`background()` in `setup()` does not persist

In Processing (Java), calling background() inside setup() sets the initial canvas background, which remains visible unless explicitly changed in draw().

In libprocessing / mewnala, calling background() inside setup() appears to have no effect once draw() starts.

Example

from mewnala import *

def setup():
    size(600, 600)
    background(255)

def draw():
    fill(255, 0, 0)
    rect(100, 100, 200, 200)

run()

See screenshot below for output.

Expected behavior (Processing Java)

White background with a red rectangle drawn on top.

Actual behavior (libprocessing / mewnala)

Black background with a red rectangle, suggesting the background set in setup() is cleared or ignored when draw() runs.

Screenshot

Commencez par reproduire le problème avec l’exemple de setup(), draw() et run() du rapport, puis suivez le cycle de rendu entre setup() et draw(). Vérifiez que le comportement implémenté laisse visible l’arrière-plan blanc de setup() sous le rectangle rouge, comme dans Processing Java.