pygame moving left and right issue - python

I have started making something on pygame but I have encountered an issue when moving left or right. if I quickly change from pressing the right arrow key to pressing the left one and also let go of the right one the block just stops moving. this is my code
bg = "sky.jpg"
ms = "ms.png"
import pygame, sys
from pygame.locals import *
x,y = 0,0
movex,movey=0,0
pygame.init()
screen=pygame.display.set_mode((664,385),0,32)
background=pygame.image.load(bg).convert()
mouse_c=pygame.image.load(ms).convert_alpha()
m = 0
pygame.event.pump()
while 1:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type==KEYDOWN:
if event.key==K_LEFT:
movex =-0.5
m = m + 1
if event.key==K_RIGHT:
movex=+0.5
m = m + 1
elif event.type == KEYUP:
if event.key==K_LEFT and not event.key==K_RIGHT:
movex = 0
if event.key==K_RIGHT and not event.key==K_LEFT:
movex =0
x+=movex
y=200
screen.blit(background, (0,0))
screen.blit(mouse_c,(x,y))
pygame.display.update()
is there a way I can change this so if the right arrow key is pressed and the left arrow key is released that it will go right instead of stopping?
P.S
I am still learning pygame and am very new to the module. I'm sorry if this seems like a stupid question but i couldn't find any answers to it.

Your problem is that when you test the KEYDOWN events with
if event.key==K_LEFT and not event.key==K_RIGHT:
you always get True, because when event.key==K_LEFT is True,
it also always is not event.key==K_RIGHT (because the key of the event is K_LEFT after all).
My approach to this kind of problem is to separate
the intent from the action. So, for the key
events, I would simply keep track of what action
is supposed to happen, like this:
moveLeft = False
moveRight = False
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == KEYDOWN:
if event.key == K_LEFT: moveLeft = True
if event.key == K_RIGHT: moveRight = True
elif event.type == KEYUP:
if event.key == K_LEFT: moveLeft = False
if event.key == K_RIGHT: moveRight = False
Then, in the "main" part of the loop, you can
take action based on the input, such as:
while True:
for event in pygame.event.get():
...
if moveLeft : x -= 0.5
if moveRight : x += 0.5

the problem is that you have overlapping key features; If you hold down first right and then left xmove is first set to 1 and then changes to -1. But then you release one of the keys and it resets xmove to 0 even though you are still holding the other key. What you want to do is create booleans for each key. Here is an example:
demo.py:
import pygame
window = pygame.display.set_mode((800, 600))
rightPressed = False
leftPressed = False
white = 255, 255, 255
black = 0, 0, 0
x = 250
xmove = 0
while True:
window.fill(white)
pygame.draw.rect(window, black, (x, 300, 100, 100))
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_RIGHT:
rightPressed = True
if event.key == pygame.K_LEFT:
leftPressed = True
if event.type == pygame.KEYUP:
if event.key == pygame.K_RIGHT:
rightPressed = False
if event.key == pygame.K_LEFT:
leftPressed = False
xmove = 0
if rightPressed:
xmove = 1
if leftPressed:
xmove = -1
x += xmove
pygame.display.flip()

One way could be to create a queue that keeps track of the button that was pressed last. If we press the right arrow key we'll put the velocity first in the list, and if we then press the left arrow key we put the new velocity first in the list. So the button that was pressed last will always be first in the list. Then we just remove the button from the list when we release it.
import pygame
pygame.init()
screen = pygame.display.set_mode((720, 480))
clock = pygame.time.Clock()
FPS = 30
rect = pygame.Rect((350, 220), (32, 32)) # Often used to track the position of an object in pygame.
image = pygame.Surface((32, 32)) # Images are Surfaces, so here I create an 'image' from scratch since I don't have your image.
image.fill(pygame.Color('white')) # I fill the image with a white color.
velocity = [0, 0] # This is the current velocity.
speed = 200 # This is the speed the player will move in (pixels per second).
dx = [] # This will be our queue. It'll keep track of the horizontal movement.
while True:
dt = clock.tick(FPS) / 1000.0 # This will give me the time in seconds between each loop.
for event in pygame.event.get():
if event.type == pygame.QUIT:
raise SystemExit
elif event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
dx.insert(0, -speed)
elif event.key == pygame.K_RIGHT:
dx.insert(0, speed)
elif event.type == pygame.KEYUP:
if event.key == pygame.K_LEFT:
dx.remove(-speed)
elif event.key == pygame.K_RIGHT:
dx.remove(speed)
if dx: # If there are elements in the list.
rect.x += dx[0] * dt
screen.fill((0, 0, 0))
screen.blit(image, rect)
pygame.display.update()
# print dx # Uncomment to see what's happening.
You should of course put everything in neat functions and maybe create a Player class.

I know my answer is pretty late but im new to Pygame to and for beginner like me doing code like some previous answer is easy to understand but i have a solution to.I didn`t use the keydown line code, instead i just put the moving event code nested in the main game while loop, im bad at english so i give you guy an example code.
enter code here
while run:
clock.tick(60)
for event in pygame.event.get():
if event.type == pygame.QUIT or event.type == pygame.K_ESCAPE:
run = False
win.blit(bg, (0, 0))
pressed = pygame.key.get_pressed()
if pressed[pygame.K_LEFT]:
x -= 5
if pressed[pygame.K_RIGHT]:
x += 5
if pressed[pygame.K_UP]:
y -= 5
if pressed[pygame.K_DOWN]:
y += 5
win.blit(image,(x,y))
pygame.display.update()
pygame.quit()
This will make the image move rapidly without repeating pushing the key, at long the code just in the main while loop with out inside any other loop.

Related

Is there a way to make the square move continuously by just pressing 1 time? [duplicate]

This question already has an answer here:
How to get if a key is pressed pygame [duplicate]
(1 answer)
Closed 1 year ago.
click here to see the image
PROGRAMING LANGUAGE THAT I USE IS PYTHON
As on the photo,i have a character(square) and i want when i press the left, right, up, down keys, it has to keep moving in that direction until it hits the wall then stops.But when i press those keys, it only moves once and not continuously like i thought.how to make it move continuously
import pygame
pygame.init()
clock = pygame.time.Clock()
#display
window = pygame.display.set_mode((600,600))
caption = pygame.display.set_caption('SwipeIt')
#player
square = pygame.image.load('asset/square.png').convert_alpha()
square_rect = square.get_rect(center = (100,150))
#wall
wall1 = pygame.image.load('asset/wall1.png').convert()
wall2 = pygame.image.load('asset/wall2.png').convert()
screw = pygame.image.load('asset/screw.png').convert()
white = (255,252,252)
gravity = 0.25
swipe = 0
loop = True
while loop:
print(window)
window.fill(white)
#wall
window.blit(wall1,(0,0))
window.blit(wall2,(0,0))
window.blit(wall2,(565,0))
window.blit(wall1,(0,566))
window.blit(screw,(0,0))
window.blit(screw,(0,566))
window.blit(screw,(565,0))
window.blit(screw,(565,566))
#player
window.blit(square,(square_rect))
for event in pygame.event.get():
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_DOWN:
swipe += gravity
square_rect.centery += swipe
if event.key == pygame.K_UP:
swipe -= gravity
square_rect.centery -= swipe
if event.key == pygame.K_RIGHT:
swipe += gravity
square_rect.centerx += swipe
if event.key == pygame.K_LEFT:
swipe -= gravity
square_rect.centerx -= swipe
if event.type == pygame.QUIT:
loop = False
pygame.display.flip()
pygame.display.update()
clock.tick(120)
If you need, here is the link to download the files I have used .
''https://www.mediafire.com/file/ilogoklz3t9abpa/asset.rar/file''
I've made a snake game before and how I did it is by using a variable called direction.
Here is a little snippet from it.
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
quit()
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_UP:
direction = "up"
if event.key == pygame.K_DOWN:
direction = "down"
if event.key == pygame.K_RIGHT:
direction = "right"
if event.key == pygame.K_LEFT:
direction = "left"
Then I would check the current direction and change the position depending on the direction.
For example:
one would be
if direction == "up":
player_y += 5

how do i make the snake constantly go in the direction the user inputted [duplicate]

This question already has answers here:
How can I make a sprite move when key is held down
(6 answers)
Closed 1 year ago.
right now it just moves in the direction i tell it to put it just stops. How do i go about making it KEEP going in the direction I inputted by? And make it constantly go in the direction, but be able to control how fast it moves, right now i want it to move every 4 minutes
import pygame
from pygame.locals import *
pygame.init()
surface = pygame.display.set_mode((600, 600))
background = pygame.image.load('back.png')
surface.blit(background, (0, 0))
block = pygame.image.load('block.png').convert()
block_y = 0
block_x = 0
surface.blit(block, (block_x, block_y))
def draw():
surface.blit(background, (0, 0))
surface.blit(block, (block_x, block_y))
pygame.display.flip()
direction = ''
pygame.display.flip()
running = True
while running:
for event in pygame.event.get():
if event.type == KEYDOWN:
if event.key == K_ESCAPE:
running = False
if event.key == K_UP:
block_y -= 10
draw()
if event.key == K_DOWN:
block_y += 10
draw()
if event.key == K_LEFT:
block_x -= 10
draw()
if event.key == K_RIGHT:
block_x += 10
draw()
elif event.type == QUIT:
running = False
```
Here's an option with minimal changes to your program. I changed the event handlers to update speed variables, which update the position in an added update() function. The speeds are zeroed when the key is released. I've also removed the duplicated draw() functions. Note this code is untested.
import pygame
from pygame.locals import *
pygame.init()
surface = pygame.display.set_mode((600, 600))
background = pygame.image.load('back.png')
surface.blit(background, (0, 0))
block = pygame.image.load('block.png').convert()
block_y = 0
block_x = 0
speed_x = 0
speed_y = 0
surface.blit(block, (block_x, block_y))
def draw():
surface.blit(background, (0, 0))
surface.blit(block, (block_x, block_y))
pygame.display.flip()
def update():
"""Update game state"""
block_x += speed_x
block_y += speed_y
direction = ''
pygame.display.flip()
clock = pygame.time.Clock()
running = True
while running:
for event in pygame.event.get():
if event.type == KEYDOWN:
if event.key == K_ESCAPE:
running = False
elif event.key == K_UP:
speed_y -= 10
elif event.key == K_DOWN:
speed_y += 10
elif event.key == K_LEFT:
speed_x -= 10
elif event.key == K_RIGHT:
speed_x += 10
elif event.type == KEYUP:
if event.key in (K_DOWN, K_UP):
speed_y = 0
elif event.key in (K_LEFT, K_RIGHT):
speed_x = 0
elif event.type == QUIT:
running = False
update()
draw()
clock.tick(60) # limit frame rate to 60 FPS
EDIT: Added frame rate limiting
Use pygame.key.get_pressed() instead of the KEYDOWN event.
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.
pygame.key.get_pressed() returns a sequence 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
running = True
while running:
for event in pygame.event.get():
if event.type == KEYDOWN:
if event.key == K_ESCAPE:
running = False
elif event.type == QUIT:
running = False
keys = pygame.key.get_pressed()
if keys[pygame.K_UP]:
block_y -= 10
if keys[pygame.K_DOWN]:
block_y += 10
if keys[pygame.K_LEFT]:
block_x -= 10
if keys[pygame.K_RIGHT]:
block_x += 10
draw()
The code can be further simplified:
running = True
while running:
for event in pygame.event.get():
if event.type == KEYDOWN:
if event.key == K_ESCAPE:
running = False
elif event.type == QUIT:
running = False
keys = pygame.key.get_pressed()
block_x += (keys[pygame.K_RIGHT] - keys[pygame.K_LEFT]) * 10
block_y += (keys[pygame.K_DOWN] - keys[pygame.K_UP]) * 10
draw()

Key to be pressed multiple times to move image in pygame [duplicate]

This question already has answers here:
Pygame - Mouse clicks not getting detected
(2 answers)
Closed 2 years ago.
While I was learning how to move images in pygame, when I held down a key(any one: up, down, left, right) to move my image(a racecar), the image only moved once, even though holding down the key should've made the image move move in that particular directions continuously, but it only moved one unit. The fix that I found was that the declaration of the variables used to change the original position (x_vary and y_vary, original position: x and y) were not be added in the main while loop of my game.
My question is why? Why does it make a difference where I declare x_vary and y_vary
Here is the unfixed code:
import pygame
pygame.init()
clock = pygame.time.Clock()
game_window = pygame.display.set_mode((800, 600))
game_icon = pygame.image.load('icon2.jpg')
game_caption = pygame.display.set_caption('Racecar Game')
x = 800 * 0.45
y = 600 * 0.08
racecar = pygame.image.load('racecar.png')
def car(x, y):
game_window.blit(racecar,(x,y))
game_run = False
while game_run == False:
x_vary = 0
y_vary = 0
for event in pygame.event.get():
if event.type == pygame.QUIT:
game_run = True
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_LEFT:
x_vary = -10
elif event.key == pygame.K_RIGHT:
x_vary = +10
elif event.key == pygame.K_UP:
y_vary = -10
elif event.key == pygame.K_DOWN:
y_vary = +10
if event.type == pygame.KEYUP:
if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT or event.key == pygame.K_UP or event.key == pygame.K_DOWN:
x_vary = 0
y_vary = 0
x += x_vary
y += y_vary
game_window.fill((128, 0, 0))
car(x, y)
pygame.display.update()
clock.tick(60)
pygame.quit()
quit()
The keyboard events (pygame.KEYDOWN, pygame.KEYUP) occur only one time when a key is pressed, respectively released.
If x_vary = 0 and y_vary = 0 are declared in the main application loop, then they are set when a button is pressed, but they are reinitialized (0) immediately in the next frame. You've to presse a button again to set them.
If x_vary = 0 and y_vary = 0 are declared before the main application loop, then they keep the value, which is set when a button is pressed. If a button is released, then both are set 0.
Use pygame.key.get_pressed(), to evaluate if the state of a key is pressed. pygame.key.get_pressed() get the state of all keyboard buttons and a the state of a key is True as long the keyboard is pressed down. e.g.:
game_run = False
while game_run == False:
for event in pygame.event.get():
if event.type == pygame.QUIT:
game_run = True
keys = pygame.key.get_pressed()
x_vary, y_vary = 0, 0
if keys[pygame.K_LEFT]:
x_vary = -10
if keys[pygame.K_RIGHT]:
x_vary = +10
if keys[pygame.K_UP]:
y_vary = -10
if keys[pygame.K_DOWN]:
y_vary = +10
x += x_vary
y += y_vary
game_window.fill((128, 0, 0))
car(x, y)
pygame.display.update()
clock.tick(60)

How do I make a game object move continuously as long as the key is pressed?

I am trying to make a game object (here, the welcome text) move as long as the key is pressed on the keyboard. But in this code of mine,
import pygame , sys
from pygame.locals import *
pygame.init()
WHITE = (255 , 255 , 255)
RED = (255 , 0 , 0)
DISPLAYSURF = pygame.display.set_mode((800 , 400))
pygame.display.set_caption('Welcome Tanks')
#render(text, antialias, color, background=None)
fontObj = pygame.font.SysFont('serif' , 40)
text = fontObj.render('Welcome Folks' , True , RED )
x = 150
y = 29
while True:
DISPLAYSURF.fill(WHITE)
DISPLAYSURF.blit(text ,(x , y))
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit(0)
elif event.type == KEYDOWN or event.type == KEYUP:
if event.key == K_ESCAPE:
pygame.quit()
sys.exit(0)
elif event.key == K_DOWN:
y += 15
elif event.key == K_UP:
y -= 15
elif event.key == K_RIGHT:
x += 14
elif event.key == K_LEFT:
x -= 15
else:
x = 150
y = 29
pygame.display.update()
The object moves only once, even though the key is continuously pressed for a long time. In other words, the object changes its position only once when the keyboard button is pressed. I want it to move continuously while I hold the key.
Which event should I look for instead of event.KEYDOWN?
I suggest you to use the key.get_pressed(), e.g.
while True:
DISPLAYSURF.fill(WHITE)
DISPLAYSURF.blit(text ,(x , y))
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit(0)
elif event.type == KEYDOWN or event.type == KEYUP:
if event.key == K_ESCAPE:
pygame.quit()
sys.exit(0)
if pygame.key.get_pressed()[K_LEFT]:
x -= 15
if pygame.key.get_pressed()[K_RIGHT]:
x += 14
if pygame.key.get_pressed()[K_UP]:
y -= 15
if pygame.key.get_pressed()[K_DOWN]:
y += 15
pygame.display.update()
pygame.key.get_pressed()
Returns a sequence of boolean values representing the state of every
key on the keyboard. Use the key constant values to index the array. A
True value means the that button is pressed.
Getting the list of pushed buttons with this function is not the
proper way to handle text entry from the user. You have no way to know
the order of keys pressed, and rapidly pushed keys can be completely
unnoticed between two calls to pygame.key.get_pressed(). There is also
no way to translate these pushed keys into a fully translated
character value. See the pygame.KEYDOWN events on the event queue for
this functionality.
Also you can take a look at doc
keyState = pygame.key.get_pressed()
Declare that, and then you use keystate:
if KeyState()[K_DOWN]:
y += 15
You could try:
if key.get_pressed()
down = True
while down = True:
y+= 15
Then get FPS clock so it does not just flow over the screen!

Character only maintains movement while mouse is moving on screen?

My while loops only maintains the movement for the sprite while the cursor is moving inside of the screen. I've tried reorganizing some of the screen.blits and display.update() and display.flip(). I can't seem to figure out why the character stops after a change in one pixel instead of continuing like it I intended.
background_image = 'Terrain_Grass_First.png'
import pygame, sys
from pygame.locals import *
pygame.init()
pygame.display.set_caption('Hans')
screen_width = 600
screen_height = 400
screen = pygame.display.set_mode((screen_width, screen_height),0,32)
pygame.mouse.set_visible(False)
sprite = pygame.image.load('Hans_front_still.png').convert_alpha()
x,y = (0,0)
movex, movey = (0,0)
while True:
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit()
if event.type == KEYDOWN:
if event.key == K_ESCAPE:
pygame.quit()
sys.exit()
if event.key == K_w:
y = -1
elif event.key == K_a:
x = -1
elif event.key == K_s:
y = +1
elif event.key == K_d:
x = +1
elif event.type == KEYUP:
if event.key == K_w:
y = 0
elif event.key == K_a:
x = 0
elif event.key == K_s:
y = 0
elif event.key == K_d:
x = 0
movex += x
movey += y
screen.fill((0,0,0))
screen.blit(sprite,(movex,movey))
pygame.display.flip()
Your loop blocks on pygame.event.get.
You don't schedule any events of your own.
So, you do nothing until the OS has an event (mouse move, redraw, etc.) to give you.
And, even if you fixed that, you're calling movex += x once per event. So, when the OS is throwing a lot of events at you, your sprite will go zipping madly across the screen, but when the events are coming more slowly, it will crawl along. That's almost never what you want.
An easy fix for both problems is to just schedule your own events. For example, with pygame.time.set_timer(), you can make sure you get an event every, say, 250 milliseconds, and you can only move the sprite on those events. For example:
timer_event = pygame.USEREVENT + 1
pygame.time.set_timer(timer_event, 250)
while True:
for event in pygame.event.get():
# ...
elif event.type == timer_event:
movex += x
movey += y
Another alternative is to design your game with a fixed framerate.
A trivial example looks like this:
FRAME_TIME = 50 # 50ms = 20fps
next_frame_time = pygame.time.get_ticks() + FRAMES
while True:
while True:
event = pygame.event.poll()
if event.type == pygame.NOEVENT:
break
elif # ...
pygame.display.flip()
now = pygame.time.get_ticks()
if now < next_frame_time:
pygame.time.wait(next_frame_time - now)
next_frame_time += FRAMES
Now you can just move every 5th frame.
A realistic example has to deal with missed frames, too many events in the queue, choose between wait and delay appropriately, etc.
But I'd go with the event-driven version with a timer instead of a fixed-framerate version in most cases, especially if you're already going down that line.
The only problem is your Indentation!
The fifth and sixth lines from the bottom have wrong indentation, and you need to delete them.
These two lines:
movex += x
movey += y
should be:
movex += x
movey += y
And it works

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