pygame screen failing to display - python

I have the following code in Python 3 (and pygame), but the white surface fails to display and I don't understand why. Has it got something to do with where it has been placed? I tried de-indenting, but that didn't work either? The code is as below:
import pygame
from pygame.locals import*
pygame.init()
screen=pygame.display.set_mode((800,600))
# Variable to keep our main loop running
running = True
# Our main loop!
while running:
# for loop through the event queue
for event in pygame.event.get():
# Check for KEYDOWN event; KEYDOWN is a constant defined in pygame.locals, which we imported earlier
if event.type == KEYDOWN:
# If the Esc key has been pressed set running to false to exit the main loop
if event.key == K_ESCAPE:
running = False
# Check for QUIT event; if QUIT, set running to false
elif event.type == QUIT:
running = False
# Create the surface and pass in a tuple with its length and width
surf = pygame.Surface((50, 50))
# Give the surface a color to differentiate it from the background
surf.fill((255, 255, 255))
rect = surf.get_rect()
screen.blit(surf, (400, 300))
pygame.display.flip()

So it does appear that your indentation is wrong.
You need to define the surface and update the screen etc. outside of the event loop.
At the very least you must move the screen.blit(surf, (400, 300)) and pygame.display.flip() outside of the event loop.
This is it fixed:
# Our main loop!
while running:
# for loop through the event queue
for event in pygame.event.get():
# Check for KEYDOWN event; KEYDOWN is a constant defined in pygame.locals, which we imported earlier
if event.type == KEYDOWN:
# If the Esc key has been pressed set running to false to exit the main loop
if event.key == K_ESCAPE:
running = False
# Check for QUIT event; if QUIT, set running to false
elif event.type == QUIT:
running = False
# Create the surface and pass in a tuple with its length and width
surf = pygame.Surface((50, 50))
# Give the surface a color to differentiate it from the background
surf.fill((255, 255, 255))
rect = surf.get_rect()
screen.blit(surf, (400, 300))
pygame.display.flip()

Related

Is there a way to close the pygame window with a MOUSEBUTTONDOWN event?

I am trying to make a clickable image that exits pygame, but im not sure how to make it close. I have tried using the pygame.quit() and sys.exit() but that loads for a second but doesn't do anyhting. I will show the code I have here(the only relevant code is the x and y variables nad the exit button down the bottom):
import pygame, sys
clock = pygame.time.Clock()
from pygame.locals import *
pygame.init() # inititates Pygame
pygame.display.set_caption('Lightmind')
screen = pygame.display.set_mode((0, 0), pygame.FULLSCREEN) # initiates the window
logo = pygame.image.load("GameLogo.png").convert()
logo = pygame.transform.scale(logo, (256, 256))
start_button = pygame.image.load("StartButton.png").convert()
start_button = pygame.transform.scale(start_button, (256, 256))
exit_button = pygame.image.load("ExitButton.png").convert()
exit_button = pygame.transform.scale(exit_button, (256, 100))
x_2 = 560
y_2 = 400
fade_in = True
fade_out = True
fade_in_ball = True
fade_in_start = True
fade_in_exit = True
running = True
while running: # game loop
for event in pygame.event.get():
if event.type == QUIT:
running = False
pygame.quit()
sys.exit()
# fade in the logo
if fade_in == True:
for i in range(255):
screen.fill((0,0,0))
logo.set_alpha(i)
screen.blit(logo, (560,260))
pygame.display.flip()
clock.tick(60)
fade_in = False
# fade out the logo
if fade_out == True:
for i in range(255):
screen.fill((0,0,0))
logo.set_alpha(255-i)
screen.blit(logo, (560,260))
pygame.display.flip()
clock.tick(60)
fade_out = False
# fade in the start button
if fade_in_start == True:
for i in range(255):
start_button.set_alpha(i)
screen.blit(start_button, (560, 240))
pygame.display.flip()
clock.tick(60)
fade_in_start = False
# fade in the exit button
if fade_in_exit == True:
for i in range(255):
exit_button.set_alpha(i)
screen.blit(exit_button, (x_2, y_2))
pygame.display.flip()
clock.tick(60)
fade_in_exit = False
# make exit button exit game
if event.type == pygame.MOUSEBUTTONDOWN:
x_2, y_2 = event.pos
if exit_button.get_rect().collidepoint(x_2, y_2):
pygame.quit()
sys.exit()
pygame.display.update()
Any help is appreciated!
You're checking the event outside of your event loop. Move it up instead:
for event in pygame.event.get():
if event.type == QUIT:
running = False
pygame.quit()
sys.exit()
elif event.type == pygame.MOUSEBUTTONDOWN:
x_2, y_2 = event.pos
if exit_button.get_rect().collidepoint(x_2, y_2):
pygame.quit()
pygame.event.get() get all the messages and remove them from the queue. See the documentation:
This will get all the messages and remove them from the queue. [...]
If pygame.event.get() is called in multiple event loops, only one loop receives the events, but never all loops receive all events. As a result, some events appear to be missed.
You must handle the click detection in the event loop.
pygame.Surface.get_rect.get_rect() returns a rectangle with the size of the Surface object, but it returns a rectangle that always starts at (0, 0) since a Surface object has no position.
The Surface is placed at a position on the display with the blit function.
You've to set the location of the rectangle, either by a keyword argument, e.g:
running = True
while running: # game loop
for event in pygame.event.get():
if event.type == QUIT:
running = False
if event.type == pygame.MOUSEBUTTONDOWN:
extit_button_rect = exit_button.get_rect(topleft = (x_2, y_2))
if extit_button_rect.collidepoint(event.pos):
running = False
# [...]
pygame.quit()
sys.exit()

How to fix pygame menu (space invaders)?

This is my first game so excuse the messy code. I am making a space invaders game and everything i implemented is working fine (sprites, function of the game, music, pause screen, etc). I wanted to implement a really simple menu screen where, if you press C, the game starts. However, the problem with this is that no matter where i call the menu function, there is always a problem, here is the code (im just going to post the menu function and main loop since everything else i believe is not needed).
import pygame
import random
import math
from pygame import mixer
# Start pygame
pygame.init()
# Create Screen
screen = pygame.display.set_mode((1000, 710))
# Background Image
background = pygame.image.load('background.png').convert_alpha()
# Menu Variables
menu_font = pygame.font.Font('freesansbold.ttf', 65)
menuX = 380
menuY = 250
# Menu Function
def game_intro(x, y):
menu = True
while menu:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_c:
menu = False
if event.key == pygame.K_q:
pygame.quit()
quit()
# Menu Text
menu_text = menu_font.render("Space Invaders", True, (255, 255, 255))
screen.blit(menu_text, (x, y))
pygame.display.update()
# Game Loop
running = True
while running:
# RGB - Red, Green, Blue
screen.fill((0, 0, 0))
# Background Image
screen.blit(background, (0, 0))
----game_intro(menuX,menuY)---IF I PUT IT HERE, THE ACTUAL GAME APPEARS FOR ONE SECOND AND IT GOES BACK TO MAIN MENU-----------
# Making the screen stay still
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
--------game_intro(menuX,menuY)--- IF I PUT IT HERE, THE GAME APPEARS ONLY WHEN 'c' IS BEING HELD DOWN-----------------
*more code*
# Updating
pygame.display.update()
if i put it above pygame.display.update(), then the same thing happens: the game appears for one second and then it goes back to the menu screen. I have tried to search everywhere but the videos either are from 2014, and the websites with some similar problem don't explain how to fix it. Please help.
First of all you should throw the while loop out of your function.
def game_intro(x, y):
# Menu Text
menu_text = menu_font.render("Space Invaders", True, (255, 255, 255))
screen.blit(menu_text, (x, y))
the missing code gets put in the mainloop like this
...
# Making the screen stay still
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_c:
menu = False
if event.key == pygame.K_q:
pygame.quit()
...
now in your mainloop you need to decide whether to draw the menu or the game
if menu:
game_intro(x, y)
else:
#CODE THAT DRAWS THE GAME
all together:
import pygame
import random
import math
from pygame import mixer
# Start pygame
pygame.init()
# Create Screen
screen = pygame.display.set_mode((1000, 710))
# Background Image
background = pygame.image.load('background.png').convert_alpha()
# Menu Variables
menu_font = pygame.font.Font('freesansbold.ttf', 65)
menuX = 380
menuY = 250
# Menu Function
def game_intro(x, y):
# Menu Text
menu_text = menu_font.render("Space Invaders", True, (255, 255, 255))
screen.blit(menu_text, (x, y))
# Game Loop
running = True
while running:
# RGB - Red, Green, Blue
screen.fill((0, 0, 0))
# Background Image
screen.blit(background, (0, 0))
# Making the screen stay still
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_c:
menu = False
if event.key == pygame.K_q:
pygame.quit()
if menu:
game_intro(x, y)
else:
# CODE THAT DRAWS THE GAME
# Updating
pygame.display.update()
this should work
note that you need to set menu to True somewhere to get into the menu

can you help me it wont display my rectangle

import pygame,sys
pygame.init()
screen = pygame.display.set_mode((800,600))
game_over = False
while not game_over:
for event in pygame.event.get():
if event.type == pygame.QUIT:
sys.exit()
pygame.draw.rect(screen, (255,0,0),(400,300,50,50))
pygame.display.flip()
As #Furas writes, the screen update code is not being called from within the loop. Python uses indentation to designate code blocks, so if the function call (or other code section) is not indented to the correct column, it is literally a completely different set of operations.
Since a piece of sample code is worth a thousand words:
import pygame,sys
pygame.init()
screen = pygame.display.set_mode((800,600))
game_over = False
while not game_over:
# Handle user-events
for event in pygame.event.get():
if event.type == pygame.QUIT:
game_over = True
# Re-draw the screen
pygame.draw.rect(screen, (255,0,0), (400,300,50,50))
pygame.display.flip()
pygame.quit()
sys.exit()

pygame start menu not rendering when the program starts

I'm currently learning pygame and writing a simple 2d game. I've come to the point when I need to introduce a start menu. The problem is though the startSCreen function doesn't render the "press space to start" label when the program is started but it does after the character dies for the first time (as can you see below, the function runs in an infinite loop, startScreen is recalled again after the player loses). The way the game works is displayed below:
pygame.init()
win = pygame.display.set_mode((600, 900))
pygame.display.set_caption('The Game')
start_font = pygame.font.SysFont('Arial', 25, bold = True)
def startScreen():
start = True
while start:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
mainGame()
start = False
win.fill((0,0,0))
start_text = start_font.render('PRESS SPACE TO START', 1, (255, 255, 255))
win.blit(start_text, (50, 300))
pygame.display.update()
def mainGame():
main game code
while True:
startScreen()
I didn't paste the mainGame function code as I doubt it affects the issue. Hope somebody can spot the mistake :).
The problem with your code is that until you run mainGame(), start=True and only when you've run the game does start become False. However, the "press space to start text"'s placed after the loop therefore it will only run once the loop has been exited (which means you have played the game at least once.
To solve this problem simply place the display code before the loop as shown below:
def startScreen():
# Display Start Text
win.fill((0,0,0))
start_text = start_font.render('PRESS SPACE TO START', 1, (255, 255, 255))
win.blit(start_text, (50, 300))
pygame.display.update()
# Loop until exited or game is played
start = True
while start:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
if event.type == pygame.KEYDOWN and event.key == pygame.K_SPACE:
mainGame()
start = False

Lock mouse in window Pygame

I want to make a FPS game in Pygame in windowed mode.
I need to be able to move my camera around for 360 degrees and more without limitation and with the hidden cursor.
I used Pygame's set_visible and set_pos but it doesn't prevent my mouse going out of the window and blocking on the screen borders.
import pygame
pygame.init()
game_display = pygame.display.set_mode((800,600))
pygame.mouse.set_visible(False)
exit = False
while (not exit):
pygame.mouse.set_pos = (400, 300)
mouse_move = (0,0)
for event in pygame.event.get():
if event.type == pygame.QUIT:
exit = True
if event.type == pygame.MOUSEMOTION:
mouse_move = event.rel
if mouse_move != (0,0):
print(mouse_move)
pygame.quit()
You have to call pygame.event.set_grab(True) as well.
Better allow the users to exit with the Esc or another key, because they won't be able to click the x button anymore to close the window.
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_ESCAPE:
exit = True

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