Develop Reference

How can I add collisions to a list of objects (circles) in tkinter?

import time
from tkinter import *
import random
class SpaceField:
def __init__(self):
self.window = Tk()
self.window.title("Asteriods")
self.canvas = self.canvas_display() #creates canvas
self.asteriods = self.asteriod_creation_seperation() #creates asteroids
self.active = True
self.move_active() #Moves asteroids
self.canvas.update()
def asteriod_creation_seperation(self): #creation of multple asteriods
asteriod_spacingx = random.randint(1,800)
asteriod_spacingy = random.randint(1,800)
asteriod_list = list() # could list([])
for i in range(15):
asteriod = self.canvas.create_oval( 30, 50 , 80 , 100 , tags="asteriod", width=2, outline="white")
asteriod_list.append("asteriod")
self.canvas.move(asteriod, asteriod_spacingx, asteriod_spacingy)
asteriod_spacingx = random.randint(1,500)
asteriod_spacingy = random.randint(1,500)
print(asteriod_spacingy)
return asteriod_list
Asteroid Creation. Creates asteroids and gives them random positions.
def asteriod_update(self): #asteriods movement method #MAin problem
x12 = 1
self.canvas.move("asteriod", 3, x12)
pos = self.canvas.coords("asteriod")
print(pos)
if (pos)[2] > 500:
x12 *= 5
I think this is where I need to add the collision detection. I just have no idea how to combine the lists of the circles and the collisions.
def move_active(self): #Basically a true loop
if self.active:
self.asteriod_update()
self.window.after(40, self.move_active)
def canvas_display(self): #canvas
canvas = Canvas(self.window, width=500, height=400, background='black')
canvas.pack(expand=True, fill="both")
canvas.update()
return canvas
Canvas display nothing special
def run(self):
self.window.mainloop()
if __name__ == '__main__':
SpaceF = SpaceField()
SpaceF.run()

Asteroids is a classic game but there were a number of problems in your code. The main one was calling move_active during initialization. This prevented the code from completing its mainloop initialization.
The other problem was the asteroid_update method that basically didn't do anything, also using tags to control all asteroids didn't work either.
Everything else was OK, although you might consider using polygons.
Here is one way to produce a bouncing objects program. I've inserted remarks that describe the methods used.
Objects change the speed and direction when they hit the boundary so their trajectories are randomized.
from tkinter import *
from random import randint as rnd
class SpaceField:
def __init__(self):
self.window = Tk()
self.window.title("Asteriods")
# Define canvas size and active flag
self.wide, self.high, self.active = 500, 400, True
self.canvas_display()
self.asteriod_creation_seperation()
def asteriod_creation_seperation(self):
self.asteroids, self.speed = [], []
size, radius = 50, 25
for i in range(15):
spacex = rnd(size, self.wide - size)
spacey = rnd(size, self.high - size)
self.asteroids.append( # Store oval item id
self.canvas.create_oval(
spacex, spacey, spacex+size, spacey+size,
width=2, tags = "asteriod", outline = "white"))
self.speed.append((rnd(1,4),rnd(1,4))) # Store random speed x, y
def asteriod_update(self): # MAIN DRIVER: Work on ALL asteroids
for i, a in enumerate(self.asteroids):
xx, yy = self.speed[i] # get speed data
x, y, w, h = self.canvas.coords(a)
# check for boundary hit then change direction and speed
if x < 0 or w > self.wide:
xx = -xx * rnd(1, 4)
if y < 0 or h > self.high:
yy = -yy * rnd(1, 4)
# Limit max and min speed then store it
self.speed[i] = (max( -4, min( xx, 4)), max( -4, min( yy, 4 )))
self.canvas.move(a, xx, yy) # update asteroid position
def move_active(self):
if self.active:
self.asteriod_update()
self.window.after(40, self.move_active)
def canvas_display(self):
self.canvas = Canvas(
self.window, width = self.wide,
height = self.high, background = "black")
self.canvas.pack(expand = True, fill = "both")
def run(self): # Begin asteroids here so that mainloop is executed
self.window.after(200, self.move_active)
self.window.mainloop()
if __name__ == "__main__":
SpaceF = SpaceField()
SpaceF.run()

AttributeError: 'Event' object has no attribute 'wider'

I have this program in which I draw a rectangle on a canvas and when I press either the < arrow key or the > key the rectangle should get wider or narrower. But when I run this program and press either of those keys the python shell prints out AttributeError: 'Event' object has no attribute 'wider' (or 'narrower')... A. How can I fix this? and B. Why does it do that?
from tkinter import *
root = Tk()
canvas = Canvas(root, width=400, height=300, bg="#000000")
canvas.pack()
x1 = 150
y1 = 100
x2 = 250
y2 = 200
class ResizeRect:
def __init__(self, x1, y1, x2, y2):
self.x1 = x1
self.y1 = y1
self.x2 = x2
self.y2 = y2
self.rect = canvas.create_rectangle(0,0,1,1)
def draw(self):
canvas.delete(self.rect)
self.rect = canvas.create_rectangle(x1, y1, x2, y2,outline="#00B000", width=2)
def narrower(self):
self.x1 = self.x1 + 5
self.x2 = self.x2 - 5
def wider(self):
self.x1 = self.x1 - 5
self.x2 = self.x2 + 5
r = ResizeRect(150, 100, 250, 200)
r.draw()
def left(r):
r.narrower()
def right(r):
r.wider()
canvas.bind_all('<KeyPress-Left>', left)
canvas.bind_all('<KeyPress-Right>', right)
I also don't know if/when I fix this, there will still be a ton of errors. So it would be great if you help me with the specific problem. But it would be even cooler if you could tell me if/how to fix the other errors that come after this one.
Thanks

You need to provide an argument for the event that tkinter sends when using bind:
def left(event):
r.narrower()
Those methods will also need to call canvas.coords; simply updating the numbers won't cause the display to change.

Your left() and right() routines are receiving an event, which you are not currently accepting. You can change your routines to be like this:
def left(e):
r.narrower()
def right(e):
r.wider()
This gets rid of your error messages. The routines for narrowing and widening will now be called, but they won't work. To resize the rectangle, you'll need to work with the coords() method. By changing the coordinates of the rectangle, you can effectively move or resize it.
current_coords = canvas.coords(rectangleTagId)
# update the coords to new_coords
canvas.coords(rectangleTagId, *new_coords)

pyglet - loading/blitting image with alpha

I'm trying to make a simple application with pyglet. My main problem so far is that I can't seem to blit an image with alpha - all of the transparent pixels are converted into black pixels. I'm not sure whether the problem is with the loading of the image or the blitting. Here is a very basic overview of how I'm trying to render the image:
import pyglet
import pyglet.clock
window = pyglet.window.Window()
window.config.alpha_size = 8
#fancy text
text = pyglet.resource.image("text.png")
#background image
bg = pyglet.resource.image("bg.png")
bg.blit(0, 0)
text.blit(100, 100)
pyglet.app.run()
Any help is appreciated. Thanks in advance.

You most likely just need to enable GL ALPHA blends.
from pyglet.gl import *
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
But first of all, your code is not able to run.
Mostly because you don't declare a window.event function to handle the on_draw where you normally render things.
Secondly, you never clear your window (which will cause a mess).
Here's a minimal working example of your code:
import pyglet
import pyglet.clock
window = pyglet.window.Window()
window.config.alpha_size = 8
#fancy text
text = pyglet.resource.image("text.png")
#background image
bg = pyglet.resource.image("bg.png")
#window.event
def on_draw():
window.clear()
bg.blit(0, 0)
text.blit(100, 100)
pyglet.app.run()
Now this generates this:
And here's a working example of how you use the GL_BLEND feature:
import pyglet
import pyglet.clock
from pyglet.gl import *
window = pyglet.window.Window()
window.config.alpha_size = 8
#fancy text
text = pyglet.resource.image("text.png")
#background image
bg = pyglet.resource.image("bg.png")
#window.event
def on_draw():
window.clear()
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
bg.blit(0, 0)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
text.blit(100, 100)
pyglet.app.run()
This yields a result like so:
However, this code will quickly become messy.
So there's two things you can do. You can first, put your images into sprite objects. Secondly, make this a bit more object oriented.
First, we'll use sprites.
self.fancy_background = pyglet.sprite.Sprite(pyglet.image.load('bg.png'))
self.fancy_background.draw() # not blit!
Sprites automatically uses transparency, which makes your life (and code) a lot easier.
Secondly, we'll put these into a batch.
Batches are made to bunch A LOT of sprites so you can call .draw() on the batch, and all sprites in that batch gets insta-rendered.
self.background = pyglet.graphics.Batch()
self.fancy_background = pyglet.sprite.Sprite(pyglet.image.load('bg.png'), batch=self.background)
self.background.draw() # background, not fancy_background! And also not blit!!
Last and most certainly not least.
We'll put this into a class so we can do cool stuff later on.
import pyglet
import pyglet.clock
from pyglet.gl import *
key = pyglet.window.key
class main(pyglet.window.Window):
def __init__ (self, width=800, height=600, fps=False, *args, **kwargs):
super(main, self).__init__(width, height, *args, **kwargs)
self.x, self.y = 0, 0
self.background = pyglet.graphics.Batch()
self.texts = pyglet.graphics.Batch()
self.fancy_background = pyglet.sprite.Sprite(pyglet.image.load('bg.png'), batch=self.background)
self.fancy_text = pyglet.sprite.Sprite(pyglet.image.load('text.png'), batch=self.texts)
self.mouse_x = 0
self.mouse_y = 0
self.alive = 1
def on_draw(self):
self.render()
def on_close(self):
self.alive = 0
def on_mouse_motion(self, x, y, dx, dy):
self.mouse_x = x
self.mouse_y = y
def on_mouse_press(self, x, y, button, modifiers):
if button == 1: # Left click
pass
def on_key_press(self, symbol, modifiers):
if symbol == key.ESCAPE: # [ESC]
self.alive = 0
def render(self):
self.clear()
self.background.draw()
self.texts.draw()
self.flip()
def run(self):
while self.alive == 1:
self.render()
# -----------> This is key <----------
# This is what replaces pyglet.app.run()
# but is required for the GUI to not freeze
#
event = self.dispatch_events()
if __name__ == '__main__':
x = main()
x.run()
BAM.
This code will enable you to create custom functions and custom "player objects" later on for instance. Also you can do collision detection easier and the code just looks a lot more structured (I threw in a little bonus features such as keyboard and mouse events).
Note tho, that the position of the sprites will default to x=0, y=0 as shown in the last picture. You can set the position with x=100 either on the variable/handle or when creating the sprite.

Sprite in Pyglet not doing what I want

I am trying to have a circle that, when clicked, moves somewhere else on the screen. However, when I click the circle, nothing happens.
#IMPORT STUFF
import pyglet as pg
from random import randint
mouse = pg.window.mouse
#VARS
window = pg.window.Window(width = 640, height = 480)
score = 0
circleImg = pg.image.load("circle.png")
circle = pg.sprite.Sprite(circleImg, randint(1, window.width), randint(1, window.height))
text = pg.text.Label("Click red!", font_name = "Times New Roman", font_size = 18, x = 260, y = 10)
#DETECT MOUSE PRESS ON CIRCLE
#window.event
def on_mouse_press(x, y, button, modifiers):
if x == circle.x and y == circle.y:
circle.x = randint(1, window.width)
circle.y = randint(1, window.height)
#window.event
def on_draw():
window.clear()
text.draw()
circle.draw()
pg.app.run()

import pyglet
from pyglet.gl import *
from random import randint
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
class Circle(pyglet.sprite.Sprite):
def __init__(self, radiance=5, x=0, y=0):
self.texture = pyglet.image.load('circle.png')
super(Circle, self).__init__(self.texture)
def click(self, x, y):
if x >= self.x and y >= self.y:
if x <= self.x + self.texture.width and y <= self.y + self.texture.height:
return self
mouse = pyglet.window.mouse
#VARS
window = pyglet.window.Window(width = 640, height = 480)
score = 0
#circleImg = pyglet.image.load("circle.png")
#circle = pyglet.sprite.Sprite(circleImg, randint(1, window.width), randint(1, window.height))
circle = Circle(x=50, y=50)
text = pyglet.text.Label("Click red!", font_name = "Times New Roman", font_size = 18, x = 260, y = 10)
#DETECT MOUSE PRESS ON CIRCLE
#window.event
def on_mouse_press(x, y, button, modifiers):
if circle.click(x, y):
print('Clicked in circle')
circle.x = randint(0, window.width - 10)
circle.y = randint(0, window.height - 10)
#window.event
def on_draw():
window.clear()
text.draw()
circle.draw()
pyglet.app.run()
A short description of what this does is it creates a custom class called Circle that inherits the Sprite class. It loads the circle.png as a texture with a alpha channel that gets blended by the GL library.
We add a custom function called click that checks if the lowest x,y coordinates are higher than the circles lowest x,y, then we check if the cursor is below x+width and same for y of the image region.
If that's the case, we return the circle sprite class as a True value in case we want to use the sprite.
Future enhancements:
You should draw the circle using gl functions, hence why I've defined radiance in the class definitions. However radiance here is never used, it's a placeholder for the future.
This is so you can use math to defined if you actually clicked within the circle, but this is beyond my scope of quick answers.. I would have to do a lot of debugging myself in order to get the math to add up (it's not my strong side).
What makes it work now is that we use the image width, height, x and y data to crudely check if we're within the image, aka "the circle".
trying to draw over sprite or change picture pyglet
As a bonus, I'll add this answer to the list of enhancements because it contains some stuff that might be useful. One would be to replace 90% of your code with a custom pyglet.window.Window class to replace global variables and decorators and stuff.
And it would look something like this:
import pyglet
from pyglet.gl import *
from random import randint
glEnable(GL_BLEND)
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
key = pyglet.window.key
class Circle(pyglet.sprite.Sprite):
def __init__(self, radiance=5, x=0, y=0):
self.texture = pyglet.image.load('circle.png')
super(Circle, self).__init__(self.texture)
def click(self, x, y):
if x >= self.x and y >= self.y:
if x <= self.x + self.texture.width and y <= self.y + self.texture.height:
return self
class MainScreen(pyglet.window.Window):
def __init__ (self):
super(MainScreen, self).__init__(800, 600, fullscreen = False)
self.x, self.y = 0, 0
self.bg = pyglet.sprite.Sprite(pyglet.image.load('background.jpg'))
self.sprites = {}
self.sprites['circle'] = Circle(x=50, y=50)
self.sprites['label'] = pyglet.text.Label("Click red!", font_name = "Times New Roman", font_size = 18, x = 260, y = 10)
self.alive = 1
def on_draw(self):
self.render()
def on_close(self):
self.alive = 0
def on_mouse_press(self, x, y, button, modifiers):
if self.sprites['circle'].click(x, y):
print('Clicked in circle')
self.sprites['circle'].x = randint(0, self.width - 10)
self.sprites['circle'].y = randint(0, self.height - 10)
def on_key_press(self, symbol, modifiers):
if symbol == key.ESCAPE: # [ESC]
self.alive = 0
def render(self):
self.clear()
self.bg.draw()
for sprite_name, sprite_obj in self.sprites.items():
sprite_obj.draw()
self.flip()
def run(self):
while self.alive == 1:
self.render()
# -----------> This is key <----------
# This is what replaces pyglet.app.run()
# but is required for the GUI to not freeze
#
event = self.dispatch_events()
x = MainScreen()
x.run()

I'm not familiar with pyglet, but I'm guessing the problem is that you're checking whether x == circle.x etc, which means it only moves when you click the single pixel at the exact centre of the circle. Try some kind of maximum distance from the centre (e.g. a hypotenuse math.sqrt( (x-circle.x)**2 + (y-circle.y)**2) < circle.radius

Swinging pendulum does not work

I am having a little trouble with this project. I have to create a pendulum using key handles and the code I have for the key's up and down don't seem to be working. "up" is suppose to make the pendulum go faster and "down" makes it go slower. This is the code that I have so far. can somebody please help.
from tkinter import * # Import tkinter
import math
width = 200
height = 200
pendulumRadius = 150
ballRadius = 10
leftAngle = 120
rightAngle = 60
class MainGUI:
def __init__(self):
self.window = Tk() # Create a window, we may call it root, parent, etc
self.window.title("Pendulum") # Set a title
self.canvas = Canvas(self.window, bg = "white",
width = width, height = height)
self.canvas.pack()
self.angle = leftAngle # Start from leftAngle
self.angleDelta = -1 # Swing interval
self.delay = 200
self.window.bind("<Key>",self.key)
self.displayPendulum()
self.done = False
while not self.done:
self.canvas.delete("pendulum") # we used delete(ALL) in previous lab
# here we only delete pendulum object
# in displayPendulum we give the tag
# to the ovals and line (pendulum)
self.displayPendulum() # redraw
self.canvas.after(self.delay) # Sleep for 100 milliseconds
self.canvas.update() # Update canvas
self.window.mainloop() # Create an event loop
def displayPendulum(self):
x1 = width // 2;
y1 = 20;
if self.angle < rightAngle:
self.angleDelta = 1 # Swing to the left
elif self.angle > leftAngle:
self.angleDelta = -1 # Swing to the right
self.angle += self.angleDelta
x = x1 + pendulumRadius * math.cos(math.radians(self.angle))
y = y1 + pendulumRadius * math.sin(math.radians(self.angle))
self.canvas.create_line(x1, y1, x, y, fill="blue", tags = "pendulum")
self.canvas.create_oval(x1 - 2, y1 - 2, x1 + 2, y1 + 2,
fill = "red", tags = "pendulum")
self.canvas.create_oval(x - ballRadius, y - ballRadius,
x + ballRadius, y + ballRadius,
fill = "green", tags = "pendulum")
def key(self,event):
print(event.keysym)
print(self.delay)
if event.keysym == 'up':
print("up arrow key pressed, delay is",self.delay)
if self.delay >10:
self.delay -= 1
if event.keysym == 'Down':
print("Down arrow key pressed,delay is",self.delay)
if self.delay < 200:
self.delay += 1
if event.keysym=='q':
print ("press q")
self.done = True
self.window.destroy()
MainGUI()

The root of the problem is that the event keysym is "Up" but you are comparing it to the all-lowercase "up". Naturally, the comparison fails every time. Change the if statement to if event.keysym == 'Up':
Improving the animation
In case you're interested, there is a better way to do animation in tkinter than to write your own infinite loop. Tkinter already has an infinite loop running (mainloop), so you can take advantage of that.
Create a function that draws one frame, then have that function arrange for itself to be called again at some point in the future. Specifically, remove your entire "while" loop with a single call to displayFrame(), and then define displayFrame like this:
def drawFrame(self):
if not self.done:
self.canvas.delete("pendulum")
self.displayPendulum()
self.canvas.after(self.delay, self.drawFrame)
Improving the bindings
Generally speaking, your code will be marginally easier to manage and test if you have specific bindings for specific keys. So instead of a single catch-all function, you can have specific functions for each key.
Since your app supports the up key, the down key, and the "q" key, I recommend three bindings:
self.window.bind('<Up>', self.onUp)
self.window.bind('<Down>', self.onDown)
self.window.bind('<q>', self.quit)
You can then define each function to do exactly one thing:
def onUp(self, event):
if self.delay > 10:
self.delay -= 1
def onDown(self, event):
if self.delay < 200:
self.delay += 1
def onQuit(self, event):
self.done = True
self.window.destroy()