, screen):
key = pygame.key.get_pressed()
### Collision
if self.rect.top <= 0:
self.rect.centery = (screen.get_height() - self.img.get_height() * 2) + 10
elif self.rect.top >= screen.get_height() - self.img.get_height() * 2:
self.rect.centery = 20
### Movement
if key[pygame.K_w] or key[pygame.K_UP]:
self.rect.centery -= 6
self.img = pygame.image.load('images/player/bob_up.png').convert_alpha()
### Gravity
else:
self.img = pygame.image.load('images/player/bob.png').convert_alpha()
self.rect.centery += 4
screen.blit(self.img, self.rect)
My folders are sorted like this:
Right now, I'd like that the trash.py is also a class with a function called "update". When that function is executed, obstacles (preferably in the form of an image) come out of the right side of the display, doing what I said above.
Any help is appreciated. Thanks in advance :)

You should make a sprite class group, but first you need to import the random module:
import random
Now you can create the Obstacle Sprite class, this is just an example:
class Obstacle(pygame.sprite.Sprite):
def __init__(self, pos): #pos is the starting position
super().__init__()
self.image = pygame.Surface((10,10)) # You can change this with pygame.image.load('...')
self.rect = self.image.get_rect(topleft = pos)
self.vel = random.randint(4,6) #random speed of the obstacle
def collisions(self, player): #collisions function
if self.rect.colliderect(player.rect):
print('collision!') #write what you want to happen
def movement(self): #the blocks are moving left
if self.rect.x > -100: #just putting some limits
self.rect.x -= self.vel
def update(self, player): #try to put all the other functions in the update one
self.collisions(player)
self.movement()
Once you created the class, you only need to create some objects of that class (every obstacle).
First we create a sprite group before of the while loop:
obstacles = pygame.sprite.Group()
Then, inside your main loop, you need a condition that generates the obstacles.
I've done something like this, but you really should change it:
if x < 10: #I created x before the while (x=0)
posx = SCREEN_WIDTH + 50 #the starting x will be 50 pixels right of the screen
posy = random.randint(0, SCREEN_HEIGHT) #Im setting this to random
obs = Obstacle((posx, posy))
obstacles.add(obs)
x +=1
This basically creates 9 obstacles when we start the game, with different random x speed and y location, and draw them on the screen. If you collide with one of the blocks, the code just prints "collision!" (see the Obstacle class). Hope it was helpful and I didn't miss something.

Making rows of sprites re-appear at top of screen in pygame

I'm trying to make the rows of sprites reappear at the top of the screen when they disappear off of the bottom. I'm able to make the sprites move downwards and off the screen but don't know to get them to reappear as soon as one row moves off. Here is the code I have so far:
import pygame
import sys
from pygame.sprite import Sprite
class Rain:
def __init__(self):
pygame.init()
self.screen = pygame.display.set_mode((1200, 800))
pygame.display.set_caption("Rain Drops")
self.bg_color = (100,100,100)
self.rain_drops = pygame.sprite.Group()
self._create_drop()
drop = Drop()
def run_rain(self):
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_q:
sys.exit()
self.screen.fill(self.bg_color)
self._update_drops()
self.rain_drops.draw(self.screen)
pygame.display.flip()
def _create_drop(self):
drop = Drop()
drop.rect.x = -10
drop.rect.y = 4
drop_start_x = drop.rect.x
drop_start_y = drop.rect.y
for row_number in range(5):
for drop_number in range(20):
drop = Drop()
drop.rect.x = drop_start_x + 70 * drop_number
drop.rect.y = drop_start_y + 100 * row_number
self.rain_drops.add(drop)
def _update_drops(self):
self.rain_drops.update()
class Drop(Sprite):
def __init__(self):
super().__init__()
self.image = pygame.image.load('smaller_drop.bmp')
self.rect = self.image.get_rect()
def update(self):
self.rect.y += 1
rain = Rain()
rain.run_rain()

This sort of thing is best done in your sprite's .update() function. Check to see if the y co-ordinate of the sprites Rect is past the height of the window, and if-so move it back to the top.
However, you have hard-coded the window dimensions inside the display initialisation function. We need to know the window length in the update, so these need to be moved out to constant variables.
class Rain:
WINDOW_WIDTH = 1200
WINDOW_HEIGHT= 800
def __init__(self):
pygame.init()
self.screen = pygame.display.set_mode((self.WINDOW_WIDTH, self.WINDOW_HEIGHT))
pygame.display.set_caption("Rain Drops")
Now in the DropSprite it's pretty easy to compare the position against the window height. if the position is greater than the window height,
class Drop(Sprite):
def __init__(self):
super().__init__()
self.image = pygame.image.load('smaller_drop.bmp')
self.rect = self.image.get_rect()
def update(self):
self.rect.y += 1
# if we go off the bottom of the window, move back to top
if ( self.rect.y > Rain.WINDOW_HEIGHT ):
self.rect.y = 0
You may also want the drop to start just above the screen so it "falls" into view. In this case start it with an x of (0 - self.rect.height), since the x,y of a rect is the top-left co-ordinate. Moving it to 0 makes it suddenly appear at the top. Moving it to -height puts it just above the player's view.

enemy class overlap with each other

import pygame
import os
import random
from pygame.locals import * # Constants
import math
import sys
import random
pygame.init()
screen=pygame.display.set_mode((1280,700)) #(length,height)
screen_rect=screen.get_rect()
background = pygame.Surface(screen.get_size())
background.fill((255,255,255)) # fill the background white
background = pygame.image.load('stage.png').convert()
Black=(0,0,0)
class Player(pygame.sprite.Sprite):
x = 20
y = 615
def __init__(self):
super().__init__() # calls the parent class allowing sprite to initalize
self.image = pygame.Surface((50,25)) # this is used to create a blank image with the size inputted
self.image.fill((0,0,128)) # fills the blank image with colour
self.rect = self.image.get_rect(topleft =(20,615)) # This place the player at the given position
self.dist = 10
def update(self): # code to make the character move when the arrow keys are pressed
if self.rect.right > 100: # These are to make the player so move constantly
self.rect.y += 1
self.rect.x += 2
if self.rect.bottom == 700:
pygame.quit()
keys = pygame.key.get_pressed()
if keys[K_LEFT]:
self.rect.move_ip(-1,0)
elif keys[K_RIGHT]:
self.rect.move_ip(0.5,0)
elif keys[K_UP]:
self.rect.move_ip(0,-0.5)
elif keys[K_DOWN]:
self.rect.move_ip(0,1)
self.rect.clamp_ip(screen_rect)
#while self.rect == (20,615):
if keys [K_SPACE]:
self.rect = self.image.get_rect(topleft =(100,100))
class Enemy(pygame.sprite.Sprite): # the enemy class which works fine
def __init__(self):
super().__init__()
x = random.randint(50,450)
self.image = pygame.Surface((50,25))
self.image.fill((128,0,0))
self.rect = self.image.get_rect(topleft (300, 50))
self.direction = 0
def update(self):
self.rect.y += 2 if self.direction == 0 else -2
if self.rect.bottom >= 600:
self.direction = 1
if self.rect.top <= 50:
self.direction = 0
clock = pygame.time.Clock() # A clock to limit the frame rate.
player = Player()
enemy = Enemy()
enemy_list = pygame.sprite.Group() # a group where the enemys will be put
sprites = pygame.sprite.Group(player) # The group where evry spirte will be put into
for i in range (5): # creates 5 enemy spirtes
enemy = Enemy() # calls the enemy class
enemy.rect.x = random.randrange(200, 1100) # makes the enemny spawn random
enemy.rect.y = random.randrange(50, 600)
enemy_list.add(enemy) # adds the enemy to the group
sprites.add(enemy)
I got the code so that the enemies will randomly and then they will move up and down however since the spawning is random they will sometimes overlap i was wondering how i would get it so that they don't overlap when they move up and down
i was wondering if i could do it so they have a gap when they spawns e.g. 50 in x axis but still spawn five enemies
def main(): #my main loop
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
sprites.update()
screen.blit(background, (0, 0))
sprites.draw(screen)
clock.tick(100) # Limit the frame rate to 60 FPS.
pygame.display.flip() #updates the whole screen
#Collison check
player_hit_list = pygame.sprite.spritecollide(player, enemy_list, True)
for enemy in player_hit_list:
pygame.quit()
if __name__ == '__main__':
main()

Try this approach (I've purposely made the code a little verbose to try to explain what's going on):
...
number_of_enemies = 5
min_enemy_x = 200
max_enemy_x = 1100
enemy_x_range = max_enemy_x - min_enemy_x # zone in which enemies can spawn
enemy_zone_width = enemy_x_range / number_of_enemies # zone width for each enemy
pixel_buffer = 50 # gap between enemies
for i in range (number_of_enemies): # creates 5 enemy spirtes
enemy = Enemy() # calls the enemy class
min_x = min_enemy_x + enemy_zone_width * i + pixel_buffer / 2 # minimum x at which current enemy can spawn (including buffer)
max_x = min_enemy_x + enemy_zone_width * (i + 1) - pixel_buffer / 2 # maximum x at which current enemy can spawn (including buffer)
enemy.rect.x = random.randrange(min_x, max_x) # makes the enemy spawn random
enemy.rect.y = random.randrange(50, 600)
enemy_list.add(enemy) # adds the enemy to the group
...
Note that this will produce a 25 pixel buffer at the start and end (so enemies will actually spawn between 225 and 1075), but you can either adjust min_enemy_x and max_enemy_x to compensate, or remove the buffering for the first and last loop iterations.

Pygame - sprite collision with sprite group

I have created two simple sprites in PyGame and one of them is an Umbrella, the other one is a rain drop.
The Raindrops are added into a sprite group called all_sprites. The Umbrella sprite has its own group called Umbrella_sprite
The raindrops are "falling" from top of the screen and if one of them touches the umbrella / collides with it.. the raindrop is supposed to be deleted. BUT instead of that specific raindrops all other are affected by this.
main file (rain.py)
#!/usr/bin/python
VERSION = "0.1"
import os, sys, raindrop
from os import path
try:
import pygame
from pygame.locals import *
except ImportError, err:
print 'Could not load module %s' % (err)
sys.exit(2)
# main variables
WIDTH, HEIGHT, FPS = 300, 300, 30
# initialize game
pygame.init()
screen = pygame.display.set_mode((WIDTH,HEIGHT))
pygame.display.set_caption("Rain and Rain")
# background
background = pygame.Surface(screen.get_size())
background = background.convert()
background.fill((40,44,52))
# blitting
screen.blit(background,(0,0))
pygame.display.flip()
# clock for FPS settings
clock = pygame.time.Clock()
def main():
all_sprites = pygame.sprite.Group()
umbrella_sprite = pygame.sprite.Group()
# a function to create new drops
def newDrop():
nd = raindrop.Raindrop()
all_sprites.add(nd)
# creating 10 rain drops
for x in range(0,9): newDrop()
# variable for main loop
running = True
# init umbrella
umb = raindrop.Umbrella()
# all_sprites.add(umb)
umbrella_sprite.add(umb)
# event loop
while running:
clock.tick(FPS)
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
for enemy in all_sprites:
gets_hit = pygame.sprite.spritecollideany(umb, all_sprites)
if gets_hit:
all_sprites.remove(enemy)
screen.blit(background,(100,100))
# clear
all_sprites.clear(screen,background)
umbrella_sprite.clear(screen,background)
# update
all_sprites.update()
umbrella_sprite.update()
# draw
all_sprites.draw(screen)
umbrella_sprite.draw(screen)
# flip the table
pygame.display.flip()
pygame.quit()
if __name__ == '__main__':
main()
raindrop.py ( Raindrop() & Umbrella() )
import pygame
from pygame.locals import *
from os import path
from random import randint
from rain import HEIGHT, WIDTH
img_dir = path.join(path.dirname(__file__), 'img')
class Raindrop(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.width = randint(32, 64)
self.height = self.width + 33
self.image = pygame.image.load(path.join(img_dir, "raindrop.png")).convert_alpha()
self.image = pygame.transform.scale(self.image, (self.width, self.height))
self.speedy = randint(1, 15)
self.rect = self.image.get_rect()
self.rect.x = randint(0, 290)
self.rect.y = -self.height
def reset(self):
self.rect.y = -self.height
def update(self):
self.rect.y += self.speedy
if self.rect.y >= HEIGHT:
self.rect.y = -self.height
self.rect.x = randint(0, 290)
class Umbrella(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.width = 50
self.height = 50
self.image = pygame.image.load(path.join(img_dir,"umbrella.png")).convert_alpha()
self.image = pygame.transform.scale(self.image, (self.width, self.height))
self.speedx = 10
self.rect = self.image.get_rect()
self.rect.x = (WIDTH/2) - self.width
self.rect.y = (0.7 * HEIGHT)
def update(self):
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT] and self.rect.x > 0:
self.rect.x -= self.speedx
elif keys[pygame.K_RIGHT] and self.rect.x < (WIDTH - self.width):
self.rect.x += self.speedx

This is your problem:
for enemy in all_sprites:
gets_hit = pygame.sprite.spritecollideany(umb, all_sprites)
if gets_hit:
all_sprites.remove(enemy)
You're looping through the group, and if any sprite collides, deleting all of them.
You don't need to loop through the group - the collision functions take care of that. You just need to use the spritecollide function, which compares a sprite versus a group. That function will return a list of collisions, as well as using the DOKILL flag to delete them automatically:
gets_hit = pygame.sprite.spritecollide(umb, all_sprites, True)

spritecollideany checks if the sprite collides with any sprite in the group and returns this sprite, so gets_hit is a trueish value as long as the collided sprite in the group is not removed and the if gets_hit: block gets executed. That means the code in the for loop simply keeps deleting every sprite in the group that appears before the collided sprite is reached and removed. A simple fix would be to check if the hit sprite is the enemy: if enemy == gets_hit:, but the code would still be inefficient, because spritecollideany has to loop over the all_sprites group again and again inside of the for loop.
I recommend to use spritecollide instead of spritecollideany as well, since it's more efficient and just one line of code.

Python pygame - Deleting offscreen sprites

I created a simple 2D game with python 2 and pygame where you have to avoid squares that are moving down. I created this class for the 'enemy':
class Enemy(pygame.sprite.Sprite):
def __init__(self, game):
self.groups = game.all_sprites
pygame.sprite.Sprite.__init__(self, self.groups)
self.game = game
self.image = pygame.Surface((TILESIZE + 10, TILESIZE + 10))
self.image.fill(ENEMY_COLOR)
self.rect = self.image.get_rect()
self.x = random.uniform(0, WIDTH - TILESIZE)
self.rect.x = self.x
self.y = 0
def update(self):
if self.rect.colliderect(self.game.player.rect):
self.game.deaths += 1
self.game.score = 0
self.game.run()
self.rect.y += (self.game.score + 500) / 50
Then, I have a thread that creates an instance of the enemy:
class Create_Enemy(Thread):
def __init__(self):
Thread.__init__(self)
def run(self):
while True:
while not game.game_paused:
time.sleep((game.score + 1) / game.speed)
Enemy(game)
Then in the draw method i just write self.all_sprites.draw()
The game is an infinite runner, and every frame the enemies move a few pixels down. The problem is that after a bit the game gets laggy since, when the blocks go offscreen, the sprites don't get deleted.
Is there a way to automatically delete the offscreen instances?
I tried the following but it just deletes all the enemies onscreen.
if self.rect.y >= WIDTH:
self.rect.kill()
I was thinking I could do something like game.all_sprites.pop(1) (the position 0 is the player) but I couldn't find a way to archive something similar ...

The enemies can remove themselfs from the game by calling self.kill() if their rect is no longer inside the screen, e.g.:
def update(self):
if self.rect.colliderect(self.game.player.rect):
self.game.restart() # reset score + count deaths
# we can simply use move_ip here to move the rect
self.rect.move_ip(0, (self.game.score + 500) / 100)
# check if we are outside the screen
if not self.game.screen.get_rect().contains(self.rect):
self.kill()
Also, instead of the thread, you can use pygame's event system to spawn your enemies. Here's a simple, incomplete but runnable example (note the comments):
import random
import pygame
TILESIZE = 32
WIDTH, HEIGHT = 800, 600
# a lot of colors a already defined in pygame
ENEMY_COLOR = pygame.color.THECOLORS['red']
PLAYER_COLOR = pygame.color.THECOLORS['yellow']
# this is the event we'll use for spawning new enemies
SPAWN = pygame.USEREVENT + 1
class Enemy(pygame.sprite.Sprite):
def __init__(self, game):
# we can use multiple groups at once.
# for now, we actually don't need to
# but we could do the collision handling with pygame.sprite.groupcollide()
# to check collisions between the enemies and the playerg group
pygame.sprite.Sprite.__init__(self, game.enemies, game.all)
self.game = game
self.image = pygame.Surface((TILESIZE + 10, TILESIZE + 10))
self.image.fill(ENEMY_COLOR)
# we can use named arguments to directly set some values of the rect
self.rect = self.image.get_rect(x=random.uniform(0, WIDTH - TILESIZE))
# we dont need self.x and self.y, since we have self.rect already
# which is used by pygame to get the position of a sprite
def update(self):
if self.rect.colliderect(self.game.player.rect):
self.game.restart() # reset score + count deaths
# we can simply use move_ip here to move the rect
self.rect.move_ip(0, (self.game.score + 500) / 100)
# check if we are outside the screen
if not self.game.screen.get_rect().contains(self.rect):
self.kill()
class Player(pygame.sprite.Sprite):
def __init__(self, game):
pygame.sprite.Sprite.__init__(self, game.all, game.playerg)
self.game = game
self.image = pygame.Surface((TILESIZE, TILESIZE))
self.image.fill(PLAYER_COLOR)
self.rect = self.image.get_rect(x=WIDTH/2 - TILESIZE/2, y=HEIGHT-TILESIZE*2)
def update(self):
# no nothing for now
pass
class Game(object):
def __init__(self):
# for now, we actually don't need mujtiple groups
# but we could do the collision handling with pygame.sprite.groupcollide()
# to check collisions between the enemies and the playerg group
self.enemies = pygame.sprite.Group()
self.all = pygame.sprite.Group()
self.playerg = pygame.sprite.GroupSingle()
self.running = True
self.score = 0
self.deaths = -1
self.clock = pygame.time.Clock()
def restart(self):
# here we set the timer to create the SPAWN event
# every 1000 - self.score * 2 milliseconds
pygame.time.set_timer(SPAWN, 1000 - self.score * 2)
self.score = 0
self.deaths += 1
def run(self):
self.restart()
self.player = Player(self)
self.screen = pygame.display.set_mode((WIDTH, HEIGHT))
while self.running:
for e in pygame.event.get():
if e.type == pygame.QUIT:
self.running = False
# when the SPAWN event is fired, we create a new enemy
if e.type == SPAWN:
Enemy(self)
# draw and update everything
self.screen.fill(pygame.color.THECOLORS['grey'])
self.all.draw(self.screen)
self.all.update()
pygame.display.flip()
self.clock.tick(40)
if __name__ == '__main__':
Game().run()

Check the values of self.rect.y, WIDTH, maybe the method kill. It looks like self.rect.y is always greater or equal WIDTH, that's why it kills them all.