a white grid over a black background in pygame [duplicate] - pygame

i have started a new project in python using pygame and for the background i want the bottom half filled with gray and the top black. i have used rect drawing in projects before but for some reason it seems to be broken? i don't know what i am doing wrong. the weirdest thing is that the result is different every time i run the program. sometimes there is only a black screen and sometimes a gray rectangle covers part of the screen, but never half of the screen.
import pygame, sys
from pygame.locals import *
pygame.init()
DISPLAY=pygame.display.set_mode((800,800))
pygame.display.set_caption("thing")
pygame.draw.rect(DISPLAY, (200,200,200), pygame.Rect(0,400,800,400))
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()

You need to update the display.
You are actually drawing on a Surface object. If you draw on the Surface associated to the PyGame display, this is not immediately visible in the display. The changes become visibel, when the display is updated with either pygame.display.update() or pygame.display.flip().
See pygame.display.flip():
This will update the contents of the entire display.
While pygame.display.flip() will update the contents of the entire display, pygame.display.update() allows updating only a portion of the screen to updated, instead of the entire area. pygame.display.update() is an optimized version of pygame.display.flip() for software displays, but doesn't work for hardware accelerated displays.
The typical PyGame application loop has to:
handle the events by calling either pygame.event.pump() or pygame.event.get().
update the game states and positions of objects dependent on the input events and time (respectively frames)
clear the entire display or draw the background
draw the entire scene (draw all the objects)
update the display by calling either pygame.display.update() or pygame.display.flip()
limit frames per second to limit CPU usage with pygame.time.Clock.tick
import pygame
from pygame.locals import *
pygame.init()
DISPLAY = pygame.display.set_mode((800,800))
pygame.display.set_caption("thing")
clock = pygame.time.Clock()
run = True
while run:
# handle events
for event in pygame.event.get():
if event.type == QUIT:
run = False
# clear display
DISPLAY.fill(0)
# draw scene
pygame.draw.rect(DISPLAY, (200,200,200), pygame.Rect(0,400,800,400))
# update display
pygame.display.flip()
# limit frames per second
clock.tick(60)
pygame.quit()
exit()
repl.it/#Rabbid76/PyGame-MinimalApplicationLoop See also Event and application loop

simply change your code to:
import pygame, sys
from pygame.locals import *
pygame.init()
DISPLAY=pygame.display.set_mode((800,800))
pygame.display.set_caption("thing")
pygame.draw.rect(DISPLAY, (200,200,200), pygame.Rect(0,400,800,400))
pygame.display.flip() #Refreshing screen
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
it should help

Related

Pygame screen initialisation odd artefacts

I want to learn pygame and code small fun games with it. So I have started learning this library.
After running this code;
import pygame
from sys import exit
pygame.init()
display_surface = pygame.display.set_mode((800, 400))
pygame.display.set_caption("My Game")
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
exit()
# draw all our elements
# update everything
pygame.display.update()
I see a black screen but there are some artefacts in the screen, like this;
The screen I am talking about
In the Youtube tutorial I am following, the screen is solid black. I don't understand why my screen is different and has some green points in it. My computer works normally and if I restart the program or the computer nothing changes. The pattern is always the same. I can of course fill the display surface black with extra code, and then it works.
My question is, why do I have these points on the display surface in the first place? If someone is knowledgeable about the topic; what do these green lines mean?
I am just curious : )
MacOS Mojave 10.14.6
You must clear the screen with display_surface.fill(0):
run = True
while run :
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
display_surface.fill(0)
# draw all our elements
# update everything
pygame.display.update()
pygame.quit()
exit()

builtins.AttributeError: 'Screen' object has no attribute 'blit' [duplicate]

I would like to know how to draw images using pygame. I know how to load them.
I have made a blank window.
When I use screen.blit(blank, (10,10)), it does not draw the image and instead leaves the screen blank.
This is a typical layout:
myimage = pygame.image.load("myimage.bmp")
imagerect = myimage.get_rect()
while 1:
your_code_here
screen.fill(black)
screen.blit(myimage, imagerect)
pygame.display.flip()
import pygame, sys, os
from pygame.locals import *
pygame.init()
screen = pygame.display.set_mode((100, 100))
player = pygame.image.load(os.path.join("player.png"))
player.convert()
while True:
screen.blit(player, (10, 10))
pygame.display.flip()
pygame.quit()
Loads the file player.png.
Run this and it works perfectly. So hopefully you learn something.
Images are represented by "pygame.Surface" objects. A Surface can be created from an image with pygame.image.load:
my_image_surface = pygame.load.image('my_image.jpg')
However, the pygame documentation notes that:
The returned Surface will contain the same color format, colorkey and alpha transparency as the file it came from. You will often want to call convert() with no arguments, to create a copy that will draw more quickly on the screen.
For alpha transparency, like in .png images, use the convert_alpha() method after loading so that the image has per pixel transparency.
Use the appropriate conversion method for best performance:
image_surface = pygame.load.image('my_image.jpg').convert()
alpha_image_surface = pygame.load.image('my_icon.png').convert_alpha()
A Surface can be drawn on or blended with another Surface using the blit method. The first argument to blit is the Surface that should be drawn. The second argument is either a tuple (x, y) representing the upper left corner or a rectangle. With a rectangle, only the upper left corner of the rectangle is taken into account. It should be mentioned that the window respectively display is also represented by a Surface. Therefore, drawing a Surface in the window is the same as drawing a Surface on a Surface:
window_surface.blit(image_surface, (x, y))
window_surface.blit(image_surface,
image_surface.get_rect(center = window_surface.get_rect().center))
Minimal example:
import pygame
pygame.init()
window = pygame.display.set_mode((300, 300))
clock = pygame.time.Clock()
pygameSurface = pygame.image.load('apple.png').convert_alpha()
run = True
while run:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
window.fill((127, 127, 127))
window.blit(pygameSurface, pygameSurface.get_rect(center = window.get_rect().center))
pygame.display.flip()
pygame.quit()
exit()
pygame.image.load is bale to load most images. According to the documentation the following formats are supported: JPG, PNG, GIF (non-animated), BMP, PCX, TGA (uncompressed), TIF, LBM (and PBM), PBM (and PGM, PPM), XPM.
If you want to use images in PyGame that are loaded with other libraries, see:
PIL and pygame.image
How do I convert an OpenCV (cv2) image (BGR and BGRA) to a pygame.Surface object
For information on loading Scalable Vector Graphics (SVG) files, see:
SVG rendering in a PyGame application
Loading animated GIF files is presented at:
How can I load an animated GIF and get all of the individual frames in PyGame?
How do I make a sprite as a gif in pygame?
Or see how to load NumPy frames:
Pygame and Numpy Animations
After using blit or any other update on your drawing surface, you have to call pygame.display.flip() to actually update what is displayed.

How to preserve what is on the old screen after rescaling a pygame window?

I am trying to make a pygame window that can be resized but after resizing it just deletes everything on it. So I thought of a solution on my own.
pygame.init()
screen=pygame.display.set_mode((640,360),pygame.RESIZABLE)
clock=pygame.time.Clock()
screen.blit(somesurface,(0,0))
pygame.display.flip()
while True:
clock.tick(100)
for event in pygame.event.get():
if event.type==pygame.QUIT:
pygame.quit()
sys.exit()
if event.type==pygame.VIDEORESIZE:
old=screen
screen=pygame.display.set_mode(event.size,pygame.RESIZABLE)
screen.blit(old,(0,0))
del old
pygame.display.flip()
But this doesnt work. The blitted surface just disappears after resizing.
I'm using python 3.8.5 and pygame 1.9.6
The main issue is that pygame.display.set_mode does not create a new surface object. It just resets the existing one. When you're 'saving' the old surface, you're just creating another reference to the same object. If you want to save the current screen surface, use surface.copy().
I updated your code to copy the screen then redraw the saved screen surface centered on the new screen. I also print the screen memory address before and after set_mode. You can see the screen address doesn't change.
import pygame
pygame.init()
screen=pygame.display.set_mode((640,360),pygame.RESIZABLE)
clock=pygame.time.Clock()
somesurface = pygame.Surface((640,360)) # new surface
somesurface.fill((255,255,255)) # fill white
pygame.draw.circle(somesurface,(100,100,255),(320,190),50) # draw blue circle
screen.blit(somesurface,(0,0)) # draw surface onto screen
pygame.display.flip()
while True:
clock.tick(100)
for event in pygame.event.get():
if event.type==pygame.QUIT:
pygame.quit()
exit()
if event.type==pygame.VIDEORESIZE:
print(id(screen)) # memory address of screen object
old=screen.copy() # copy current screen to temp surface
screen=pygame.display.set_mode(event.size,pygame.RESIZABLE) # reset screen
print(id(screen)) # memory address of 'new' screen object, same address :(
screen.blit(old,((event.w-old.get_width())//2,(event.h-old.get_height())//2)) # draw back temp surface centered
del old # delete temp surface
pygame.display.flip()

My screen's black after I tried to implement collision and gravity in my game [duplicate]

i have started a new project in python using pygame and for the background i want the bottom half filled with gray and the top black. i have used rect drawing in projects before but for some reason it seems to be broken? i don't know what i am doing wrong. the weirdest thing is that the result is different every time i run the program. sometimes there is only a black screen and sometimes a gray rectangle covers part of the screen, but never half of the screen.
import pygame, sys
from pygame.locals import *
pygame.init()
DISPLAY=pygame.display.set_mode((800,800))
pygame.display.set_caption("thing")
pygame.draw.rect(DISPLAY, (200,200,200), pygame.Rect(0,400,800,400))
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
You need to update the display.
You are actually drawing on a Surface object. If you draw on the Surface associated to the PyGame display, this is not immediately visible in the display. The changes become visibel, when the display is updated with either pygame.display.update() or pygame.display.flip().
See pygame.display.flip():
This will update the contents of the entire display.
While pygame.display.flip() will update the contents of the entire display, pygame.display.update() allows updating only a portion of the screen to updated, instead of the entire area. pygame.display.update() is an optimized version of pygame.display.flip() for software displays, but doesn't work for hardware accelerated displays.
The typical PyGame application loop has to:
handle the events by calling either pygame.event.pump() or pygame.event.get().
update the game states and positions of objects dependent on the input events and time (respectively frames)
clear the entire display or draw the background
draw the entire scene (draw all the objects)
update the display by calling either pygame.display.update() or pygame.display.flip()
limit frames per second to limit CPU usage with pygame.time.Clock.tick
import pygame
from pygame.locals import *
pygame.init()
DISPLAY = pygame.display.set_mode((800,800))
pygame.display.set_caption("thing")
clock = pygame.time.Clock()
run = True
while run:
# handle events
for event in pygame.event.get():
if event.type == QUIT:
run = False
# clear display
DISPLAY.fill(0)
# draw scene
pygame.draw.rect(DISPLAY, (200,200,200), pygame.Rect(0,400,800,400))
# update display
pygame.display.flip()
# limit frames per second
clock.tick(60)
pygame.quit()
exit()
repl.it/#Rabbid76/PyGame-MinimalApplicationLoop See also Event and application loop
simply change your code to:
import pygame, sys
from pygame.locals import *
pygame.init()
DISPLAY=pygame.display.set_mode((800,800))
pygame.display.set_caption("thing")
pygame.draw.rect(DISPLAY, (200,200,200), pygame.Rect(0,400,800,400))
pygame.display.flip() #Refreshing screen
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
it should help

error in coding in pygame

import pygame
from pygame.locals import *
screen=pygame.display.set_mode()
nin=pygame.image.load('/home/satyajit/Desktop/nincompoop0001.bmp')
screen.blit(nin,(50,100))
according to the code i should get a screen with an image of nin on it . But I only get a black screen which doesnt go even though i press the exit button on it. how to get the image on the screen?
You have to call pygame.display.flip() whenever you want the screen to be updated.
As well as calling pygame.display.flip() (or pygame.display.update() if it is a software based surface). you will also need to call pygame.init() at the start of your program and eventually call pygame.quit() to close down the window and do cleanup.
you code might then be
import pygame,time
from pygame.locals import *
pygame.init()
screen=pygame.display.set_mode()
nin=pygame.image.load('/home/satyajit/Desktop/nincompoop0001.bmp')
screen.blit(nin,(50,100))
pygame.display.flip()
time.sleep(10)
pygame.quit()
Try this:
import pygame
from pygame.locals import *
screen=pygame.display.set_mode()
nin=pygame.image.load('nincompoop0001.bmp')
screen.blit(nin,(50,100))
Then, place the image in the same directory as your script.