Why Does My Pygame Ball Stretch Instead of Moving Smoothly?

Understanding Ball Movement in Pygame

When developing a pong game in Pygame, it's crucial to comprehend why the ball stretches instead of moving smoothly. Let's delve into the provided code to unravel the cause.

Analysis of the Code

The problem lies in the absence of a vital step in the code: clearing the display surface before drawing each frame. Without this step, the ball's position is updated, but the previous frame's drawing remains on the display, resulting in the ball stretching effect.

Solution: Clearing the Display

To address this issue, the display surface must be cleared at the start of every frame. Insert the line screen.fill(0) into the code before drawing elements, as shown below:

while True:
    # [...]

    # Clear the display surface
    screen.fill(0)

    main.draw_elements()
    main.move_ball()
    main.ball.x_pos += main.ball.speed
    pygame.display.flip()

    # [...]

Explanation

In Pygame, every frame is drawn onto the display surface. To prevent the accumulation of previous drawings, it's essential to clear the surface before each frame. This ensures that only the current frame's objects are displayed.

PyGame Application Loop

The typical Pygame application loop typically consists of the following key steps:

• Handle events using pygame.event.get().
• Update game states and object positions based on inputs and frames.
• Clear the display or draw the background.
• Draw all objects on the display surface.
• Update the display using pygame.display.update() or pygame.display.flip().

By incorporating these steps, developers can ensure smooth movement and object rendering in their Pygame applications.

The above is the detailed content of Why Does My Pygame Ball Stretch Instead of Moving Smoothly?. For more information, please follow other related articles on the PHP Chinese website!