pygame.time.set_timer not working properly

[Matiiss]

It doesn't seem to actually do any delaying (probably because usage of threads?), it apparently posts those events almost immediately, here you can see how that looks like visually (possible epilepsy warning!!!): https://matiiss.github.io/wasm_test/ and here is the source:

import asyncio
import itertools

import pygame


WIDTH, HEIGHT = 500, 400
FPS = 60
COLOR_CHANGE_EVENT = pygame.event.custom_type()
COLOR_CYCLE = itertools.cycle(pygame.color.THECOLORS.keys())


async def main():
    pygame.init()
    screen = pygame.display.set_mode((WIDTH, HEIGHT))
    clock = pygame.time.Clock()

    pygame.time.set_timer(COLOR_CHANGE_EVENT, 500, 0)
    bg_color = next(COLOR_CYCLE)

    running = True
    while running:
        clock.tick(FPS)
        screen.fill(bg_color)

        events = pygame.event.get()
        for event in events:
            if event.type == pygame.QUIT:
                running = False
            if event.type == COLOR_CHANGE_EVENT:
                bg_color = next(COLOR_CYCLE)

        pygame.display.flip()
        await asyncio.sleep(0)


def run():
    asyncio.run(main())


if __name__ == "__main__":
    run()

[pmp-p]

maybe it's an error in the timing calculation, iirc cpython had to change the time function for wasm to function properly. maybe sdl2 still use the wrong one. would need to see the time delta beetween firing event : is it always next frame (~ 1.0/60) or some bad timing value ?

i'll get to investigate after fixing sdl_image. if it is not fixable at C level , would a python workaround (aio can inject event in pygame queue) be ok for typical usage ?

[Matiiss]

If not fixable at C level, then seemingly having at least a Python implementation would be better than nothing so I guess yes, it would be ok for typical usage.

In case it wouldn't be as efficient as manual timing (can't see how that could really happen), then that should be noted somewhere to inform users that manual timing may be preferred over pygame.time.set_timer.

[pmp-p]

simplest way i've found is by using green threads https://gist.github.com/pmp-p/fb25df0c8beb84d5c771c1875d7594bd
if it's confirmed to work ok, the patching can be done here https://github.com/pygame-web/python-wasm-plus/blob/6ab8d8ee4d014a14df90de5db393d2755d95b5aa/support/__EMSCRIPTEN__/pygame/__init__.py#L150

[pmp-p]

patch applied https://github.com/pygame-web/python-wasm-plus/blob/8d8d1154edef66667449e42263026057074bffa9/support/__EMSCRIPTEN__.overlay/pygame/wasm_patches.py#L11
should be up in a few minutes

[pmp-p]

apparently it's working fine.