Atm I'm working on a game using tkinter. I'm working on algorithm that moves enemies through the game map.
I will post only relevant lines, since the code is quiet hard-to-read.
I'm using class Timer imported from threading.
2 relevant functions are:
def add_enemies(self):
enemy = self.enemies.pop(0)
if enemy in '.':
Timer(1, self.add_enemies).start()
else:
self.move_enemy(enemy,set())
if not self.game_ended and self.enemies:
Timer(1, self.add_enemies).start()
def move_enemy(self, enemy, visited):
if type(enemy) == str:
if enemy in 'm':
enemy = Mongol(self.canvas, *self.start)
visited.add((enemy.x,enemy.y))
for move in (-1,0),(0,1),(1,0),(0,-1):
pos = (enemy.x + move[0], enemy.y+move[1])
if pos in self.way and pos not in visited:
print(pos)
enemy.move(*move)
enemy.take_shot(6)
visited.add(pos)
Timer(0.5, lambda: self.move_enemy(enemy, visited)).start()
This function should move the enemy, wait 0.5 second, then create a thread in which it recursively calls itself and moves the enemy again.
It might not be the best solution the create another thread inside the thread, but all other solutions made my GUI to freeze while executing the function.
Problem is, that Timer executes function move_enemy twice. Nothing else in the code can cause this problem.
Simple print test of enemy position shows this:
It simply moves the enemy twice, and increases its position twice as shown on the picture.
This is a wild guess, but substituting the enemy object with a new enemy object with a modified location in
Timer(0.5, lambda: self.move_enemy(enemy, visited)).start() might get the inbetween coordinates ((3,1),(5,1) and others). (If you do the same thing twice with the same input, you get two identical values.)
From the output I deduce: visited.add(pos) doesn't add positions to visited hence the if pos in self.way and pos not in visited: clause doesn't filter out already tested values (hence the (2,1)(2,1) printout). Try, if .append() works better.
I tried my best :D gl hf
Judging from the output, it looks like what's actually happening is that you were expecting things to execute in this order
print
move
print
move
print
move
print
move
....
but you failed to include enough synchronization and they are instead happening in this order:
print
print
move
move
print
print
move
move
....
It's not doing anything extra: it's just doing things not in the order you were hoping for.
Problem was, that tkinter is not thread safe hence it doesn't act deterministic.
I solved the problem by using Queue. My main thread, in which tkinter runs, periodically checks wheter or not it has something to draw.
Related
I'm new to python and programming in general and am working on a final project for a python centric class. One of the requirements that I cant seem to figure out how to make work is to integrate recursion into our code in order to show a working knowledge. I've worked up a simple "bullet hell" style game using pygame.
My goal is that when contact is made between a bullet and an enemy, that a series of bullet sets will be launched from the player position as a sort of short-term modifier.
This code runs in the main loop whenever a bullet hits an enemy:
for i in reversed(range(len(bullets))):
for j in reversed(range(len(enemies))):
if bullets[i].collided(enemies[j].rect):
del enemies[j]
del bullets[I]
s.global_score += 100
more_bullets(10)
#print("Hit!")
#print(s.global_score)
break
The "more_bullets" function is the focus of my recursion, and calls this:
def more_bullets(n):
if(n > 0):
spawnx = sq.rect.x+10 + sq.rect.width/2 - 10
b = Square(s.red, spawnx,sq.rect.y, 10,30)
b.direction = 'N'
b.player_speed = 10
bullets.append(b)
spawnx = sq.rect.x-10 + sq.rect.width/2 - 10
b = Square(s.red, spawnx,sq.rect.y, 10,30)
b.direction = 'N'
b.player_speed = 10
bullets.append(b)
pygame.display.update()
more_bullets(n-1)
print(f"Fired x {n}")
The outcome currently is that my debug does print 10 times making me think that the recursion is functioning correctly, however only one set of bullets is firing when the collision occurs. I'm thinking that all 10 bullets are firing faster than I can register it and just stacking on the screen.
Is there an easy-to-use function that might slow down the firing of the bullets? or have messed up something more fundamentally here?
I'm thinking that all 10 bullets are firing faster than I can register it and just stacking on the screen.
You're correct.
I don't believe there's an "easy way" to do what you're asking the way you think. The recursion is immediate, meaning that the function runs 10 times right away when it's called. For it to send out a burst of staggered bullets, you'd need some kind of timer or queue or something along those lines that runs alongside your main loop, and recursion isn't really a natural fit for that. The same will go for any kind of game logic function that plays out over a period of time.
This isn't what's being asked, but here's an idea of what you could do, even though it's kind of a redundant use of recursion: add a parameter to that function that dictates the angle the bullet is being shot. Then, add a little bit to that parameter on every recursive call. That way an arc of bullets will be shot at the same time.
This is the programme I wrote but I'm not sure what's wrong:-
import turtle
import random
bob = turtle.Turtle()
screen = turtle.Screen()
def coord(x,y):
print(x,y)
turtle.onscreenclick(None)
turtle.onscreenclick(coord)
turtle.listen()
print('hello')
turtle.done()
The programme works fine except that the print('hello') part happens first, followed by the on screen event. How do I make the onscreen event occur first before the rest of my programme?
You can simply make the rest of your code part of the coord function:
def coord():
print(x,y)
turtle.onscreenclick(None)
print("Hello")
# The rest of your program goes here.
However, a few things to note:
This isn't an amazing elegant solution, especially if you intend to set up other events further into your code. It can become quite hard to keep track of.
It's imperative that you remove the event binding (in this case the binding of coord to onscreenclick) as soon as it's been used, otherwise you could end up with multiple instances of the same code running at once if someone double-clicked the screen, for example. In your case you've already done this (with turtle.onscreenclick(None)), but it is something to keep in mind.
If you choose to go this route, don't forget to rename the coord function something more representative of what that section of your code will do.
I am trying to create a game that moves to the end of a square. Inside the game I created obstacles by making a list of true and false (false=obstacles). What I have (but did not post) is something that detects an obstacle ONLY IF the user lands on the obstacle. However, I want to find a way to detect an obstacle BEFORE the user makes its next move and make it stay in place if the next spot will be an obstacle. In other words I want to find the next index of list before proceeding. Here's some pseudo code for a better picture:
if next_left != [[False]]: # if there is no obstacle
officially_move_left
else: # if there is an obstacle
user_do_nothing
What I have (in pseudo):
def moving_pos(user):
copy_user.pos = user.pos
if copy_user.pos +1 == [True]
user.pos += 1
copy_user.pos += 1
else:
return user.pos
if (user_position == obstacle):
next_square_is_obstacle = true
user_move_backwards
ie, move the player, detect the object, move the player back again. It's very difficult to help without seeing the actual implementation
Edit: Okay, in your new edit I don't see any reason why the program should have such constraints. However, let me suggest something new-
obstacle_index = [obs1, obs2, obs3...]
if user_position+1 in obstacle_index:
do_nothing;
else
user_move_forward;
Can you post the actual minimal working code, or at least a more detailed pseudocode of the implementation?
I'll admit, i am a newbie with python, but here is my issue.
the version is 2.6.5 (i know i'ts an old version but there's reasons to this) and livewires is used
Bascially this game has a bunch of colored balloons in which you need to click them to make them disappear. Adjacent balloons of the same color disappear along with the clicked balloon. Once the balloons are cleared it moves on to the next level.
I need to create a timer on the top right of my screen. This timer needs to countdown in seconds (from 30 might be a good start.) However no matter what i try, either the timer does not display or the numbers are overlap eachother. I would like to know how to do this, as it has been driving me up the wall as of late.
...Of course it also needs to end the game if it reaches zero and add more time if the level is complete...
But for now i just want to focus on displaying the timer and having it count down to zero on screen.
class Timer(games.Sprite):
""" countdown timer """
def __init__(self):
timer_message = games.Text(
value = 30,
size = 50,
color = red,
x = 600,
y = 30
)
def start(self):
while self.timer_message.value != 0:
time.sleep(1)
self.timer_message.value -= 1
game.screen.add(timer_message)
Alright. I fixed the "compressing balloons table" (accidentally deleted the self_update lol) problem, but now it is saying that "global name timer_message is not defined"... despite the fact that it says timer_message = games.Text
I would paste the whole code, but i can't get the indentation right (this is my first time using this website.)
So, I understand it's been some time and if you don't need an answer anymore that's alright.
For now it's hard to answer your question in general because I don't understand the structure of the rest of your code or how you're displaying graphics. However, I can tell you while you're getting the
global name timer_message is not defined
error. It's because when you define timer_message within the __init__ function you are defining it within the local scope of the function but not for the class. In order to make it accessible to the class you need to assign to self.timer_message.
This is a consequence of how python imitates object oriented programming, but making this change should address your immediate error.
I am new to programming with Python. I have been working through a tutorial book that I found, and got the game up and running, but then decided I wanted to have a "Play Again?" option at the end. I can get the game to quit out with a press of the "n" key, but cannot work out how to get the game to restart.
Here is the code I think is giving the trouble:
#player reaches treasure
if player_rectangle.colliderect(treasure_rectangle):
#display text
screen.blit(text,(screen_width/2-195,screen_height/2-25))
if event.type==pygame.KEYDOWN:
if event.key==pygame.K_n:
exit()
elif event.key==pygame.K_y:
pygame.display.update()
I know something needs to go after the elif event, and I have tried all that I can think of. I tried to define the whole program, and call it but that stopped the whole thing running. I have looked around internet sites, but just cannot seem to come up with a answer.
Can some one help out in easy terms how to get the game to restart to the starting position when the y key is pressed? I know it has something to do with a loop, I just cannot place my finger on what.
Many thanks.
It's not entirely clear how your code is organized, so I'll be very general. Usually games are implemented with a "main loop" that handles all of the action. In "pseudo"-python:
def main_loop():
while True:
handle_next_action()
draw_screen()
if game_is_over():
break
Before you start the loop, you usually do some setup to get the game state how you want it:
def main():
setup()
main_loop()
shut_down()
Given those parts, you can reset the game by having the main loop code call setup again (it may need to be specifically designed to be runable more than once):
def main_loop():
while True:
handle_events()
draw_screen()
if game_is_over():
if play_again(): # new code here!
setup()
else:
break
You might want to split the setup code into two parts, one which only needs to be run when the program begins (to read configuration files and set up things like the window system), and a second that gets repeated for each new game (setting up the game's state).
To restart a game you normally need to reset all variables to their initial value (e.g. number of lives, score, initial position, ...).
The best way is to put all initialisations inside a procedure:
def init():
global score,lives # use these global variables
score=0
lives=3
init() # call init() to define and reset all values
while 1: # main loop
...
elif event.key==pygame.K_y:
init() # restart the game