Develop Reference

pygame wont draw my circle in my pymunk simulation [duplicate]

This question already has answers here:
Why is nothing drawn in PyGame at all?
(2 answers)
Closed 1 year ago.
I'm fairly new to pymunk and I wanted to make physics engine for my future games, there's just a small problem, My code won't draw the circle that pygame is trying to visualize. Here's my code.
import pygame
import pymunk
import sys
def create_item(space):
body = pymunk.Body(1, 100, body_type = pymunk.Body.DYNAMIC)
body.position = (450, 50)
shape = pymunk.Circle(body, 80)
space.add(body, shape)
return shape
def draw_items(items):
for item in items:
pygame.draw.circle(screen, item_color, item.body.position, 80)
def quit():
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
def display_update():
screen.fill(bg_color)
clock.tick(FPS)
space.step(1/60)
pygame.display.flip()
# Constructor
pygame.init()
# Constants and Variables
WIDTH = 900
HEIGHT = 600
screen = pygame.display.set_mode((WIDTH, HEIGHT))
FPS = 60
clock = pygame.time.Clock()
# Colors
bg_color = 30, 30, 40
item_color = 200, 200, 200
# Pymunk Variables
space = pymunk.Space()
space.gravity = (0, 500)
items = []
items.append(create_item(space))
# Loops
def main():
running = True
while running:
quit()
display_update()
draw_items(items)
main()
I don't really know what the problem is here, it doesn't give me an error or something like that and I only get a clean blank canvas with my bg color.(also sorry for the bad comments)

You have to draw the objects before updating the display
def main():
running = True
while running:
quit()
screen.fill(bg_color)
draw_items(items)
pygame.display.flip()
clock.tick(FPS)
space.step(1/60)
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().
The typical PyGame application loop has to:
handle the events by 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 (blit all the objects)
update the display by either pygame.display.update() or pygame.display.flip()
limit frames per second to limit CPU usage

why do i keep getting "video system not initialized" my pygame game? [duplicate]

So i wrote this code:
# Pygame development 4
# Focus on making code object oriented
# Introduce classes and objects into our code
# Gain access to the pygame library
import pygame
# Size of the screen
SCREEN_TITLE = 'Crossy RPG'
SCREEN_WIDTH = 500
SCREEN_HEIGHT = 500
# Colors according to RGB codes
WHITE_COLOR = (255, 255, 255)
BLACK_COLOR = (0, 0 , 0)
# Clock used to update game events and frames
clock = pygame.time.Clock()
pygame.font.init()
font = pygame.font.SysFont('comicsans', 75)
class Game:
# Typical rate of 60, equivalent to fps
TICK_RATE = 60
# Initializer for the game class to set up the width, height, and title
def __init__(self, title, width, height):
self.title = title
self.width = width
self.height = height
# Create the window of specified size in white to display the game
self.game_screen = pygame.display.set_mode((width, height))
# Set the game window color to white
self.game_screen.fill(WHITE_COLOR)
pygame.display.set_caption(title)
def run_game_loop(self):
is_game_over = False
# Main game loop, used to update all gameplay suh as movement, check, and graphics
# Runs unit is_game_over = True
while not is_game_over:
# A loop to get a;l of the events occuring at any given time
# Events are most often mouse movement, mouse and button clicks, or eit events
for event in pygame.event.get():
# If we have a quite type event(exit out) then exit out of the game loop
if event.type == pygame.QUIT:
is_game_over = True
print(event)
# Update all game graphics
pygame.display.update()
# Tick the clock to update everything within the game
clock.tick(self.TICK_RATE)
pygame.init()
new_game = Game(SCREEN_TITLE, SCREEN_WIDTH, SCREEN_HEIGHT)
new_game.run_game_loop()
pygame.quit()
quit()
Right now I am learning to code with python so im following a course online and since I couldn't get help from the forums of that website I thought I might ask the question here! So I've looked at the code multiple times to check for spelling mistakes but I couldn't find any and anyway i think that it's' not about something missing but it has something to do with pygame.display.update ! Can somebody pls help me?

Without running your code or having a stack trace of where the problem happens, we need to debug the code for you first. So it would be beneficial to add a full stack trace to your questions. I'm pretty confident however that there's two issues that you should work out.
pygame.display.update() should be correctly indented to be in the while loop of your main game event loop. Secondly, the pygame.init() should be run before any other initialization (or at least so I've been taught over the years and every example points to)
Try this out, I think it solves your problem:
# Pygame development 4
# Focus on making code object oriented
# Introduce classes and objects into our code
# Gain access to the pygame library
import pygame
pygame.init()
# Size of the screen
SCREEN_TITLE = 'Crossy RPG'
SCREEN_WIDTH = 500
SCREEN_HEIGHT = 500
# Colors according to RGB codes
WHITE_COLOR = (255, 255, 255)
BLACK_COLOR = (0, 0 , 0)
# Clock used to update game events and frames
clock = pygame.time.Clock()
pygame.font.init()
font = pygame.font.SysFont('comicsans', 75)
class Game:
# Typical rate of 60, equivalent to fps
TICK_RATE = 60
# Initializer for the game class to set up the width, height, and title
def __init__(self, title, width, height):
self.title = title
self.width = width
self.height = height
# Create the window of specified size in white to display the game
self.game_screen = pygame.display.set_mode((width, height))
# Set the game window color to white
self.game_screen.fill(WHITE_COLOR)
pygame.display.set_caption(title)
def run_game_loop(self):
is_game_over = False
# Main game loop, used to update all gameplay suh as movement, check, and graphics
# Runs unit is_game_over = True
while not is_game_over:
# A loop to get a;l of the events occuring at any given time
# Events are most often mouse movement, mouse and button clicks, or eit events
for event in pygame.event.get():
# If we have a quite type event(exit out) then exit out of the game loop
if event.type == pygame.QUIT:
is_game_over = True
print(event)
# Update all game graphics
pygame.display.update()
# Tick the clock to update everything within the game
clock.tick(self.TICK_RATE)
new_game = Game(SCREEN_TITLE, SCREEN_WIDTH, SCREEN_HEIGHT)
new_game.run_game_loop()
pygame.quit()
This also seams to be a school assignment and not a online course (but I might be wrong here), never the less I'll leave this piece of advice if I'm right. I strongly suggest that if you bump into problems, ask your teacher for guidance. As there's always a reason for teachers giving you a challenge/problem to solve. It teaches you the latest techniques you've learned in class, and if you can't solve the problem with the tools that you've been given - you've most likely haven't learned the fundamentals that has been taught out - and you should really re-do some steps.

why is my pygame widow only staying open for one second before it closes?

I am currently following a beginner pygame tutorial on YouTube here but even though I copied the code exactly from the tutorial my pygame window only stays open for about a second and then closes.
note: someone asked this question about three years ago here but it didn't fix my problem.
my code is below
import pygame
pygame.init()
win = pygame.display.set_mode((500, 500))
pygame.display.set_caption('hello world')

Your script is ending and so pygame closes everything.
You have to create a loop in order for your game to continue running, with a condition to exit the loop.
You also need to initialize the display with pygame.display.init()
import pygame
pygame.init()
pygame.display.init()
win = pygame.display.set_mode((500, 500))
pygame.display.set_caption('hello world')
clock = pygame.time.Clock()
FPS = 60 # Frames per second.
# Some shortcuts for colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
# For example, display a white rect
rect = pygame.Rect((0, 0), (32, 32))
image = pygame.Surface((32, 32))
image.fill(WHITE)
# Game loop
while True:
# Ensure game runs at a constant speed
clock.tick(FPS)
# 1. Handle events
for event in pygame.event.get():
# User pressed the close button ?
if event.type == pygame.QUIT:
quit()
# Close the program. Other methods like 'raise SystemExit' or 'sys.exit()'.
# Calling 'pygame.quit()' won't close the program! It will just uninitialize the modules.
# 2. Put updates to the game logic here
# 3. Render
win.fill(BLACK) # first clear the screen
win.blit(image, rect) # draw whatever you need
pygame.display.flip() # copy to the screen

Images not showing on surface in pygame

I am attempting to make a game with two surfaces. However when I try and add an image to the game layer it doesn't show up. I have tried using pygame.display.flip() which, from what I understand, should update everything on the screen.
If I try to use either Game_Layer.update() or Game_Layer.flip() as seen in the code below... (I think Game_Layer.flip() doesn't work because .flip is used to update the entire screen and thus can't be called for specific layers but correct me if I am wrong).
#game play
def Dragon():
DragonIMG=pygame.image.load("Green Dragon.gif")
DragonIMG.convert()
global Game_Layer
x=0
y=0
Game_Layer.blit(DragonIMG,(x,y))
Game_Layer.update()
Dragon()
I get the following error message:
RESTART: C:\Users\Alex\OneDrive\A- Levels\1 COMPUTER SCIENCE\Course work\Coding\CSCW Pre Alfa 1.9.5.py
Traceback (most recent call last):
File "C:\Users\Alex\OneDrive\A- Levels\1 COMPUTER SCIENCE\Course work\Coding\CSCW Pre Alfa 1.9.5.py", line 133, in <module>
Dragon()
File "C:\Users\Alex\OneDrive\A- Levels\1 COMPUTER SCIENCE\Course work\Coding\CSCW Pre Alfa 1.9.5.py", line 131, in Dragon
Game_Layer.update()
AttributeError: 'pygame.Surface' object has no attribute 'update'
>>>
However when I try to display an image on the root layer using the code below it works.
#game play
def Dragon():
DragonIMG=pygame.image.load("Green Dragon.gif")
DragonIMG.convert()
global Base_Layer
x=0
y=0
Base_Layer.blit(DragonIMG,(x,y))
pygame.display.flip()
Dragon()
Below is the code I am using to set up the layers:
#libraries
import time, random, pygame, sqlite3, GIFimage2
pygame.init()
#screen setup
#variables
clock=pygame.time.Clock() #for use in .tick
black=pygame.color.Color("black") #set black
white=pygame.color.Color("white") #set white
#set up the base layer
Base_Layer=pygame.display.set_mode((1000,600)) #desplay setup
pygame.display.set_caption("Dragon King: Legacy") #set caption
black=(0,0,0) #colour set
Base_Layer.fill(black) #colour set
Base_Layer.convert() #converts the base layer, may have no effect in current position
icon=pygame.image.load("LOGO.png") #find logo
pygame.display.set_icon(icon) #set icon to logo
#set up the game layer
Game_Layer=pygame.Surface((600,600)) #set layer peramaters
Game_Layer.fill(white) #set layer to white
Game_Layer.convert() #converts the game layer, may have no effect in current position
Base_Layer.blit(Game_Layer, (10, 0)) #blit layer on to screen
pygame.display.flip() #get the layer to show
If anyone could explain to me why this is not working I would appreciate it. I would also appreciate if someone knows a way to display my images in the way I am currently (within a definition) without using global variables.

Pygame programs are usually structured similarly to the following example. First of all, initialize everything and load the images and other resources (do that only once ahead of the main loop), then, in the main while loop, handle the events, update the game and blit everything. Finally, call pygame.display.flip() or pygame.display.update() to make all changes visible and clock.tick(fps) to limit the frame rate.
import pygame
pygame.init()
screen = pygame.display.set_mode((1000, 600))
# Constants (use uppercase letters to signal that these shouldn't be modified).
BLACK = pygame.color.Color("black")
WHITE = pygame.color.Color("white")
GAME_LAYER = pygame.Surface((600, 600))
GAME_LAYER.fill(WHITE)
# convert() returns a new surface, so you have to assign it to a variable.
DRAGON_IMG = pygame.image.load("Green Dragon.gif").convert()
def main(screen):
clock = pygame.time.Clock()
# Variables
x = 0
y = 0
while True:
# Handle events.
for event in pygame.event.get():
if event.type == pygame.QUIT:
return
# Game logic.
x += 1
# Clear the screen and blit everything.
screen.fill(BLACK)
screen.blit(GAME_LAYER, (10, 0))
screen.blit(DRAGON_IMG, (x, y))
pygame.display.flip()
clock.tick(60)
if __name__ == '__main__':
main(screen)
pygame.quit()
If you want to blit onto a background surface instead of the screen/display and it's unicolored, you can just fill the background surface each frame with the fill method, then blit the dragon and finally blit the background onto the screen:
game_layer.fill(WHITE)
game_layer.blit(DRAGON_IMG, (x, y))
screen.blit(game_layer, (10, 0))
Or if your background surface is an actual image, you can create a copy each frame and then blit onto this copy:
game_layer_copy = GAME_LAYER.copy()
game_layer_copy.blit(DRAGON_IMG, (x, y))
screen.blit(game_layer_copy, (10, 0))

Game_Layer is a surface, and surfaces have no update method. update is a function of pygame.display. pygame.display.update is like pygame.display.flip except you can specify what parts of the screen should be flipped.
Also, please don't use global if you have any other choice. It's considered better to wrap everything into a class, pass Game_Layer as a argument, or use pygame.display.get_surface()

Having Trouble Blitting Image From Dictionary

So I'm trying to get into using Pygame, but all of the tutorials I can find online utilize only one file. I played around with ideas on how I can load all of the images in a single function. and decided on saving them in a Dictionary. Problem is, when I try to paste the image from the dictionary, I get the following error:
Traceback (most recent call last):
File "J:\Growth of Deities\Main.py", line 32, in <module>
pygame.Surface.blit(Sprites["TileWastelandBasic"], (0, 0))
TypeError: argument 1 must be pygame.Surface, not tuple
So I played around with the code a bit and googled it for an hour or so, but I can't figure out why I'm getting an error. I assume it's because I can't save images in dictionaries, but I'm not certain. Does anyone have any ideas on how to fix it?
My Main File:
import pygame
from Startup import LoadTextures
pygame.init()
#Sets the color White
WHITE = (255, 255, 255)
#Sets screen size Variable
size = (900, 900)
#Sets Screen Size
screen = pygame.display.set_mode(size)
#Sets name of Game
pygame.display.set_caption("Growth of Deities")
closeWindow = False
clock = pygame.time.Clock()
Sprites = LoadTextures.Load()
while not closeWindow:
#Repeat while game is playing
for event in pygame.event.get():
#Close Window if you close the window
if event.type == pygame.QUIT:
closeWindow = True
#Logic Code
#Rendering Code
pygame.Surface.blit(Sprites["TileWastelandBasic"], (0, 0))
#Clear Screen
screen.fill(WHITE)
#Update Screen
pygame.display.flip()
#Set Tick Rate
clock.tick(60)
#Closes Game
pygame.quit()
My Image Loading File:
import pygame
import os, sys
def Load():
Sprites = {}
WastelandSprites = 'Assets\Textures\Tile Sprites\Wasteland'
Sprites["TileWastelandBasic"] = pygame.image.load(os.path.join(WastelandSprites + "\WastelandBasic.png")).convert_alpha()
Sprites["TileWastelandBasic"] = pygame.transform.scale(Sprites["TileWastelandBasic"], (50, 50)).convert_alpha()
return Sprites

The problem is not because of your dictionary. The signature of blit is
blit(source, dest, area=None, special_flags = 0) -> Rect
where source must be a surface. However, this assumes that blit is being invoked with a pygame.Surface instance as the receiver. Instead, you're calling the blit function from its class, which means that its signature is effectively
blit(self, source, dest, area=None, special_flags = 0) -> Rect
where self must also be a surface. You could fix your problem by changing the call to
pygame.Surface.blit(screen, Sprites["TileWastelandBasic"], (0, 0))
but I would recommend the more idiomatic
screen.blit(Sprites["TimeWastelandBasic"], (0, 0))
instead.
See: http://www.pygame.org/docs/ref/surface.html#pygame.Surface.blit