How to Make a Bouncing Ball in PyGame without Relying on Vector2 Class?

Bouncing Ball in PyGame Without Vector2 Class

In this scenario, you're encountering an issue making a ball bounce off walls in PyGame's script, particularly when colliding with the top wall. Despite your research, you're still experiencing challenges.

Nested Loops and Alternative Approach:

The main issue is multiple nested loops. Instead, continuously move the ball within the application loop.

<code class="python">box.y -= box.vel_y        
box.x += box.vel_x</code>

Defining a Rectangular Region:

Create a rectangular region, or bounds, for the ball using a PyGame Rect object. This will define the area within which the ball can move.

<code class="python">bounds = window.get_rect() # full screen</code>

Or, you can specify a specific rectangular region:

<code class="python">bounds = pygame.Rect(450, 200, 300, 200) </code>

Changing Direction of Movement:

When the ball hits the bounds, change its direction of movement using the following code:

<code class="python">if box.x - box.radius < bounds.left or box.x + box.radius > bounds.right:
    box.vel_x *= -1 
if box.y - box.radius < bounds.top or box.y + box.radius > bounds.bottom:
    box.vel_y *= -1 </code>

Example:

Here's an example that demonstrates this approach:

<code class="python">import pygame

box = Circle(600,300,10)

run = True
start = False
clock = pygame.time.Clock()

while run:                     
    clock.tick(120)  

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    keys = pygame.key.get_pressed()
    if keys[pygame.K_SPACE]:
        start = True

    bounds = pygame.Rect(450, 200, 300, 200)
    if start:
        box.y -= box.vel_y        
        box.x += box.vel_x

        if box.x - box.radius < bounds.left or box.x + box.radius > bounds.right:
            box.vel_x *= -1 
        if box.y - box.radius < bounds.top or box.y + box.radius > bounds.bottom:
            box.vel_y *= -1 

    window.fill((0,0,0))
    pygame.draw.rect(window, (255, 0, 0), bounds, 1)
    pygame.draw.circle(window, (44,176,55), (box.x, box.y), box.radius)
    pygame.display.update()</code>

This example includes a red rectangle representing the bounds within which the ball moves and bounces off the walls.

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