[Python] Square distortion during window resizing problem

I tried to make a square that maintains its size and aspect ratio during window resizing using SDL3 and SDL_SetRenderLogicalPresentation() with the SDL_LOGICAL_PRESENTATION_LETTERBOX mode:

import sdl3

# Function to draw a square
def draw_square(renderer, x, y, size):
sdl3.SDL_SetRenderDrawColor(renderer, 255, 255, 255, 255) # White color
rect = sdl3.SDL_FRect(x=x, y=y, w=size, h=size)
sdl3.SDL_RenderFillRect(renderer, rect)

# Initialize SDL3
if sdl3.SDL_Init(sdl3.SDL_INIT_VIDEO) < 0:
print(f"SDL initialization error: {sdl3.SDL_GetError().decode()}")
exit(1)

# Create window
window = sdl3.SDL_CreateWindow(b"Hello World", 640, 480, sdl3.SDL_WINDOW_RESIZABLE)
if not window:
print(f"Window creation error: {sdl3.SDL_GetError().decode()}")
exit(1)

# Create renderer
renderer = sdl3.SDL_CreateRenderer(window, b"metal")
if not renderer:
print(f"Renderer creation error: {sdl3.SDL_GetError().decode()}")
exit(1)

# Set logical rendering size
logical_width, logical_height = 640, 480
sdl3.SDL_SetRenderLogicalPresentation(renderer, logical_width, logical_height, sdl3.SDL_LOGICAL_PRESENTATION_LETTERBOX)

# Parameters for positioning the square
square_size = 100 # Fixed square size
square_x = (logical_width - square_size) / 2 # Center horizontally
square_y = (logical_height - square_size) / 2 # Center vertically

running = True
while running:
# Event handling
event = sdl3.SDL_Event()
while sdl3.SDL_PollEvent(event):
if event.type == sdl3.SDL_EVENT_QUIT:
running = False

# Rendering
sdl3.SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255) # Black background
sdl3.SDL_RenderClear(renderer)
# Draw square with fixed size and centered position
draw_square(renderer, square_x, square_y, square_size)
sdl3.SDL_RenderPresent(renderer)

# Cleanup
sdl3.SDL_DestroyRenderer(renderer)
sdl3.SDL_DestroyWindow(window)
sdl3.SDL_Quit()


Currently, the square only resets to its original width and height after I release the mouse button (when resizing ends). During the resizing process itself, the square gets stretched or squashed — it deforms.

Is this the expected behavior of SDL_SetRenderLogicalPresentation? How can I make the square that never deforms at all, no matter how the window is resized? Are there workarounds or best practices for this? (Mac user)

For example, would converting the square into a texture or something similar help keep its aspect ratio stable during resizing?

My code written in Python but feel free to answer in any programming language, main goal is to get the way how to do window resizing without distortion.

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