Pygame sprite constantly redrawn to screen and not moving - python

I can't see what's wrong with the below code. All I want to do is make the frog move across the screen, but it is simply redrawing many, many frogs all one pixel apart. How do I move the frog rather than just draw it again?
import pygame
from pygame.constants import *
pygame.init()
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
class Frog(pygame.sprite.Sprite):
def __init__(self):
super().__init__()
self.image = pygame.transform.scale(pygame.image.load('frog.png'), (64, 64))
self.rect = self.image.get_rect()
self.dx = 1
def update(self, *args):
self.rect.x += self.dx
running = True
frog = Frog()
entities = pygame.sprite.Group()
entities.add(frog)
while running:
for event in pygame.event.get():
if event.type == QUIT:
running = False
entities.update()
entities.draw(screen)

That is how you do it in Pygame, you just redraw objects every iteration to give the illusion that they're moving but you must cover up the previous drawn objects by filling your window with a solid color e.g.
screen.fill((255, 255, 255))
This should be at the start of your game loop so you have a fresh canvas for drawing your objects each iteration.
while running:
screen.fill((255,255,255))
for event in pygame.event.get():
if event.type == QUIT:
running = False
entities.update()
entities.draw(screen)
pygame.display.update()
You may have to use the pygame.display.update() function to update the whole screen rather than just your entities.

Related

How to overwrite the y position of the bird in the game? [duplicate]

im trying to get my image (bird) to move up and down on the screen but i cant figure out how to do it here is what i tried im sure its way off but im trying to figure it out if anyone can help that would be great!
import pygame
import os
screen = pygame.display.set_mode((640, 400))
running = 1
while running:
event = pygame.event.poll()
if event.type == pygame.QUIT:
running = 0
screen.fill([255, 255, 255])
clock = pygame.time.Clock()
clock.tick(0.5)
pygame.display.flip()
bird = pygame.image.load(os.path.join('C:\Python27', 'player.png'))
screen.blit( bird, ( 0, 0 ) )
pygame.display.update()
class game(object):
def move(self, x, y):
self.player.center[0] += x
self.player.center[1] += y
if event.key == K_UP:
player.move(0,5)
if event.key == K_DOWN:
player.move(0,-5)
game()
im trying to get it to move down on the down button press and up on the UP key press
As stated by ecline6, bird is the least of your worries at this point.
Consider reading this book..
For now, First let's clean up your code...
import pygame
import os
# let's address the class a little later..
pygame.init()
screen = pygame.display.set_mode((640, 400))
# you only need to call the following once,so pull them out of the while loop.
bird = pygame.image.load(os.path.join('C:\Python27', 'player.png'))
clock = pygame.time.Clock()
running = True
while running:
event = pygame.event.poll()
if event.type == pygame.QUIT:
running = False
screen.fill((255, 255, 255)) # fill the screen
screen.blit(bird, (0, 0)) # then blit the bird
pygame.display.update() # Just do one thing, update/flip.
clock.tick(40) # This call will regulate your FPS (to be 40 or less)
Now the reason that your "bird" is not moving is:
When you blit the image, ie: screen.blit(bird, (0, 0)),
The (0,0) is constant, so it won't move.
Here's the final code, with the output you want (try it) and read the comments:
import pygame
import os
# it is better to have an extra variable, than an extremely long line.
img_path = os.path.join('C:\Python27', 'player.png')
class Bird(object): # represents the bird, not the game
def __init__(self):
""" The constructor of the class """
self.image = pygame.image.load(img_path)
# the bird's position
self.x = 0
self.y = 0
def handle_keys(self):
""" Handles Keys """
key = pygame.key.get_pressed()
dist = 1 # distance moved in 1 frame, try changing it to 5
if key[pygame.K_DOWN]: # down key
self.y += dist # move down
elif key[pygame.K_UP]: # up key
self.y -= dist # move up
if key[pygame.K_RIGHT]: # right key
self.x += dist # move right
elif key[pygame.K_LEFT]: # left key
self.x -= dist # move left
def draw(self, surface):
""" Draw on surface """
# blit yourself at your current position
surface.blit(self.image, (self.x, self.y))
pygame.init()
screen = pygame.display.set_mode((640, 400))
bird = Bird() # create an instance
clock = pygame.time.Clock()
running = True
while running:
# handle every event since the last frame.
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit() # quit the screen
running = False
bird.handle_keys() # handle the keys
screen.fill((255,255,255)) # fill the screen with white
bird.draw(screen) # draw the bird to the screen
pygame.display.update() # update the screen
clock.tick(40)
The keyboard events (see pygame.event module) occur only once when the state of a key changes. The KEYDOWN event occurs once every time a key is pressed. KEYUP occurs once every time a key is released. Use the keyboard events for a single action or a step-by-step movement.
If you want to achieve a continuously movement, you have to use pygame.key.get_pressed(). pygame.key.get_pressed() returns a list with the state of each key. If a key is held down, the state for the key is True, otherwise False. Use pygame.key.get_pressed() to evaluate the current state of a button and get continuous movement.
See also Key and Keyboard event and How can I make a sprite move when key is held down.
Minimal example:
import pygame
import os
class Bird(object):
def __init__(self):
self.image = pygame.image.load(os.path.join('C:\Python27', 'player.png'))
self.center = [100, 200]
def move(self, x, y):
self.center[0] += x
self.center[1] += y
def draw(self, surf):
surf.blit(self.image, self.center)
class game(object):
def __init__(self):
self.screen = pygame.display.set_mode((640, 400))
self.clock = pygame.time.Clock()
self.player = Bird()
def run(self):
running = 1
while running:
self.clock.tick(60)
event = pygame.event.poll()
if event.type == pygame.QUIT:
running = 0
keys = pygame.key.get_pressed()
move_x = keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]
move_y = keys[pygame.K_DOWN] - keys[pygame.K_UP]
self.player.move(move_x * 5, move_y * 5)
self.screen.fill([255, 255, 255])
self.player.draw(self.screen)
pygame.display.update()
g = game()
g.run()

Sprite not working/not being displayed (Python/Pygame)

Please help me I am starting a game and my sprite is not showing on screen. Take a look, I am using two files, which include pygame and classes. I hope that's enough information.
Adventure.py --
import pygame, random
pygame.init()
BROWN = (205,192,176)
DEEPBROWN = (139,131,120)
CL = (156,102,31)
from LittleMan import LittleMan
playerSprite = LittleMan(CL, 200, 300)
size = (1000, 600)
screen = pygame.display.set_mode(size)
pygame.display.set_caption("Adventure")
all_sprites_list = pygame.sprite.Group()
playerSprite.rect.x = 200
playerSprite.rect.y = 300
carryOn = True
clock = pygame.time.Clock()
while carryOn:
for event in pygame.event.get():
screen.fill(BROWN)
pygame.draw.rect(screen, DEEPBROWN, [55, 250, 900, 70],0)
all_sprites_list.draw(screen)
all_sprites_list.add()
all_sprites_list.update()
pygame.display.flip()
clock.tick(60)
if event.type == pygame.QUIT:
carryOn = False
if event.type==pygame.KEYDOWN:
if event.key==pygame.K_x: #Pressing the x Key will quit the game
carryOn=False
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
LittleMan.moveLeft(5)
if keys[pygame.K_RIGHT]:
LittleMan.moveRight(5)
LitlleMan.py --
import pygame
CL = (156,102,31)
WHITE = (255,255,255)
class LittleMan (pygame.sprite.Sprite):
def __init__(self, color, width, height):
super().__init__()
self.image = pygame.Surface([50, 75])
self.image.fill(CL)
self.image.set_colorkey(WHITE)
pygame.draw.rect(self.image, CL, [0, 0, width, height])
self.rect = self.image.get_rect()
def moveRight(self, pixels):
self.rect.x += pixels
def moveLeft(self, pixels):
self.rect.x -= pixels
Anyone know why this could be? I've looked everywhere but I've done it in two files and no-one seems to have an answer to that and if there is a decent answer please link it. Thank you.
I think the real crux of the problem is the code is not adding playerSprite to the all_sprites_list. If a sprite is not in this list, the sprite update and paint calls do not include it. At first I thought the initial position of the sprite may be off-screen, so I parameterised the screen dimensions, and positioned the sprite in the middle.
There's a bunch of other indentation issues in the question's code too, but I think these may be from pasting the question into SO.
I cleaned-up and re-organised the code, it seems to run, and pressing Left/right moves the brown box.
I merged both files together to make my debugging easier, my apologies.
import pygame, random
pygame.init()
BROWN = (205,192,176)
DEEPBROWN = (139,131,120)
CL = (156,102,31)
WHITE = (255,255,255)
WINDOW_WIDTH=500
WINDOW_HEIGHT=500
# Setup the pyGame window
size = (WINDOW_WIDTH, WINDOW_HEIGHT)
screen = pygame.display.set_mode(size)
pygame.display.set_caption("Adventure")
class LittleMan (pygame.sprite.Sprite):
def __init__(self, color, width, height):
super().__init__()
self.image = pygame.Surface([50, 75])
self.image.fill(CL)
self.image.set_colorkey(WHITE)
self.rect = self.image.get_rect()
self.rect.center = ( WINDOW_WIDTH//2 , WINDOW_HEIGHT//2 )
def moveRight(self, pixels):
self.rect.x += pixels
def moveLeft(self, pixels):
self.rect.x -= pixels
# Create the player sprite
playerSprite = LittleMan(CL, 200, 300)
# Add user sprite into PyGame sprites list
all_sprites_list = pygame.sprite.Group()
all_sprites_list.add(playerSprite);
clock = pygame.time.Clock()
carryOn = True
while carryOn:
# Handle user input
for event in pygame.event.get():
if event.type == pygame.QUIT:
carryOn = False
if event.type==pygame.KEYDOWN:
if event.key==pygame.K_x: #Pressing the x Key will quit the game
carryOn=False
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
playerSprite.moveLeft(5)
if keys[pygame.K_RIGHT]:
playerSprite.moveRight(5)
# Update and Reapint the screen
screen.fill(BROWN)
pygame.draw.rect(screen, DEEPBROWN, [55, 250, 900, 70],0)
all_sprites_list.update()
all_sprites_list.draw(screen)
pygame.display.flip()
clock.tick(60)
The LittleMan class does not include an update() function, which all_sprites_list.update() would normally call. I expect you just haven't needed this part yet.
EDIT: More notes on the sprite update() function ~
The sprite's update() function is called by pygame during the all_sprites_list.update() function. So that means any sprite added to this group, has its update run quasi-automatically. Ideally all sprites have an update function, and it handles the look, position and collisions (etc.) of the sprite.
The idea behind this function is to do any updates to the sprite. So of you had a sprite that was moving, this function would calculate the next position, and set the sprite's self.rect. Or perhaps that sprite is animated - the update function would set the sprite's image to the next frame of the animation based on the time.
Obviously all this work can be performed outside of the update function. But it provides a simple and clean programming mechanism for sprite mechanics.

About releasing memory when using pygame and Python

For example, a projectile flies off screen, does the program still compute its location, speed, etc.?
If so, how to release it?
import pygame
from pygame.locals import *
from sys import exit
pygame.init()
screen = pygame.display.set_mode((640, 480), 0, 32)
background = pygame.image.load(background_image_filename).convert()
sprite = pygame.image.load(sprite_image_filename)
x = 0.
while True:
for event in pygame.event.get():
if event.type == QUIT:
exit()
screen.blit(background, (0,0))
screen.blit(sprite, (x, 100))
x+= 10.
pygame.display.update()
Yes, the location, speed, etc. still have to be computed, otherwise no object that is off-screen could ever enter the screen area again. Pygame is smart enough not to attempt to render these objects.
It's usually advisable to use pygame sprites and sprite groups which allow you to remove sprites simply by calling self.kill(). You could also use lists or sets to store your objects, but then you have to write a bit more code yourself.
So I'd first define a pygame.Rect (the game_area) with the size of your screen or a bit larger (in the example below I use a smaller one). Rects have a contains method that you can use to check if your sprite's rect is inside the game_area rect. If the sprite is outside, just call self.kill() and pygame will remove the sprite from all associated sprite groups.
import random
import pygame as pg
from pygame.math import Vector2
class Projectile(pg.sprite.Sprite):
def __init__(self, pos, game_area):
super().__init__()
self.image = pg.Surface((5, 5))
self.image.fill(pg.Color('aquamarine2'))
self.rect = self.image.get_rect(center=pos)
self.vel = Vector2(2, 0).rotate(random.randrange(360))
self.pos = Vector2(pos)
self.game_area = game_area
def update(self):
self.pos += self.vel
self.rect.center = self.pos
if not self.game_area.contains(self.rect):
self.kill()
def main():
screen = pg.display.set_mode((640, 480))
game_area = pg.Rect(60, 60, 520, 360)
game_area_color = pg.Color('aquamarine2')
clock = pg.time.Clock()
all_sprites = pg.sprite.Group(Projectile(game_area.center, game_area))
done = False
while not done:
for event in pg.event.get():
if event.type == pg.QUIT:
done = True
all_sprites.add(Projectile(game_area.center, game_area))
all_sprites.update()
screen.fill((30, 30, 30))
all_sprites.draw(screen)
pg.draw.rect(screen, game_area_color, game_area, 2)
pg.display.flip()
clock.tick(60)
if __name__ == '__main__':
pg.init()
main()
pg.quit()
Yes it does, but since you have only a single projectile (incremented using x), you can easily choose what to do using a few if statements. The process becomes harder when there are multiple projectiles (which you need to store in a container), you should apply this.
Here is an example
for projectile in projectile_list:
# Check if the position is inside the screen
if 0 < projectile.x < WIDTH and 0 < projectile.y < HEIGHT:
# Do position operations
This way, you only process what is required. You can apply similar method to remove unused projectiles from the list or whatever container you are using.

why does my pygame load into a blank screen on mac?

For some reason when i run the code in netbeans i only get a blank screen
import pygame
import random
WIDTH = 480
HEIGHT = 600
FPS = 60
# define colours
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
# initialize pygame and create window
pygame.init()
pygame.mixer.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("My Game")
clock = pygame.time.Clock()
class Player(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((40, 50))
self.image.fill(BLUE)
self.rect = self.image.get_rect()
self.rect.centerx = WIDTH / 2
self.rect.bottom = HEIGHT - 10
self.speedx = 0
def update(self):
self.rect.x += self.speedx
all_sprites = pygame.sprite.Group()
player = Player()
all_sprites.add(player)
# Game loop
running = True
while running:
# keep loop running at the right speed
clock.tick(FPS)
# Process input (events)
for event in pygame.event.get():
# check for closing window
if event.type == pygame.QUIT:
running = False
# Update
all_sprites.update()
# Draw / render
screen.fill(BLACK)
all_sprites.draw(screen)
# *after* drawing everything, flip the display
pygame.display.flip()
pygame.quit()
please help me. when i run the code in netbeans it works but the screen where the game should be is blank, when i close the screen there is a frame of it in colour before it closes the window. I'm using OSX sierra
The sprites update and rendering calls are not being made in your while loop.
As pointed out in the comments, you need to indent the seven lines below # Update. Try this:
while running:
# keep loop running at the right speed
clock.tick(FPS)
# Process input (events)
for event in pygame.event.get():
# check for closing window
if event.type == pygame.QUIT:
running = False
# Update
all_sprites.update()
# Draw / render
screen.fill(BLACK)
all_sprites.draw(screen)
# *after* drawing everything, flip the display
pygame.display.flip()
pygame.quit()

How to move Sprite in Pygame

im trying to get my image (bird) to move up and down on the screen but i cant figure out how to do it here is what i tried im sure its way off but im trying to figure it out if anyone can help that would be great!
import pygame
import os
screen = pygame.display.set_mode((640, 400))
running = 1
while running:
event = pygame.event.poll()
if event.type == pygame.QUIT:
running = 0
screen.fill([255, 255, 255])
clock = pygame.time.Clock()
clock.tick(0.5)
pygame.display.flip()
bird = pygame.image.load(os.path.join('C:\Python27', 'player.png'))
screen.blit( bird, ( 0, 0 ) )
pygame.display.update()
class game(object):
def move(self, x, y):
self.player.center[0] += x
self.player.center[1] += y
if event.key == K_UP:
player.move(0,5)
if event.key == K_DOWN:
player.move(0,-5)
game()
im trying to get it to move down on the down button press and up on the UP key press
As stated by ecline6, bird is the least of your worries at this point.
Consider reading this book..
For now, First let's clean up your code...
import pygame
import os
# let's address the class a little later..
pygame.init()
screen = pygame.display.set_mode((640, 400))
# you only need to call the following once,so pull them out of the while loop.
bird = pygame.image.load(os.path.join('C:\Python27', 'player.png'))
clock = pygame.time.Clock()
running = True
while running:
event = pygame.event.poll()
if event.type == pygame.QUIT:
running = False
screen.fill((255, 255, 255)) # fill the screen
screen.blit(bird, (0, 0)) # then blit the bird
pygame.display.update() # Just do one thing, update/flip.
clock.tick(40) # This call will regulate your FPS (to be 40 or less)
Now the reason that your "bird" is not moving is:
When you blit the image, ie: screen.blit(bird, (0, 0)),
The (0,0) is constant, so it won't move.
Here's the final code, with the output you want (try it) and read the comments:
import pygame
import os
# it is better to have an extra variable, than an extremely long line.
img_path = os.path.join('C:\Python27', 'player.png')
class Bird(object): # represents the bird, not the game
def __init__(self):
""" The constructor of the class """
self.image = pygame.image.load(img_path)
# the bird's position
self.x = 0
self.y = 0
def handle_keys(self):
""" Handles Keys """
key = pygame.key.get_pressed()
dist = 1 # distance moved in 1 frame, try changing it to 5
if key[pygame.K_DOWN]: # down key
self.y += dist # move down
elif key[pygame.K_UP]: # up key
self.y -= dist # move up
if key[pygame.K_RIGHT]: # right key
self.x += dist # move right
elif key[pygame.K_LEFT]: # left key
self.x -= dist # move left
def draw(self, surface):
""" Draw on surface """
# blit yourself at your current position
surface.blit(self.image, (self.x, self.y))
pygame.init()
screen = pygame.display.set_mode((640, 400))
bird = Bird() # create an instance
clock = pygame.time.Clock()
running = True
while running:
# handle every event since the last frame.
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit() # quit the screen
running = False
bird.handle_keys() # handle the keys
screen.fill((255,255,255)) # fill the screen with white
bird.draw(screen) # draw the bird to the screen
pygame.display.update() # update the screen
clock.tick(40)
The keyboard events (see pygame.event module) occur only once when the state of a key changes. The KEYDOWN event occurs once every time a key is pressed. KEYUP occurs once every time a key is released. Use the keyboard events for a single action or a step-by-step movement.
If you want to achieve a continuously movement, you have to use pygame.key.get_pressed(). pygame.key.get_pressed() returns a list with the state of each key. If a key is held down, the state for the key is True, otherwise False. Use pygame.key.get_pressed() to evaluate the current state of a button and get continuous movement.
See also Key and Keyboard event and How can I make a sprite move when key is held down.
Minimal example:
import pygame
import os
class Bird(object):
def __init__(self):
self.image = pygame.image.load(os.path.join('C:\Python27', 'player.png'))
self.center = [100, 200]
def move(self, x, y):
self.center[0] += x
self.center[1] += y
def draw(self, surf):
surf.blit(self.image, self.center)
class game(object):
def __init__(self):
self.screen = pygame.display.set_mode((640, 400))
self.clock = pygame.time.Clock()
self.player = Bird()
def run(self):
running = 1
while running:
self.clock.tick(60)
event = pygame.event.poll()
if event.type == pygame.QUIT:
running = 0
keys = pygame.key.get_pressed()
move_x = keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]
move_y = keys[pygame.K_DOWN] - keys[pygame.K_UP]
self.player.move(move_x * 5, move_y * 5)
self.screen.fill([255, 255, 255])
self.player.draw(self.screen)
pygame.display.update()
g = game()
g.run()

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