pygame won't blit inside function? - python

I have a block of code that worked outside of a function, but not inside.
I also made sure the necessary variables were global.
I can get the width of the surface using chair.get_width() inside the function and it works fine, but I cannot execute screen.blit(chair, (10,10)) for some reason. I don't get an error, it just doesn't do anything...
Here is my script (it creates a window, then calls a function every 100 milliseconds that gets the mouse position, rotates an image x degrees and then blits (or should blit) the image to the window):
cif = "images/chair3.png"
import pygame, sys
from pygame.locals import *
pygame.init()
screen = pygame.display.set_mode((640,480),0,32)
chair = pygame.image.load(cif).convert_alpha()
pygame.time.set_timer(USEREVENT + 1, 100)
def cursor(speed):
global i
global chair
global screen
x,y = pygame.mouse.get_pos()
x -= chair.get_width()/2
y -= chair.get_height()/2
if i < 360:
i = i + 360/(1000/speed)
else:
i = 0
orig_chair_rect = chair.get_rect()
chair1 = pygame.transform.rotate(chair, i);
rot_chair_rect = orig_chair_rect.copy()
rot_chair_rect.center = chair1.get_rect().center
chair1 = chair1.subsurface(rot_chair_rect).copy()
print chair.get_width()
screen.blit(chair1,(x,y))
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == USEREVENT + 1:
cursor(50)

You do need to use pygame.display.flip() or pygame.display.update(), the screen will never update if you don't, and therefore your chair will not be blitted onto the screen.
Tried it, it works. If it doesn't work for you, reinstall Pygame, and try again.

You need to call pygame.display.flip() at the end of your function -- otherwise, your drawing never gets copied from the backbuffer to the live display.

Related

Problem with making Circle properly appear on screen in Pygame

I think my understanding of Pygame is a little bit weak. I would appreciate any help in general about the intricacies of the code (since this was given by the teacher) or simply how I can at least make the obstacle visible.
def draw(screen, background, boids, obstaclearray):
#redrawing the whole window
boids.clear(screen, background)
dirty = boids.draw(screen)
for element in obstaclearray:
pygame.draw.circle(screen, (255,255,255), (element.x, element.y), element.radius)
pygame.display.update(dirty)
Above is where I actually do the drawing and attempt to draw the circle.
The CircularObstacle class is a very simple class that looks like this:
import pygame
class CircularObstacle():
def __init__(self, x, y, radius): #MAYBE ADD A SIZE
self.x = x
self.y = y
self.radius = radius
The problem is that the circle only draws itself when the boids have went over it, which is really weird. I think it has to do with the way the pygame has been setup with and the Surfaces and everything, so below is all the code in main. Of course the obstacle does not work as intended, but I plan to fix that later, first I want to at least get a circle to show.
Below is my full code because I believe it is crucial to solving the issue:
import pygame
from pygame.locals import *
import argparse
import sys
from boid import Boid
from Obstacle import CircularObstacle
def add_boids(boids,num_boids):
for boid in range (num_boids):
boids.add(Boid())
def update(dt, boids):
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit(0)
elif event.type == KEYDOWN:
mods = pygame.key.get_mods()
if event.key == pygame.K_q:
# quit
pygame.quit()
sys.exit(0)
elif event.key == pygame.K_UP:
# add boids
if mods & pygame.KMOD_SHIFT:
add_boids(boids, 100)
else:
add_boids(boids, 10)
elif event.key == pygame.K_DOWN:
# remove boids
if mods & pygame.KMOD_SHIFT:
boids.remove(boids.sprites()[:100])
else:
boids.remove(boids.sprites()[:10])
#ADD STUFF LIKE THE SLIDER AND STUFF
for b in boids:
b.update(dt, boids)
def draw(screen, background, boids, obstaclearray):
#redrawing the whole window
boids.clear(screen, background)
dirty = boids.draw(screen)
for element in obstaclearray:
pygame.draw.circle(screen, (255,255,255), (element.x, element.y), element.radius)
pygame.display.update(dirty)
default_boids = 0
default_geometry = "1000x1000"
# Initialise pygame.
pygame.init()
pygame.event.set_allowed([pygame.QUIT, pygame.KEYDOWN, pygame.KEYUP])
# keep a good framerate so the graphics are better
fps = 60.0
fpsClock = pygame.time.Clock()
# Set up pygamme window
window_width, window_height = 800,600
flags = DOUBLEBUF
screen = pygame.display.set_mode((window_width, window_height), flags)
screen.set_alpha(None)
background = pygame.Surface(screen.get_size()).convert()
background.fill(pygame.Color('black'))
boids = pygame.sprite.RenderUpdates()
add_boids(boids, default_boids)
obstaclearray = []
defaultcircleobstacle = CircularObstacle(200,200,13)
obstaclearray.append(defaultcircleobstacle)
#The "game loop"
dt = 1/fps # here dt means the amount of time elapsed since the last frame
#it seems like thie is a forever loop but in reality this is not since in the update method we provide functinality to quit the program
while True:
update(dt, boids)
draw(screen, background, boids, obstaclearray)
dt = fpsClock.tick(fps)
When you call pygame.display.update() you have 2 options. You can call it without any parameter. In this case the complete screen is updated.
pygame.display.update()
Or call it with a list of rectangular regions that need to be updated. In this case, only the rectangular areas will be updated.
pygame.display.update(rect_list)
You do the 2nd option, but the areas where the circles are drawn are not in the dirty list, therefore this regions are not updated.
pygame.display.update(dirty)
Either update the whole screen with pygame.display.update() or add the regions of the circles to the dirty list:
def draw(screen, background, boids, obstaclearray):
boids.clear(screen, background)
dirty = boids.draw(screen)
for element in obstaclearray:
dirty_rect = pygame.draw.circle(screen, (255,255,255), (element.x, element.y), element.radius)
dirty.append(dirty_rect)
pygame.display.update(dirty)

Why are there black lines appearing between the red and green squares whenever they "move" [duplicate]

In Pygame, I have wrote a Minesweeper clone. However, when I blit the final image stating YOU LOSE or YOU WIN, I get this result:
I'm sure you notice the thick black line surrounding the text. Here is the function in which the image is blitted onto the window:
def play():
SIZE = (WIDTH, HEIGHT) = (16, 16)
MINES = 40
PIXELS_PER_CELL = 30
pygame.init()
screen = pygame.display.set_mode((WIDTH * PIXELS_PER_CELL,
HEIGHT * PIXELS_PER_CELL))
pygame.display.set_caption("PyMines")
board = create_board(SIZE, MINES)
board.draw(screen)
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
elif (event.type == pygame.MOUSEBUTTONDOWN and board.is_playing and
not board.is_solved):
board.mouse_handler(event, screen)
message = None
if not board.is_playing:
board.show_mines(screen)
message = pygame.image.load("images/lose.png").convert_alpha()
elif board.is_solved:
message = pygame.image.load("images/win.png").convert_alpha()
if message:
message = pygame.transform.scale(message, (screen.get_width(),
screen.get_height() //
5))
screen.blit(message, (0, 0))
pygame.display.update()
As I am not sure which part of the code you should be looking at, here is the full code.
Another reason why I think this behaviour is so bizarre, is that when I first created PyMines, the image blitted perfectly like so (as you can see, there is a very slight shadow to the text):
This however, is not a optimized version, as after each cycle, the whole board is redrawn (so it takes a very long time on a 16x16 board as shown in the first image, so I used a 9x9 - but the results are the same). Here is the play() function of the original version:
def play():
SIZE = (WIDTH, HEIGHT) = (9, 9)
MINES = 10
PIXELS_PER_CELL = 30
pygame.init()
screen = pygame.display.set_mode((WIDTH * PIXELS_PER_CELL,
HEIGHT * PIXELS_PER_CELL))
pygame.display.set_caption("PyMines")
board = create_board(SIZE, MINES)
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
elif (event.type == pygame.MOUSEBUTTONDOWN and board.is_playing and
not board.is_solved):
board.mouse_handler(event, screen)
message = None
if not board.is_playing:
board.show_mines()
message = pygame.image.load("lose.png").convert_alpha()
elif board.is_solved:
message = pygame.image.load("win.png").convert_alpha()
board.draw(screen)
if message:
message = pygame.transform.scale(message, (screen.get_width(),
screen.get_height() //
5))
screen.blit(message, (0, 0))
pygame.display.update()
I would attach a link to the full code, but pastebin is down, so here is the full code for the original game without the strange black line.
EDIT: I have already tried dropping the convert_alpha() and adding convert() or even nothing at all.
.convert():
NOTHING:
Why are all these black lines there, how do I get rid of them and which version (convert/convert_alpha/NOTHING) should I use (and how to decide which one to use).
The text has a black shadow with an alpha channel. In your original version, you render the board, then render the text, and the shadow gets blended with the board.
In the revised version, you render the board, then repeatedly render the text over it. On the first pass, it renders correctly, with the shadow blending with the board. On the second pass, the shadow blends with the shadow you've already rendered, making a slightly darker shadow. On the next pass, the shadow gets slightly darker, and so on.
You can't use alpha blending without keeping tight control over what you're blending over. Each time you render the text, you'll need to render at least the section of the board behind the text, if not the full board.

Pygame- Odd trail occurring even though I am updating my image. Whats going on?

Image of what is occurring
Hi guys, so i'm new to pygame and I'm trying to do something fairly simple. Just move an image across the screen. I've done it before and haven't had this issue. The only change I've made is that I am now blitting 1 image on top of the other.
For some odd reason, this is causing a trail to be left behind.
I've tried Clearing the screen and redrawing and have had no positive results.
Any help would be appreciated.
def main():
pygame.init()
screen = pygame.display.set_mode((700,680),0,32)
clock = pygame.time.Clock()
bgd_image = pygame.image.load("Grid.png").convert()
#X Motor Pieces
MotorXbase = pygame.image.load("MotorXBase.png").convert()
MotorXbase.set_colorkey((34,177,76))
MotorXMovePiece = pygame.image.load("MotorXMovePiece.png").convert()
MotorXMovePiece.set_colorkey((34,177,76))
#Y Motor Pieces
MotorYbase = pygame.image.load("MotorYBase.png").convert()
MotorYbase.set_colorkey((34,177,76))
MotorYMovePiece = pygame.image.load("MotorYMovePiece.png").convert()
MotorYMovePiece.set_colorkey((34,177,76))
screen.fill([34,177,76])
black = (0,0,0)
running = True
xpos = 16
ypos = 14
xstep = 1
ystep = 1
while running:
screen.blit(bgd_image,(0,0))
screen.blit(MotorXbase, [50,550])
MotorXbase.blit(MotorXMovePiece,[xpos,18])
screen.blit(MotorYbase, [550,50])
MotorYbase.blit(MotorYMovePiece,[20,ypos])
clock.tick(60)
pygame.display.update()
screen.fill(black)
xpos += xstep
ypos += ystep
if xpos >399 or xpos <16:
xstep = -xstep
if ypos > 397 or ypos < 14:
ystep = -ystep
# event handling, gets all event from the eventqueue
for event in pygame.event.get():
# only do something if the event is of type QUIT
if event.type == pygame.QUIT:
# change the value to False, to exit the main loop
running = False
From comments:
Well, you're blitting the piece images onto the base images, rather than directly onto the screen. This is a destructive operation, you'd have to keep an unmodified copy of the base images, or reload them from disk, to undo the blit.

How to stop drawing a specific rectangle pygame

My program is a 'Piano Hero' game in pygame which works in the same way as guitar hero except that it is for a computer keyboard and its based on playing the piano rather than the guitar. I am using a design similar to Synthesia for my interface where rectangles come down to a 'hitline' and you have to press the key at the right time.
My problem is that although the rectangles are drawing and working as intended at first, they do not seem to update so that the top ever stops. In other words, every note in the song is infinitely long.
I feel like this is probably where the error is although I am not 100% sure.
def Draw(self,hitLine):
if self.coords[2][1]<hitLine:
self.coords[0][1]+=2
self.coords[1][1]+=2
self.coords[2][1]+=2
self.coords[3][1]+=2
elif self.coords[2][1]>=hitLine and self.coords[0][1]<hitLine:
self.coords[0][1]+=2
self.coords[1][1]+=2
else:
self.drawing = False
pygame.draw.polygon(screen,BLUE,self.coords,0)
pygame.display.update()
This line is inside a while loop which just updates all of the rectangles in the song one at a time.
for z in notes:
if z.drawing:
z.Draw(hitLine)
I found you're question quite fun to work on and is very interesting!
Some items to consider.
It doesn't seem that there is any reason to use a "pygame polygon" for your Note objects which are clearly rectangles. In my code below I used "pygame Rect" objects.
You're main loop doesn't clear the screen every frame.
In your main loop you need to clear the screen every frame. In my code I used Rect objects. The Note stops drawing itself when it's top hits the hitLine.
import pygame
pygame.init()
gameScreen = pygame.display.set_mode((1100, 692))
hitLine = 500
class Note:
def __init__(self, rect):
self.rect = rect
self.drawing = True
def draw(self):
if self.rect.y < hitLine:
self.rect.y += 2
else:
self.drawing = False;
pygame.draw.rect(gameScreen, (0, 0, 255), self.rect, 0)
fNote = Note(pygame.Rect(500, -550, 80, 550))
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
gameScreen.fill((0, 0, 0))
if fNote.drawing:
fNote.draw()
pygame.display.update()

Can't click on image again, what's wrong with my pygame code?

Okay, I'am trying to create a Tom and Jerry game with the pygame library.
The game focuses on catching mice by clicking on them as they appear in their holes. The problem
is that sometimes a cat appears instead of a mouse and should the player erroneously click on the
cat (s)he looses all earned points, but the game continues.
The mouse is an image of a mouse and the cat is an image of an cat.
If you click on the mouse, you get mouse, otherwise the cat gets the points.
The code is a mess, that's because I don't know what I'am doing and just set an another event loop because then it works, because it runs after I create the mouse. It works to click on the mouse but then you click somewhere else and after that it's like you did not clicked on the mouse.
The mouse is created in a loop and is supposed to wait for 5 seconds and if you click on the mouse within these seconds then an appropriate message prints out in the console ,,Jerry clicked!" else "1 click". If you don't click on the mouse within 5 seconds a image covers the mouse so she disappears.
Now, what I'am trying to do right now is to print the message 1 click when the player does not click on anything but print 1 click jerry clicked when the player clicks on the mouse. I have a image of the mousehole and then I put the mouse on the mousehole, that is, on an another image.
This code works with one image at least:
pygame.init()
width=350;
height=400
screen = pygame.display.set_mode( (width, height ) )
pygame.display.set_caption('clicked on image')
redSquare = pygame.image.load("images/red-square.png").convert()
x = 20; # x coordnate of image
y = 30; # y coordinate of image
screen.blit(redSquare , ( x,y)) # paint to screen
pygame.display.flip() # paint screen one time
running = True
while (running):
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.MOUSEBUTTONDOWN:
# Set the x, y postions of the mouse click
x, y = event.pos
if redSquare.get_rect().collidepoint(x, y):
print('clicked on image')
#loop over, quite pygame
pygame.quit()
My problem is that, when I click on the mouse and then I don't click on the mouse I can't click on the mouse again at another position.
So what's wrong? What I'am doing wrong here?
Here is my code:
import pygame
from pygame import *
from random import *
init()
run = True
screen = (800,800)
screen = display.set_mode(screen)
xpos = 0
ypos = 0
mouseorcatxpos = 5
mouseorcatypos = 0
mousehole = image.load("mousehole.png").convert()
cat = image.load("tom.png")
jerry = image.load("jerry.png")
def makeholes():
global ypos
global xpos
for holey in range(1,9):
for holex in range(1,9):
screen.blit(mousehole,(xpos,ypos))
display.flip()
xpos += 100
ypos += 100
xpos = 0
def mouseorcat():
global xpos
mouseorcatxpos = 5
ypos = 0
for mousecaty in range(1,9):
pygame.event.pump()
for mousecatx in range(1,9):
randommouse = randint(1, 3)
randomcat = randint(1, 10)
if(randommouse == 2):
screen.blit(jerry, (mouseorcatxpos, ypos))
display.flip()
for event in pygame.event.get():
if (event.type == MOUSEBUTTONDOWN):
if jerry.get_rect().collidepoint(xpos, ypos) == False:
print("l clicked!")
x, y = event.pos
if jerry.get_rect().collidepoint(xpos, y):
print("JERRY CLICKED!!")
x, y = event.pos
print(x, y)
time.wait(5000)
#screen.blit(mousehole, (mouseorcatxpos - 5, ypos))
display.flip()
elif(randomcat == 2):
screen.blit(cat, (mouseorcatxpos, ypos))
display.flip()
time.wait(1500)
screen.blit(mousehole, (mouseorcatxpos-5, ypos))
display.flip()
mouseorcatxpos += 100
mouseorcatxpos = 0
ypos += 100
makeholes()
while run == True:
for event in pygame.event.get():
mouseorcat()
if event.type == QUIT:
run = False
I rewrote your game to show you how I would do it.
To keep track of the time and to limit the framerate I used a pygame.time.Clock and a timer variable. The clock returns the time in milliseconds since clock.tick was called the last time, which is used to increase the timer variable. The cat just replaces the mouse after two seconds and the mouse is set to a new position. I use pygame.Rects to store the positions, but you could also use lists or tuples.
import sys
import random
import pygame
pygame.init()
size = (800, 800)
screen = pygame.display.set_mode(size)
# Images replaced by pygame.Surface. Do that too
# in the future before you post your code.
mousehole = pygame.Surface((40, 40)).convert()
mousehole.fill(pygame.Color(30, 30, 30))
cat = pygame.Surface((40, 40)).convert()
cat.fill(pygame.Color(110, 110, 130))
jerry = pygame.Surface((40, 40)).convert()
jerry.fill(pygame.Color(190, 130, 0))
# Create the background image and blit the holes.
background = pygame.Surface(size).convert()
for holey in range(8):
for holex in range(8):
background.blit(mousehole, (holex*100, holey*100))
def new_position():
"""Return a random position between 0-700 in steps of 100."""
return (random.randrange(0, 701, 100), random.randrange(0, 701, 100))
def main():
fps = 30
clock = pygame.time.Clock()
jerry_rect = jerry.get_rect() # Stores jerry's position and size.
jerry_rect.topleft = new_position() # New random position.
# The cat is outside of the screen first.
cat_rect = cat.get_rect(topleft=(-100, -100))
points = 0
timer = 0
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.MOUSEBUTTONDOWN:
if jerry_rect.collidepoint(event.pos):
points += 1
print('Jerry caught! Points:', points)
timer = 0
jerry_rect.topleft = new_position()
else:
print('Missed. Points:', points)
# Run logic.
timer += clock.tick(fps) / 1000 # timer + seconds since last tick.
if timer > 2: # Cat catches mouse after 2 seconds.
cat_rect.topleft = jerry_rect.topleft
jerry_rect.topleft = new_position()
timer = 0
points = 0
print('Tom caught Jerry.')
# Draw.
# Clear the screen by blitting the bg.
screen.blit(background, (0, 0))
screen.blit(jerry, jerry_rect)
screen.blit(cat, cat_rect)
pygame.display.flip()
if __name__ == '__main__':
main()
pygame.quit()
sys.exit()
Side notes:
Don't use star imports (from module import *), because that can make code harder to read. If you want you can use from pygame.locals import *, if it's the only star import.
Don't use global variables, because they can make code harder to read, understand and maintain. Pass variables to functions as arguments and then return the result.
Update: Some notes about your program:
The first big problem is that your game has two event loops and the important one is deeply nested inside of two other for loops and a if. The event loop should be directly under the main while loop (one indentation level (when you have more experience you can put it into a function or class method)).
The two for loops seem to have the purpose to let the code run until randommouse or randomcat are 2. To run code until a condition is met is the purpose of a while loop. But in this case you should better just pick a random number and write the if/elif conditions so that they always apply. For example, you want a 2/3 chance for mouse and 1/3 for a cat,
random_number = random.randint(1, 3)
if random_number < 3:
print("2/3 probability. It's a mouse")
else:
print("1/3 probability. It's a cat")
Or use random.choice with a list:
>>> random.choice(['mouse', 'mouse', 'cat'])
'mouse'
time.wait(5000) shouldn't be used because the game just hangs in this time. You can't even close the window. Limit the framerate and get the time since the last tick with a pygame.time.Clock.
pygame.event.pump() is not needed.
If you call get_rect() without an argument, the rect is positioned at (0, 0).
if jerry.get_rect().collidepoint(xpos, y):
That's the reason why clicking on jerry only works in the top row, and because you use the global xpos here. Since xpos is 0, the whole top row counts as Jerry.
You can pass coordinates to get_rect like so (you can also use center or other args instead of topleft):
jerry_rect = jerry.get_rect(topleft=(50, 100))
I'm sorry but I don't think I can simply fix your code. I've tried it several times, but I always end up re-writing it completely.
I begin by extracting the event loop out of the two nested for loops, then remove these loops, create rects for the mouse and cat, fix the collision detection, add a timer and so on. Take a close look at my example and try to rewrite your game in a similar way, and keep asking questions if you don't understand something.

Categories