Allowing to adjust the scaling factor with pygame.SCALED (3575)

[GalacticEmperor1]

Issue №3575 opened by karat-1 at 2022-11-18 13:27:59

Description

The performance when using the SCALED flag is really good especially when not wanting to use pygame._sdl2

The only downside is that we can not adjust the resolution, it will always go to the biggest possible resolution.

I do believe it would be a lot more useful if we could at least change the scaling factor via another flag (e.g. instead of scaling up to 1920x1080 it would only scale up to 1280x720).

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Comments

[gresm]

Maybe also some way to limit the window size (minimal, maximal, only specified proportions, etc...).

[bigwhoopgames]

This would be fantastic.

[gresm]

Just FYI to anyone running into this problem, you can actually achieve this without too much trouble using a couple functions from pygame._sdl2. In particular, you can create a HIDDEN | SCALED display using set_mode, grab the window using _sdl2.Window.from_display_module(), set its size to the exact dimensions you want (in screen-space), and then show() the window. Then you'll have a SCALED window with whatever initial scale factor you want.

Here's an example:

import pygame
import pygame._sdl2 as sdl2

pygame.init()

WIDTH, HEIGHT = (256, 128)
flags = pygame.SCALED
flags |= pygame.RESIZABLE  # optional

# create the display in "hidden" mode, because it isn't properly sized yet
pygame.display.set_mode((WIDTH, HEIGHT), flags | pygame.HIDDEN)

# choose the initial scale factor for the window
initial_scale_factor = 3  # <-- adjustable
window = sdl2.Window.from_display_module()
window.size = (WIDTH * initial_scale_factor, HEIGHT * initial_scale_factor)
window.position = sdl2.WINDOWPOS_CENTERED
window.show()

# bonus: specify the color of the out-of-bounds area in RESIZABLE mode (it's black by default)
OUTER_FILL_COLOR = "plum4"
renderer = sdl2.Renderer.from_window(window)
renderer.draw_color = pygame.Color(OUTER_FILL_COLOR)

clock = pygame.time.Clock()

while True:
    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            raise SystemExit
    screen = pygame.display.get_surface()
    screen.fill("black")

    t = pygame.time.get_ticks() / 1000
    pygame.draw.circle(screen, "gray40", ((30 * t) % WIDTH, (20 * t) % HEIGHT), 16)
    pygame.draw.circle(screen, "gray50", ((-20 * t) % WIDTH, (30 * t) % HEIGHT), 24)
    pygame.draw.circle(screen, "gray60", ((100 + 50 * t) % WIDTH, (30 - 10 * t) % HEIGHT), 32)

    pygame.display.flip()
    clock.tick(60)

Originally posted by @davidpendergast in https://github.com/pygame/pygame/issues/3575#issuecomment-1436060895