ball animation is really junky while running pong game - python

the ball animation while running the program is very stuttery and i can't figure out why.
this is just the beggining of the program so ignore the fact that the game isn't ready to play yet.
this is the code: https://www.codepile.net/pile/dqKZa8OG
i want the ball to move smoothly without stuttering.
and in addition how do i make it so the program deletes the last location of the ball after each update?

It's not "junky" because of the timer, you can only see updates since you're probably moving the mouse in the meantime, then you're updating the ball position everytime you move it (which is wrong, as you're updating the position anytime any events is processed).
The problem is that you're using Clock in the wrong way: the pygame.time.Clock class creates an «object that can be used to track an amount of time», meaning that it is not a timer that can "react" once it times out. The tick method you're calling only updates the current Clock returning how many milliseconds have passed since the last call to tick itself, based on the fps argument you are providing.
What you need is to set a timer, possibly by using a specific eventid just for the updates. Also, since you're updating the ball position based on the events, you'll get more movements if you move the mouse (or any other event is called) making the ball move faster even if it shouldn't - and that's what you'll need the Clock object for.
# I'm using a smaller speed, otherwise it'll be too fast; it should
# depend on the window size to ensure that bigger windows don't get
# slower speeds
ball_velocity = .2
fps = 60
UPDATEEVENT = 24
[...]
def start_move_ball(angle):
ticks = clock.tick()
speed = ball_velocity * ticks
# "global ball" is not required, as you are assigning values to an
# existing object, not declaring it everytime.
# You can also use in-place operations to set the speeds, which is
# better for readability too.
ball[0] += angle[0] * speed
ball[1] += angle[1] * speed
def main_loop():
angle = choose_angle()
pygame.time.set_timer(UPDATEEVENT, 1000 // fps)
while True:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
return False
# update only if necessary!
elif event.type == UPDATEEVENT:
window.fill((0,0,0))
start_move_ball(angle)
draw_mid(window)
draw_players(window)
draw_ball(window)
pygame.display.flip()
The timer is set outside the while cycle, as it automatically sends the event each time interval. You could also leave it within the while (the once=True argument is not really required in this case, as it automatically updates the timer based on the same eventid), but wouldn't make much sense, since set_timer always fires the event after the first time it's set.
I'm using 24 (pygame.USEREVENT) as an eventid, but you can set its id up to pygame.NUMEVENTS - 1, as suggested in the event documentation. If for any reason you want to stop the timer, just use pygame.time.set_timer(eventid, 0) and the timer for that eventid (24 in this case) will not be fired up again.
A couple of suggestions, besides all:
Remove the pygame.display.update() line in draw_mid(window), since it causes flickering while painting.
Avoid using external services to link code (it's not your case, but if the code is too long, first try to reduce it to minimal, reproducible example, eventually leaving all the relevant parts), as they could become unavailable sometime in the future, making your question hard to understand to somebody that is facing a similar issue and reads your answer some time after you posted it.

Related

how to sleep in one function without sleeping the whole program

So I am trying to make a game, in this game I call upon a function that I want to slowly execute, but when I use "time.sleep(x)" it pauses everything in the file instead of just pausing the process of the function. I am trying to add a jump feature to a 2-d game, so if there is a better way to do it then I would be grateful for any advice but this is just the first idea that game to me.
for n in range(15):
Dino.rect.bottom -= 5
update_screen(Dino, screen, cactus)
time.sleep(0.01)
time.sleep(0.25)
inair = False
for n in range(15):
Dino.rect.bottom += 5
update_screen(Dino, screen, cactus)
time.sleep(0.01)
so I have it so that when I jump, it gives me a slow jump instead of just teleporting but like I said, it pauses everything while jumping.
This is not a good approach to timing. As you say, this sleeps the entire program. Multi-threading is a bit complex for simply moving a sprite.
A simple way to solve this problem is to use the PyGame function time.get_ticks() which returns an ever-increasing time in milliseconds.
Using this time-stamp, record the previous-time of an operation, but then do not update again until enough time has elapsed.
For example:
DINO_UPDATE_DELAY = 100 # milliseconds
next_dino_update = 0 # time next move due
[...]
# Move dino, if necessary
time_now = pygame.time.get_ticks()
if ( time_now > next_dino_update ):
Dino.rect.bottom += 5
next_dino_update = time_now + DINO_UPDATE_DELAY # in the future
# Paint the dino, wherever it is
update_screen(Dino, screen, cactus)
It's also possible to request a timer to send the event-loop a message in the future.
MOVE_DINO_EVENT = pygame.USEREVENT + 1
[...]
pygame.time.set_timer( MOVE_DINO_EVENT, DINO_UPDATE_DELAY )
EDIT: More in-depth explanation.
So basically you're implementing an animation, like an anime/cartoon. The thing on the display moves at some speed. In the above code, you seem to be moving a "dino" in the direction of y + 5 every 0.01 seconds (10 milliseconds).
Right now, you paint the dino, then sleep(), then move & paint again. When it hits the apogee of the jump, you wait 250 milliseconds, then repeat the previous phase for the down-jump.
So the problem with using sleep() is that it holds up the whole program (including the event loop, which can cause bad stuff to happen).
So instead of sleeping for some time period, the above example simply looks at the PyGame clock to determine if that same time-period has past. This allows the program to know if the animation needs to be updated.
The whole idea is to keep looking at the clock, using the time as the arbiter of what/where to draw next, rather than multiple calls to sleep().

What is the best way to make a player move at every interval in pygame?

Is there a library or a simple way to only loop something every 0.5 seconds without interrupting the rest of the program?
I have just started using pygame and have made a simple platformer and a Pong replica so far. I decided to try and make a Snake replica (I only currently have the head) and I need the snake to only move every 0.5 seconds while inputs can be registered at the 30 fps which I have the rest of the game running at. This is my current workaround:
while running: #this is tabbed back in my code
# keep loop running at the right speed
clock.tick(FPS)
# get time at each iteration
currentTime = str(time.time()).split(".")[0]
gameTime = int (currentTime) - int (startTime)
# this is used to check for something every 0.5 second (500 ms)
currentTimeMs = str(time.time()).split(".")[1]
# snake will move evry 0.5 second in a direction
if currentTimeMs[0] in ["5","0"] and moveDone == False:
moveDone = True
player1.move(direction)
elif currentTimeMs[0] not in ["5","0"]:
moveDone = False
There is more code within the while running: loop to get the direction and display the sprites but its not necessary for this. My current code works fine and will repeat the move function for my player1 every time that x in mm:ss:x is 0 or 5 (0.5 seconds apart) and will not repeat if it is that multiple times over a few frames.
This code needs to work within the running loop and not stop the program so time.sleep() doesn't work. I have also tried using the schedule library but it will not work as it cannot seem to allow the direction variable to change when passing it into the function.
My question therefore is; Is there a library or a shorter way to accomplish what I need?
Thanks in advance and I can message you the whole code if you need.
I suggest using pygames event mechanics and pygame.time.set_timer() (see here for docs).
You would do something like this:
pygame.time.set_timer(pygame.USEREVENT, 500)
and in the event loop look for the event type.
if event.type == pygame.USEREVENT:
If this is the only user defined event that you are using in your program you can just use USEREVENT.
When you detect the event the timer has expired and you move your snake or whatever. A new timer can be set for another 1/2 second. If you need more accuracy you can keep tabs on the time and set the timer for the right amount of time, but for you situation just setting it for 1/2 sec each time is okay.
If you need multiple timers going and need to tell them apart, you can create an event with an attribute that you can set to different values to track them. Something like this (though I have not run this particular code snippet, so there could be a typo):
my_event = pygame.event.Event(pygame.USEREVENT, {"tracker": something})
pygame.time.set_timer(my_event , 500)
You can store the moment of last move and then compare to actual time. To do it you can use perf_counter from time. Here is an example
last_move_time = perf_counter()
while running:
if perf_counter() - last_move_time > 0.5:
# move player
last_move_time = perf_counter()

How to move from one screen to another, with any input from the user, in pygame? [duplicate]

I'm making a little game and I want to make another window separately from my main one.
I have the the main game in a main window, and I want to open a new window and do a little animation when the user does something.
In my example code below, when the user presses "a" I want it to open a new window and blit to there.
Here I set up the two windows: (I know this doesnt work, its what I'm asking how to do)
SCREEN_X = 400
SCREEN_Y = 400
BSCREEN_X = 240
BSCREEN_Y = 160
BATTLE_SCENE = pygame.display.set_mode((BSCREEN_X, BSCREEN_Y))
SCREEN = pygame.display.set_mode((SCREEN_X, SCREEN_Y))
and then the program:
def run_ani ():
#Do animation, blitting to BATTLE_SCENE
return
def main_game():
ending=False
while ending==False:
clock.tick(30)
for event in pygame.event.get():
if event.type == pygame.QUIT: ending=True
if event.type == KEYDOWN: # key down or up?
if event.key == K_ESCAPE:
ending=True # Time to leave
print("Stopped Early by user")
elif event.key == K_a:
run_ani()
#Normal screen motion, blitting to SCREEN
if ending: pygame.quit()
return
So far what this does is draws the main screen, then when A is pressed, it stops drawing the main screen animations, but still draws the other animations on the main screen and draws in the top left corner.
I'm pretty sure it does this because I am setting BATTLE_SCENE to be smaller than the main screen, thus when blitting to BATTLE_SCENE it blits to the area I created (240x160) in the top corner of the main screen.
However I want BATTLE_SCENE to be a seperate window, so that when I press 'a' it will pop up, do its thing, then close or at least go behind the main screen.
How to do this? Is it even possible?
Do you really need multiple windows? I mean, do you really need them?
If yes, then you should probably use pyglet/cocos2d instead.
To have multiple windows in pygame, you need multiple processes (one for each window). While this is doable, it's not worth the efford. You'll need IPC to exchange data between the windows, and I guess your code will become error-prone and ugly.
Go with pyglet when you need more than one window.
The better solution is probably to divide your game into scenes. Create multiple scenes so that each one represent one stage of the game, something like MenuScene, MainScene, BattleScene, GameOverScene, OptionScene etc.
Then let each of those scenes handle input/drawing of that very part of the game.
MenuScene handles drawing and input etc. of the game's menu
MainScene handles drawing and input etc. of the running game
BattleScene handles drawing and input etc. of whatever you do in run_ani
In your mainloop, just pass control over to the current scene by implementing the methods draw(), handle_event(), and update().
Some example code to get the idea:
scenes = {'Main': MainScene(),
'Battle': BattleScene()} #etc
scene = scenes['Main']
class MainScene():
...
def handle_event(self, event):
if event.type == KEYUP:
if event.key == K_a:
scene = scenes['Battle']
...
class BattleScene():
...
def draw(self):
# draw your animation
def update(self):
# if animation is over:
scene = scenes['Main']
...
def main_game():
ending=False
While Not ending:
clock.tick(30)
for event in pygame.event.get():
scene.handle_event(event)
scene.update()
scene.draw()
This is an easy way to cleanly seperate the game logic and allow context switching.
======================================Edit=========================================
Actually it won't work. Apperantly pygame only supports one display screen, and when you initialize another, it will close the first. You will stay with two varibles, which in fact are the same surface. You can have instead the game increasing the window size and playing the battle scene on the side of it, to do this, you can call the pygame.display.set_mode() again with different values. The varible which references the display screen will still be usable, as it change its reference to the new one. After the scene is over you can decrease the window back the same way.
==================================================================================
What basically happens is you run a loop, and each iteration of it is rendering and displaying a new frame.
When you call a function inside a loop, it doesn't continue to run until you finish running the function.
One way to solve this problen is just keep calling the function that updates the battle scene in the main loop.
Another way is by using threading. Threading is basically running multiple scripts ("Threads") in the same time.
Luckily, python already implemented this for us with the threading module.
It's too long for me to explain the module here, but you can learn it here. It might be a little complex if you haven't use threads before, but after some time it will be easier.
And If you want to learn more about threading you can go here.
Specificly here, you can have two threads, one for each loop/window, and run them in the same time.
Hope I helped you!
Yes, that is possible. SDL2 is able to open multiple windows. In the example folder you can take a look at "video.py".
https://github.com/pygame/pygame/blob/main/examples/video.py
"This example requires pygame 2 and SDL2. _sdl2 is experimental and will change."

Pygame, Draw the same frame for a set amount of time

I want to display a message for two seconds.
The logic that im using right now is making the code wait using pygame.time.delay(2000) after pygame.display.flip.
A short example: (I use this flip-delay on my code a lot)
write_gui("{0} has appeared".format(monster.name), BLUE, 24, TEXT_CORNER_X, TEXT_CORNER_Y)
pygame.display.flip()
pygame.time.delay(2000)
This does work but it tends to "hang" the entire process, so when this happens I get some bugs because of this, mainly some frame loss because the program can keep up with the sleep-awake cycle.
So what I'm thinking right now is to draw the same frame for two seconds.
So what do you guys recommend I should do?
Because one of my answers was to put every flip on a while loop, so there has to be a better line-conservative approach to solve this.
your program "hangs" because you are not calling pygame.event.get() when you are sleeping, pygame.event.get()lets pygame handle its internal events.
The simplest way to solve is to use the return value from dt = clock.tick(), in this case dtwill be the time since your last call to clock.tick(), this value will be in milliseconds.
You could then use that value to increment a counter on how long to show the message.
You could write a function like this if you wanted and call it with how long to wait:
def waitFor(waitTime): # waitTime in milliseconds
screenCopy = screen.copy()
waitCount = 0
while waitCount < waitTime:
dt = clock.tick(60) # 60 is your FPS here
waitCount += dt
pygame.event.pump() # Tells pygame to handle it's event, instead of pygame.event.get()
screen.blit(screenCopy, (0,0))
pygame.display.flip()
This function will wait for the specified time and keep the screen as it was before the call.

Slowing down PyGame sprite animation without lowering frame rate

I am trying to learn pygame sprite animation. I have tried to follow a tutorial and everything is fine. There is just one problem that I can't get my head around.
In the below code I am trying to run a sprite animation of simples square.
This is the sprite:
https://www.dropbox.com/s/xa39gb6m3k8085c/playersprites.png
I can get it working, but the animation is too fast. I want it to be little smoother so that the fading effect can be seen. I saw some solutions using clock.tick but that would slow down the whole game I guess.
how can I get the animation slower while maintaing the usual frame rate for my window?
Below is my code:
lightblue=(0,174,255)
import pygame
pygame.init()
screen = pygame.display.set_mode((400, 300))
done = False
screen.fill(lightblue)
images=pygame.image.load('playersprites.png')
noi=16
current_image=0
while not done:
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
pygame.quit()
quit()
if(current_image>noi-1):
current_image=0
else:
current_image+=1
screen.blit(images,(50,100),(current_image*32,0,32,32))
pygame.display.flip()
Use an integer value which you add to in the loop and check for divisibility. See here for more.
You could use time
So your sprite has 16 frames and lets say it wants to run at ten frames a second regardless of the frame rate of the game.
You could do something along the lines of
import time
start_frame = time.time()
noi = 16
frames_per_second = 10
Then in your loop put
current_image = int((time.time() - start_frame) * frames_per_second % noi)
time.time() counts up in seconds and has several decimal places after it. If you leave leave out frames_per_second then just use the modulo operator on noi (presumably "number of images"), every time a second has gone by, the result will tick up one until it reaches 16 and return to 0.
When you multiply the difference between start_frame and current time (time.time()), you force the "seconds" to go by frames_per_second times as fast.
Coercing the result which will be a float to an int, will allow you to use it as an index.
Now if the frame rate of the game fluctuates, it won't matter because the frame rate of the sprite is tied to the system clock. The sprites should still run at as close to exactly the chosen frame rate as can be rendered.
Clock.tick() is the correct solution.
While you may want to run the code of your game as fast as possible, you don't want the animation to run at an arbitrary speed. Animation is always "frames per second" and this value should be stable; otherwise it will look ugly or confusing. A good value is the same as the refresh rate of your monitor (usually 60 FPS) to avoid tearing.

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