Make two balls move on the screen and make them collide

To the code of the previos post now we add other code to add another yellow ball bouncing in the screen and check if they collide and if they collide make them bounce away from each other

To add another ball that bounces on the screen and bounces off the first ball when they collide, you can use the following code:

import pygame

# Initialize Pygame and set up the display
pygame.init()
screen = pygame.display.set_mode((640, 480))

# Set up the first ball's initial position and velocity
x1 = 320
y1 = 240
vx1 = 1
vy1 = 1

# Set up the second ball's initial position and velocity
x2 = 100
y2 = 100
vx2 = 2
vy2 = 2

# Set the balls' radius
radius = 20

# Run the game loop
running = True
while running:
    # Handle user input
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                vx1 = -1
            elif event.key == pygame.K_RIGHT:
                vx1 = 1
            elif event.key == pygame.K_UP:
                vy1 = -1
            elif event.key == pygame.K_DOWN:
                vy1 = 1
        elif event.type == pygame.KEYUP:
            vx1 = 0
            vy1 = 0
    
    # Update the balls' positions
    x1 += vx1
    y1 += vy1
    x2 += vx2
    y2 += vy2
    
    # Check if the balls are out of bounds and reverse their velocities if necessary
    if x1 - radius < 0 or x1 + radius > 640:
        vx1 = -vx1
    if y1 - radius < 0 or y1 + radius > 480:
        vy1 = -vy1
    if x2 - radius < 0 or x2 + radius > 640:
        vx2 = -vx2
    if y2 - radius < 0 or y2 + radius > 480:
        vy2 = -vy2
    
    # Check if the balls collide and reverse their velocities if necessary
    dx = x1 - x2
    dy = y1 - y2
    distance = (dx ** 2 + dy ** 2) ** 0.5
    if distance < 2 * radius:
        vx1, vx2 = vx2, vx1
        vy1, vy2 = vy2, vy1
    
    # Draw the balls and update the display
    screen.fill((0, 0, 0))
    pygame.draw.circle(screen, (255, 255, 255), (x1, y1), radius)
    pygame.draw.circle(screen, (255, 255, 0), (x2, y2), radius)
    pygame.display.flip()

# Quit Pygame when the game loop is finished
pygame.quit()

Good.

This code sets up two balls with different initial positions and velocities, and it updates their positions in the game loop. It also checks if the balls are out of bounds and bounces them off the edges of the screen as before.

The distance between the balls is given by the square root of the distance of the coordinates x and y of the balls. like the infamous Pyitaghorean theorem teaches